Function of 27K nuclease in relation to apoptosis in the digestive organ of the silkworm, Bombyx mori.
| Project/Area Number |
08456036
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
蚕糸・昆虫利用学
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
FURUSAWA Toshiharu Kyoto Institute of Technology, Faculty of Textile Science, Professor, 繊維学部, 教授 (70127166)
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| Co-Investigator(Kenkyū-buntansha) |
KOTANI Eiji Kyoto Institute of Technology, Faculty of Textile Science, Research Associate, 繊維学部, 助手 (10273541)
MORI Hajime Kyoto Institute of Technology, Faculty of Textile Science, Associate Professor, 繊維学部, 助教授 (80201812)
SUGIMURA Yukiko Kyoto Institute of Technology, Faculty of Textile Science, Associate Professor, 繊維学部, 助教授 (20273542)
ODA Kouhei Kyoto Institute of Technology, Faculty of Textile Science, Professor, 繊維学部, 教授 (50081584)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,700,000 (Direct Cost: ¥7,700,000)
Fiscal Year 1997: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1996: ¥5,800,000 (Direct Cost: ¥5,800,000)
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| Keywords | Silkworm / Midgut / Apoptosis / Protease / Nuclease / Programd Cell Death / RNA結合蛋白質 |
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| Research Abstract |
A.When the digestive juice of the silkworm, Bombyx mori, was separated by CM-Sepharose chromatography, nucleases (dsRNase, ssRNase and DNase) and protease were co-isolated in 0.33M NaCl elute. These alkaline hydrolases could be fractionated individually by gel electrofocusing. The protease was characterized on the basis of enzymatic and genetic analyzes : (1) isoelectric point : pH11, (2) optimum pH for enzyme activity : pH10, (3) substrate specificity : positive in substrates used for serine protease, (4) N-terminal amino acids : IVGGSAANAGAHPHLA, (5) amino acid sequence predicted from a full-length cDNA (0.92kbp) : the presence of His^<45>, Asp^<92> and Ser^<186> residues, which are known as the catalytic triad of chymotripsin-type serine protease, (6) transcription product in midgut tissue : the accumulation of proenzyme in larval midgut cells after spinning stage.
B.A poly A^+ RNA binding protein (TIA-1) is a key effector for mammalian cell apoptosis. The TIA-1 homologous sequence was present at the 5' upstream of the protease coding region, and the gene expression was increased in the mudgut tissue on the day of pupation.
C.One of the typical indications of apoptosis is to induce the DNA degradation showing ladder band in electrophoretic pattern. The DNA extracted from larval epithelial cells, which were released to lumen from the midgut tissue, was fragmented at various sizes of melecules. This ladder fragmentation was occurred from the biginning of pupation stage, when the cells were disordered ultrastructually.
Judging from these evidences, the hydolases and TIA-1 homologoue clarified in this study might be involved in the programd cell death of the midgut tissue during larval-pupal metamorphosis.
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Report
(3 results)
Research Products
(3 results)
