9 results on '"Ohshima, Y."'
Search Results
2. Alternaria extract activates autophagy that induces IL-18 release from airway epithelial cells.
- Author
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Murai H, Okazaki S, Hayashi H, Kawakita A, Hosoki K, Yasutomi M, Sur S, and Ohshima Y
- Subjects
- Allergens isolation & purification, Asthma etiology, Asthma immunology, Asthma pathology, Caspase 1 metabolism, Caspase 8 metabolism, Cell Line, Tumor, Cells, Cultured, Enzyme Activation drug effects, Humans, Inflammasomes drug effects, Inflammasomes immunology, Lipopolysaccharides toxicity, Respiratory Mucosa pathology, Allergens toxicity, Alternaria immunology, Alternaria pathogenicity, Autophagy drug effects, Autophagy immunology, Interleukin-18 biosynthesis, Respiratory Mucosa drug effects, Respiratory Mucosa immunology
- Abstract
Alternaria alternata is a major outdoor allergen that causes allergic airway diseases. Alternaria extract (ALT-E) has been shown to induce airway epithelial cells to release IL-18 and thereby initiate Th2-type responses. We investigated the underlying mechanisms involved in IL-18 release from ALT-E-stimulated airway epithelial cells. Normal human bronchial epithelial cells and A549 human lung adenocarcinoma cells were stimulated with ALT-E in the presence of different inhibitors of autophagy or caspases. IL-18 levels in culture supernatants were measured by ELISA. The numbers of autophagosomes, an LC3-I to LC3-II conversion, and p62 degradation were determined by immunofluorescence staining and immunoblotting. 3-methyladenine and bafilomycin, which inhibit the formation of preautophagosomal structures and autolysosomes, respectively, suppressed ALT-E-induced IL-18 release by cells, whereas caspase 1 and 8 inhibitors did not. ALT-E-stimulation increased autophagosome formation, LC-3 conversion, and p62 degradation in airway epithelial cells. LPS-stimulation induced the LC3 conversion in A549 cells, but did not induce IL-18 release or p62 degradation. Unlike LPS, ALT-E induced airway epithelial cells to release IL-18 via an autophagy dependent, caspase 1 and 8 independent pathway. Although autophagy has been shown to negatively regulate canonical inflammasome activity in TLR-stimulated macrophages, our data indicates that this process is an unconventional mechanism of IL-18 secretion by airway epithelial cells., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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3. The fission yeast ptr1+ gene involved in nuclear mRNA export encodes a putative ubiquitin ligase.
- Author
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Andoh T, Azad AK, Shigematsu A, Ohshima Y, and Tani T
- Subjects
- Active Transport, Cell Nucleus, Amino Acid Sequence, Cloning, Molecular, Cosmids genetics, Diploidy, Genes, Suppressor, Molecular Sequence Data, Mutation, Protein Structure, Tertiary, Recombinant Proteins genetics, Recombinant Proteins metabolism, Saccharomyces cerevisiae enzymology, Saccharomyces cerevisiae genetics, Schizosaccharomyces enzymology, Schizosaccharomyces growth & development, Schizosaccharomyces metabolism, Schizosaccharomyces pombe Proteins genetics, Schizosaccharomyces pombe Proteins metabolism, Sequence Homology, Amino Acid, Cell Nucleus metabolism, Homeodomain Proteins genetics, RNA, Messenger metabolism, Saccharomyces cerevisiae Proteins genetics, Schizosaccharomyces genetics, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism
- Abstract
Fission yeast ptr1-1 is one of the mRNA transport mutants that accumulate poly(A)+ RNA in the nuclei at the nonpermissive temperature. We found that the ptr1+ gene encodes a homolog of Saccharomyces cerevisiae Tom1p, a hect type ubiquitin ligase. In ptr1-1, a conserved amino acid in the hect domain of Ptr1p is mutated. The ptr1+ gene is essential for growth and its mutation did not affect nuclear protein export. A ptr1-1 rae1-167 double mutant showed a synthetic effect on a growth defect, indicating that Ptr1p functionally interacts with an essential mRNA export factor Rae1p. We also isolated a multi-copy suppressor for ptr1-1 and found that it is the mpd2+ gene isolated as a multi-copy suppressor of cdc7-PD1.
- Published
- 2004
- Full Text
- View/download PDF
4. A mutation in the gene involved in sister chromatid separation causes a defect in nuclear mRNA export in fission yeast.
- Author
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Kalam Azad A, Ideue T, Ohshima Y, and Tani T
- Subjects
- In Situ Hybridization, Fluorescence, Schizosaccharomyces metabolism, Cell Nucleus metabolism, Chromatids, Mutation, RNA, Messenger metabolism, Schizosaccharomyces genetics
- Abstract
Fission yeast ptr4-1 is one of the mRNA transport mutants that accumulate poly(A)(+) RNA in the nuclei at the nonpermissive temperature. We cloned the ptr4(+) gene and found that it is identical with the cut1(+) gene essential for chromosome segregation during mitosis. ptr4/cut1 has no defects in nucleocytoplasmic transport of a protein, indicative of a specific blockage of mRNA export by this mutation. A mutant of Cut2p cooperating with Cut1p in sister chromatid separation also showed defective mRNA export at the nonpermissive temperature. Our results suggest a novel linkage between the cell division cycle and nuclear mRNA export in eukaryotic cells.
- Published
- 2003
- Full Text
- View/download PDF
5. Caenorhabditis elegans reticulon interacts with RME-1 during embryogenesis.
- Author
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Iwahashi J, Kawasaki I, Kohara Y, Gengyo-Ando K, Mitani S, Ohshima Y, Hamada N, Hara K, Kashiwagi T, and Toyoda T
- Subjects
- Animals, Caenorhabditis elegans metabolism, Caenorhabditis elegans Proteins genetics, Cell Line, Gonads embryology, Gonads metabolism, Kinetics, RNA, Helminth biosynthesis, Two-Hybrid System Techniques, Caenorhabditis elegans embryology, Caenorhabditis elegans Proteins metabolism, Calcium-Binding Proteins metabolism, Phosphoproteins metabolism
- Abstract
Reticulon (RTN) family proteins are localized in the endoplasmic reticulum (ER). At least four different RTN genes have been identified in mammals, but in most cases, the functions of the encoded proteins except mammalian RTN4-A and RTN4-B are unknown. Each RTN gene produces 1-3 proteins by different promoters and alternative splicing. In Caenorhabditis elegans, there is a single gene (rtn gene) encoding three reticulon proteins, nRTN-A, B, and C. mRNA of nRTN-C is expressed in germ cells and embryos. However, nRTN-C protein is only expressed during embryogenesis and rapidly disappears after hatch. By yeast two-hybrid screening, two clones encoding the same C-terminal region of RME-1, a protein functioning in the endocytic recycling, were isolated. These findings suggest that nRTN-C functions in the endocytic pathway during embryogenesis., (Copyright 2002 Elsevier Science (USA).)
- Published
- 2002
- Full Text
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6. Important role of junctophilin in nematode motor function.
- Author
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Yoshida M, Sugimoto A, Ohshima Y, and Takeshima H
- Subjects
- Animals, Base Sequence, Caenorhabditis elegans genetics, Calcium Signaling, Cloning, Molecular, DNA, Complementary genetics, Drosophila melanogaster genetics, Drosophila melanogaster physiology, Genes, Helminth, Genes, Insect, Locomotion physiology, Membrane Proteins genetics, Molecular Sequence Data, Muscle Contraction genetics, Muscle Contraction physiology, Species Specificity, Caenorhabditis elegans physiology, Membrane Proteins physiology
- Abstract
Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are shared by excitable cells and seem to be the structural ground for cross-talk between cell-surface and intracellular ionic channels. Our current studies have identified junctophilins (JPs) as members of a novel transmembrane protein family in the junctional membrane complex. Biochemical and gene-knockout studies have suggested that JPs contribute to the formation of the junctional membrane complex by spanning the intracellular store membrane and interacting with the plasma membrane. We report here invertebrate JPs in fruit fly and nematode. Three distinct JP subtype genes are found in the mammalian genome, while a single JP gene exists in either invertebrate genome. Mammalian and invertebrate JPs share characteristic structural features, although some intervening sequences are found in invertebrate JPs. A reporter assay indicated that the JP gene is predominantly activated in muscle cells in nematode. Nematodes, in which expression of JP was inhibited by RNA-mediated interference (RNAi), showed hypolocomotion. Taking account of the cell-type-specific expression and data from previous reports, the hypolocomotion is likely to be due to the deficiency of junctional membrane structures and the resulting reduction of Ca(2+) signaling during excitation-contraction coupling in muscle cells., (Copyright 2001 Academic Press.)
- Published
- 2001
- Full Text
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7. Cyclic GMP elevation by 5-hydroxytryptamine is due to nitric oxide derived from endogenous nitrosothiol in NG108-15 cells.
- Author
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Arima T, Ohshima Y, Mizuno T, Kitamura Y, Segawa T, and Nomura Y
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- Animals, Glioma, Hybrid Cells, Kinetics, Neuroblastoma, Nitrates analysis, Nitrites analysis, Nitroprusside pharmacology, Oxyhemoglobins pharmacology, Cyclic GMP pharmacology, Nitric Oxide physiology, Nitroso Compounds metabolism, Serotonin pharmacology, Sulfhydryl Compounds metabolism
- Abstract
To clarify the involvement of nitric oxide (NO) derived from nitrosothiols (RSNO) in 5-hydroxytryptamine (5-HT)-induced Ca(2+)-independent cGMP formation (CIGF) in NG108-15 cells, we investigated the effects of 5-HT on intracellular contents of RSNO as well as of NO metabolites. 5-HT stimulation resulted in an increase in the intracellular contents of nitrate and cGMP. RSNO was detected in NG108-15 cells and was decreased by 5-HT stimulation. Furthermore, the time course of nitrate increase was coincident with that of RSNO decrease. CarboxyPTIO inhibited 5-HT-induced CIGF, whereas oxyhemoglobin failed to inhibit it. The data suggest that NO is stored in a stable form as RSNO and that 5-HT stimulates NO generation from endogenous RSNO, which is followed by elevation of cGMP via activation of cytosolic guanylyl cyclase by NO in NG108-15 cells. We suggest the existence of a novel 5-HT signal transduction pathway involved in NO generation in NG108-15 cells.
- Published
- 1996
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8. A novel antibody which precipitates 7.5S RNA is isolated from a patient with autoimmune disease.
- Author
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Nakao Y, Mukai R, Kabashima T, Ohshima Y, Hamaguchi H, Kashiwagi H, and Okada N
- Subjects
- Fluorescent Antibody Technique, HeLa Cells analysis, Humans, Lupus Erythematosus, Systemic immunology, Molecular Weight, RNA, Ribosomal isolation & purification, Ribonucleoproteins analysis, Antibodies isolation & purification, Autoimmune Diseases immunology, RNA, Ribosomal immunology
- Published
- 1982
- Full Text
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9. Pre-mRNA with a trimethylguanosine cap structure can be spliced efficiently in vitro.
- Author
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Tokumoto Y, Iwase R, Sekine M, Hata T, and Ohshima Y
- Subjects
- Binding, Competitive, Cell Nucleus physiology, HeLa Cells, In Vitro Techniques, Kinetics, Structure-Activity Relationship, RNA Caps, RNA Splicing
- Abstract
A chemically synthesized 2,2,7-trimethylguanosine cap (TMG-cap) analogue was added to an in vitro pre-mRNA splicing system. A slight inhibition of the splicing was observed, but it was much less remarkable than that by a 7-methylguanosine cap analogue. This result does not favor a direct role of the TMG-cap structure of small nuclear RNAs in pre-mRNA splicing, and suggests that the TMG-cap does not effectively interact with the 7-methylguanosine cap binding factors. Using the SP6 in vitro transcription system and a TMG-cap analogue, we prepared a beta-globin transcript which has a TMG-cap at the 5' end. This TMG-capped transcript was spliced accurately and efficiently in vitro.
- Published
- 1989
- Full Text
- View/download PDF
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