| Project/Area Number |
08458235
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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 |
Cell biology
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| Research Institution | The Tokyo Metropolitan Institute of Medical Science |
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Principal Investigator |
MATSUMOTO Seiji (1997) RINSHOKEN,Cell Biology, Research Associate, 細胞生物学研究部門, 研究員 (40190532)
矢原 一郎 (1996) 財団法人東京都臨床医学総合研究所, 副所長 (60109957)
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| Co-Investigator(Kenkyū-buntansha) |
AIZAWA Hiroyuki RINSHOKEN,Cell Biology, Research Associate, 細胞生物学研究部門, 研究員 (90221704)
IIDA Kazuko RINSHOKEN,Cell Biology, Research Associate, 細胞生物学研究部門, 研究員 (40151229)
MOTIYAMA Kenji RINSHOKEN,Cell Biology, Research Associate, 細胞生物学研究部門, 研究員 (00250217)
松本 清治 財団法人東京都臨床医学総合研究所, 細胞生物, 研究員 (40190532)
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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 |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Keywords | stress protein / heat shock protein / stress response / cell defense mechanism / HSP90 / molecular chaperone / cofilin / Actin |
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| Research Abstract |
1-1. We found taht heated HSP90 binds and protects denatured firefly luciferase from irreversible aggregation. Luciferase can be released from the complexes when post-incubated in HSP70, HSP40 and another chaperone contained in reticulocyte lysate.
1-2. We found taht monoclonal antibodies specific to the N-terminus of HSP90 bound to both ends of HSP90 dimers. This indicates that HSP90 monomers align side-by-side in an antiparallel fashion and form dimers through their C-termini.
1-3. In the budding yeast, the expression level of Hsc82 was found to be reversibly proportional to the degree of stress tolerance.
2-1. We have determined tertiary structure of destrin, a cofilin-related protein, by NMR.The structure is similar to that of a unitary segment of gelsolin. The structure provides molecula basis for Ca^<2+> -independent binding of cofilin to actin.
2-2. Overexpression of cofilin in Dictyostelium cells induced a number of actin bundles. This was suggested to be a result of transformation from actin meshwork to bundles by cofilin-induced severing of F-actin. We further demonstrated that the bundles contracted in response to osmotic stress.
2-3. We found that cofilin was inactivated by phosphorylation of the Ser-3
2-4. A multicopy suppressor to a cofilin-ts mutant in Saccharomyces cerevisiae was isolated. The suppressor gene SCF1 encodes a WD40-repeat protein which is identidal to Aip1 previously described as an actin-intereating protein. SCF1 is not essential for cell viability.
2-5. Biochemical evidence has been obtained that Dictyostelium Aip1 binds to F-actin and seisitizes it to destruction by cofiin.
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