1991 Fiscal Year Final Research Report Summary
Studies on Regulation of Cellular Function by Calpastatin
| Project/Area Number |
01580157
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
物質生物化学
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| Research Institution | Kyoto University |
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Principal Investigator |
MAKI Masatoshi Kyoto University Institute for Virus Research Associate Professor, ウイルス研究所, 助教授 (40183610)
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| Co-Investigator(Kenkyū-buntansha) |
ADACHI Yoshifumi Kyoto University Faculty of Medicine Instructor (50201893)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Calpain / Calpastatin / Proteinase / Proteinase Inhibitor / Protein Kinase C / calcium channel |
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| Research Abstract |
Calpastatin is endogenous inhibitor protein acting specifically on intracellular calcium dependent proteinase(calpain). In the present study we extended structure-function analyses of calpastatin and examined roles of this inhibitor in animal cells. The major results obtained were as follows :
1. Locus of human calpastatin gene was assigned to chromosome 5ql4-22.
2. Highly conserved regions among the four internally repetitive domains were separated by introns in the genomic DNA.
3. The 27-residue synthetic oligopeptide corresponding to'the Exon 1B was active as calpain inhibitor, and it suppressed TPA induced down-regulation of protein kinase C when added to culture medium of BIM cells(neuroblastoma cell line).
4.2-dimensional NMR studies have revaeled that the oligopeptide forms type I beta-turn structure in the highly conserved sequence.
5. Monoclonal antibodies were prepared for human calpastatin, and a method of distinguishing two types(muscle and erythrocyte)of calpastatin molecules were developed.
In contrast to mammalian erythrocytes, chicken erythrocytes(nucleated cells)were suggested to retain amino-terminal domains of calpastatin and to have a muscle type structure.
6. MRNA and protein levels of m-calpain and calpastatin were found to be elevated in HTLV-I infected T-cell leukemia cell lines, but not in HTLV-I tax-transformed fibroblast cell lines.
7. Besides calpain inhibition, calpastatin was suggested to have L-type calcium channel activating function.
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