1991 Fiscal Year Final Research Report Summary
A study on the mechanism of cell volume regulation based on the osmoelastic coupling of F-actin
| Project/Area Number |
02808053
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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 |
生物物性学
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| Research Institution | Kyoto University |
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Principal Investigator |
ITO Tadanao Kyoto Univetsity, Faculty of Science, Associate Professor, 理学部, 助教授 (90093187)
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| Project Period (FY) |
1990 – 1991
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| Keywords | F-actin / cytoskeleton / cell volume regulation / ABP / gelsolin / water flow / osmotic stress / osmoelastic coupling |
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| Research Abstract |
we have studied the role of cytoskeleton composed of actin filaments(F-actin)in the cell volume regulation in vitro. We have used the Zimm-Myerson osmometer as a "model cell" and obtained following results.
(1)The F-actin in the 'model cell" retarded osmotically driven water flow across a semipermeable membrane and above a critical concentration at which F-actin predictably become immobilized(>3 mg/ml)water flow completely stopped.
(2)Actin-binding protein(ABP)promotes the perpendicular branching of F-actin, thereby serving as an efficient actin gelation protein. Gels of actin cross-linked by ABP completely stopped the osmotically driven-water flow at a low concentration of F-actin of 0.5 mg/ml
(3)Gelsolin severs F-actin in the presence of mm calcium, and solate the actin gel. When the gel was solated by calcium-activated gelsolin, osmotically driven water flow appeared.
These results suggest that the ABP-bases actin networks in the cell periphery could constitute a relative strong buffer against cell swelling or shrinkage by small fluctuation in osmotic pressures that constantly affect cell of mammalian organisms.
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