166 results on '"Byeong Jae Lee"'
Search Results
2. SPS1 deficiency-triggered PGRP-LC and Toll expression controls innate immunity in Drosophila S2 cells
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Tack-Jin Yoo, Myoung Sup Shim, Jeyoung Bang, Jin-Hong Kim, and Byeong Jae Lee
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sps1 ,innate immune system ,imd pathway ,toll pathway ,pgrp-lc ,toll ,Science ,Biology (General) ,QH301-705.5 - Abstract
Selenophosphate synthetase 1 (SPS1) is an essential gene for the cell growth and embryogenesis in Drosophila melanogaster. We have previously reported that SPS1 deficiency stimulates the expression of genes responsible for the innate immune system, including antimicrobial peptides (AMPs), in Drosophila S2 cells. However, the underlying mechanism has not been elucidated. Here, we investigated the immune pathways that control the SPS1-deficiency-induced expression of AMPs in S2 cells. It was found that the activation of AMP expression is regulated by both immune deficiency (IMD) and the Toll pathway. Double knockdown of the upstream genes of each pathway with SPS1 showed that the peptidoglycan recognition protein-LC (PGRP-LC) and Toll genes are targeted by SPS1 for regulating these pathways. We also found that the IMD and Toll pathway regulate AMP expression by cross-talking. The levels of PGRP-LC and Toll mRNAs were upregulated upon Sps1 knockdown (6.4±0.36 and 3.2±0.45-fold, respectively, n=3). Overexpression of each protein also upregulated AMPs. Interestingly, PGRP-LC overexpression upregulated AMP more than Toll overexpression. These data strongly suggest that SPS1 controls the innate immune system of D. melanogaster through regulating PGRP-LC and Toll expression.
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- 2022
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3. The role of selenium metabolism and selenoproteins in cartilage homeostasis and arthropathies
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Donghyun Kang, Jeeyeon Lee, Cuiyan Wu, Xiong Guo, Byeong Jae Lee, Jang-Soo Chun, and Jin-Hong Kim
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Medicine ,Biochemistry ,QD415-436 - Abstract
Joint health: the rare micronutrient selenium may be crucial Selenium, a micronutrient found in brazil nuts, shiitake mushrooms, and most meats, may aid in treating joint diseases, including the most common form of arthritis, osteoarthritis (OA). In addition to thyroid hormone metabolism and immunity, selenium is important in antioxidant defense. Oxidative damage can destroy cartilage and harm joints, and selenium deficiency is implicated in several joint diseases. Jin-Hong Kim at Seoul National University in South Korea and co-workers reviewed selenium metabolism, focusing on OA and and Kashin–Beck disease, a skeletal development disorder prevalent in selenium-deficient areas of northeast Asia. They report that selenium-containing proteins protect cells against oxidative damage and that selenium is crucial to cartilage production. Further investigation of selenium metabolism may point the way to new treatments for OA and other joint diseases.
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- 2020
- Full Text
- View/download PDF
4. Identification of Signaling Pathways for Early Embryonic Lethality and Developmental Retardation in Sephs1−/− Mice
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Jeyoung Bang, Minguk Han, Tack-Jin Yoo, Lu Qiao, Jisu Jung, Jiwoon Na, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield, Jin-Hong Kim, Lark Kyun Kim, and Byeong Jae Lee
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selenium ,selenoprotein ,SEPHS1 ,early embryogenesis ,embryonic lethality ,reactive oxygen species ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Selenophosphate synthetase 1 (SEPHS1) plays an essential role in cell growth and survival. However, the underlying molecular mechanisms remain unclear. In the present study, the pathways regulated by SEPHS1 during gastrulation were determined by bioinformatical analyses and experimental verification using systemic knockout mice targeting Sephs1. We found that the coagulation system and retinoic acid signaling were most highly affected by SEPHS1 deficiency throughout gastrulation. Gene expression patterns of altered embryo morphogenesis and inhibition of Wnt signaling were predicted with high probability at E6.5. These predictions were verified by structural abnormalities in the dermal layer of Sephs1−/− embryos. At E7.5, organogenesis and activation of prolactin signaling were predicted to be affected by Sephs1 knockout. Delay of head fold formation was observed in the Sephs1−/− embryos. At E8.5, gene expression associated with organ development and insulin-like growth hormone signaling that regulates organ growth during development was altered. Consistent with these observations, various morphological abnormalities of organs and axial rotation failure were observed. We also found that the gene sets related to redox homeostasis and apoptosis were gradually enriched in a time-dependent manner until E8.5. However, DNA damage and apoptosis markers were detected only when the Sephs1−/− embryos aged to E9.5. Our results suggest that SEPHS1 deficiency causes a gradual increase of oxidative stress which changes signaling pathways during gastrulation, and afterwards leads to apoptosis.
- Published
- 2021
- Full Text
- View/download PDF
5. Constitutive Oxidative Stress by SEPHS1 Deficiency Induces Endothelial Cell Dysfunction
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Jisu Jung, Yoomin Kim, Jiwoon Na, Lu Qiao, Jeyoung Bang, Dongin Kwon, Tack-Jin Yoo, Donghyun Kang, Lark Kyun Kim, Bradley A. Carlson, Dolph L. Hatfield, Jin-Hong Kim, and Byeong Jae Lee
- Subjects
selenium ,selenoprotein ,selenophosphate synthetase ,endothelial cell ,reactive oxygen species ,cell growth ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The primary function of selenophosphate synthetase (SEPHS) is to catalyze the synthesis of selenophosphate that serves as a selenium donor during selenocysteine synthesis. In eukaryotes, there are two isoforms of SEPHS (SEPHS1 and SEPHS2). Between these two isoforms, only SEPHS2 is known to contain selenophosphate synthesis activity. To examine the function of SEPHS1 in endothelial cells, we introduced targeted null mutations to the gene for SEPHS1, Sephs1, in cultured mouse 2H11 endothelial cells. SEPHS1 deficiency in 2H11 cells resulted in the accumulation of superoxide and lipid peroxide, and reduction in nitric oxide. Superoxide accumulation in Sephs1-knockout 2H11 cells is due to the induction of xanthine oxidase and NADPH oxidase activity, and due to the decrease in superoxide dismutase 1 (SOD1) and 3 (SOD3). Superoxide accumulation in 2H11 cells also led to the inhibition of cell proliferation and angiogenic tube formation. Sephs1-knockout cells were arrested at G2/M phase and showed increased gamma H2AX foci. Angiogenic dysfunction in Sephs1-knockout cells is mediated by a reduction in nitric oxide and an increase in ROS. This study shows for the first time that superoxide was accumulated by SEPHS1 deficiency, leading to cell dysfunction through DNA damage and inhibition of cell proliferation.
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- 2021
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6. SEPHS1: Its evolution, function and roles in development and diseases
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Jeyoung Bang, Donghyun Kang, Jisu Jung, Tack-Jin Yoo, Myoung Sup Shim, Vadim N. Gladyshev, Petra A. Tsuji, Dolph L. Hatfield, Jin-Hong Kim, and Byeong Jae Lee
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Adenosine Triphosphatases ,Biophysics ,Biochemistry ,Phosphates ,Selenocysteine ,Adenosine Diphosphate ,Mice ,Selenium ,Adenosine Triphosphate ,Animals ,Cysteine ,Reactive Oxygen Species ,Molecular Biology ,Phylogeny - Abstract
Selenophosphate synthetase (SEPHS) was originally discovered in prokaryotes as an enzyme that catalyzes selenophosphate synthesis using inorganic selenium and ATP as substrates. However, in contrast to prokaryotes, two paralogs, SEPHS1 and SEPHS2, occur in many eukaryotes. Prokaryotic SEPHS, also known as SelD, contains either cysteine (Cys) or selenocysteine (Sec) in the catalytic domain. In eukaryotes, only SEPHS2 carries out selenophosphate synthesis and contains Sec at the active site. However, SEPHS1 contains amino acids other than Sec or Cys at the catalytic position. Phylogenetic analysis of SEPHSs reveals that the ancestral SEPHS contains both selenophosphate synthesis and another unknown activity, and that SEPHS1 lost the selenophosphate synthesis activity. The three-dimensional structure of SEPHS1 suggests that its homodimer is unable to form selenophosphate, but retains ATPase activity to produce ADP and inorganic phosphate. The most prominent function of SEPHS1 is that it is implicated in the regulation of cellular redox homeostasis. Deficiency of SEPHS1 leads to the disturbance in the expression of genes involved in redox homeostasis. Different types of reactive oxygen species (ROS) are accumulated in response to SEPHS deficiency depending on cell or tissue types. The accumulation of ROS causes pleiotropic effects such as growth retardation, apoptosis, DNA damage, and embryonic lethality. SEPHS1 deficiency in mouse embryos affects retinoic signaling and other related signaling pathways depending on the embryonal stage until the embryo dies at E11.5. Dysregulated SEPHS1 is associated with the pathogenesis of various diseases including cancer, Crohn's disease, and osteoarthritis.
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- 2022
7. Identification of Signaling Pathways for Early Embryonic Lethality and Developmental Retardation in Sephs1−/− Mice
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Lu Qiao, Tack-Jin Yoo, Dolph L. Hatfield, Jisu Jung, Byeong Jae Lee, Jin-Hong Kim, Bradley A. Carlson, Jiwoon Na, Jeyoung Bang, Vadim N. Gladyshev, Lark Kyun Kim, and Minguk Han
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QH301-705.5 ,Retinoic acid ,Morphogenesis ,selenoprotein ,Biology ,medicine.disease_cause ,Article ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Mice ,Pregnancy ,medicine ,Animals ,Biology (General) ,Physical and Theoretical Chemistry ,selenium ,QD1-999 ,Molecular Biology ,Spectroscopy ,Mice, Knockout ,reactive oxygen species ,embryonic lethality ,Organic Chemistry ,Gastrulation ,Phosphotransferases ,Wnt signaling pathway ,Gene Expression Regulation, Developmental ,Embryo ,General Medicine ,Computer Science Applications ,Cell biology ,Mice, Inbred C57BL ,Chemistry ,early embryogenesis ,chemistry ,Knockout mouse ,Embryo Loss ,Female ,SEPHS1 ,Signal transduction ,Oxidative stress ,Gene Deletion ,Signal Transduction - Abstract
Selenophosphate synthetase 1 (SEPHS1) plays an essential role in cell growth and survival. However, the underlying molecular mechanisms remain unclear. In the present study, the pathways regulated by SEPHS1 during gastrulation were determined by bioinformatical analyses and experimental verification using systemic knockout mice targeting Sephs1. We found that the coagulation system and retinoic acid signaling were most highly affected by SEPHS1 deficiency throughout gastrulation. Gene expression patterns of altered embryo morphogenesis and inhibition of Wnt signaling were predicted with high probability at E6.5. These predictions were verified by structural abnormalities in the dermal layer of Sephs1−/− embryos. At E7.5, organogenesis and activation of prolactin signaling were predicted to be affected by Sephs1 knockout. Delay of head fold formation was observed in the Sephs1−/− embryos. At E8.5, gene expression associated with organ development and insulin-like growth hormone signaling that regulates organ growth during development was altered. Consistent with these observations, various morphological abnormalities of organs and axial rotation failure were observed. We also found that the gene sets related to redox homeostasis and apoptosis were gradually enriched in a time-dependent manner until E8.5. However, DNA damage and apoptosis markers were detected only when the Sephs1−/− embryos aged to E9.5. Our results suggest that SEPHS1 deficiency causes a gradual increase of oxidative stress which changes signaling pathways during gastrulation, and afterwards leads to apoptosis.
- Published
- 2021
- Full Text
- View/download PDF
8. Constitutive Oxidative Stress by SEPHS1 Deficiency Induces Endothelial Cell Dysfunction
- Author
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Jeyoung Bang, Dolph L. Hatfield, Lu Qiao, Tack-Jin Yoo, Yoomin Kim, Byeong Jae Lee, Lark Kyun Kim, Jisu Jung, Bradley A. Carlson, Jin-Hong Kim, Donghyun Kang, Jiwoon Na, and Dongin Kwon
- Subjects
QH301-705.5 ,SOD3 ,SOD1 ,selenoprotein ,Article ,Catalysis ,Cell Line ,Inorganic Chemistry ,Superoxide dismutase ,chemistry.chemical_compound ,angiogenesis ,Gene Knockout Techniques ,Mice ,Superoxides ,cell growth ,Animals ,Humans ,Biology (General) ,Physical and Theoretical Chemistry ,selenium ,QD1-999 ,Molecular Biology ,Spectroscopy ,chemistry.chemical_classification ,reactive oxygen species ,Reactive oxygen species ,biology ,Lipid peroxide ,Chemistry ,Cell growth ,Superoxide ,selenophosphate synthetase ,Organic Chemistry ,Phosphotransferases ,Endothelial Cells ,General Medicine ,Reactive Nitrogen Species ,Computer Science Applications ,Cell biology ,Endothelial stem cell ,Oxidative Stress ,HEK293 Cells ,biology.protein ,endothelial cell ,Lipid Peroxidation ,Gene Deletion - Abstract
The primary function of selenophosphate synthetase (SEPHS) is to catalyze the synthesis of selenophosphate that serves as a selenium donor during selenocysteine synthesis. In eukaryotes, there are two isoforms of SEPHS (SEPHS1 and SEPHS2). Between these two isoforms, only SEPHS2 is known to contain selenophosphate synthesis activity. To examine the function of SEPHS1 in endothelial cells, we introduced targeted null mutations to the gene for SEPHS1, Sephs1, in cultured mouse 2H11 endothelial cells. SEPHS1 deficiency in 2H11 cells resulted in the accumulation of superoxide and lipid peroxide, and reduction in nitric oxide. Superoxide accumulation in Sephs1-knockout 2H11 cells is due to the induction of xanthine oxidase and NADPH oxidase activity, and due to the decrease in superoxide dismutase 1 (SOD1) and 3 (SOD3). Superoxide accumulation in 2H11 cells also led to the inhibition of cell proliferation and angiogenic tube formation. Sephs1-knockout cells were arrested at G2/M phase and showed increased gamma H2AX foci. Angiogenic dysfunction in Sephs1-knockout cells is mediated by a reduction in nitric oxide and an increase in ROS. This study shows for the first time that superoxide was accumulated by SEPHS1 deficiency, leading to cell dysfunction through DNA damage and inhibition of cell proliferation.
- Published
- 2021
9. The Differentiation of Human Cytomegalovirus Infected-Monocytes Is Required for Viral Replication
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Chan-Ki Min, Akhalesh K. Shakya, Byeong-Jae Lee, Daniel N. Streblow, Patrizia Caposio, and Andrew D. Yurochko
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0301 basic medicine ,Microbiology (medical) ,Human cytomegalovirus ,integrin ,viruses ,EGFR ,macrophage polarization ,030106 microbiology ,Immunology ,Macrophage polarization ,lcsh:QR1-502 ,Cytomegalovirus ,Review ,macrophage ,Biology ,Virus Replication ,Microbiology ,Monocytes ,Virus ,lcsh:Microbiology ,03 medical and health sciences ,Cellular and Infection Microbiology ,medicine ,Humans ,Macrophage ,Cells, Cultured ,HCMV ,Monocyte ,Virus receptor ,Cell Differentiation ,differentiation ,medicine.disease ,Virology ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,Viral replication ,Monocyte differentiation ,Cytomegalovirus Infections ,monocyte ,signaling - Abstract
Viral dissemination is a key mechanism responsible for persistence and disease following human cytomegalovirus (HCMV) infection. Monocytes play a pivotal role in viral dissemination to organ tissue during primary infection and following reactivation from latency. For example, during primary infection, infected monocytes migrate into tissues and differentiate into macrophages, which then become a source of viral replication. In addition, because differentiated macrophages can survive for months to years, they provide a potential persistent infection source in various organ systems. We broadly note that there are three phases to infection and differentiation of HCMV-infected monocytes: (1) Virus enters and traffics to the nucleus through a virus receptor ligand engagement event that activates a unique signalsome that initiates the monocyte-to-macrophage differentiation process. (2) Following initial infection, HCMV undergoes a "quiescence-like state" in monocytes lasting for several weeks and promotes monocyte differentiation into macrophages. While, the initial event is triggered by the receptor-ligand engagement, the long-term cellular activation is maintained by chronic viral-mediated signaling events. (3) Once HCMV infected monocytes differentiate into macrophages, the expression of immediate early viral (IE) genes is detectable, followed by viral replication and long term infectious viral particles release. Herein, we review the detailed mechanisms of each phase during infection and differentiation into macrophages and discuss the biological significance of the differentiation of monocytes in the pathogenesis of HCMV.
- Published
- 2020
10. The role of selenium metabolism and selenoproteins in cartilage homeostasis and arthropathies
- Author
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Byeong Jae Lee, Cuiyan Wu, Donghyun Kang, Jeeyeon Lee, Xiong Guo, Jin-Hong Kim, and Jang-Soo Chun
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0301 basic medicine ,inorganic chemicals ,Antioxidant ,medicine.medical_treatment ,Clinical Biochemistry ,chemistry.chemical_element ,Physiology ,Arthritis ,QD415-436 ,Review Article ,medicine.disease_cause ,Biochemistry ,Models, Biological ,03 medical and health sciences ,Selenium ,0302 clinical medicine ,food ,Selenium deficiency ,Osteoarthritis ,medicine ,Animals ,Homeostasis ,Humans ,Selenoproteins ,Molecular Biology ,030203 arthritis & rheumatology ,Cartilage homeostasis ,business.industry ,food and beverages ,medicine.disease ,Micronutrient ,food.food ,030104 developmental biology ,Cartilage ,Mechanisms of disease ,chemistry ,Medicine ,Molecular Medicine ,Joint Diseases ,business ,Oxidative stress ,Brazil nut - Abstract
As an essential nutrient and trace element, selenium is required for living organisms and its beneficial roles in human health have been well recognized. The role of selenium is mainly played through selenoproteins synthesized by the selenium metabolic system. Selenoproteins have a wide range of cellular functions including regulation of selenium transport, thyroid hormones, immunity, and redox homeostasis. Selenium deficiency contributes to various diseases, such as cardiovascular disease, cancer, liver disease, and arthropathy—Kashin–Beck disease (KBD) and osteoarthritis (OA). A skeletal developmental disorder, KBD has been reported in low-selenium areas of China, North Korea, and the Siberian region of Russia, and can be alleviated by selenium supplementation. OA, the most common form of arthritis, is a degenerative disease caused by an imbalance in matrix metabolism and is characterized by cartilage destruction. Oxidative stress serves as a major cause of the initiation of OA pathogenesis. Selenium deficiency and dysregulation of selenoproteins are associated with impairments to redox homeostasis in cartilage. We review the recently explored roles of selenium metabolism and selenoproteins in cartilage with an emphasis on two arthropathies, KBD and OA. Moreover, we discuss the potential of therapeutic strategies targeting the biological functions of selenium and selenoproteins for OA treatment., Joint health: the rare micronutrient selenium may be crucial Selenium, a micronutrient found in brazil nuts, shiitake mushrooms, and most meats, may aid in treating joint diseases, including the most common form of arthritis, osteoarthritis (OA). In addition to thyroid hormone metabolism and immunity, selenium is important in antioxidant defense. Oxidative damage can destroy cartilage and harm joints, and selenium deficiency is implicated in several joint diseases. Jin-Hong Kim at Seoul National University in South Korea and co-workers reviewed selenium metabolism, focusing on OA and and Kashin–Beck disease, a skeletal development disorder prevalent in selenium-deficient areas of northeast Asia. They report that selenium-containing proteins protect cells against oxidative damage and that selenium is crucial to cartilage production. Further investigation of selenium metabolism may point the way to new treatments for OA and other joint diseases.
- Published
- 2019
11. Mapping of nucleic acid binding in proteolytic domains of HIV-1 reverse transcriptase
- Author
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Kumar, Amalendra, Hyeung-Rak Kim, Sobol, Robert W., Becerra, S. Patricia, Byeong-Jae Lee, Hatfield, Dolph L., Suhadolnik, Robert J., and Wilson, Samuel H.
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HIV (Viruses) -- Usage ,Nucleic acids -- Research ,Biological sciences ,Chemistry - Abstract
Two proteases were used for the domain mapping of the human immunodeficiency virus type-1 (HIV-1) and its reverse transcriptase (RT). Domain fragments were emitted after the disintegration of three forms of RT by V8 protease. North western and south western blotting techniques were used to test the domain fragments for nucleic acid binding. RT nucleic acid binding takes place in two domains in the N-terminal of p66.
- Published
- 1993
12. Selenophosphate synthetase 1 is an essential protein with roles in regulation of redox homoeostasis in mammals
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Jang Hoe Huh, Daniel Beaglehole, Lino Tessarollo, Petra A. Tsuji, Ji-Woon Na, Young-Yun Kong, Bradley A. Carlson, Xue-Ming Xu, Ulrich Schweizer, Vadim N. Gladyshev, Ryuta Tobe, David S. Salomon, Eileen Southon, Sang-Goo Lee, Byeong Jae Lee, Harold E. Seifried, Nadia P. Castro, Jeyoung Bang, and Dolph L. Hatfield
- Subjects
0301 basic medicine ,Biology ,Biochemistry ,Selenophosphate synthetase 1 ,Article ,Cell Line ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Glutaredoxin ,Animals ,Homeostasis ,Humans ,Molecular Biology ,Glutaredoxins ,Mice, Knockout ,chemistry.chemical_classification ,Reactive oxygen species ,Glutathione Disulfide ,Cell growth ,Phosphotransferases ,fungi ,Cell Biology ,Glutathione ,030104 developmental biology ,Liver ,chemistry ,Cell culture ,Pyridoxal Phosphate ,Knockout mouse ,Glutathione disulfide ,Oxidation-Reduction - Abstract
Selenophosphate synthetase (SPS) was initially detected in bacteria and was shown to synthesize selenophosphate, the active selenium donor. However, mammals have two SPS paralogues, which are designated SPS1 and SPS2. Although it is known that SPS2 catalyses the synthesis of selenophosphate, the function of SPS1 remains largely unclear. To examine the role of SPS1 in mammals, we generated a Sps1-knockout mouse and found that systemic SPS1 deficiency led to embryos that were clearly underdeveloped by embryonic day (E)8.5 and virtually resorbed by E14.5. The knockout of Sps1 in the liver preserved viability, but significantly affected the expression of a large number of mRNAs involved in cancer, embryonic development and the glutathione system. Particularly notable was the extreme deficiency of glutaredoxin 1 (GLRX1) and glutathione transferase Omega 1 (GSTO1). To assess these phenotypes at the cellular level, we targeted the removal of SPS1 in F9 cells, a mouse embryonal carcinoma (EC) cell line, which affected the glutathione system proteins and accordingly led to the accumulation of hydrogen peroxide in the cell. Furthermore, we found that several malignant characteristics of SPS1-deficient F9 cells were reversed, suggesting that SPS1 played a role in supporting and/or sustaining cancer. In addition, the overexpression of mouse or human GLRX1 led to a reversal of observed increases in reactive oxygen species (ROS) in the F9 SPS1/GLRX1-deficient cells and resulted in levels that were similar to those in F9 SPS1-sufficient cells. The results suggested that SPS1 is an essential mammalian enzyme with roles in regulating redox homoeostasis and controlling cell growth.
- Published
- 2016
13. Human Cytomegalovirus Encodes a Novel FLT3 Receptor Ligand Necessary for Hematopoietic Cell Differentiation and Viral Reactivation
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Lindsey B. Crawford, Jung Heon Kim, Donna Collins-McMillen, Byeong-Jae Lee, Igor Landais, Christine Held, Jay A. Nelson, Andrew D. Yurochko, Patrizia Caposio, and Anne Moscona
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0301 basic medicine ,Human cytomegalovirus ,Cellular differentiation ,viruses ,CD34 ,viral reactivation ,Cytomegalovirus ,Biology ,Flt3 receptor ,Microbiology ,03 medical and health sciences ,Viral Envelope Proteins ,Virology ,medicine ,Humans ,Protein kinase B ,Cells, Cultured ,PI3K/AKT/mTOR pathway ,Glycoproteins ,pUL7 ,Cell Differentiation ,Hematopoietic Stem Cells ,medicine.disease ,hematopoiesis ,QR1-502 ,3. Good health ,Cell biology ,Haematopoiesis ,030104 developmental biology ,fms-Like Tyrosine Kinase 3 ,human cytomegalovirus ,Monocyte differentiation ,Host-Pathogen Interactions ,embryonic structures ,Virus Activation ,Signal transduction ,Research Article ,Protein Binding ,Signal Transduction - Abstract
The ability of human cytomegalovirus (HCMV) to reactivate from latent infection of hematopoietic progenitor cells (HPCs) is intimately linked to cellular differentiation. HCMV encodes UL7 that our group has shown is secreted from infected cells and induces angiogenesis. In this study, we show that UL7 is a ligand for Fms-like tyrosine kinase 3 receptor (Flt-3R), a well-known critical factor in HPC differentiation. We observed that UL7 directly binds Flt-3R and induces downstream signaling cascades, including phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways. Importantly, we show that UL7 protein induces differentiation of both CD34+ HPCs and CD14+ monocytes. Last, we show that an HCMV mutant lacking UL7 fails to reactivate in CD34+ HPCs in vitro as well as in humanized mice. These observations define the first virally encoded differentiation factor with significant implications not only for HCMV reactivation but also for alteration of the hematopoietic compartment in transplant patients., IMPORTANCE Human cytomegalovirus (HCMV) remains a significant cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant recipients. CD34+ hematopoietic progenitor cells (HPCs) represent a critical reservoir of latent HCMV in the transplant population, thereby providing a source of virus for dissemination to visceral organs. HCMV reactivation has been linked to HPC/myeloid cellular differentiation; however, the mechanisms involved in these events are poorly understood at the molecular level. In this study, we show that a viral protein is a ligand for Fms-like tyrosine kinase 3 receptor (Flt-3R) and that the binding of HCMV UL7 to the Flt-3R triggers HPC and monocyte differentiation. Moreover, the loss of UL7 prevents viral reactivation in HPCs in vitro as well as in humanized mice. These observations define the first virally encoded differentiation factor with significant implications not only for HCMV reactivation but also for alteration of the hematopoietic compartment in transplant patients.
- Published
- 2018
14. Selenophosphate synthetase 1 and its role in redox homeostasis, defense and proliferation
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Qiao Lu, Dolph L. Hatfield, Ji-Woon Na, Jin-Hong Kim, Byeong Jae Lee, Vadim N. Gladyshev, Jisu Jung, Bradley A. Carlson, Xiong Guo, and Jeyoung Bang
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,Selenocysteine ,Cell growth ,Chemistry ,Alternative splicing ,Phosphotransferases ,Biochemistry ,Selenophosphate synthetase 1 ,Amino acid ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,ATP hydrolysis ,Physiology (medical) ,Animals ,Homeostasis ,Humans ,Gene ,Oxidation-Reduction ,Gene knockout ,Cell Proliferation - Abstract
Selenophosphate synthetase (SEPHS) synthesizes selenophosphate, the active selenium donor, using ATP and selenide as substrates. SEPHS was initially identified and isolated from bacteria and has been characterized in many eukaryotes and archaea. Two SEPHS paralogues, SEPHS1 and SEPHS2, occur in various eukaryotes, while prokaryotes and archaea have only one form of SEPHS. Between the two isoforms in eukaryotes, only SEPHS2 shows catalytic activity during selenophosphate synthesis. Although SEPHS1 does not contain any significant selenophosphate synthesis activity, it has been reported to play an essential role in regulating cellular physiology. Prokaryotic SEPHS contains a cysteine or selenocysteine (Sec) at the catalytic domain. However, in eukaryotes, SEPHS1 contains other amino acids such as Thr, Arg, Gly, or Leu at the catalytic domain, and SEPHS2 contains only a Sec. Sequence comparisons, crystal structure analyses, and ATP hydrolysis assays suggest that selenophosphate synthesis occurs in two steps. In the first step, ATP is hydrolyzed to produce ADP and gamma-phosphate. In the second step, ADP is further hydrolyzed and selenophosphate is produced using gamma-phosphate and selenide. Both SEPHS1 and SEPHS2 have ATP hydrolyzing activities, but Cys or Sec is required in the catalytic domain for the second step of reaction. The gene encoding SEPHS1 is divided by introns, and five different splice variants are produced by alternative splicing in humans. SEPHS1 mRNA is abundant in rapidly proliferating cells such as embryonic and cancer cells and its expression is induced by various stresses including oxidative stress and salinity stress. The disruption of the SEPHS1 gene in mice or Drosophila leads to the inhibition of cell proliferation, embryonic lethality, and morphological changes in the embryos. Targeted removal of SEPHS1 mRNA in insect, mouse, and human cells also leads to common phenotypic changes similar to those observed by in vivo gene knockout: the inhibition of cell growth/proliferation, the accumulation of hydrogen peroxide in mammals and an unidentified reactive oxygen species (ROS) in Drosophila, and the activation of a defense system. Hydrogen peroxide accumulation in SEPHS1-deficient cells is mainly caused by the down-regulation of genes involved in ROS scavenging, and leads to the inhibition of cell proliferation and survival. However, the mechanisms underlying SEPHS1 regulation of redox homeostasis are still not understood.
- Published
- 2018
15. Human Cytomegalovirus Utilizes a Nontraditional Signal Transducer and Activator of Transcription 1 Activation Cascade via Signaling through Epidermal Growth Factor Receptor and Integrins To Efficiently Promote the Motility, Differentiation, and Polarization of Infected Monocytes
- Author
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Stephen J. Cieply, Caroline R. Spohn, Andrew D. Yurochko, Gary C. Chan, Emily V. Stevenson, Donna Collins-McMillen, Maciej T. Nogalski, Byeong Jae Lee, Jung Heon Kim, and Robert W. Frost
- Subjects
Transcriptional Activation ,0301 basic medicine ,Human cytomegalovirus ,Integrins ,viruses ,Immunology ,Macrophage polarization ,Cytomegalovirus ,Microbiology ,Monocytes ,Proinflammatory cytokine ,Gene product ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Virology ,medicine ,Humans ,Gene Regulatory Networks ,STAT1 ,Cells, Cultured ,biology ,Monocyte ,Cell Polarity ,Cell Differentiation ,medicine.disease ,Up-Regulation ,Virus-Cell Interactions ,Cell biology ,ErbB Receptors ,STAT1 Transcription Factor ,030104 developmental biology ,medicine.anatomical_structure ,Insect Science ,Cytomegalovirus Infections ,STAT protein ,biology.protein ,Signal transduction ,Signal Transduction ,030215 immunology - Abstract
Human cytomegalovirus (HCMV) infects peripheral blood monocytes and triggers biological changes that promote viral dissemination and persistence. We have shown that HCMV induces a proinflammatory state in infected monocytes, resulting in enhanced monocyte motility and transendothelial migration, prolonged monocyte survival, and differentiation toward a long-lived M1-like macrophage phenotype. Our data indicate that HCMV triggers these changes, in the absence of de novo viral gene expression and replication, through engagement and activation of epidermal growth factor receptor (EGFR) and integrins on the surface of monocytes. We previously identified that HCMV induces the upregulation of multiple proinflammatory gene ontologies, with the interferon-associated gene ontology exhibiting the highest percentage of upregulated genes. However, the function of the HCMV-induced interferon (IFN)-stimulated genes (ISGs) in infected monocytes remained unclear. We now show that HCMV induces the enhanced expression and activation of a key ISG transcriptional regulator, signal transducer and activator of transcription (STAT1), via an IFN-independent but EGFR- and integrin-dependent signaling pathway. Furthermore, we identified a biphasic activation of STAT1 that likely promotes two distinct phases of STAT1-mediated transcriptional activity. Moreover, our data show that STAT1 is required for efficient early HCMV-induced enhanced monocyte motility and later for HCMV-induced monocyte-to-macrophage differentiation and for the regulation of macrophage polarization, suggesting that STAT1 may serve as a molecular convergence point linking the biological changes that occur at early and later times postinfection. Taken together, our results suggest that HCMV reroutes the biphasic activation of a traditionally antiviral gene product through an EGFR- and integrin-dependent pathway in order to help promote the proviral activation and polarization of infected monocytes. IMPORTANCE HCMV promotes multiple functional changes in infected monocytes that are required for viral spread and persistence, including their enhanced motility and differentiation/polarization toward a proinflammatory M1 macrophage. We now show that HCMV utilizes the traditionally IFN-associated gene product, STAT1, to promote these changes. Our data suggest that HCMV utilizes EGFR- and integrin-dependent (but IFN-independent) signaling pathways to induce STAT1 activation, which may allow the virus to specifically dictate the biological activity of STAT1 during infection. Our data indicate that HCMV utilizes two phases of STAT1 activation, which we argue molecularly links the biological changes that occur following initial binding to those that continue to occur days to weeks following infection. Furthermore, our findings may highlight a unique mechanism for how HCMV avoids the antiviral response during infection by hijacking the function of a critical component of the IFN response pathway.
- Published
- 2017
16. Long noncoding RNA expression profile reveals lncRNAs signature associated with extracellular matrix degradation in kashin-beck disease
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Yujie Ning, Sen Wang, Xiong Guo, Wanzhen Shao, Feng’e Zhang, Mikko J. Lammi, Lei Yang, Guanghui Zhao, Byeong Jae Lee, Cuiyan Wu, and Huan Liu
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Male ,0301 basic medicine ,Cell- och molekylärbiologi ,lcsh:Medicine ,Down-Regulation ,target prediction ,Biology ,DEPTOR ,Article ,long non-coding RNAs ,03 medical and health sciences ,Gene expression ,Genetics ,medicine ,Humans ,Genetik ,lcsh:Science ,cartilage ,Aged ,Medicinsk genetik ,Kashin-Beck Disease ,Kashin–Beck disease ,Multidisciplinary ,Microarray analysis techniques ,Gene Expression Profiling ,lcsh:R ,Biochemistry and Molecular Biology ,Middle Aged ,medicine.disease ,Long non-coding RNA ,Extracellular Matrix ,Up-Regulation ,Cell biology ,Gene expression profiling ,FBLN1 ,030104 developmental biology ,Kashin-Beck disease ,lcsh:Q ,Female ,RNA, Long Noncoding ,Medical Genetics ,Extracellular Matrix Degradation ,Cell and Molecular Biology ,Biokemi och molekylärbiologi - Abstract
Kashin-Beck disease (KBD) is a deformative, endemic osteochondropathy involving degeneration and necrosis of growth plates and articular cartilage. The pathogenesis of KBD is related to gene expression and regulation mechanisms, but long noncoding RNAs (lncRNAs) in KBD have not been investigated. In this study, we identified 316 up-regulated and 631 down-regulated lncRNAs (≥ 2-fold change) in KBD chondrocytes using microarray analysis, of which more than three-quarters were intergenic lncRNAs and antisense lncRNAs. We also identified 232 up-regulated and 427 down-regulated mRNAs (≥ 2-fold change). A lncRNA-mRNA correlation analysis combined 343 lncRNAs and 292 mRNAs to form 509 coding-noncoding gene co-expression networks (CNC networks). Eleven lncRNAs were predicted to have cis-regulated target genes, including NAV2 (neuron navigator 2), TOX (thymocyte selection-associated high mobility group box), LAMA4 (laminin, alpha 4), and DEPTOR (DEP domain containing mTOR-interacting protein). The differentially expressed mRNAs in KBD significantly contribute to biological events associated with the extracellular matrix. Meanwhile, 34 mRNAs and 55 co-expressed lncRNAs constituted a network that influences the extracellular matrix. In the network, FBLN1 and LAMA 4 were the core genes with the highest significance. These novel findings indicate that lncRNAs may play a role in extracellular matrix destruction in KBD.
- Published
- 2017
17. Cell Proliferation and Motility Are Inhibited by G1 Phase Arrest in 15-kDa Selenoprotein-Deficient Chang Liver Cells
- Author
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Qiao Lu, Ji-Woon Na, Petra A. Tsuji, Dolph L. Hatfield, Bradley A. Carlson, Byeong Jae Lee, Jeyoung Bang, Jang Hoe Huh, Vadim N. Gladyshev, and Ryuta Tobe
- Subjects
Cell cycle checkpoint ,Cell ,SEP15 ,Biology ,Article ,Cell Line ,Focal adhesion ,Cell Movement ,medicine ,Humans ,cyclin E ,RNA, Small Interfering ,Selenoproteins ,selenium ,15-kDa selenoprotein ,Molecular Biology ,chemistry.chemical_classification ,Cell growth ,G1 Phase ,Cell Biology ,General Medicine ,Cell cycle ,Molecular biology ,Cell biology ,cell proliferation ,medicine.anatomical_structure ,chemistry ,cell cycle arrest ,Cell culture ,Selenoprotein - Abstract
The 15-kDa selenoprotein (Sep15) is a selenoprotein residing in the lumen of the endoplasmic reticulum (ER) and implicated in quality control of protein folding. Herein, we established an inducible RNAi cell line that targets Sep15 mRNA in Chang liver cells. RNAi-induced Sep15 deficiency led to inhibition of cell proliferation, whereas cell growth was resumed after removal of the knockdown inducer. Sep15-deficient cells were arrested at the G1 phase by upregulating p21 and p27, and these cells were also characterized by ER stress. In addition, Sep15 deficiency led to the relocation of focal adhesions to the periphery of the cell basement and to the decrease of the migratory and invasive ability. All these changes were reversible depending on Sep15 status. Rescuing the knockdown state by expressing a silent mutant Sep15 mRNA that is resistant to siRNA also reversed the phenotypic changes. Our results suggest that SEP15 plays important roles in the regulation of the G1 phase during the cell cycle as well as in cell motility in Chang liver cells, and that this selenoprotein offers a novel functional link between the cell cycle and cell motility.
- Published
- 2015
18. Selenocysteine tRNA
- Author
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Bradley A, Carlson, Byeong Jae, Lee, Petra A, Tsuji, Paul R, Copeland, Ulrich, Schweizer, Vadim N, Gladyshev, and Dolph L, Hatfield
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Chromatography, Reverse-Phase ,Sequence Analysis, RNA ,Isotope Labeling ,Protein Biosynthesis ,Selenium Radioisotopes ,Animals ,Humans ,Nucleic Acid Conformation ,RNA, Transfer, Amino Acid-Specific ,Blotting, Northern ,Selenoproteins ,Chromatography, Affinity ,Article - Abstract
The selenocysteine (Sec) tRNA[Ser]Sec population consists of two isoforms that differ from each other by a single 2’-O-methylribosyl moiety at position 34 (Um34). These two isoforms, which are encoded in a single gene, Trsp, and modified post-transcriptionally, are involved individually in the synthesis of two subclasses of selenoproteins, designated housekeeping and stress-related selenoproteins. Techniques used in obtaining these isoforms for their characterization include extraction of RNA from mammalian cells and tissues, purifying the tRNA[Ser]Sec population by one or more procedures and finally resolving the two isoforms from each other. Since some of the older techniques for isolating tRNA[Ser]Sec and resolving the isoforms are used in only a few laboratories, these procedures will be discussed briefly and references provided for more detailed information, while the more recently developed procedures are discussed in detail. In addition, a novel technique that was developed in sequencing tRNA[Ser]Sec for identifying their occurrence in other organisms is also presented.
- Published
- 2017
19. Selenocysteine tRNA[Ser]Sec, the Central Component of Selenoprotein Biosynthesis: Isolation, Identification, Modification, and Sequencing
- Author
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Paul R. Copeland, Ulrich Schweizer, Dolph L. Hatfield, Petra A. Tsuji, Bradley A. Carlson, Vadim N. Gladyshev, and Byeong Jae Lee
- Subjects
0301 basic medicine ,Gene isoform ,chemistry.chemical_classification ,education.field_of_study ,030102 biochemistry & molecular biology ,Selenocysteine ,SEPP1 ,SEP15 ,Population ,RNA ,Biology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Biochemistry ,chemistry ,Transfer RNA ,Selenoprotein ,education - Abstract
The selenocysteine (Sec) tRNA[Ser]Sec population consists of two isoforms that differ from each other by a single 2'-O-methylribosyl moiety at position 34 (Um34). These two isoforms, which are encoded in a single gene, Trsp, and modified posttranscriptionally, are involved individually in the synthesis of two subclasses of selenoproteins, designated housekeeping and stress-related selenoproteins. Techniques used in obtaining these isoforms for their characterization include extraction of RNA from mammalian cells and tissues, purifying the tRNA[Ser]Sec population by one or more procedures, and finally resolving the two isoforms from each other. Since some of the older techniques for isolating tRNA[Ser]Sec and resolving the isoforms are used in only a few laboratories, these procedures will be discussed briefly and references provided for more detailed information, while the more recently developed procedures are discussed in detail. In addition, a novel technique that was developed in sequencing tRNA[Ser]Sec for identifying their occurrence in other organisms is also presented.
- Published
- 2017
20. Selenoprotein Gene Nomenclature
- Author
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Ulrich Schweizer, Josef Köhrle, Michael T. Howard, Laurent Chavatte, Regina Brigelius-Flohé, Gustavo Salinas, Philip D. Whanger, Kaixun Huang, Fulvio Ursini, Matilde Maiorino, Raymond F. Burk, Marla J. Berry, Ick Young Kim, Dolph L. Hatfield, Miljan Simonović, Alexei V. Lobanov, Donna M. Driscoll, Margaret P. Rayman, Sharon Rozovsky, Alain Krol, Peter R. Hoffmann, Elias S.J. Arnér, Roger A. Sunde, Marcus Conrad, Fiona R. Green, Vadim N. Gladyshev, Byeong Jae Lee, Elspeth A. Bruford, Qiong Liu, Sergi Castellano, Ana Ferreiro, Xin Gen Lei, Bradley A. Carlson, Byung Cheon Lee, Gregory V. Kryukov, Alan M. Diamond, Paul R. Copeland, Yan Zhang, Edward E. Schmidt, Leopold Flohé, John E. Hesketh, Joseph Loscalzo, Marco Mariotti, Hwa-Young Kim, Roderic Guigó, Petra A. Tsuji, Lutz Schomburg, K. Sandeep Prabhu, Susan Tweedie, Diane E. Handy, Arne Holmgren, Alain Lescure, Robert J. Hondal, Harvard Medical School [Boston] (HMS), Broad Institute of MIT and Harvard (BROAD INSTITUTE), Harvard Medical School [Boston] (HMS)-Massachusetts Institute of Technology (MIT)-Massachusetts General Hospital [Boston], Karolinska Institutet [Stockholm], University of Hawai‘i [Mānoa] (UHM), German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), European Bioinformatics Institute [Hinxton] (EMBL-EBI), EMBL Heidelberg, Vanderbilt University School of Medicine [Nashville], National Institutes of Health [Bethesda] (NIH), Max Planck Institute for Evolutionary Anthropology [Leipzig], Max-Planck-Gesellschaft, Expression de l'ARN chez les virus et les eucaryotes - RNA Expression in Viruses and Eukaryotes (REVE), Centre International de Recherche en Infectiologie (CIRI), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institute for Developmental Genetics [Neuherberg] (IDG), German Research Center for Environmental Health - Helmholtz Center München (GmbH), Robert Wood Johnson Medical School [Piscataway, NJ] (RWJMS), University of Illinois [Chicago] (UIC), University of Illinois System, Cleveland Clinic, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Universidad de la República [Montevideo] (UDELAR), Università degli Studi di Padova = University of Padua (Unipd), University of Manchester [Manchester], Centre for Genomic Regulation [Barcelona] (CRG), Universitat Pompeu Fabra [Barcelona] (UPF)-Centro Nacional de Analisis Genomico [Barcelona] (CNAG), Newcastle University [Newcastle], University of Vermont [Burlington], University of Utah, Huazhong University of Science and Technology [Wuhan] (HUST), Yeungnam University [South Korea], Korea University [Seoul], Charité - UniversitätsMedizin = Charité - University Hospital [Berlin], Architecture et Réactivité de l'ARN (ARN), Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), KSQ Therapeutics [Cambridge MA], Seoul National University [Seoul] (SNU), Cornell University [New York], Shenzhen University [Shenzhen], Pennsylvania State University (Penn State), Penn State System, University of Surrey (UNIS), University of Delaware [Newark], Instituto de Higiene [Montevideo], Montana State University (MSU), Rheinische Friedrich-Wilhelms-Universität Bonn, University of Wisconsin-Madison, Towson University [Towson, MD, United States], University of Maryland System, Oregon State University (OSU), Centre International de Recherche en Infectiologie - UMR (CIRI), Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Centre de référence des maladies rares neuromusculaires, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Universidad de la República [Montevideo] (UCUR), Universita degli Studi di Padova, and Universidad de la República (UDELAR)
- Subjects
0301 basic medicine ,GPX2 ,SEPP1 ,selenocysteine ,SEP15 ,function ,gene name ,genomics ,nomenclature ,selenium ,selenoprotein ,structure-function ,Biochemistry ,Molecular Biology ,Cell Biology ,Biology ,03 medical and health sciences ,Terminology as Topic ,Humans ,education ,Selenoproteins ,chemistry.chemical_classification ,Genetics ,education.field_of_study ,030102 biochemistry & molecular biology ,Selenoprotein N ,Selenoprotein P ,Methods and Resources ,Selenoprotein T ,Selenoprotein W ,030104 developmental biology ,chemistry ,Selenoprotein ,[CHIM.OTHE]Chemical Sciences/Other - Abstract
International audience; The human genome contains 25 genes coding for selenocysteine-containing proteins (selenoproteins). These proteins are involved in a variety of functions, most notably redox homeostasis. Selenoprotein enzymes with known functions are designated according to these functions: TXNRD1, TXNRD2, and TXNRD3 (thioredoxin reductases), GPX1, GPX2, GPX3, GPX4, and GPX6 (glutathione peroxidases), DIO1, DIO2, and DIO3 (iodothyronine deiodinases), MSRB1 (methionine sulfoxide reductase B1), and SEPHS2 (selenophosphate synthetase 2). Selenoproteins without known functions have traditionally been denoted by SEL or SEP symbols. However, these symbols are sometimes ambiguous and conflict with the approved nomenclature for several other genes. Therefore, there is a need to implement a rational and coherent nomenclature system for selenoprotein-encoding genes. Our solution is to use the root symbol SELENO followed by a letter. This nomenclature applies to SELENOF (selenoprotein F, the 15-kDa selenoprotein, SEP15), SELENOH (selenoprotein H, SELH, C11orf31), SELENOI (selenoprotein I, SELI, EPT1), SELENOK (selenoprotein K, SELK), SELENOM (selenoprotein M, SELM), SELENON (selenoprotein N, SEPN1, SELN), SELENOO (selenoprotein O, SELO), SELENOP (selenoprotein P, SeP, SEPP1, SELP), SELENOS (selenoprotein S, SELS, SEPS1, VIMP), SELENOT (selenoprotein T, SELT), SELENOV (selenoprotein V, SELV), and SELENOW (selenoprotein W, SELW, SEPW1). This system, approved by the HUGO Gene Nomenclature Committee, also resolves conflicting, missing, and ambiguous designations for selenoprotein genes and is applicable to selenoproteins across vertebrates.
- Published
- 2016
21. Combination of TLR1/2 and TLR3 ligands enhances CD4+ T cell longevity and antibody responses by modulating type I IFN production
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Sang Jun Ha, Byeong Jae Lee, Bo Ryeong Lee, Jung Sun Yum, Sung Jae Shin, Soo Kyung Jeong, and Byung Cheol Ahn
- Subjects
0301 basic medicine ,Adoptive cell transfer ,Ovalbumin ,medicine.medical_treatment ,T cell ,Priming (immunology) ,Mice, Transgenic ,Biology ,Ligands ,Article ,03 medical and health sciences ,Mice ,Immune system ,Antigen ,Adjuvants, Immunologic ,Interferon ,medicine ,Animals ,Antigens ,Multidisciplinary ,T-Lymphocytes, Helper-Inducer ,Adoptive Transfer ,Toll-Like Receptor 1 ,Toll-Like Receptor 2 ,Immunity, Humoral ,Toll-Like Receptor 3 ,Mice, Inbred C57BL ,030104 developmental biology ,medicine.anatomical_structure ,Poly I-C ,RAW 264.7 Cells ,Gene Expression Regulation ,Immunology ,Interferon Type I ,Cancer research ,Immunization ,Signal transduction ,Adjuvant ,medicine.drug - Abstract
Despite the possibility of combining Toll-like receptor (TLR) ligands as adjuvants to improve vaccine efficacy, it remains unclear which combinations of TLR ligands are effective or what their underlying mechanisms may be. Here, we investigated the mechanism of action of L-pampo, a proprietary adjuvant composed of TLR1/2 and TLR3 ligands. L-pampo dramatically increased humoral immune responses against the tested target antigens, which was correlated with an increase in follicular helper T cells and the maintenance of antigen-specific CD4+ T cells. During the initial priming phase, in contrast to the induction of type I interferon (IFN) and pro-inflammatory cytokines stimulated by polyI:C, L-pampo showed a greatly diminished induction of type I IFN, but not of other cytokines, and remarkably attenuated IRF3 signaling, which appeared to be critical to L-pampo-mediated adjuvanticity. Collectively, our results demonstrate that the adjuvant L-pampo contributes to the promotion of antigen-specific antibodies and CD4+ T cell responses via a fine regulation of the TLR1/2 and TLR3 signaling pathways, which may be helpful in the design of improved vaccines.
- Published
- 2016
- Full Text
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22. Short-term manganese inhalation decreases brain dopamine transporter levels without disrupting motor skills in rats
- Author
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JuOae Chang, Jin Ha Yoon, Byeong Jae Lee, Jonghan Kim, Kyuhong Lee, and Devina Saputra
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Male ,medicine.medical_specialty ,Time Factors ,Striatum ,010501 environmental sciences ,Lung injury ,Motor Activity ,Toxicology ,01 natural sciences ,Risk Assessment ,Rotarod performance test ,Receptors, Dopamine ,Rats, Sprague-Dawley ,03 medical and health sciences ,0302 clinical medicine ,Neurochemical ,Chlorides ,Internal medicine ,medicine ,Animals ,0105 earth and related environmental sciences ,Dopamine transporter ,Inhalation exposure ,Dopamine Plasma Membrane Transport Proteins ,Inhalation Exposure ,biology ,Behavior, Animal ,Chemistry ,Manganese Poisoning ,Brain ,Lung Injury ,Olfactory bulb ,Up-Regulation ,Endocrinology ,Manganese Compounds ,Dopamine receptor ,Rotarod Performance Test ,biology.protein ,030217 neurology & neurosurgery - Abstract
Manganese (Mn) is used in industrial metal alloys and can be released into the atmosphere during methylcyclopentadienyl manganese tricarbonyl combustion. Increased Mn deposition in the brain after long-term exposure to the metal by inhalation is associated with altered dopamine metabolism and neurobehavioral problems, including impaired motor skills. However, neurotoxic effects of short-term exposure to inhaled Mn are not completely characterized. The purpose of this study is to define the neurobehavioral and neurochemical effects of short-term inhalation exposure to Mn at a high concentration using rats. Male Sprague-Dawley rats were exposed to MnCl2 aerosol in a nose-only inhalation chamber for 3 weeks (1.2 µm, 39 mg/m(3)). Motor coordination was tested on the day after the last exposure using a rotarod device at a fixed speed of 10 rpm for 2 min. Also, dopamine transporter and dopamine receptor protein expression levels in the striatum region of the brain were determined by Western blot analysis. At a rotarod speed of 10 rpm, there were no significant differences in the time on the bar before the first fall or the number of falls during the two-minute test observed in the exposed rats, as compared with controls. The Mn-exposed group had significantly higher Mn levels in the lung, blood, olfactory bulb, prefrontal cortex, striatum, and cerebellum compared with the control group. A Mn concentration gradient was observed from the olfactory bulb to the striatum, supporting the idea that Mn is transported via the olfactory pathway. Our results demonstrated that inhalation exposure to 39 mg/m(3) Mn for 3 weeks induced mild lung injury and modulation of dopamine transporter expression in the brain, without altering motor activity.
- Published
- 2016
23. Interplay of Selenoproteins and Different Antioxidant Systems in Various Cancers
- Author
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Petra A. Tsuji, Vadim N. Gladyshev, Byeong Jae Lee, Bradley A. Carlson, and Dolph L. Hatfield
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0301 basic medicine ,chemistry.chemical_classification ,GPX2 ,Antioxidant ,medicine.medical_treatment ,Glutathione peroxidase ,SEP15 ,Biology ,medicine.disease ,medicine.disease_cause ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,chemistry ,Thioredoxin Reductase 1 ,030220 oncology & carcinogenesis ,medicine ,Cancer research ,Liver cancer ,Carcinogenesis ,Oxidative stress - Abstract
Malignant tumors are known to require robust antioxidant systems to sustain their rapidly dividing cells and protect them from oxidative damage. The dietary trace mineral selenium, through its incorporation into selenoproteins such as thioredoxin reductase 1 (TXNRD1), glutathione peroxidase (GPX) 2 and the 15 kDa selenoprotein (SEP15), has been shown to play important roles in redox-regulation. Given that the functions of these selenoenzymes protect both normal and malignant cells from oxidative stress, these very same redox-regulatory processes are thought to result in both anti- and pro-tumorigenic effects at a tissue-specific and cellular level; thus, these selenoproteins are often referred to as having a “Dr. Jekyll and Mr. Hyde personality”. Herein, we summarize the main findings with emphasis on TXNRD1 and SEP15, and their roles in the regulation of specific studies of lung, liver and colon cancers to illustrate the differences in the antioxidants involved, and the complexities of their interplay with other antioxidants or antioxidant systems. It should be noted that it remains to be established if any of the observed anti- and pro-tumorigenic effects of TXNRD1 and SEP15 are possibly tumor stage or grade-dependent.
- Published
- 2016
24. Selenocysteine tRNA[Ser]Sec: From Nonsense Suppressor tRNA to the Quintessential Constituent in Selenoprotein Biosynthesis
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Dolph L. Hatfield, Ulrich Schweizer, Petra A. Tsuji, Bradley A. Carlson, Jin Mo Park, Ryuta Tobe, Vadim N. Gladyshev, and Byeong Jae Lee
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,education.field_of_study ,Selenocysteine ,Chemistry ,Nonsense mutation ,Population ,Serine ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Nonsense suppressor ,Biochemistry ,Transfer RNA ,Protein biosynthesis ,Selenoprotein ,education ,030217 neurology & neurosurgery - Abstract
When selenocysteine (Sec) tRNA[Ser]Sec was originally discovered, it was proposed to be the first nonsense suppressor tRNA found in mammalian and avian tissues, since it exclusively decoded the nonsense codon, UGA, which normally dictates the cessation of protein synthesis. This tRNA was subsequently shown to be Sec tRNA, which inserted Sec into protein as the 21st proteinogenic amino acid. Once it was established that this tRNA was aminoacylated with serine by seryl-tRNA synthetase and served as the scaffold for Sec synthesis, Sec tRNA was appropriately named Sec tRNA[Ser]Sec. The mammalian Sec-tRNA[Ser]Sec population consists of two isoforms that differ from each other by a single 2′-O-methyl moiety on the uridine at position 34, designated Um34. The non-Um34 isoform is involved in the synthesis of a subclass of selenoproteins, called housekeeping selenoproteins, while the Um34 isoform supports synthesis of stress-related selenoproteins. These novel functions and other unique features of Sec tRNA are the subjects of this chapter, supporting the idea that this tRNA is the quintessential constituent in selenoprotein biosynthesis.
- Published
- 2016
25. Influenza M1 VLPs containing neuraminidase induce heterosubtypic cross-protection
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Sang-Moo Kang, Min Chul Kim, Richard W. Compans, Jae-Min Song, Fu-Shi Quan, and Byeong-Jae Lee
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Cross Protection ,viruses ,Neuraminidase ,Hemagglutinin (influenza) ,Chick Embryo ,Antibodies, Viral ,medicine.disease_cause ,complex mixtures ,Article ,Virus ,Viral Matrix Proteins ,Mice ,Viral Proteins ,Influenza A Virus, H1N1 Subtype ,Orthomyxoviridae Infections ,Immunity ,Virology ,Influenza A virus ,medicine ,Animals ,Vaccines, Virus-Like Particle ,Lung ,Administration, Intranasal ,Mice, Inbred BALB C ,Protection ,Viral matrix protein ,biology ,Immune Sera ,Influenza A Virus, H3N2 Subtype ,Vaccination ,virus diseases ,Virus-like particles ,biochemical phenomena, metabolism, and nutrition ,Influenza ,Immunization ,Influenza Vaccines ,biology.protein - Abstract
Influenza virus like particles (VLPs) containing hemagglutinin were previously demonstrated to induce protection against the homologous strains. However, little information is available on the protective role of neuraminidase (NA), the second major glycoprotein. In this study, we developed VLPs (NA VLPs) containing NA and M1 derived from A/PR/8/34 (H1N1) influenza virus, and investigated their ability to induce protective immunity. Intranasal immunization with NA VLPs induced serum antibody responses to H1N1 and H3N2 influenza A viruses as well as significant neuraminidase inhibition activity. Importantly, mice immunized with NA VLPs were 100% protected against lethal infection by the homologous A/PR/8/34 (H1N1) as well as heterosubtypic A/Philippines/82 (H3N2) virus, although body weight loss was observed after lethal challenge with heterosubtypic H3N2 virus. The present study therefore provides evidence that influenza VLPs containing M1 and NA are capable of inducing immunity to homologous as well as antigenically distinct influenza A virus strains.
- Published
- 2012
26. Selenoprotein dSelK in Drosophila elevates release of Ca2+ from endoplasmic reticulum by upregulating expression of inositol 1,4,5-tris-phosphate receptor
- Author
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L. Xia, C. L. Chen, J. Wang, H. Bai, L. G. Sun, S. B. Ben, J. Z. Xia, M. S. Shim, Byeong Jae Lee, J. Cui, F. Yang, and Q. Y. Wang
- Subjects
Cytoplasm ,Gene knockdown ,biology ,Schneider 2 cells ,Endoplasmic reticulum ,General Medicine ,Inositol trisphosphate receptor ,Golgi apparatus ,Endoplasmic Reticulum ,biology.organism_classification ,Biochemistry ,Molecular biology ,Up-Regulation ,symbols.namesake ,Drosophila melanogaster ,Gene expression ,symbols ,Animals ,Drosophila Proteins ,Inositol 1,4,5-Trisphosphate Receptors ,Calcium ,Signal transduction ,Selenoproteins ,Signal Transduction - Abstract
dSelK (G-rich), a homolog of human and mouse SelK, is one of three selenoproteins in Drosophila melanogaster. It is the only trans-membrane selenoprotein in D. melanogaster integrated into both the endoplasmic reticulum (ER) membrane and the Golgi apparatus. The gene expression profile of Drosophila Schneider 2 (S2) cells after the dsRNA interference (dsRNAi) targeting of dSelK was examined with the GeneChip Drosophila Genome 2.0 Array (Affymetrix), a high-density oligonucleotide microarray encompassing nearly the full Drosophila genome. The results showed that the transcriptional expression of eight genes whose proteins are located on (or related to) the ER or the Golgi apparatus was highly induced or repressed by the dsRNAi treatment. The mRNA levels of the inositol 1,4,5-tris-phosphate receptor (IP3 receptor), whose gene product is integrated into the ER membrane and regulates the release of Ca2+ from the ER to the cytosol, were significantly downregulated. In contrast, the expression of inositol 1,4,5-tris-phosphate kinase 1, which is a cytosolic protein with opposing functions to the IP3 receptor, was significantly upregulated. Quantitative real-time PCR verified these results. The concentration of intracellular free Ca2+ of the Drosophila S2 cells was significantly decreased after the knockdown of dSelK, whereas overexpression of dSelK significantly increased the intracellular free Ca2+ concentration. These results indicate that dSelK in D. melanogaster is involved in regulating the release of Ca2+ from the ER to the cytosol and may play important roles in the signal transduction pathways involving Ca2+ mobilization.
- Published
- 2011
27. HCMV Infection and Apoptosis: How Do Monocytes Survive HCMV Infection?
- Author
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Bailey S. Mosher, Byeong Jae Lee, Reynell Brooks, Heather L Fulkerson, Liudmila S. Chesnokova, Donna Collins-McMillen, and Andrew D. Yurochko
- Subjects
Gene Expression Regulation, Viral ,0301 basic medicine ,Human cytomegalovirus ,Cell signaling ,Programmed cell death ,Cell Survival ,viruses ,lcsh:QR1-502 ,Cytomegalovirus ,Review ,Biology ,survival ,lcsh:Microbiology ,Monocytes ,Virus ,Viral Proteins ,03 medical and health sciences ,Virology ,medicine ,Humans ,cell signaling ,Macrophage ,programmed cell death ,030102 biochemistry & molecular biology ,Macrophages ,apoptosis ,Cell Differentiation ,differentiation ,Dendritic cell ,medicine.disease ,3. Good health ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,human cytomegalovirus ,Apoptosis ,Cytomegalovirus Infections ,Bone marrow - Abstract
Human cytomegalovirus (HCMV) infection of peripheral blood monocytes plays a key role in the hematogenous dissemination of the virus to multiple organ systems following primary infection or reactivation of latent virus in the bone marrow. Monocytes have a short life span of 1–3 days in circulation; thus, HCMV must alter their survival and differentiation to utilize these cells and their differentiated counterparts—macrophages—for dissemination and long term viral persistence. Because monocytes are not initially permissive for viral gene expression and replication, HCMV must control host-derived factors early during infection to prevent apoptosis or programmed cell death prior to viral induced differentiation into naturally long-lived macrophages. This review provides a short overview of HCMV infection of monocytes and describes how HCMV has evolved to utilize host cell anti-apoptotic pathways to allow infected monocytes to bridge the 48–72 h viability gate so that differentiation into a long term stable mature cell can occur. Because viral gene expression is delayed in monocytes following initial infection and only occurs (begins around two to three weeks post infection in our model) following what appears to be complete differentiation into mature macrophages or dendritic cells, or both; virally-encoded anti-apoptotic gene products cannot initially control long term infected cell survival. Anti-apoptotic viral genes are discussed in the second section of this review and we argue they would play an important role in long term macrophage or dendritic cell survival following infection-induced differentiation.
- Published
- 2018
28. Human selenophosphate synthetase 1 has five splice variants with unique interactions, subcellular localizations and expression patterns
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Dolph L. Hatfield, Kwang Hee Lee, Jin Young Kim, Xue-Ming Xu, Myoung Sup Shim, Bradley A. Carlson, Hyein Shin, and Byeong Jae Lee
- Subjects
Regulation of gene expression ,Cell cycle checkpoint ,Cell Cycle ,Phosphotransferases ,Alternative splicing ,Biophysics ,Cell Biology ,Biology ,Cell cycle ,Biochemistry ,Selenophosphate synthetase 1 ,Article ,Cell Line ,Cell biology ,Alternative Splicing ,Cytoplasm ,Humans ,splice ,RNA, Messenger ,Molecular Biology ,Gene ,HeLa Cells - Abstract
Selenophosphate synthetase 1 (SPS1) is an essential cellular gene in higher eukaryotes. Five alternative splice variants of human SPS1 (major type, DeltaE2, DeltaE8, +E9, +E9a) were identified wherein +E9 and +E9a make the same protein. The major type was localized in both the nuclear and plasma membranes, and the others in the cytoplasm. All variants form homodimers, and in addition, the major type forms a heterodimer with DeltaE2, and DeltaE8 with +E9. The level of expression of each splice variant was different in various cell lines. The expression of each alternative splice variant was regulated during the cell cycle. The levels of the major type and DeltaE8 were gradually increased until G2/M phase and then gradually decreased. DeltaE2 expression peaked at mid-S phase and then gradually decreased. However, +E9/+E9a expression decreased gradually after cell cycle arrest. The possible involvement of SPS1 splice variants in cell cycle regulation is discussed.
- Published
- 2010
29. Elevation of Glutamine Level by Selenophosphate Synthetase 1 Knockdown Induces Megamitochondrial Formation in Drosophila Cells
- Author
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Myoung Sup Shim, Bradley A. Carlson, Ki Woo Kim, Dolph L. Hatfield, Kwang Hee Lee, Jin Young Kim, Xue Ming Xu, Byeong Jae Lee, Ick Young Kim, and Hee Kyoung Jung
- Subjects
Glutamine ,Tetrazolium Salts ,Mitochondrion ,Biology ,Biochemistry ,Selenophosphate synthetase 1 ,Cell Line ,Selenium ,Adenosine Triphosphate ,Glutamine synthetase ,Animals ,Humans ,Molecular Biology ,Gene knockdown ,Microscopy, Confocal ,Phosphotransferases ,fungi ,Megamitochondria ,Cell Biology ,Molecular biology ,Recombinant Proteins ,Mitochondria ,Microscopy, Electron ,Thiazoles ,Metabolism and Bioenergetics ,Phenotype ,Cell culture ,Drosophila ,RNA Interference ,Intracellular - Abstract
Although selenophosphate synthetase 1 (SPS1/SelD) is an essential gene in Drosophila, its function has not been determined. To elucidate its intracellular role, we targeted the removal of SPS1/SelD mRNA in Drosophila SL2 cells using RNA interference technology that led to the formation of vacuole-like globular structures. Surprisingly, these structures were identified as megamitochondria, and only depolarized mitochondria developed into megamitochondria. The mRNA levels of l(2)01810 and glutamine synthetase 1 (GS1) were increased by SPS1/SelD knockdown. Blocking the expression of GS1 and l(2)01810 completely inhibited the formation of megamitochondria induced by loss of SPS1/SelD activity and decreased the intracellular levels of glutamine to those of control cells suggesting that the elevated level of glutamine is responsible for megamitochondrial formation. Overexpression of GS1 and l(2)01810 had a synergistic effect on the induction of megamitochondrial formation and on the synthesis of glutamine suggesting that l(2)01810 is involved in glutamine synthesis presumably by activating GS1. Our results indicate that, in Drosophila, SPS1/SelD regulates the intracellular glutamine by inhibiting GS1 and l(2)01810 expression and that elevated levels of glutamine lead to a nutritional stress that provides a signal for megamitochondrial formation.
- Published
- 2009
30. Ribavirin inhibits Borna disease virus proliferation and fatal neurological diseases in neonatally infected gerbils
- Author
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Byeong-Jae Lee, Hidenori Matsunaga, Kazuyoshi Ikuta, and Keizo Tomonaga
- Subjects
Male ,animal diseases ,viruses ,Neurological disorder ,Virus Replication ,Gerbil ,Antiviral Agents ,Virus ,Rodent Diseases ,chemistry.chemical_compound ,Virology ,Ribavirin ,medicine ,Animals ,Borna disease virus ,Mononegavirales ,Pharmacology ,biology ,Cell growth ,Brain ,virus diseases ,biology.organism_classification ,medicine.disease ,digestive system diseases ,Animals, Newborn ,chemistry ,Borna Disease ,Immunology ,Female ,Viral disease ,Nervous System Diseases ,Gerbillinae - Abstract
By using neonatal gerbils, we assessed the effect of ribavirin on the proliferation of Borna disease virus (BDV) in the brain. The intracranial inoculation of ribavirin reduced viral propagation in the acutely infected brain, resulting in protection from fatal neurological disorders. We found that the treatment with ribavirin markedly reduces the numbers of OX-42-positive microglial cells, but does not activate expression of Th1 cytokines, in BDV-infected gerbil brains. Our results suggested that ribavirin directly inhibits BDV replication and might be a potential tool for the treatment of BDV infection.
- Published
- 2008
31. Length Requirements for Membrane Fusion of Influenza Virus Hemagglutinin Peptide Linkers to Transmembrane or Fusion Peptide Domains
- Author
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Konrad C. Bradley, Zhu-Nan Li, Byeong-Jae Lee, Rupert J. Russell, David A. Steinhauer, and William A. Langley
- Subjects
Protein Folding ,DNA, Complementary ,Immunology ,Hemagglutinin (influenza) ,Hemagglutinin Glycoproteins, Influenza Virus ,Peptide ,Biology ,Microbiology ,Cell Line ,Dogs ,Virology ,Animals ,Humans ,chemistry.chemical_classification ,Structure and Assembly ,Cell Membrane ,Lipid bilayer fusion ,Fluoresceins ,Transmembrane protein ,Protein Structure, Tertiary ,Amino acid ,Transmembrane domain ,chemistry ,Biochemistry ,Insect Science ,Mutation ,Biophysics ,biology.protein ,Protein folding ,Peptides ,Viral Fusion Proteins ,HeLa Cells ,Membrane Fusion Activity - Abstract
During membrane fusion, the influenza A virus hemagglutinin (HA) adopts an extended helical structure that contains the viral transmembrane and fusion peptide domains at the same end of the molecule. The peptide segments that link the end of this rod-like structure to the membrane-associating domains are approximately 10 amino acids in each case, and their structure at the pH of fusion is currently unknown. Here, we examine mutant HAs and influenza viruses containing such HAs to determine whether these peptide linkers are subject to specific length requirements for the proper folding of native HA and for membrane fusion function. Using pairwise deletions and insertions, we show that the region flanking the fusion peptide appears to be important for the folding of the native HA structure but that mutant proteins with small insertions can be expressed on the cell surface and are functional for membrane fusion. HA mutants with deletions of up to 10 residues and insertions of as many as 12 amino acids were generated for the peptide linker to the viral transmembrane domain, and all folded properly and were expressed on the cell surface. For these mutants, it was possible to designate length restrictions for efficient membrane fusion, as functional activity was observed only for mutants containing linkers with insertions or deletions of eight residues or less. The linker peptide mutants are discussed with respect to requirements for the folding of native HAs and length restrictions for membrane fusion activity.
- Published
- 2008
32. Infectivity Studies of Influenza Virus Hemagglutinin Receptor Binding Site Mutants in Mice
- Author
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Jeffrey Meisner, Konrad C. Bradley, Zhu-Nan Li, Javier Martin, Byeong-Jae Lee, John J. Skehel, Jacqueline M. Katz, David A. Steinhauer, Kristy J. Szretter, Sudha Thoennes, William A. Langley, and Rupert J. Russell
- Subjects
Models, Molecular ,Immunology ,Orthomyxoviridae ,Mutant ,Mutation, Missense ,Hemagglutinins, Viral ,Hemagglutinin (influenza) ,Chick Embryo ,Antibodies, Viral ,Virus Replication ,medicine.disease_cause ,Microbiology ,Virus ,Cell Line ,Mice ,Viral Proteins ,Dogs ,Orthomyxoviridae Infections ,Virology ,Influenza A virus ,medicine ,Animals ,Binding site ,Lung ,Infectivity ,Mice, Inbred BALB C ,Binding Sites ,Virulence ,biology ,Body Weight ,Embryonated ,Hemagglutination Inhibition Tests ,biology.organism_classification ,Molecular biology ,Protein Structure, Tertiary ,Amino Acid Substitution ,Insect Science ,biology.protein ,Pathogenesis and Immunity - Abstract
The replicative properties of influenza virus hemagglutinin (HA) mutants with altered receptor binding characteristics were analyzed following intranasal inoculation of mice. Among the mutants examined was a virus containing a Y98F substitution at a conserved position in the receptor binding site that leads to a 20-fold reduction in binding. This mutant can replicate as well as wild-type (WT) virus in MDCK cells and in embryonated chicken eggs but is highly attenuated in mice, exhibiting titers in lungs more than 1,000-fold lower than those of the WT. The capacity of the Y98F mutant to induce antibody responses and the structural locations of HA reversion mutations are examined.
- Published
- 2008
33. Analysis of residues near the fusion peptide in the influenza hemagglutinin structure for roles in triggering membrane fusion
- Author
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Sudha Thoennes, John J. Skehel, William A. Langley, David A. Steinhauer, Byeong-Jae Lee, Zhu-Nan Li, and Rupert J. Russell
- Subjects
Models, Molecular ,Conformational change ,Protein Conformation ,Endosome ,Membrane fusion ,Hemagglutinin (influenza) ,Hemagglutinin Glycoproteins, Influenza Virus ,Article ,Cell Line ,Fusion peptide ,Viral entry ,Cricetinae ,Virology ,Animals ,Humans ,Trypsin ,Hemagglutinin ,Tyrosine ,Phylogeny ,Histidine ,chemistry.chemical_classification ,biology ,Influenza A Virus, H3N2 Subtype ,Lipid bilayer fusion ,Hydrogen-Ion Concentration ,Recombinant Proteins ,Influenza ,HA structure ,Amino Acid Substitution ,chemistry ,Biochemistry ,Mutagenesis, Site-Directed ,Biophysics ,biology.protein ,Glycoprotein ,Viral Fusion Proteins - Abstract
Influenza virus entry occurs in endosomes, where acidification triggers irreversible conformational changes of the hemagglutinin glycoprotein (HA) that are required for membrane fusion. The acid-induced HA structural rearrangements have been well documented, and several models have been proposed to relate these to the process of membrane fusion. However, details regarding the role of specific residues in the initiation of structural rearrangements and membrane fusion are lacking. Here we report the results of studies on the HA of A/Aichi/2/68 virus (H3 subtype), in which mutants with changes at several ionizable residues in the vicinity of the “fusion peptide” were analyzed for their effects on the pH at which conformational changes and membrane fusion occur. A variety of phenotypes was obtained, including examples of substitutions that lead to an increase in HA stability at reduced pH. Of particular note was the observation that a histidine to tyrosine substitution at HA1 position 17 resulted in a decrease in pH at which HA structural changes and membrane fusion take place by 0.3 relative to WT. The results are discussed in relation to possible mechanisms by which HA structural rearrangements are initiated at low pH and clade-specific differences near the fusion peptide.
- Published
- 2008
34. Purification and characterization of antimicrobial peptides from the skin secretion of Rana dybowskii
- Author
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Jiyeol Chung, Myoung Sup Shim, Sukwon S. Kim, Doo-yeon Lim, and Byeong Jae Lee
- Subjects
Ranidae ,Physiology ,Molecular Sequence Data ,Antimicrobial peptides ,Peptide ,Microbial Sensitivity Tests ,In Vitro Techniques ,Hemolysis ,Biochemistry ,Microbiology ,Cellular and Molecular Neuroscience ,Endocrinology ,Valine ,Candida albicans ,Animals ,Humans ,Amino Acid Sequence ,Peptide sequence ,Skin ,Antibacterial agent ,chemistry.chemical_classification ,Bacteria ,Sequence Homology, Amino Acid ,biology ,Antimicrobial ,biology.organism_classification ,Rana dybowskii ,Molecular Weight ,chemistry ,Antimicrobial Cationic Peptides - Abstract
Six antimicrobial peptides designated dybowskins were isolated from the skin secretion of Rana dybowskii, an edible frog in Korea. Dybowskin-1 (FLIGMTHGLICLISRKC) and dybowskin-2 (FLIGMTQGLICLITRKC) were isoforms differing in only two amino acid residues at the 7th and 14th positions from the N-terminus, and they showed amino acid sequence similarities with ranalexin peptides. Dybowskin-3 (GLFDVVKGVLKGVGKNVAGSLLEQLKCKLSGGC), dybowskin-4 (VWPLGLVICKALKIC), dybowskin-5 (GLFSVVTGVLKAVGKNVAKNVGGSLLEQLKCKISGGC), and dybowskin-6 (FLPLLLAGLPLKLCFLFKKC) differed in both size and sequence, and they were, in terms of amino acid sequence similarities, related to brevinin-2, japonicin-2, esculentin-2, and brevinin-1 peptides, respectively. All the peptides presented in this paper contained Rana-box, the cyclic heptapeptide domain, which is conserved in other antimicrobial peptides derived from the genus Rana. All the dybowskin peptides showed a broad spectrum of antimicrobial activity against the Gram-positive and Gram-negative bacteria (minimum inhibition concentrations (MIC), 12.5 to >100 μg/ml) and against Candida albicans (MIC, 25 to >100 μg/ml). Especially, dybowskin-4 with valine at its N-terminus was the most abundant and showed the strongest antimicrobial activity among all the dybowskin peptides. This result indicates that the dybowskin peptides from R. dybowskii, whose main habitats are mountains or forests, have evolved differently from antimicrobial peptides isolated from other Korean frogs, whose habitats are plain fields.
- Published
- 2007
35. Differences in Redox Regulatory Systems in Human Lung and Liver Tumors Suggest Different Avenues for Therapy
- Author
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Petra A. Tsuji, Bradley A. Carlson, Vadim N. Gladyshev, Ryuta Tobe, Byeong Jae Lee, and Dolph L. Hatfield
- Subjects
Cancer Research ,Liver tumor ,Biology ,Peroxiredoxin 1 ,medicine.disease_cause ,lcsh:RC254-282 ,Article ,thioredoxin 1 ,03 medical and health sciences ,0302 clinical medicine ,Thioredoxin Reductase 1 ,medicine ,thioredoxin reductase 1 ,antioxidant systems ,glutathione ,glutathione peroxidase ,Lung cancer ,030304 developmental biology ,0303 health sciences ,lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,medicine.disease ,3. Good health ,Oncology ,030220 oncology & carcinogenesis ,Cancer cell ,Immunology ,Cancer research ,Adenocarcinoma ,Thioredoxin ,Oxidative stress - Abstract
A common characteristic of many cancer cells is that they suffer from oxidative stress. They, therefore, require effective redox regulatory systems to combat the higher levels of reactive oxygen species that accompany accelerated growth compared to the normal cells of origin. An elevated dependence on these systems in cancers suggests that targeting these systems may provide an avenue for retarding the malignancy process. Herein, we examined the redox regulatory systems in human liver and lung cancers by comparing human lung adenocarcinoma and liver carcinoma to their respective surrounding normal tissues. Significant differences were found in the two major redox systems, the thioredoxin and glutathione systems. Thioredoxin reductase 1 levels were elevated in both malignancies, but thioredoxin was highly upregulated in lung tumor and only slightly upregulated in liver tumor, while peroxiredoxin 1 was highly elevated in lung tumor, but downregulated in liver tumor. There were also major differences within the glutathione system between the malignancies and their normal tissues. The data suggest a greater dependence of liver on either the thioredoxin or glutathione system to drive the malignancy, while lung cancer appeared to depend primarily on the thioredoxin system.
- Published
- 2015
36. Genomic structure and transcriptional studies on the mouse ribosomal protein S3 gene: Expression of U15 small nucleolar RNA
- Author
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Eun Pyo Moon, Mijin Kim, Byeong Jae Lee, Seong Min Lee, Jin-Young Choi, and Joon Kim
- Subjects
Ribosomal Proteins ,Microinjections ,Transcription, Genetic ,Xenopus ,Molecular Sequence Data ,Biology ,Mice ,Exon ,Transcription (biology) ,Ribosomal protein ,Sequence Homology, Nucleic Acid ,Gene expression ,Genetics ,Animals ,RNA, Small Nucleolar ,Small nucleolar RNA ,Base Pairing ,Gene ,Base Sequence ,Intron ,Promoter ,Exons ,General Medicine ,Introns ,Oocytes ,Nucleic Acid Conformation ,5' Untranslated Regions - Abstract
Ribosomal protein S3 (rpS3) is a multifunctional ribosomal protein (RP) which is known to function as a DNA repair endonuclease as well as an RP. Recently, it was reported that rpS3 is involved in apoptosis. We identified the complete 4760 base pair genomic structure of the mouse rpS3 gene, which is composed of 7 exons and 6 introns. Promoter study revealed that transcription of the mouse rpS3 gene started at two C residues embedded in the 5'-terminal oligopyrimidine tract (5'-TOP); this was then compared with the human counterpart. Functional U15 small nucleolar RNAs (snoRNAs) were expressed from the first and the fifth introns. About 300 base pairs (bps) upstream of the 5'-untranslated region (5'-UTR) of the mouse rpS3 gene was sufficient to show maximum transcription activity. This report shows the conservation of the genomic structure of the rpS3 gene in vertebrates and characteristics of its promoter similar to those of promoters of other mammalian RPs.
- Published
- 2006
37. Deficiency of the 15-kDa selenoprotein led to cytoskeleton remodeling and non-apoptotic membrane blebbing through a RhoA/ROCK pathway
- Author
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Jang Hoe Huh, Ji-Woon Na, Bradley A. Carlson, Vadim N. Gladyshev, Ryuta Tobe, Dolph L. Hatfield, Byeong Jae Lee, Jeyoung Bang, Mihyun Jang, Petra A. Tsuji, and Myoungsup Shim
- Subjects
RHOA ,Myosin light-chain kinase ,genetic structures ,Pyridines ,SEP15 ,Biophysics ,Apoptosis ,macromolecular substances ,Cell morphology ,Biochemistry ,Cell Membrane Structures ,Article ,Cell Line, Tumor ,Humans ,Bleb (cell biology) ,Cytoskeleton ,Selenoproteins ,Molecular Biology ,Myosin-Light-Chain Kinase ,Actin ,rho-Associated Kinases ,biology ,Cell Biology ,Molecular biology ,Amides ,eye diseases ,Cell biology ,Gene Knockdown Techniques ,biology.protein ,sense organs ,rhoA GTP-Binding Protein ,Signal Transduction - Abstract
The 15-kDa selenoprotein (Sep15) has been implicated in etiology of some types of cancer. Herein, inducible RNAi cell lines were established and cell morphology and motility were analyzed. The majority of Sep15-deficient cells (>95%) formed membrane blebs in a dynamic manner. Blebbing cells transformed cell morphology from a normal flat spindle shape to a spherical morphology. In blebbing cells, actin fibers moved to the cell periphery, covering and obscuring visualization of α-tubulin. Bleb formation was suppressed by the inhibitors of Rho-associated protein kinase (ROCK), RhoA or myosin light chain (MLC), restoring blebbing cells to wild-type morphology. RhoA activation and phosphorylation of myosin phosphatase target subunit 1 was induced by Sep15 knockdown. Sep15-deficient cells were non-apoptotic, and displayed a distinct relative localization of F-actin and α-tubulin from typical apoptotic blebbing cells. Our data suggest that Sep15 in Chang liver cells regulates the pathway that antagonizes RhoA/ROCK/MLC-dependent non-apoptotic bleb formation.
- Published
- 2014
38. Role of C-terminal heptapeptide in pore-forming activity of antimicrobial agent, gaegurin 4
- Author
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H. J. Kim, Byeong Jae Lee, Pan Dong Ryu, Suryong Kim, and Moo-Yeol Lee
- Subjects
Time Factors ,Ranidae ,Stereochemistry ,Amino Acid Motifs ,Lipid Bilayers ,Antimicrobial peptides ,Peptide ,Biochemistry ,Dithiothreitol ,chemistry.chemical_compound ,Endocrinology ,Protein structure ,Anti-Infective Agents ,Cations ,Escherichia coli ,Animals ,Protein Precursors ,Lipid bilayer ,Ions ,chemistry.chemical_classification ,Chemistry ,Cell Membrane ,Protein Structure, Tertiary ,Amino acid ,Electrophysiology ,Kinetics ,Membrane ,Potassium ,Efflux ,Chlorine ,Peptides ,Antimicrobial Cationic Peptides - Abstract
Gaegurin 4 (GGN4) is an antimicrobial peptide of 37 amino acids isolated from the skin of a frog, Rana rugosa. GGN4 has a disulfide bond between the residues 31 and 37, which is highly conserved among the antimicrobial peptides isolated from skin of the genus, Rana. However, the role of this C-terminal heptapeptide motif is not well understood. In this work, we compared the membrane effects of the full-length GGN4 (C37) and GGN4 1-30 (C30), which is devoid of the C-terminal seven amino acids to elucidate the function of the C-terminal motif. C37 induced significantly larger membrane conductance (>10x) in the model lipid bilayers formed with acidic and neutral phospholipids and larger K+ efflux from gram-positive (>30x) and gram-negative bacteria. However, the pores induced by C37 and C30 were not different in their permeability to K+ over Cl- (permeability ratio of K+ to Cl- = 4.8-7.1). In addition, the pore-forming effect of C37 or C30 in acidic membranes was not different from that in neutral membranes. Furthermore, C37-induced K+ efflux was not significantly decreased by the reducing agent, dithiothreitol. The results indicate that C-terminal heptapeptide sequence plays an important role in maintaining the high pore-forming activity of GGN4, but does not participate in forming GGN4-induced pore structure. The disulfide bond in this region does not appear critical for such high ionophoric activity of GGN4.
- Published
- 2004
39. Synergistic Inhibitory Effect of Cationic Peptides and Antimicrobial Agents on the Growth of Oral Streptococci
- Author
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Byungkuk Hyun, Eunshin Kim, Sunkyu Kim, Byeong Jae Lee, Kack-Kyun Kim, and Sukwon S. Kim
- Subjects
Colony Count, Microbial ,Microbial Sensitivity Tests ,Dental Caries ,Xylitol ,Drug synergism ,Microbiology ,Streptococcus mutans ,chemistry.chemical_compound ,medicine ,Humans ,Protein Precursors ,General Dentistry ,Inhibitory effect ,Streptococcus sobrinus ,Chemistry ,Chlorhexidine ,Cationic polymerization ,Streptococcus ,Drug Synergism ,Antimicrobial ,Cariostatic Agents ,Anti-Bacterial Agents ,Anti-Infective Agents, Local ,Colony count ,Streptococcus sanguis ,Anti-Infective Agents ,Antimicrobial Cationic Peptides ,medicine.drug - Abstract
Although chlorhexidine is one of the most efficacious antimicrobial agents used for the prevention of dental caries, side effects limit its application. The effects of gaegurin 6 (GGN6), an animal-derived cationic peptide, and its derivatives PTP6 and PTP12 on the growth of oral streptococci were investigated to assess the potential of these agents for use in the prevention of dental caries. The minimal inhibitory concentrations of the peptides for inhibition of the growth of oral streptococci (Streptococcus mutans, S. sobrinus, S. sanguis and S. gordonii) ranged from 1.2 to 8.2 µM. The peptides also exhibited marked synergistic antibacterial effects with chlorhexidine or xylitol. The most effective combinations (fractional inhibitory concentration index of 0.5) were xylitol with GGN6 against S. gordonii 10558 and chlorhexidine with either GGN6 or PTP6 against S. sobrinus OMZ-175. These results indicate that cationic peptides alone or in combination with chlorhexidine or xylitol might prove effective for the inhibition of the growth of cariogenic oral streptococci in situ.
- Published
- 2003
40. Effects of a tryptophanyl substitution on the structure and antimicrobial activity of C-terminally truncated gaegurin 4
- Author
-
Hyung Eun Kim, Bong-Jin Lee, Sang-Ho Park, Mijin Kim, Byeong Jae Lee, Hyung-Sik Won, and Byongkuk Hyun
- Subjects
chemistry.chemical_classification ,Molecular mass ,medicine.drug_class ,Chemistry ,Stereochemistry ,Antibiotics ,Tryptophan ,Peptide ,Antimicrobial ,Biochemistry ,Fluorescence spectroscopy ,Aspartic acid ,Amphiphile ,medicine - Abstract
Gaegurin 4 (GGN4), a 37-residue antimicrobial peptide, consists of two amphipathic α helices (residues 2–10 and 16–32) connected by a flexible loop region (residues 11–15). As part of an effort to develop new peptide antibiotics with low molecular mass, the activities of C-terminally truncated GGN4 analogues were tested. Δ24−37 GGN4, a peptide analogue with 14 residues truncated from the C-terminus of GGN4, showed a complete loss of antimicrobial activity. However, the single substitution of aspartic acid 16 by tryptophan (D16W) in the Δ24−37 GGN4 completely restored the antimicrobial activity, without any significant hemolytic activity. In contrast, neither the D16F nor K15W substitution of the Δ24−37 GGN4 allowed such a dramatic recovery of activity. In addition, the D16W substitution of the native GGN4 significantly enhanced the hemolytic activity as well as the antimicrobial activity. The structural effect of the D16W substitution in the Δ24−37 GGN4 was investigated by CD, NMR, and fluorescence spectroscopy. The results showed that the single tryptophanyl substitution at position 16 of the Δ24−37 GGN4 induced an α helical conformation in the previously flexible loop region in intact GGN4, thereby forming an entirely amphipathic α helix. In addition, the substituted tryptophan itself plays an important role in the membrane-interaction of the peptide.
- Published
- 2002
41. Selenoprotein W is a glutathione‐dependent antioxidant in vivo
- Author
-
Byeong Jae Lee, Taesoo Kim, Ick Young Kim, Youn Wook Chung, and Dae Won Jeong
- Subjects
DNA, Complementary ,Antioxidant ,medicine.medical_treatment ,Biophysics ,CHO Cells ,Biology ,Transfection ,Biochemistry ,Antioxidants ,chemistry.chemical_compound ,Structural Biology ,Cricetinae ,Tumor Cells, Cultured ,Genetics ,medicine ,Extracellular ,Animals ,Humans ,Cloning, Molecular ,Selenoproteins ,Molecular Biology ,Chinese hamster ovary cell ,Proteins ,Hydrogen Peroxide ,Cell Biology ,Glutathione ,Selenoprotein W ,Molecular biology ,Peroxides ,Selenocysteine ,chemistry ,Cell culture ,Intracellular - Abstract
The function of selenoprotein W (Se-W) was investigated by cloning the corresponding cDNA from mouse brain and expressing it in CHO cells and H1299 human lung cancer cells. Overexpression of Se-W markedly reduced the sensitivity of both cell lines to H2O2 cytotoxicity. The intracellular peroxide concentration of the transfected cells was lower than that of the parental cells in the absence or presence of extracellular H2O2. The resistance to oxidative stress conferred by Se-W was dependent on glutathione. Expression of Se-W mutants in which selenocysteine-13 or cysteine-37 was replaced by serine did not confer resistance to H2O2, implicating these residues in the antioxidant activity of Se-W in vivo.
- Published
- 2002
42. Complete genomic structure of human rpS3: identification of functional U15b snoRNA in the fifth intron
- Author
-
Seong Min Lee, Joon Kim, Byeong Jae Lee, Jae Yung Lee, Yoon Lim, Eun Pyo Moon, and Mijin Kim
- Subjects
Ribosomal Proteins ,Microinjections ,Sequence analysis ,Xenopus ,Molecular Sequence Data ,Gene Expression ,Biology ,Exon ,Ribosomal protein ,Genetics ,Animals ,Humans ,RNA, Small Nucleolar ,Small nucleolar RNA ,Gene ,Base Sequence ,urogenital system ,Fugu ,Fishes ,Intron ,RNA ,DNA ,Exons ,Sequence Analysis, DNA ,General Medicine ,Blotting, Northern ,Introns ,Genes ,Oocytes ,Female ,Sequence Alignment - Abstract
Analysis of the complete genomic structure of the human ribosomal protein S3 (rpS3) gene revealed the presence of a functional U15b snoRNA gene in its intron. Human ribosomal protein S3 (rpS3) gene of 6115 bp long has been identified to contain six introns and seven exons in this study. The first and fifth introns of human S3 gene contain functional U15 snoRNA genes. Although Xenopus and Fugu counterparts also have six introns and seven exons, S3 gene of Fugu contains two functional U15 snoRNAs in the fourth and sixth introns and two pseudo genes for U15 snoRNAs in the first and fifth introns. In Xenopus S1 gene encoding ribosomal protein S3, however, three of its six introns contain U15 snoRNA gene sequence. Sequence comparison of the U15 genes from Xenopus, Fugu and human revealed that the regions involved in binding to 28S rRNA and the consensus sequence (C, D and D' boxes) for snoRNAs are highly conserved among those genes from these three species. Human U15a and U15b RNAs which are derived from the first and the fifth introns, respectively, have been identified to be functional by microinjection of human U15a and U15b snoRNAs into Xenopus oocyte. Northern blot and primer extension analyses confirm that human U15b snoRNA is expressed in vivo.
- Published
- 2002
43. Air pollution exposure and cardiovascular disease
- Author
-
Kyuhong Lee, Bumseok Kim, and Byeong Jae Lee
- Subjects
medicine.medical_specialty ,Pediatrics ,business.industry ,Health, Toxicology and Mutagenesis ,Respiratory disease ,Air pollution ,Cardiorespiratory fitness ,Disease ,Articles ,Toxicology ,medicine.disease_cause ,medicine.disease ,Cardiovascular disease ,Blood pressure ,Environmental health ,Epidemiology ,medicine ,Respiratory system ,business ,Particulate matter ,Stroke - Abstract
Ambient air pollution (AAP) and particulate matters (PM) have been closely associated with adverse health effects such as respiratory disease and cardiovascular diseases. Previous studies have examined the adverse health effects associated with short- and long-term exposure to AAP and outdoor PM on respiratory disease. However, the effect of PM size (PM2.5 and PM10) on cardiovascular disease has not been well studied. Thus, it remains unclear how the size of the inhalable particles (coarse, fine, or ultrafine) affects mortality and morbidity. Airborne PM concentrations are commonly used for ambient air quality management worldwide, owing to the known effects on cardiorespiratory health. In this article, we assess the relationship between cardiovascular diseases and PM, with a particular focus on PM size. We discuss the association of PM2.5 and PM10, nitrogen dioxide (NO2), and elemental carbon with mortality and morbidity due to cardiovascular diseases, stroke, and altered blood pressure, based on epidemiological studies. In addition, we provide evidence that the adverse health effects of AAP and PM are more pronounced among the elderly, children, and people with preexisting cardiovascular and respiratory conditions. Finally, we critically summarize the literature pertaining to cardiovascular diseases, including atherosclerosis and stroke, and introduce potential studies to better understand the health significance of AAP and PM on cardiovascular disease.
- Published
- 2014
44. The MED-7 transcriptional mediator encoded bylet-49is required for gonad and germ cell development inCaenorhabditis elegans
- Author
-
Junho Lee, Jeongsil Kim-Ha, Byeong Jae Lee, and Jae Young Kwon
- Subjects
Male ,Transcription, Genetic ,Nonsense mutation ,Biophysics ,Pair-rule gene ,Transcriptional mediator ,Embryonic Development ,Biology ,medicine.disease_cause ,Biochemistry ,med-7 ,Structural Biology ,RNA interference ,Transcription (biology) ,Genetics ,medicine ,Animals ,Coding region ,Caenorhabditis elegans ,Caenorhabditis elegans Proteins ,Gonads ,Molecular Biology ,Gene ,Genes, Helminth ,RNA, Double-Stranded ,Mutation ,Gonad development ,let-49 ,Cell Biology ,Physical Chromosome Mapping ,biology.organism_classification ,Germ Cells ,Phenotype ,Oocytes ,Trans-Activators ,Female ,Transcription Factors - Abstract
Transcription mediators are evolutionarily conserved from yeast to human. We previously reported the specific in vivo roles of mediators during development. Transcriptional mediators including med-6, med-7, and med-10 were shown to be involved in the regulated transcription of specific genes, but not in the transcription of ubiquitous genes. In this report we have identified and characterized the Caenorhabditis elegans med-7 gene. A genetic mutation in the med-7 gene was identified by comparing genetic and physical maps and determining the molecular lesion. let-49 was found to have a nonsense mutation in the coding region of the med-7 gene. The identification of let-49 as the med-7 gene was confirmed by rescue experiments. The phenotype of the let-49 mutation indicated that the med-7 gene is required for normal postembryonic development. RNAi experiments showed that med-7 is also involved in embryogenesis and the gonad and germ cell development.
- Published
- 2001
45. Structural study of novel antimicrobial peptides, nigrocins, isolated fromRana nigromaculata
- Author
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Sangho Park, Sang-Ho Park, Hee-Chul Ahn, Sunkyu Kim, Sunny S. Kim, Byeong Jae Lee, and Bong-Jin Lee
- Subjects
Models, Molecular ,Circular dichroism ,Magnetic Resonance Spectroscopy ,Ranidae ,Molecular Sequence Data ,Antimicrobial peptides ,Biophysics ,In Vitro Techniques ,Hemolysis ,Biochemistry ,Micelle ,Amphibian Proteins ,Protein Structure, Secondary ,Nuclear magnetic resonance ,chemistry.chemical_compound ,Anti-Infective Agents ,Structural Biology ,Candida albicans ,Gram-Negative Bacteria ,Genetics ,Animals ,Humans ,Amino Acid Sequence ,Sodium dodecyl sulfate ,Molecular Biology ,Peptide sequence ,Micelles ,Skin ,chemistry.chemical_classification ,Sequence Homology, Amino Acid ,Circular Dichroism ,Solution structure ,Protein primary structure ,Cell Biology ,Nuclear magnetic resonance spectroscopy ,Anti-Bacterial Agents ,Amino acid ,Solutions ,Micrococcus luteus ,chemistry ,Antimicrobial peptide ,Antimicrobial Cationic Peptides - Abstract
Novel cationic antimicrobial peptides, named nigrocin 1 and 2, were isolated from the skin of Rana nigromaculata and their amino acid sequences were determined. These peptides manifested a broad spectrum of antimicrobial activity against various microorganisms with different specificity. By primary structural analysis, it was revealed that nigrocin 1 has high sequence homology with brevinin 2 but nigrocin 2 has low sequence homology with any other known antimicrobial peptides. To investigate the structure-activity relationship of nigrocin 2, which has a unique primary structure, circular dichroism (CD) and homonuclear nuclear magnetic resonance spectroscopy (NMR) studies were performed. CD investigation revealed that nigrocin 2 adopts mainly an alpha-helical structure in trifluoroethanol (TFE)/H(2)O solution, sodium dodecyl sulfate (SDS) micelles, and dodecylphosphocholine micelles. The solution structures of nigrocin 2 in TFE/H(2)O (1:1, v/v) solution and in SDS micelles were determined by homonuclear NMR. Nigrocin 2 consists of a typical amphipathic alpha-helix spanning residues 3-18 in both 50% TFE solution and SDS micelles. From the structural comparison of nigrocin 2 with other known antimicrobial peptides, nigrocin 2 could be classified into the family of antimicrobial peptides containing a single linear amphipathic alpha-helix that potentially disrupts membrane integrity, which would result in cell death.
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- 2001
46. Borna Disease Virus Phosphoprotein Binds a Neurite Outgrowth Factor, Amphoterin/HMG-1
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Kazuyoshi Ikuta, Guoqi Zhang, Wataru Kamitani, Keizo Tomonaga, Makiko Watanabe, Takeshi Kobayashi, Byeong-Jae Lee, and Yuko Shoya
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Intracellular Fluid ,Transcription, Genetic ,Neurite ,Immunoprecipitation ,animal diseases ,viruses ,Receptor for Advanced Glycation End Products ,Immunology ,Microbiology ,Cell Line ,Viral Proteins ,Dogs ,Cell Movement ,Laminin ,Virology ,Chlorocebus aethiops ,Neurites ,Tumor Cells, Cultured ,Animals ,Humans ,HMGB1 Protein ,Receptors, Immunologic ,Borna disease virus ,Receptor ,Neurons ,COS cells ,biology ,High Mobility Group Proteins ,virus diseases ,Phosphoproteins ,Molecular biology ,Virus-Cell Interactions ,Rats ,Blot ,Cell culture ,Insect Science ,Phosphoprotein ,COS Cells ,biology.protein ,Carrier Proteins - Abstract
The Borna disease virus (BDV) p24 phosphoprotein is an abundant protein in BDV-infected cultured cells and animal brains. Therefore, there is a possibility that binding of the p24 protein to cellular factor(s) induces functional alterations of infected neural cells in the brain. To identify a cellular protein(s) that interacts with BDV p24 protein, we performed far-Western blotting with extracts from various cell lines. Using recombinant p24 protein as a probe, we detected a 30-kDa protein in all cell lines examined. Binding between the 30-kDa and BDV p24 proteins was also demonstrated using BDV p24 affinity and ion-exchange chromatography columns. Microsequence analysis of the purified 30-kDa protein revealed that its N terminus showed complete homology with rat amphoterin protein, which is a neurite outgrowth factor abundant in the brain during development. Mammalian two-hybrid and immunoprecipitation analyses also confirmed that amphoterin is a specific target for the p24 protein in vivo. Furthermore, we showed that infection by BDV, as well as purified p24 protein in the medium, significantly decreased cell process outgrowth of cells grown on laminin, indicating the functional inhibition of amphoterin by interaction with the p24 protein. Immunohistochemical analysis revealed decreased levels of amphoterin protein at the leading edges of BDV-infected cells. Moreover, the expression of the receptor for advanced glycation end products, of which the extracellular moiety is a receptor for amphoterin, was not significantly activated in BDV-infected cells during the process of extension, suggesting that the secretion of amphoterin from the cell surface is inhibited by the binding of the p24 protein. These results suggested that BDV infection may cause direct damage in the developing brain by inhibiting the function of amphoterin due to binding by the p24 phosphoprotein.
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- 2001
47. Selective Inhibition of Selenocysteine tRNA Maturation and Selenoprotein Synthesis in Transgenic Mice Expressing Isopentenyladenosine-Deficient Selenocysteine tRNA
- Author
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M. A. El-Saadani, Gerald F. Combs, Byeong Jae Lee, Lionel Feigenbaum, Vadim N. Gladyshev, Qi An Sun, Raymond F. Burk, John W. Harney, Marla J. Berry, Dolph L. Hatfield, Mohamed E. Moustafa, Kristina E. Hill, Gregory V. Kryukov, Alan M. Diamond, Bradley A. Carlson, and David B. Mansur
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Molecular Sequence Data ,Population ,Gene Expression ,Mice, Transgenic ,Wobble base pair ,Biology ,Isopentenyladenosine ,Mice ,Selenium ,chemistry.chemical_compound ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,Protein biosynthesis ,Animals ,Selenoproteins ,education ,Molecular Biology ,chemistry.chemical_classification ,education.field_of_study ,integumentary system ,Base Sequence ,Selenocysteine ,Proteins ,RNA ,Cell Biology ,RNA, Transfer, Amino Acid-Specific ,Blotting, Northern ,Molecular biology ,Amino acid ,chemistry ,Biochemistry ,Protein Biosynthesis ,Transfer RNA ,Nucleic Acid Conformation ,Selenoprotein - Abstract
Selenocysteine (Sec) tRNA (tRNA([Ser]Sec)) serves as both the site of Sec biosynthesis and the adapter molecule for donation of this amino acid to protein. The consequences on selenoprotein biosynthesis of overexpressing either the wild type or a mutant tRNA([Ser]Sec) lacking the modified base, isopentenyladenosine, in its anticodon loop were examined by introducing multiple copies of the corresponding tRNA([Ser]Sec) genes into the mouse genome. Overexpression of wild-type tRNA([Ser]Sec) did not affect selenoprotein synthesis. In contrast, the levels of numerous selenoproteins decreased in mice expressing isopentenyladenosine-deficient (i(6)A(-)) tRNA([Ser]Sec) in a protein- and tissue-specific manner. Cytosolic glutathione peroxidase and mitochondrial thioredoxin reductase 3 were the most and least affected selenoproteins, while selenoprotein expression was most and least affected in the liver and testes, respectively. The defect in selenoprotein expression occurred at translation, since selenoprotein mRNA levels were largely unaffected. Analysis of the tRNA([Ser]Sec) population showed that expression of i(6)A(-) tRNA([Ser]Sec) altered the distribution of the two major isoforms, whereby the maturation of tRNA([Ser]Sec) by methylation of the nucleoside in the wobble position was repressed. The data suggest that the levels of i(6)A(-) tRNA([Ser]Sec) and wild-type tRNA([Ser]Sec) are regulated independently and that the amount of wild-type tRNA([Ser]Sec) is determined, at least in part, by a feedback mechanism governed by the level of the tRNA([Ser]Sec) population. This study marks the first example of transgenic mice engineered to contain functional tRNA transgenes and suggests that i(6)A(-) tRNA([Ser]Sec) transgenic mice will be useful in assessing the biological roles of selenoproteins.
- Published
- 2001
48. Neurological Diseases and Viral Dynamics in the Brains of Neonatally Borna Disease Virus-Infected Gerbils
- Author
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Takeshi Kobayashi, Kazuyoshi Ikuta, Byeong-Jae Lee, Makiko Watanabe, Hiroyuki Taniyama, Keizo Tomonaga, and Wataru Kamitani
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viruses ,animal diseases ,Blotting, Western ,Central nervous system ,Purkinje cell ,Hippocampus ,In situ hybridization ,Biology ,Gerbil ,Polymerase Chain Reaction ,Virus ,Viral Proteins ,Virology ,medicine ,Animals ,RNA, Messenger ,Borna disease virus ,In Situ Hybridization ,Brain ,virus diseases ,Immunohistochemistry ,medicine.anatomical_structure ,Animals, Newborn ,nervous system ,Viral replication ,Borna Disease ,Cerebral cortex ,RNA, Viral ,Nervous System Diseases ,Gerbillinae - Abstract
Borna disease virus (BDV) is a noncytolytic, neurotropic RNA virus that causes a chronic neurological disease in a wide variety of animal species. To develop a better understanding of the correlation between neurological disorders caused by BDV infection and virus distribution in the brain, we investigated viral dynamics in the central nervous system (CNS) of neonatally BDV-infected gerbils during the late stage of infection. Despite the severe symptoms and aggressive proliferation of BDV in the infected gerbils, no apparent neuroanatomical abnormalities or neuronal cell loss was observed in the infected gerbil brain. Furthermore, no or only minimal infiltration was observed in the infected gerbil brain. By in situ hybridization and real-time PCR analyses, we demonstrated that the predominant area of expression of BDV mRNA, as well as the protein, was shifted in the brain in association with progression of disease. In nondiseased gerbils, the virus replication was predominantly detected in the cerebral cortex and hippocampus of the CNS. On the other hand, diseased animals showed a high level of expression in the lower brain stem and cerebellum, especially in Purkinje cell neurons. These observations suggested that significant replication of the virus in specific areas of the CNS is critical for development of the neurological disorders in BDV-infected neonatal gerbils.
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- 2001
49. Identification of alternative splicing and negative splicing activity of a nonsegmented negative-strand RNA virus, Borna disease virus
- Author
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Byeong-Jae Lee, Keizo Tomonaga, Makiko Watanabe, Kazuyoshi Ikuta, Takeshi Kobayashi, and Wataru Kamitani
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Gene Expression Regulation, Viral ,animal diseases ,viruses ,Molecular Sequence Data ,Exonic splicing enhancer ,Genome, Viral ,Biology ,Cell Line ,Open Reading Frames ,Exon ,Dogs ,Tumor Cells, Cultured ,Animals ,Borna disease virus ,Gene ,Genetics ,Binding Sites ,Multidisciplinary ,Base Sequence ,Alternative splicing ,Intron ,virus diseases ,RNA ,RNA virus ,Biological Sciences ,biology.organism_classification ,Virology ,Rats ,Alternative Splicing ,COS Cells ,RNA splicing ,RNA, Viral ,Poly A - Abstract
Borna disease virus (BDV) is a nonsegmented negative-strand RNA virus that belongs to the Mononegavirales . Unlike other animal viruses of this order, BDV replicates and transcribes in the nucleus of infected cells. Previous studies have shown that BDV uses RNA splicing machinery for its mRNA expression. In the present study, we identified spliced RNAs that use an alternative 3′ splice site, SA3, in BDV-infected cell lines as well as infected animal brain cells. Transient transfection analysis of cDNA clones of BDV RNA revealed that although SA3 is a favorable splice site in mammalian cells, utilization of SA3 is negatively regulated in infected cells. This negative splicing activity of the SA3 site is regulated by a putative cis-acting region, the exon splicing suppressor (ESS), within the polymerase exon of BDV. The BDV ESS contains similar motifs to other known ESSs present in viral and cellular genes. Furthermore, our results indicated that a functional polyadenylation signal just upstream of the BDV ESS is also involved in the regulation of alternative splicing of BDV. These observations represent the first documentation of complex RNA splicing in animal RNA viruses and also provide new insight into the mechanism of regulation of alternative splicing in animal viruses.
- Published
- 2000
50. Methylation of the ribosyl moiety at position 34 of selenocysteine tRNA[Ser]Sec is governed by both primary and tertiary structure
- Author
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Bradley A. Carlson, Lark Kyun Kim, Tamiko Matsufuji, Dolph L. Hatfield, Sukwon S. Kim, Byeong Jae Lee, and Senya Matsufuji
- Subjects
TRNA modification ,Ribose ,Wobble base pair ,RNA, Transfer, Amino Acyl ,Biology ,Transfection ,Methylation ,Pseudouridine ,Xenopus laevis ,chemistry.chemical_compound ,Animals ,Humans ,Molecular Biology ,chemistry.chemical_classification ,Selenocysteine ,Protein tertiary structure ,Biochemistry ,chemistry ,Mutation ,Transfer RNA ,Oocytes ,Nucleic Acid Conformation ,Female ,Selenoprotein ,Research Article - Abstract
The selenocysteine (Sec) tRNA[Ser]Sec population in higher vertebrates consists of two major isoacceptors that differ from each other by a single nucleoside modification in the wobble position of the anticodon (position 34). One isoacceptor contains 5-methylcarboxymethyluridine (mcmU) in this position, whereas the other contains 5-methylcarboxymethyluridine-2'-O-methylribose (mcmUm). The other modifications in these tRNAs are N6-isopentenyladenosine (i6A), pseudouridine (psi), and 1-methyladenosine (m1A) at positions 37, 55, and 58, respectively. As methylation of the ribose at position 34 is influenced by the intracellular selenium status and the presence of this methyl group dramatically alters tertiary structure, we investigated the effect of the modifications at other positions as well as tertiary structure on its formation. Mutations were introduced within a synthetic gene encoded in an expression vector, transcripts generated and microinjected into Xenopus oocytes, and the resulting tRNA products analyzed for the presence of modified bases. The results suggest that efficient methylation of mcmU to yield mcmUm requires the prior formation of each modified base and an intact tertiary structure, whereas formation of modified bases at other positions, including mcmU, is not as stringently connected to precise primary and tertiary structure. These results, along with the observations that methylation of mcmU is enhanced in the presence of selenium and that this methyl group affects tertiary structure, further suggest that the mcmUm isoacceptor must have a role in selenoprotein synthesis different from that of the mcmU isoacceptor.
- Published
- 2000
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