37 results on '"Akihiro Sugai"'
Search Results
2. Recombinant SLAMblind Measles Virus Is a Promising Candidate for Nectin-4-Positive Triple Negative Breast Cancer Therapy
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Tomoko Fujiyuki, Yosuke Amagai, Koichiro Shoji, Takeshi Kuraishi, Akihiro Sugai, Mutsumi Awano, Hiroki Sato, Shosaku Hattori, Misako Yoneda, and Chieko Kai
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measles virus ,oncovirotherapy ,triple negative breast cancer ,nectin-4 ,oncolytic virus ,safety ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
One of the most refractory breast cancer types is triple negative (TN) breast cancer, in which cells are resistant to both hormone and Herceptin treatments and, thus, often cause recurrence and metastasis. Effective treatments are needed to treat TN breast cancer. We previously demonstrated that rMV-SLAMblind, a recombinant measles virus, showed anti-tumor activity against breast cancer cells. Here, we examined whether rMV-SLAMblind is effective for treating TN breast cancer. Nectin-4, a receptor for rMV-SLAMblind, was expressed on the surface of 75% of the analyzed TN breast cancer cell lines. rMV-SLAMblind infected the nectin-4-expressing TN breast cancer cell lines, and significantly decreased the viability in half of the analyzed cell lines in vitro. Additionally, intratumoral injection of rMV-SLAMblind suppressed tumor growth in xenografts of MDA-MB-468 and HCC70 cells. To assess treatment for metastatic breast cancer, we performed intravenous administration of the luciferase-expressing-rMV-SLAMblind to MDA xenografted mice. Virus replicated in the tumor and resulted in significant suppression of the tumor growth. The safety of the virus was tested by its intravenous injection into healthy cynomolgus monkeys, which did not cause any measles-like symptoms. These results suggest that rMV-SLAMblind is a promising candidate as a therapeutic agent for treating metastatic and/or TN type breast cancer.
- Published
- 2020
- Full Text
- View/download PDF
3. Non-genetically modified models exhibit TARDBP mRNA increase due to perturbed TDP-43 autoregulation
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Akihiro Sugai, Taisuke Kato, Akihide Koyama, Yuka Koike, Takuya Konno, Tomohiko Ishihara, and Osamu Onodera
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Amyotrophic lateral sclerosis ,TDP-43 ,autoregulation ,alternative splicing ,antisense oligonucleotides ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by accumulation of fragmented insoluble TDP-43 and loss of TDP-43 from the nucleus. Increased expression of exogenous TARDBP (encoding TDP-43) induces TDP-43 pathology and cytotoxicity, suggesting the involvement of aberrant expression of TDP-43 in the pathogenesis of ALS. In normal conditions, however, the amount of TDP-43 is tightly regulated by the autoregulatory mechanism involving alternative splicing of TARDBP mRNA. To investigate the influence of autoregulation dysfunction, we inhibited the splicing of cryptic intron 6 using antisense oligonucleotides in vivo. This inhibition doubled the Tardbp mRNA expression, increased the fragmented insoluble TDP-43, and reduced the number of motor neurons in the mouse spinal cord. In human induced pluripotent stem cell-derived neurons, the splicing inhibition of intron 6 increased TARDBP mRNA and decreased nuclear TDP-43. These non-genetically modified models exhibiting rise in the TARDBP mRNA levels suggest that TDP-43 autoregulation turbulence might be linked to the pathogenesis of ALS.
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- 2019
- Full Text
- View/download PDF
4. Robustness and Vulnerability of the Autoregulatory System That Maintains Nuclear TDP-43 Levels: A Trade-off Hypothesis for ALS Pathology Based on in Silico Data
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Akihiro Sugai, Taisuke Kato, Akihide Koyama, Yuka Koike, Sou Kasahara, Takuya Konno, Tomohiko Ishihara, and Osamu Onodera
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amyotrophic lateral sclerosis ,TDP-43 ,TARDBP ,autoregulation ,robustness ,systems biology ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abnormal accumulation of TAR DNA-binding protein 43 (TDP-43) in the cytoplasm and its disappearance from the nucleus are pathological features of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD) and are directly involved in the pathogenesis of these conditions. TDP-43 is an essential nuclear protein that readily aggregates in a concentration-dependent manner. Therefore, cells must strictly maintain an appropriate amount of nuclear TDP-43. In one relevant maintenance mechanism, TDP-43 binds to its pre-mRNA and promotes alternative splicing, resulting in mRNA degradation via nonsense-mediated mRNA decay. The level of nuclear TDP-43 is tightly regulated by these mechanisms, which control the amount of mRNA that may be translated. Based on the results of previous experiments, we developed an in silico model that mimics the intracellular dynamics of TDP-43 and examined TDP-43 metabolism under various conditions. We discovered an inherent trade-off in this mechanism between transcriptional redundancy, which maintains the robustness of TDP-43 metabolism, and vulnerability to specific interfering factors. These factors include an increased tendency of TDP-43 to aggregate, impaired nuclear-cytoplasmic TDP-43 transport, and a decreased efficiency of degrading abnormal proteins, all of which are functional abnormalities related to the gene that causes familial ALS/FTD. When these conditions continue at a certain intensity, the vulnerability of the autoregulatory machinery becomes apparent over time, and transcriptional redundancy enters a vicious cycle that ultimately results in TDP-43 pathology. The results obtained using this in silico model reveal the difference in TDP-43 metabolism between normal and disease states. Furthermore, using this model, we simulated the effect of a decrease in TDP-43 transcription and found that this decrease improved TDP-43 pathology and suppressed the abnormal propagation of TDP-43. Therefore, we propose a potential therapeutic strategy to suppress transcriptional redundancy, which is the driving force of the pathological condition caused by the specific factors described above, in patients with ALS presenting with TDP-43 pathology. An ALS animal model exhibiting TDP-43 pathology without overexpression of exogenous TDP-43 should be developed to investigate the effect of alleviating the transcriptional redundancy of TARDBP.
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- 2018
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- View/download PDF
5. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs.
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Ryuichi Miura, Takanori Kooriyama, Misako Yoneda, Akiko Takenaka, Miho Doki, Yasuyuki Goto, Chizu Sanjoba, Yasuyuki Endo, Tomoko Fujiyuki, Akihiro Sugai, Kyoko Tsukiyama-Kohara, Yoshitsugu Matsumoto, Hiroki Sato, and Chieko Kai
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Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV-LACK, rCDV-TSA, and rCDV-LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV-LACK showed markedly smaller nodules without ulceration. Although the rCDV-TSA- and rCDV-LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV-LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs.
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- 2015
- Full Text
- View/download PDF
6. Refractory Myositis Affecting the Intrinsic Muscles of the Hand
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Kensaku Kasuga, Osamu Onodera, Kosei Nakamura, Akihiro Sugai, and Etsuji Saji
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medicine.medical_specialty ,inflammatory myopathy ,Case Report ,Inflammation ,030204 cardiovascular system & hematology ,Walking disability ,Diagnosis, Differential ,Inflammatory myopathy ,03 medical and health sciences ,0302 clinical medicine ,Intravenous Immunoglobulin Therapy ,Refractory ,Internal Medicine ,medicine ,Humans ,Immunologic Factors ,Muscle, Skeletal ,Myositis ,Autoantibodies ,hand myositis ,business.industry ,Immunoglobulins, Intravenous ,General Medicine ,Middle Aged ,Hand ,medicine.disease ,intravenous immunoglobulin therapy ,Magnetic Resonance Imaging ,Dermatology ,medicine.anatomical_structure ,Female ,030211 gastroenterology & hepatology ,Muscles of the hand ,medicine.symptom ,business ,anti-SRP antibody ,Signal Recognition Particle - Abstract
Myositis generally affects the proximal muscles. However, we herein report a case of a 48-year-old woman with intractable myositis affecting the intrinsic muscles of the hands. Her myositis, which developed in childhood, was refractory to treatment with steroids and several immunosuppressants, causing walking disability. After experiencing pain and swelling in the hands for six months, she was diagnosed with myositis of the intrinsic muscles of the hands and tested positive for the anti-signal recognition particle antibody. Intravenous immunoglobulin therapy improved the myositis of the hands. This case suggests that inflammation caused by intractable myositis can extend to the hands.
- Published
- 2020
7. Amyloid β-related angiitis presenting extensive brain involvement without detection of hemorrhagic lesions: A case report
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Akiyoshi Kakita, Takuma Yamagishi, Yuya Hatano, Akihiro Sugai, Akihiro Nakajima, and Osamu Onodera
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Brain Diseases ,Pathology ,medicine.medical_specialty ,Amyloid beta-Peptides ,Amyloid β ,Amyloid ,business.industry ,medicine.disease ,Superficial siderosis ,Diffusion Magnetic Resonance Imaging ,Aphasia ,Susceptibility weighted imaging ,medicine ,Humans ,Left occipital lobe ,Female ,Neurology (clinical) ,medicine.symptom ,Vasculitis, Central Nervous System ,business ,Pathological ,After treatment ,Aged ,Cerebral Hemorrhage - Abstract
In amyloid β-related angiitis, cortical or subcortical microbleeding or cortical superficial siderosis supports clinical diagnosis. However, here we present a 75-year-old female case of amyloid β-related angiitis that did not initially show these lesions. The patient developed right homonymous hemianopia and aphasia, and subsequently became comatose. Her brain lesions progressed extensively from the left occipital lobe to the bilateral cerebral hemispheres, with diffused leptomeningeal lesions and scattered DWI high-intensity lesions. After pathological diagnosis, steroid treatment improved her symptoms as well as imaging findings. No hemorrhagic lesions were detected in the T2*-weighted imaging performed before treatment. However, susceptibility-weighted imaging performed after treatment showed a number of lesions with microbleeding. The clinical features of amyloid β-related angiitis that do not show hemorrhagic lesions at onset should be investigated for rapid therapeutic intervention in the future.
- Published
- 2020
8. Molecular mechanism of amyotrophic lateral sclerosis (ALS) from the viewpoint of the formation and degeneration of transactive response DNA-binding protein 43 kDa (TDP-43) inclusions
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Sou Kasahara, Osamu Onodera, Akihiro Sugai, Tomohiko Ishihara, and Yuka Koike
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Proteasome Endopeptidase Complex ,Protein Aggregation, Pathological ,Inclusion bodies ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Stress granule ,C9orf72 ,Autophagy ,Humans ,Medicine ,Amyotrophic lateral sclerosis ,C9orf72 Protein ,Ubiquitin ,business.industry ,Molecular pathology ,Amyotrophic Lateral Sclerosis ,medicine.disease ,Cell biology ,DNA-Binding Proteins ,Cytoplasm ,RNA-Binding Protein FUS ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Sporadic amyotrophic lateral sclerosis (SALS) and many cases of familial ALS (FALS) demonstrate cytoplasmic transactive response DNA-binding protein 43 kDa (TDP-43)-positive inclusion bodies. Thus, TDP-43 plays a vital role in ALS pathogenesis. Functional analysis of the ALS causative genes advanced the elucidation of the mechanism associated with the formation and degradation of TDP-43 aggregates. Stress granules, which are non-membranous organelles, are attracting attention as sites of aggregate formation, with involvement of FUS and C9orf72. Concurrently, ALS causative genes related to the ubiquitin-proteasome and autophagy systems, which are aggregate degradation mechanisms, have also been reported. Therefore, therapeutic research based on the molecular pathology common to SALS and FALS has been advanced.
- Published
- 2020
9. Candesartan prevents arteriopathy progression in cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy model
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Taisuke Kato, Toshiya Sato, Sachiko Hirokawa, Natsumi Fujita, Akihiro Sugai, Yusuke Kawashima, Yasuko Toyoshima, Fuyuki Kametani, Akihide Koyama, Shoji Tsuji, Hironaka Igarashi, Atsushi Sugie, Rie Saito, Masaki Matsumoto, Yuya Hatano, Masaki Fukunaga, Masato Kanazawa, Masato Hasegawa, Osamu Onodera, Hirotoshi Kawata, Ri-Ichiroh Manabe, Shoichiro Ando, Masahiro Uemura, Shigeo Murayama, Satoshi Saito, Masafumi Ihara, Akiyoshi Kakita, Masatoyo Nishizawa, Yumi Sekine, and Hiroaki Nozaki
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Pathology ,medicine.medical_specialty ,Cerebral arteries ,Tetrazoles ,Vasodilation ,Leukoencephalopathy ,Mice ,ADAMTS Proteins ,Leukoencephalopathies ,Transforming Growth Factor beta ,medicine ,Animals ,Extracellular Matrix Proteins ,business.industry ,Biphenyl Compounds ,Neurodegeneration ,Alopecia ,Cerebral Infarction ,High-Temperature Requirement A Serine Peptidase 1 ,General Medicine ,medicine.disease ,Recombinant Proteins ,Mice, Inbred C57BL ,Candesartan ,medicine.anatomical_structure ,Latent TGF-beta Binding Proteins ,Cerebral blood flow ,Cerebral cortex ,Cerebrovascular Circulation ,HTRA1 ,Disease Progression ,Benzimidazoles ,Spinal Diseases ,business ,Research Article ,medicine.drug - Abstract
Cerebral small vessel disease (CSVD) causes dementia and gait disturbance due to arteriopathy. Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a hereditary form of CSVD caused by loss of high-temperature requirement A1 (HTRA1) serine protease activity. In CARASIL, arteriopathy causes intimal thickening, smooth muscle cell (SMC) degeneration, elastic lamina splitting, and vasodilation. The molecular mechanisms were proposed to involve the accumulation of matrisome proteins as substrates or abnormalities in transforming growth factor β (TGF-β) signaling. Here, we show that HTRA1(−/−) mice exhibited features of CARASIL-associated arteriopathy: intimal thickening, abnormal elastic lamina, and vasodilation. In addition, the mice exhibited reduced distensibility of the cerebral arteries and blood flow in the cerebral cortex. In the thickened intima, matrisome proteins, including the hub protein fibronectin (FN) and latent TGF-β binding protein 4 (LTBP-4), which are substrates of HTRA1, accumulated. Candesartan treatment alleviated matrisome protein accumulation and normalized the vascular distensibility and cerebral blood flow. Furthermore, candesartan reduced the mRNA expression of Fn1, Ltbp-4, and Adamtsl2, which are involved in forming the extracellular matrix network. Our results indicate that these accumulated matrisome proteins may be potential therapeutic targets for arteriopathy in CARASIL.
- Published
- 2021
10. Age-related demethylation of the TDP-43 autoregulatory region in the human motor cortex
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Osamu Onodera, Junko Ito, Shintaro Tsuboguchi, Akio Yokoseki, Yuka Koike, Mari Tada, Tomohiko Ishihara, Akiyoshi Kakita, Takeshi Ikeuchi, Akihiro Sugai, Norikazu Hara, and Takuma Yamagishi
- Subjects
QH301-705.5 ,Medicine (miscellaneous) ,TARDBP ,Article ,General Biochemistry, Genetics and Molecular Biology ,mental disorders ,Motor system ,medicine ,Aging brain ,Homeostasis ,Humans ,Autoregulation ,Biology (General) ,Amyotrophic lateral sclerosis ,Demethylation ,DNA methylation ,Chemistry ,Alternative splicing ,Age Factors ,nutritional and metabolic diseases ,Methylation ,medicine.disease ,nervous system diseases ,Cell biology ,DNA-Binding Proteins ,Alternative Splicing ,medicine.anatomical_structure ,DNA demethylation ,General Agricultural and Biological Sciences ,Motor cortex - Abstract
In amyotrophic lateral sclerosis (ALS), TAR DNA-binding protein 43 (TDP-43), which is encoded by TARDBP, forms aggregates in the motor cortex. This aggregate formation may be triggered by an increase in the TDP-43 level with aging. However, the amount of TDP-43 is autoregulated by alternative splicing of the TARDBP 3′UTR, and how this autoregulation is affected by aging remains to be elucidated. We found that DNA demethylation in the autoregulatory region in the TARDBP 3′UTR reduced alternative splicing and increased TARDBP mRNA expression. Furthermore, in the human motor cortex, we found that this region was demethylated with aging, resulting in increased expression of TARDBP mRNA. The acceleration of DNA demethylation in the motor cortex was associated with the age of ALS onset. In summary, the dysregulation of TDP-43 autoregulation by age-related DNA demethylation in the motor cortex may explain the contribution of aging and motor system selectivity in ALS., In order to assess the effects of aging on the autoregulation of TAR DNA-binding protein 43 (TDP-43) and the potential effects of this on the role of TDP-43 in Amyotrophic Lateral Sclerosis (ALS), Koike et al examined post-mortem motor cortex tissue from ALS patients. They found that DNA demethylation in the autoregulatory region of the TARDBP 3′UTR, which encodes TDP-43, increased with age and was associated with the onset age of ALS and thus could be indicative of a role for dysregulation of TDP-43 autoregulation in ALS pathology.
- Published
- 2021
11. What role is a super-aged society demanding for home dentist
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Akihiro Sugai
- Subjects
medicine.medical_specialty ,Family medicine ,medicine ,General Medicine - Published
- 2019
12. PIM 3 kinase, a proto-oncogene product, regulates phosphorylation of the measles virus nucleoprotein tail domain at Ser 479 and Ser 510
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Misako Yoneda, Hiroki Sato, Akihiro Sugai, and Chieko Kai
- Subjects
inorganic chemicals ,0301 basic medicine ,Biophysics ,Protein Serine-Threonine Kinases ,environment and public health ,Biochemistry ,Proto-Oncogene Mas ,Cell Line ,Measles virus ,03 medical and health sciences ,chemistry.chemical_compound ,Phosphoserine ,0302 clinical medicine ,Protein Domains ,hemic and lymphatic diseases ,Proto-Oncogene Proteins ,Animals ,Humans ,Protein phosphorylation ,LY294002 ,Phosphorylation ,Protein kinase A ,Molecular Biology ,Measles Virus Nucleoprotein ,Anthracenes ,biology ,Oncogene ,Kinase ,Cell Biology ,Nucleocapsid Proteins ,biology.organism_classification ,Cell biology ,enzymes and coenzymes (carbohydrates) ,030104 developmental biology ,Nucleoproteins ,chemistry ,030220 oncology & carcinogenesis ,bacteria - Abstract
The tail domain of the measles virus (MeV) N protein is typically phosphorylated at S479 and S510. However, the protein kinase responsible for this phosphorylation has not been identified. To identify the protein kinase responsible, we conducted an in vitro kinase assay in the presence of various protein kinase inhibitors. Phosphorylation of S479 and S510 was suppressed in the presence of SP600125. We demonstrated that purified PIM 3 kinase, which is sensitive to SP600125, successfully phosphorylated both phosphorylation sites. Inhibitors of PIM kinase, CX6258 and LY294002, also suppressed phosphorylation of the N protein. These findings indicate that PIM 3 kinase is associated with the tail domain of the N protein and that PIM 3 kinase regulates N protein phosphorylation.
- Published
- 2020
13. [Molecular Pathogenesis of Amyotrophic Lateral Sclerosis]
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Shintaro, Tsuboguchi, Tomohiko, Ishihara, Akihiro, Sugai, Akio, Yokoseki, and Osamu, Onodera
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Cell Nucleus ,DNA-Binding Proteins ,Inclusion Bodies ,Amyotrophic Lateral Sclerosis ,Humans - Abstract
The molecular pathogenesis of amyotrophic lateral sclerosis (ALS) has been studied through analysis of the function of the protein produced by the causative genes of familial ALS. The products of these genes are classified as RNA binding proteins, or proteins related to proteolytic systems. However, most case of familial ALS, and sporadic ALS show TAR DNA binding protein-43 (TDP-43) immune-positive cytoplasmic inclusions. Therefore, the molecular mechanism of formation of TDP-43 inclusions and dysfunction caused by TDP-43 inclusions has been studied. As for the mechanism of inclusion formation, non-membrane organelle formation by liquid-liquid phase separation (LLPS) is important. The ubiquitin-proteasome and autophagy systems are important for the degradation of these inclusions. Several genes associated with these systems have been identified as causative genes for ALS. The formation of cytoplasmic inclusions results in the loss of TDP-43 from the nucleus, resulting in abnormalities in RNA metabolism, through the alteration of spliceosomes and Gemini of coiled bodies. Furthermore, in ALS, the regulation of TDP-43 mRNA/protein expression levels has failed. Failure of the autoregulation system facilitates TDP-43 inclusion formation. Development of treatments for ALS based on these elucidated molecular mechanisms is desirable.
- Published
- 2019
14. Increased cytoplasmicTARDBPmRNA in affected spinal motor neurons in ALS caused by abnormal autoregulation of TDP-43
- Author
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Sachiko Hirokawa, Yasuko Toyoshima, Hitoshi Takahashi, Akihide Koyama, Masatoyo Nishizawa, Osamu Onodera, Akio Yokoseki, Atsushi Shiga, Akiyoshi Kakita, Tomohiko Ishihara, Misaki Koyama, Takuya Konno, Taisuke Kato, and Akihiro Sugai
- Subjects
0301 basic medicine ,Cytoplasm ,RNA Stability ,Biology ,TARDBP ,03 medical and health sciences ,Exon ,mental disorders ,Genetics ,medicine ,Humans ,Autoregulation ,RNA, Messenger ,Amyotrophic lateral sclerosis ,Nuclear protein ,Molecular Biology ,Cell Nucleus ,Feedback, Physiological ,Motor Neurons ,Amyotrophic Lateral Sclerosis ,nutritional and metabolic diseases ,Exons ,Motor neuron ,medicine.disease ,Molecular biology ,Introns ,nervous system diseases ,DNA-Binding Proteins ,Cell nucleus ,HEK293 Cells ,030104 developmental biology ,medicine.anatomical_structure ,Gene Expression Regulation ,Spinal Cord ,RNA splicing ,Signal Transduction - Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disorder. In motor neurons of ALS, TAR DNA binding protein-43 (TDP-43), a nuclear protein encoded by TARDBP, is absent from the nucleus and forms cytoplasmic inclusions. TDP-43 auto-regulates the amount by regulating the TARDBP mRNA, which has three polyadenylation signals (PASs) and three additional alternative introns within the last exon. However, it is still unclear how the autoregulatory mechanism works and how the status of autoregulation in ALS motor neurons without nuclear TDP-43 is. Here we show that TDP-43 inhibits the selection of the most proximal PAS and induces splicing of multiple alternative introns in TARDBP mRNA to decrease the amount of cytoplasmic TARDBP mRNA by nonsense-mediated mRNA decay. When TDP-43 is depleted, the TARDBP mRNA uses the most proximal PAS and is increased in the cytoplasm. Finally, we have demonstrated that in ALS motor neurons-especially neurons with mislocalized TDP-43-the amount of TARDBP mRNA is increased in the cytoplasm. Our observations indicate that nuclear TDP-43 contributes to the autoregulation and suggests that the absence of nuclear TDP-43 induces an abnormal autoregulation and increases the amount of TARDBP mRNA. The vicious cycle might accelerate the disease progression of ALS.
- Published
- 2016
15. Robustness and Vulnerability of the Autoregulatory System That Maintains Nuclear TDP-43 Levels: A Trade-off Hypothesis for ALS Pathology Based on in Silico Data
- Author
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Akihide Koyama, Sou Kasahara, Osamu Onodera, Tomohiko Ishihara, Takuya Konno, Taisuke Kato, Akihiro Sugai, and Yuka Koike
- Subjects
0301 basic medicine ,amyotrophic lateral sclerosis ,Pathology ,medicine.medical_specialty ,TDP-43 ,Systems biology ,In silico ,robustness ,Biology ,TARDBP ,lcsh:RC321-571 ,03 medical and health sciences ,Hypothesis and Theory ,mental disorders ,medicine ,Nuclear protein ,Amyotrophic lateral sclerosis ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Messenger RNA ,General Neuroscience ,autoregulation ,Alternative splicing ,nutritional and metabolic diseases ,Robustness (evolution) ,systems biology ,medicine.disease ,nervous system diseases ,030104 developmental biology ,Neuroscience - Abstract
Abnormal accumulation of TAR DNA-binding protein 43 (TDP-43) in the cytoplasm and its disappearance from the nucleus are pathological features of amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD) and are directly involved in the pathogenesis of these conditions. TDP-43 is an essential nuclear protein that readily aggregates in a concentration-dependent manner. Therefore, cells must strictly maintain an appropriate amount of nuclear TDP-43. In one relevant maintenance mechanism, TDP-43 binds to its pre-mRNA and promotes alternative splicing, resulting in mRNA degradation via nonsense-mediated mRNA decay. The level of nuclear TDP-43 is tightly regulated by these mechanisms, which control the amount of mRNA that may be translated. Based on the results of previous experiments, we developed an in silico model that mimics the intracellular dynamics of TDP-43 and examined TDP-43 metabolism under various conditions. We discovered an inherent trade-off in this mechanism between transcriptional redundancy, which maintains the robustness of TDP-43 metabolism, and vulnerability to specific interfering factors. These factors include an increased tendency of TDP-43 to aggregate, impaired nuclear-cytoplasmic TDP-43 transport, and a decreased efficiency of degrading abnormal proteins, all of which are functional abnormalities related to the gene that causes familial ALS/FTD. When these conditions continue at a certain intensity, the vulnerability of the autoregulatory machinery becomes apparent over time, and transcriptional redundancy enters a vicious cycle that ultimately results in TDP-43 pathology. The results obtained using this in silico model reveal the difference in TDP-43 metabolism between normal and disease states. Furthermore, using this model, we simulated the effect of a decrease in TDP-43 transcription and found that this decrease improved TDP-43 pathology and suppressed the abnormal propagation of TDP-43. Therefore, we propose a potential therapeutic strategy to suppress transcriptional redundancy, which is the driving force of the pathological condition caused by the specific factors described above, in patients with ALS presenting with TDP-43 pathology. An ALS animal model exhibiting TDP-43 pathology without overexpression of exogenous TDP-43 should be developed to investigate the effect of alleviating the transcriptional redundancy of TARDBP.
- Published
- 2018
16. Nipah and Hendra Virus Nucleoproteins Inhibit Nuclear Accumulation of Signal Transducer and Activator of Transcription 1 (STAT1) and STAT2 by Interfering with Their Complex Formation
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Akihiro Sugai, Ikuyo Takayama, Hiroki Sato, Chieko Kai, and Misako Yoneda
- Subjects
0301 basic medicine ,Immunology ,Biology ,Microbiology ,Hendra Virus ,03 medical and health sciences ,Interferon ,Virology ,medicine ,Humans ,STAT1 ,STAT2 ,Cell Nucleus ,Henipavirus Infections ,Nipah Virus ,JAK-STAT signaling pathway ,STAT2 Transcription Factor ,biology.organism_classification ,Immunity, Innate ,Nucleoprotein ,Virus-Cell Interactions ,030104 developmental biology ,HEK293 Cells ,Nucleoproteins ,STAT1 Transcription Factor ,Insect Science ,Phosphoprotein ,STAT protein ,biology.protein ,medicine.drug ,Henipavirus ,HeLa Cells ,Signal Transduction - Abstract
Henipaviruses, such as Nipah (NiV) and Hendra (HeV) viruses, are highly pathogenic zoonotic agents within the Paramyxoviridae family. The phosphoprotein (P) gene products of the paramyxoviruses have been well characterized for their interferon (IFN) antagonist activity and their contribution to viral pathogenicity. In this study, we demonstrated that the nucleoprotein (N) of henipaviruses also prevents the host IFN signaling response. Reporter assays demonstrated that the NiV and HeV N proteins (NiV-N and HeV-N, respectively) dose-dependently suppressed both type I and type II IFN responses and that the inhibitory effect was mediated by their core domains. Additionally, NiV-N prevented the nuclear transport of signal transducer and activator of transcription 1 (STAT1) and STAT2. However, NiV-N did not associate with Impα5, Impβ1, or Ran, which are members of the nuclear transport system for STATs. Although P protein is known as a binding partner of N protein and actively retains N protein in the cytoplasm, the IFN antagonist activity of N protein was not abolished by the coexpression of P protein. This suggests that the IFN inhibition by N protein occurs in the cytoplasm. Furthermore, we demonstrated that the complex formation of STATs was hampered in the N protein-expressing cells. As a result, STAT nuclear accumulation was reduced, causing a subsequent downregulation of interferon-stimulated genes (ISGs) due to low promoter occupancy by STAT complexes. This novel route for preventing host IFN responses by henipavirus N proteins provides new insight into the pathogenesis of these viruses. IMPORTANCE Paramyxoviruses are well known for suppressing interferon (IFN)-mediated innate immunity with their phosphoprotein (P) gene products, and the henipaviruses also possess P, V, W, and C proteins for evading host antiviral responses. There are numerous studies providing evidence for the relationship between viral pathogenicity and antagonistic activities against IFN responses by P gene products. Meanwhile, little attention has been paid to the influence of nucleoprotein (N) on host innate immune responses. In this study, we demonstrated that both the NiV and HeV N proteins have antagonistic activity against the JAK/STAT signaling pathway by preventing the nucleocytoplasmic trafficking of STAT1 and STAT2. This inhibitory effect is due to an impairment of the ability of STATs to form complexes. These results provide new insight into the involvement of N protein in viral pathogenicity via its IFN antagonism.
- Published
- 2017
17. Newly Identified Minor Phosphorylation Site Threonine-279 of Measles Virus Nucleoprotein Is a Prerequisite for Nucleocapsid Formation
- Author
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Misako Yoneda, Chieko Kai, Masaaki Oyama, Hiroko Kozuka-Hata, Akihiro Sugai, Kyoji Hagiwara, and Hiroki Sato
- Subjects
Threonine ,Viral protein ,viruses ,Amino Acid Motifs ,Molecular Sequence Data ,Immunology ,medicine.disease_cause ,Microbiology ,Cell Line ,Measles virus ,Dephosphorylation ,Viral Proteins ,Transcription (biology) ,Virology ,medicine ,Humans ,Amino Acid Sequence ,Phosphorylation ,Nucleocapsid ,Measles Virus Nucleoprotein ,biology ,Structure and Assembly ,Nucleocapsid Proteins ,biology.organism_classification ,Nucleoprotein ,Nucleoproteins ,Biochemistry ,Insect Science ,Measles - Abstract
Measles virus nucleoprotein is the most abundant viral protein and tightly encapsidates viral genomic RNA to support viral transcription and replication. Major phosphorylation sites of nucleoprotein include the serine residues at locations 479 and 510. Minor phosphorylation residues have yet to be identified, and their functions are poorly understood. In our present study, we identified nine putative phosphorylation sites by mass spectrometry and demonstrated that threonine residue 279 (T279) is functionally significant. Minigenome expression assays revealed that a mutation at the T279 site caused a loss of activity. Limited proteolysis and electron microscopy suggested that a T279A mutant lacked the ability to encapsidate viral RNA but was not denatured. Furthermore, dephosphorylation of the T279 site by alkaline phosphatase treatment caused deficiencies in nucleocapsid formation. Taken together, these results indicate that phosphorylation at T279 is a prerequisite for successful nucleocapsid formation.
- Published
- 2014
18. Gene end-like sequences within the 3' non-coding region of the Nipah virus genome attenuate viral gene transcription
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Akihiro Sugai, Hiroki Sato, Misako Yoneda, and Chieko Kai
- Subjects
0301 basic medicine ,Gene Expression Regulation, Viral ,Transcription, Genetic ,viruses ,Molecular Sequence Data ,Genome, Viral ,Biology ,03 medical and health sciences ,chemistry.chemical_compound ,Viral Proteins ,Transcription (biology) ,Virology ,RNA polymerase ,Gene expression ,Transcriptional regulation ,Coding region ,Gene ,3' Untranslated Regions ,Polymerase ,Genetics ,Base Sequence ,Three prime untranslated region ,Nipah Virus ,030104 developmental biology ,chemistry ,biology.protein ,RNA, Viral ,DNA, Intergenic - Abstract
The regulation of transcription during Nipah virus (NiV) replication is poorly understood. Using a bicistronic minigenome system, we investigated the involvement of non-coding regions (NCRs) in the transcriptional re-initiation efficiency of NiV RNA polymerase. Reporter assays revealed that attenuation of NiV gene expression was not constant at each gene junction, and that the attenuating property was controlled by the 3' NCR. However, this regulation was independent of the gene-end, gene-start and intergenic regions. Northern blot analysis indicated that regulation of viral gene expression by the phosphoprotein (P) and large protein (L) 3' NCRs occurred at the transcription level. We identified uridine-rich tracts within the L 3' NCR that are similar to gene-end signals. These gene-end-like sequences were recognized as weak transcription termination signals by the viral RNA polymerase, thereby reducing downstream gene transcription. Thus, we suggest that NiV has a unique mechanism of transcriptional regulation.
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- 2016
19. Non-genetically modified models exhibit TARDBP mRNA increase due to perturbed TDP-43 autoregulation
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Akihide Koyama, Tomohiko Ishihara, Osamu Onodera, Taisuke Kato, Yuka Koike, Akihiro Sugai, and Takuya Konno
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0301 basic medicine ,TDP-43 ,Induced Pluripotent Stem Cells ,TARDBP ,lcsh:RC321-571 ,Pathogenesis ,Mice ,alternative splicing ,03 medical and health sciences ,0302 clinical medicine ,mental disorders ,medicine ,Animals ,Homeostasis ,Humans ,Autoregulation ,RNA, Messenger ,Amyotrophic lateral sclerosis ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Motor Neurons ,Messenger RNA ,Chemistry ,autoregulation ,Alternative splicing ,Intron ,nutritional and metabolic diseases ,medicine.disease ,nervous system diseases ,Cell biology ,DNA-Binding Proteins ,030104 developmental biology ,Spinal Cord ,Neurology ,RNA splicing ,antisense oligonucleotides ,030217 neurology & neurosurgery - Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by accumulation of fragmented insoluble TDP-43 and loss of TDP-43 from the nucleus. Increased expression of exogenous TARDBP (encoding TDP-43) induces TDP-43 pathology and cytotoxicity, suggesting the involvement of aberrant expression of TDP-43 in the pathogenesis of ALS. In normal conditions, however, the amount of TDP-43 is tightly regulated by the autoregulatory mechanism involving alternative splicing of TARDBP mRNA. To investigate the influence of autoregulation dysfunction, we inhibited the splicing of cryptic intron 6 using antisense oligonucleotides in vivo. This inhibition doubled the Tardbp mRNA expression, increased the fragmented insoluble TDP-43, and reduced the number of motor neurons in the mouse spinal cord. In human induced pluripotent stem cell-derived neurons, the splicing inhibition of intron 6 increased TARDBP mRNA and decreased nuclear TDP-43. These non-genetically modified models exhibiting rise in the TARDBP mRNA levels suggest that TDP-43 autoregulation turbulence might be linked to the pathogenesis of ALS.
- Published
- 2019
20. Phosphorylation of Measles Virus Nucleoprotein Affects Viral Growth by Changing Gene Expression and Genomic RNA Stability
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Chieko Kai, Misako Yoneda, Hiroki Sato, and Akihiro Sugai
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Gene Expression Regulation, Viral ,RNase P ,RNA Stability ,viruses ,DNA Mutational Analysis ,Immunology ,Mutation, Missense ,Virus Replication ,Microbiology ,Cell Line ,Measles virus ,Viral Proteins ,Virology ,Gene expression ,Serine ,Animals ,Humans ,Phosphorylation ,Measles Virus Nucleoprotein ,biology ,Nucleocapsid Proteins ,Viral Load ,biology.organism_classification ,Molecular biology ,Reverse Genetics ,Reverse genetics ,Genome Replication and Regulation of Viral Gene Expression ,Nucleoprotein ,Titer ,Nucleoproteins ,Insect Science ,Mutagenesis, Site-Directed ,Protein Processing, Post-Translational - Abstract
The measles virus (MV) nucleoprotein associates with the viral RNA genome to form the N-RNA complex, providing a template for viral RNA synthesis. In our previous study, major phosphorylation sites of the nucleoprotein were identified as S479 and S510. However, the functions of these phosphorylation sites have not been clarified. In this study, we rescued recombinant MVs (rMVs) whose phosphorylation sites in the nucleoprotein were substituted (rMV-S479A, rMV-S510A, and rMV-S479A/S510A) by reverse genetics and used them in subsequent analyses. In a one-step growth experiment, rMVs showed rapid growth kinetics compared with wild-type MV, although the peak titer of the wild-type MV was the same as or slightly higher than those of the rMVs. Time course analysis of nucleoprotein accumulation also revealed that viral gene expression of rMV was enhanced during the early phase of infection. These findings suggest that nucleoprotein phosphorylation has an important role in controlling viral growth rate through the regulation of viral gene expression. Conversely, multistep growth curves revealed that nucleoprotein-phosphorylation intensity inversely correlated with viral titer at the plateau phase. Additionally, the phosphorylation intensity of the wild-type nucleoprotein in infected cells was significantly reduced through nucleoprotein-phosphoprotein binding. Excessive nucleoprotein-phosphorylation resulted in lower stability against RNase and faster turnover of viral genomic RNA. These results suggest that nucleoprotein-phosphorylation is also involved in viral genomic RNA stability.
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- 2013
21. What is the key player in TDP-43 pathology in ALS: Disappearance from the nucleus or inclusion formation in the cytoplasm?
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Osamu Onodera, Mari Tada, Akihiro Sugai, Akihide Koyama, Masatoyo Nishizawa, and Takuya Konno
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Mutation ,Pathology ,medicine.medical_specialty ,nutritional and metabolic diseases ,Frontotemporal lobar degeneration ,Biology ,medicine.disease_cause ,medicine.disease ,TARDBP ,nervous system diseases ,medicine.anatomical_structure ,Neurology ,C9orf72 ,Cytoplasm ,mental disorders ,medicine ,Neurology (clinical) ,Amyotrophic lateral sclerosis ,Trinucleotide repeat expansion ,Nucleus - Abstract
C9ORF72 and the 43 kDa TAR DNA-binding protein (TDP-43) are key molecules in the development of TDP-43 pathology in amyotrophic lateral sclerosis (ALS). The hexanucleotide repeat expansion in C9ORF72 also leads to frontotemporal lobar degeneration, whereas mutation of TARDBP mainly causes ALS, indicating that TDP-43 plays a more fundamental role in the development of ALS. In tissues affected with ALS, TDP-43 is dislocated from the nucleus, forms cytoplasmic inclusions, and is phosphorylated and truncated. Accumulating evidence suggests that the disappearance of TDP-43 from the nucleus precedes inclusion formation, indicating that its disappearance from the nucleus is crucial in the development of TDP-43 pathology. Alterations in the quality and quantity of TDP-43 might result in the disappearance of TDP-43 from the nucleus. Regarding quality, phosphorylation and truncation of TDP-43 is not necessary for its disappearance from the nucleus or for inclusion formation. Although it has been speculated that studies of TDP-43 harboring ALS-associated mutations are useful for understanding the molecular pathogenesis of sporadic ALS, the functional and biochemical differences between mutated and wild-type TDP-43 remain unclear. Regarding quantity, an increased amount of TDP-43 is an attractive hypothesis as it has been shown that increased amounts of TDP-43 are toxic. Moreover, several reports have suggested that increased levels of TDP-43 are found in sporadic ALS as well as in ALS with TDP-43 mutations. However, these findings remain controversial. Increased understanding of the mechanisms responsible for regulating TDP-43 will provide a basis for determining the molecular pathogenesis of ALS.
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- 2013
22. The nucleocapsid protein of measles virus blocks host interferon response
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Misako Yoneda, Ikuyo Takayama, Hiroki Sato, Mio Omi-Furutani, Keita Kanki, Akihiro Sugai, Chieko Kai, and Akira Watanabe
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biology ,Lymphokine ,Interferon-alpha ,Interferon-beta ,Nucleocapsid Proteins ,biology.organism_classification ,Virology ,stat ,Cell Line ,N protein ,Measles virus ,Interferon-gamma ,Cell culture ,Interferon ,medicine ,Humans ,Nuclear transport ,Signal transduction ,Gene ,Measles ,medicine.drug - Abstract
Measles virus (MV) belongs to the genus Morbillivirus of the family Paramyxoviridae. A number of paramyxoviruses inhibit host interferon (IFN) signaling pathways in host immune systems by various mechanisms. Inhibition mechanisms have been described for many paramyxoviruses. Although there are inconsistencies among previous reports concerning MV, it appears that P/V/C proteins interfere with the pathways. In this study, we confirmed the effects of MV P gene products of a wild MV strain on IFN pathways and examined that of other viral proteins on it. Interestingly, we found that N protein acts as an IFN-α/β and γ-antagonist as strong as P gene products. We further investigated the mechanisms of MV-N inhibition, and revealed that MV-N blocks the nuclear import of activated STAT without preventing STAT and Jak activation or STAT degradation, and that the nuclear translocation of MV-N is important for the inhibition. The inhibitory effect of the N protein was observed as a common feature of other morbilliviruses. The results presented in this report suggest that N protein of MV as well as P/V/C proteins is involved in the inhibition of host IFN signaling pathways.
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- 2012
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23. Peroxiredoxin 1 Is Required for Efficient Transcription and Replication of Measles Virus
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Fusako Ikeda, Misako Yoneda, Akihiro Sugai, Akira Watanabe, Hiroki Sato, and Chieko Kai
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Gene Expression Regulation, Viral ,Transcription, Genetic ,Immunology ,RNA-dependent RNA polymerase ,Virus Replication ,Microbiology ,Measles virus ,Viral Proteins ,chemistry.chemical_compound ,RNA interference ,Transcription (biology) ,Virology ,RNA polymerase ,Humans ,Binding site ,Messenger RNA ,Binding Sites ,biology ,Peroxiredoxins ,Nucleocapsid Proteins ,biology.organism_classification ,Molecular biology ,Genome Replication and Regulation of Viral Gene Expression ,HEK293 Cells ,Nucleoproteins ,chemistry ,Viral replication ,Insect Science ,Measles ,Protein Binding - Abstract
Measles is a highly contagious human disease caused by the measles virus (MeV). In this study, by proteomic analysis, we identified peroxiredoxin 1 (Prdx1) as a host factor that binds to the C-terminal region of the nucleoprotein (N; N TAIL ) of MeV. Glutathione S -transferase (GST) pulldown experiments showed that the Prdx1-binding site overlapped with the MeV phosphoprotein (P)-binding site on N TAIL and that Prdx1 competed for the binding to N TAIL with the P protein, which is a component of RNA-dependent RNA polymerase (RdRp). Furthermore, RNA interference for Prdx1 resulted in a significant reduction in MeV growth in HEK293-SLAM cells. A minigenome assay indicated that Prdx1 suppression affected the viral RNA transcription and/or replication step. Relative quantification of viral RNA by real-time PCR (RT-PCR) showed that Prdx1 suppression not only reduced viral RNA transcription and replication but also enhanced polar attenuation in viral mRNA transcription. Surface plasmon resonance analysis showed that the binding affinity of Prdx1 to MeV-N was 40-fold lower than that of MeV-P to MeV-N, which suggested that Prdx1 might be involved in the early stage of MeV infection, when the expression level of Prdx1 was much higher than that of MeV-P. Since Prdx1 was expressed abundantly and constitutively in various cells, the results in this study indicate that Prdx1 is one of the inherent host factors implicated in MeV RNA synthesis.
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- 2011
24. Epitope mapping of canine distemper virus phosphoprotein by monoclonal antibodies
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Chieko Kai, Hiroki Sato, Misako Yoneda, Takanori Kooriyama, and Akihiro Sugai
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medicine.drug_class ,viruses ,animal diseases ,Immunology ,Monoclonal antibody ,Polymerase Chain Reaction ,Microbiology ,Virus ,Epitope ,Cell Line ,Epitopes ,Viral Proteins ,Western blot ,Virology ,Chlorocebus aethiops ,medicine ,Animals ,Distemper Virus, Canine ,DNA Primers ,Sequence Deletion ,biology ,medicine.diagnostic_test ,Canine distemper ,Gene Amplification ,Antibodies, Monoclonal ,Callithrix ,Phosphoproteins ,medicine.disease ,Molecular biology ,Peptide Fragments ,Recombinant Proteins ,Epitope mapping ,Phosphoprotein ,COS Cells ,biology.protein ,Antibody - Abstract
The gene for phosphoprotein (P) of CDV encodes three different proteins, P, V, and C. The P protein is involved in viral gene transcription and replication. In the present study, we produced MAbs against a unique domain of the CDV-P protein, from aa 232 to 507, and determined their antigenic sites. By immunizing BALB/c mice with the recombinant P protein-specific fragment, we obtained six MAbs. Competitive binding inhibition assays revealed that they recognized two distinct regions of the P protein. Western blot analysis and immunofluorescence assays using deletion mutants of the unique C-terminus of the CDV-P protein revealed that all MAbs recognized a central short region (aa 233-303) of the CDV-P protein. In addition, linear and conformational epitopes have been determined, and at least four antigenic sites exist in the P protein central region. Furthermore, four of the MAbs were found to react with the P protein of recent Japanese field isolates but not with that of the older CDV strains, including a vaccine strain. Thus, these MAbs could be clinically useful for quick diagnosis during the CDV outbreaks.
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- 2009
25. A case of orbital apex syndrome caused by invasive aspergillosis successfully treated during the diagnostic procedure by the use of voriconazole
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Yoshitaka Umeda, Maiko Umeda, Mutsuo Oyake, Akihiro Sugai, and Nobuya Fujita
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Antifungal ,medicine.medical_specialty ,Antifungal Agents ,Visual acuity ,genetic structures ,medicine.drug_class ,Vision Disorders ,Aspergillosis ,Ocular Motility Disorders ,Biopsy ,Orbital Diseases ,medicine ,Humans ,Aged ,Voriconazole ,medicine.diagnostic_test ,business.industry ,Syndrome ,Triazoles ,medicine.disease ,Galactomannan Antigen ,eye diseases ,Surgery ,Left eye ,Pyrimidines ,Treatment Outcome ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Orbital apex ,medicine.drug - Abstract
A 75-year-old woman developed loss of vision and decreased ocular motility in all directions. She exhibited a left orbital apex syndrome, accompanied by sphenoiditis and hypertrophic pachymeningitis. Voriconazole treatment was initiated on the basis of clinical suspicion, although use of the serum beta-D glucan had negative results and a biopsy was not performed. Five days later, the left eye movements started to improve, and at that time the use of the serum aspergillus galactomannan antigen proved to have positive results. Six months later, the patient was neurologically intact and stable, except for a lack of visual acuity in counting fingers. Earlier prognoses of invasive sino-orbital aspergillosis were dismal, especially when corticosteroid therapy was done before diagnosis. This case suggests the usefulness of antifungal agents during the diagnostic procedure even when localized invasive aspergillosis is not ruled out.
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- 2008
26. Neurolymphomatosis presenting as bilateral tongue atrophy: A case report
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Toshio Yano, Maiko Umeda, Nobuya Fujita, Mutsuo Oyake, Takuya Konno, and Akihiro Sugai
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Hypoglossal Nerve ,Weakness ,medicine.medical_specialty ,Neoplasms, Nerve Tissue ,Diagnosis, Differential ,Fasciculation ,Dysarthria ,Atrophy ,Tongue ,medicine ,Humans ,Amyotrophic lateral sclerosis ,Palsy ,medicine.diagnostic_test ,business.industry ,Amyotrophic Lateral Sclerosis ,Magnetic resonance imaging ,Middle Aged ,Pelvic cavity ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Female ,Neurology (clinical) ,Radiology ,medicine.symptom ,business - Abstract
A 62-year-old woman had progressive dysarthria for 2 months and was suspected of having amyotrophic lateral sclerosis because of the presentation of bilateral tongue atrophy and fasciculation. Brain magnetic resonance imaging (MRI) showed enlargement of the left hypoglossal nerve, and whole-body gallium scintigraphy showed abnormal uptake in the left pelvic cavity and left thigh. On the basis of the findings of biopsy of the mass lesion in the left thigh, she was diagnosed with diffuse large B-cell lymphoma. After chemotherapy for diffuse large B-cell lymphoma, the tongue atrophy improved. The patient subsequently developed left oculomotor nerve palsy, weakness of the right arm, and weakness of the right leg. The cause of these symptoms was thought to be neurolymphomatosis on the basis of the typical MRI findings observed. We report a rare case of neurolymphomatosis presenting as bilateral tongue atrophy, mimicking amyotrophic lateral sclerosis.
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- 2012
27. A non-genetically modified human neuronal model of ALS with an increased expression of intrinsic TDP-43
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Akihiro Sugai, T. Kato, Tomohiko Ishihara, and O. Osamu
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Neurology ,Expression (architecture) ,Neurology (clinical) ,Biology ,Cell biology ,Genetically modified organism - Published
- 2017
28. Downregulation of Nipah Virus N mRNA Occurs through Interaction between Its 3′ Untranslated Region and hnRNP D
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Masahiko Kato, Akihiro Sugai, Chieko Kai, Misako Yoneda, Kimihiro Hino, and Hiroki Sato
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Untranslated region ,Gene Expression Regulation, Viral ,viruses ,Immunology ,Repressor ,Down-Regulation ,Microbiology ,Genes, Reporter ,Virology ,Humans ,RNA, Messenger ,Heterogeneous-Nuclear Ribonucleoprotein D ,Gene ,3' Untranslated Regions ,Messenger RNA ,Binding Sites ,biology ,Three prime untranslated region ,Nipah Virus ,RNA ,RNA virus ,Non-coding RNA ,biology.organism_classification ,Molecular biology ,Virus-Cell Interactions ,Insect Science ,Mutation ,Gene Deletion ,HeLa Cells - Abstract
Nipah virus (NiV) is a nonsegmented, single-stranded, negative-sense RNA virus belonging to the genus Henipavirus , family Paramyxoviridae . NiV causes acute encephalitis and respiratory disease in humans, is associated with high mortality, and poses a threat in southern Asia. The genomes of henipaviruses are about 18,246 nucleotides (nt) long, which is longer than those of other paramyxoviruses (around 15,384 nt). This difference is caused by the noncoding RNA region, particularly the 3′ untranslated region (UTR), which occupies more than half of the noncoding RNA region. To determine the function(s) of the NiV noncoding RNA region, we investigated the effects of NiV 3′ UTRs on reporter gene expression. The NiV N 3′ UTR (nt 1 to 100) demonstrated strong repressor activity associated with hnRNP D protein binding to that region. Mutation of the hnRNP D binding site or knockdown of hnRNP D resulted in increased expression of the NiV N 3′ UTR reporter. Our findings suggest that NiV N expression is repressed by hnRNP D through the NiV N 3′ UTR and demonstrate the involvement of posttranscriptional regulation in the NiV life cycle. To the best of our knowledge, this provides the first report of the functions of the NiV noncoding RNA region.
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- 2013
29. Reliabilitiy and Scale Effect on Model Experiment of Wave Transformation by Permeable Breakwaters
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Yasuo Ida, Satoru Kobayashi, and Akihiro Sugai
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Engineering ,Scale (ratio) ,Armour ,business.industry ,Reynolds number ,General Medicine ,symbols.namesake ,Waves and shallow water ,Breakwater ,Precast concrete ,Wave transformation ,symbols ,Geotechnical engineering ,business ,Dimensionless quantity - Abstract
Scale effect was clearly that model experiment of wave transformation was examined for permeable breakwaters with precast concrete armour unit in shallow water region.Results of model experiment were not rely on that Reynolds number, Re was less than 4×104.These were investigated with following parameter: ratio of incident wave height to block scale, HI/d', ratio of dimensionless linealized friction coefficient, f.
- Published
- 1996
30. Visualization of Fluid Motion at Permeable Structure by Ultra High-Speed Video Camera
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Akihiro Sugai, Yasuo Ida, and Toru Sawaragi
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Flow visualization ,Physics ,Turbulence ,business.industry ,Video camera ,General Medicine ,Kalman filter ,Velocimetry ,Visualization ,law.invention ,Optics ,Particle image velocimetry ,Particle tracking velocimetry ,law ,business - Abstract
A fluid motion at permeable layer constructed model of precast concrete armor unit was visualized in ossillatory flow. Many turbulence measurements have been ever done by point measurement techniques such as LDA. In this study, a method of measurement has been conducted by a particle tracking velocimetry for 2-D space. It has been composed of Kalman's filtering theory, the Chai-Square-test and initial evaluation of velocities of particles which newly appear in the flame. Images of 30μm diameter particles were taken using a ultra high-speed video camera and Argon-ion laser slit illumination.
- Published
- 1994
31. Determination of a phosphorylation site in Nipah virus nucleoprotein and its involvement in virus transcription
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Misako Yoneda, Hiroki Sato, Akihiro Sugai, Akira Watanabe, Fusako Ikeda, Kyoji Hagiwara, Mingshu Huang, Masaaki Oyama, Hiroko Kozuka-Hata, and Chieko Kai
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RNA viruses ,Transcription, Genetic ,viruses ,Viral transformation ,Virus Replication ,Virus ,Cell Line ,Measles virus ,Viral Proteins ,VP40 ,Transcription (biology) ,Virology ,Chlorocebus aethiops ,Serine ,Animals ,Humans ,Phosphorylation ,biology ,Animal ,Nipah Virus ,biology.organism_classification ,Molecular biology ,Standard ,Nucleoprotein ,Nucleoproteins ,Viral replication ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,RNA, Viral - Abstract
Many viruses use their host’s cellular machinery to regulate the functions of viral proteins. The phosphorylation of viral proteins is known to play a role in genome transcription and replication in paramyxoviruses. The paramyxovirus nucleoprotein (N), the most abundant protein in infected cells, is a component of the N–RNA complex and supports the transcription and replication of virus mRNA and genomic RNA. Recently, we reported that the phosphorylation of measles virus N is involved in the regulation of viral RNA synthesis. In this study, we report a rapid turnover of phosphorylation in the Nipah virus N (NiV-N). The phosphorylated NiV-N was hardly detectable in steady-state cells, but was detected after inhibition of cellular protein phosphatases. We identified a phosphorylated serine residue at Ser451 of NiV-N by peptide mass fingerprinting by electrospray ionization–quadrupole time-of-flight mass spectrometry. In the NiV minigenome assay, using luciferase as a reporter gene, the substitution of Ser451 for alanine in NiV-N resulted in a reduction in luciferase activity of approximately 45 % compared with the wild-type protein. Furthermore, the substitution of Ser451 for glutamic acid, which mimics a phosphoserine, led to a more significant decrease in luciferase activity – approximately 81 %. Northern blot analysis showed that both virus transcription and replication were reduced by these mutations. These results suggest that a rapid turnover of the phosphorylation of NiV-N plays an important role in virus transcription and replication.
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- 2011
32. Efficacy of Recombinant Canine Distemper Virus Expressing Leishmania Antigen against Leishmania Challenge in Dogs
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Chieko Kai, Yoshitsugu Matsumoto, Akiko Takenaka, Tomoko Fujiyuki, Akihiro Sugai, Ryuichi Miura, Kyoko Tsukiyama-Kohara, Misako Yoneda, Yasuyuki Goto, Chizu Sanjoba, Hiroki Sato, Miho Doki, Takanori Kooriyama, and Yasuyuki Endo
- Subjects
Protozoan Vaccines ,lcsh:Arctic medicine. Tropical medicine ,lcsh:RC955-962 ,viruses ,animal diseases ,Genetic Vectors ,Leishmaniasis, Cutaneous ,Antigens, Protozoan ,Biology ,Antibodies, Viral ,Virus ,Dogs ,Cutaneous leishmaniasis ,medicine ,Animals ,Humans ,Leishmania major ,Distemper Virus, Canine ,Attenuated vaccine ,Canine distemper ,lcsh:Public aspects of medicine ,Viral Vaccine ,Public Health, Environmental and Occupational Health ,Viral Vaccines ,lcsh:RA1-1270 ,Leishmania ,biology.organism_classification ,medicine.disease ,Virology ,Vaccination ,Infectious Diseases ,Female ,Research Article - Abstract
Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV–LACK, rCDV–TSA, and rCDV–LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV–LACK showed markedly smaller nodules without ulceration. Although the rCDV–TSA- and rCDV–LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV–LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs., Author Summary More than 1 million new cases of leishmaniasis occur throughout the world every year. Leishmaniasis typically presents as one of two clinical forms, either cutaneous or visceral. Dogs harboring Leishmania act as reservoirs, and are closely associated with human infections in South America and southern Europe. Therefore, immunization of dogs with effective vaccines against Leishmania will also effectively prevent Leishmania infection in humans. In this study, we have evaluated the utility of recombinant canine distemper viruses (CDVs) that express Leishmania antigen as effective polyvalent candidate vaccines against CDV and cutaneous Leishmania infections. The results indicated that recombinant CDV completely protected against challenge with a virulent strain of CDV. Furthermore, mixed immunization with three recombinant CDVs that express different antigens that mediate distinct immune responses, significantly reduced the nodule size after Leishmania major challenge. These results strongly suggest that a cocktail of multiple antigens confers more effective immunity throughout the life cycle of Leishmania. We propose that a combination of recombinant CDV-based vaccines expressing different antigens has utility as a polyvalent vaccine for the prevention of leishmaniasis epidemics by inhibiting the transmission of the parasites through dogs.
- Published
- 2015
33. Atypical MRI Findings of Wernicke Encephalopathy in Alcoholic Patients
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Akihiro Sugai and Koki Kikugawa
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Coma ,Ataxia ,Anterograde amnesia ,Wernicke Encephalopathy ,business.industry ,Mammillary body ,Fornix ,General Medicine ,medicine.anatomical_structure ,Cerebral cortex ,Anesthesia ,medicine ,Radiology, Nuclear Medicine and imaging ,Thiamine ,medicine.symptom ,business - Abstract
AJR 2010; 195:W1–W2 0361–803X/10/1955–W1 © American Roentgen Ray Society Atypical MRI Findings of Wernicke Encephalopathy in Alcoholic Patients We read with great interest the review article by Drs. Zuccoli and Pipitone [1] in the February 2009 issue of AJR, which provides an update on the typical and atypical neuroimaging findings of acute Wernicke encephalopathy (WE). In their article, atypical MRI findings such as signal intensity alterations of the cerebral cortex have been reported only in nonalcoholic patients. We add our experience with atypical MRI findings in two patients with WE, both of whom are alcoholic. The first patient, a 45-year-old man, presented with confusional state, oculomotor abnormalities, dysarthria, and ataxia. MRI showed symmetric signal intensity alterations of the mammillary bodies, periaqueductal area, fornix, median thalami, and cerebral cortex (Fig. 1). After thiamine was immediately administered, the patient recovered consciousness and was able to walk unassisted. The diagnosis of WE was confirmed by measurement of blood thiamine concentration (15.3 ng/mL; normal range, 21.3–81.9 ng/ mL), obtained after treatment. The second patient, a 56-year-old man, presented with deep coma and bilateral Babinski reflexes. MRI revealed the typical abnormalities of WE, except for the involvement of the cerebral cortex and amygdala (Fig. 2A). After thiamine was administered, the patient’s consciousness was improved, and the bilateral Babinski reflexes disappeared. MRI obtained 10 days after treatment showed improvement of signal intensity alterations including those in the cerebral cortex and amygdala (Fig. 2B). The patient developed Korsakoff psychosis, characterized by severe anterograde amnesia, disorientation to time, and such emotional changes as apathy and mild euphoria. Drs. Zuccoli and Pipitone [1] surmise that alcohol may have a protective effect on the brain that shows atypical lesions in WE. Our two cases suggest, however, that this hypothesis is disputable, and investigation of more cases is required before a decision on the relationship between alcohol and brain lesions in WE can be made. To the best of our knowledge, our second patient is the first case showing involvement of the amygdala in WE to be documented in the literature. A neuropathologic analysis, however, revealed a significant volume reduction in the amygdala of the patients with Wernicke–Korsakoff syndrome compared with alcoholics without WE or Wernicke–Korsakoff syndrome [2]. Akihiro Sugai Koki Kikugawa Tsubame Rosai Hospital Niigata, Japan DOI:10.2214/AJR.10.4539 WEB—This is a Web exclusive article.
- Published
- 2010
34. Increased cytoplasmic TARDBP mRNA in affected spinal motor neurons in ALS caused by abnormal autoregulation of TDP-43.
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Akihide Koyama, Akihiro Sugai, Taisuke Kato, Tomohiko Ishihara, Atsushi Shiga, Yasuko Toyoshima, Misaki Koyama, Takuya Konno, Sachiko Hirokawa, Akio Yokoseki, Masatoyo Nishizawa, Akiyoshi Kakita, Hitoshi Takahashi, and Osamu Onodera
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- 2016
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35. Newly Identified Minor Phosphorylation Site Threonine-279 of Measles Virus Nucleoprotein Is a Prerequisite for Nucleocapsid Formation.
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Akihiro Sugai, Hiroki Sato, Kyoji Hagiwara, Hiroko Kozuka-Hata, Masaaki Oyama, Misako Yoneda, and Chieko Kai
- Subjects
- *
PHOSPHORYLATION , *THREONINE , *MEASLES virus , *NUCLEOPROTEINS , *NUCLEOCAPSIDS , *VIRAL genomes , *GENETIC transcription , *VIRUSES - Abstract
Measles virus nucleoprotein is the most abundant viral protein and tightly encapsidates viral genomicRNAto support viral transcription and replication. Major phosphorylation sites of nucleoprotein include the serine residues at locations 479 and 510. Minor phosphorylation residues have yet to be identified, and their functions are poorly understood. In our present study, we identified nine putative phosphorylation sites by mass spectrometry and demonstrated that threonine residue 279 (T279) is functionally significant. Minigenome expression assays revealed that a mutation at the T279 site caused a loss of activity. Limited proteolysis and electron microscopy suggested that a T279A mutant lacked the ability to encapsidate viralRNAbut was not denatured. Furthermore, dephosphorylation of the T279 site by alkaline phosphatase treatment caused deficiencies in nucleocapsid formation. Taken together, these results indicate that phosphorylation at T279 is a prerequisite for successful nucleocapsid formation. [ABSTRACT FROM AUTHOR]
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- 2014
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36. Comparative and mutational analyses of promoter regions of rinderpest virus
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Chieko Imai, Chieko Kai, Misako Yoneda, Akihiro Sugai, Fusako Shimizu, and Kentaro Fujita
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Reporter gene ,Attenuated vaccine ,Strain (chemistry) ,Reverse Transcriptase Polymerase Chain Reaction ,Virulence ,Promoter ,Genome, Viral ,Biology ,Rinderpest virus ,Virus Replication ,Virology ,Molecular biology ,Minigenome ,Cell Line ,Species Specificity ,Viral replication ,Genes, Reporter ,Promoter activity ,Mutagenesis, Site-Directed ,Animals ,RNA, Viral ,Promoter Regions, Genetic ,Gene - Abstract
Comparative and mutational analysis of promoter regions of rinderpest virus was conducted. Minigenomic RNAs harboring the genomic and antigenomic promoter of the lapinized virulent strain (Lv) or an attenuated vaccine strain (RBOK) were constructed, and the expression of the reporter gene was examined. The activities of the antigenomic promoters of these strains were similar, whereas the activity of the genomic promoter (GP) of the RBOK strain was significantly higher than that of the Lv strain, regardless of cell type and the source of the N, P and L proteins. Increased replication (and/or encapsidation) activities were observed in the minigenomes that contained RBOK GP. Mutational analysis revealed that the nucleotides specific to the RBOK strain are responsible for the strong GP activity of the strain. It was also demonstrated that other virulent strains of RPV (Kabete O, Saudi/81 and Kuwait 82/1) have weaker GPs than that of the RBOK strain.
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37. Phosphorylation of measles virus phosphoprotein at S86 and/or S151 downregulates viral transcriptional activity
- Author
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Chieko Kai, Hiroki Sato, Akihiro Sugai, and Misako Yoneda
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Gene Expression Regulation, Viral ,Transcription, Genetic ,viruses ,Coenzymes ,Biophysics ,Virus Replication ,Biochemistry ,Measles virus ,Viral Proteins ,Downregulation and upregulation ,Structural Biology ,Transcription (biology) ,Chlorocebus aethiops ,Serine ,Genetics ,Animals ,Humans ,Protein phosphorylation ,Phosphorylation ,Molecular Biology ,Polymerase ,Nucleoprotein ,biology ,Chemistry ,Cell Biology ,Phosphoproteins ,biology.organism_classification ,Molecular biology ,HEK293 Cells ,Nucleoproteins ,Phosphoprotein ,COS Cells ,biology.protein ,RNA, Viral ,Transcription - Abstract
Measles virus phosphoprotein (P protein) is a cofactor of the viral RNA polymerase (L protein) that associates with the nucleoprotein–RNA complex to support viral transcription and replication. Here, we report a significant inverse correlation between the phosphorylation level of MV-P protein and viral transcriptional activity. Upregulation of P protein phosphorylation resulted in reduction of viral transcription. Additionally, we found that strong phosphorylation at S86 and S151 of P protein, which may be generally prevented by association with nucleoprotein, downregulates the viral transcriptional activity. These findings suggest that P protein is involved in regulation of viral transcription through changes in its phosphorylation status.
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