2005 Fiscal Year Final Research Report Summary
Molecular basis and regulation of feet for leukocytes-type amoeboid movement
| Project/Area Number |
16570161
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Yamaguchi University |
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Principal Investigator |
YUMURA Shigehiko Yamaguchi University, Faculty of Science, Professor, 理学部, 教授 (70183986)
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| Project Period (FY) |
2004 – 2005
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| Keywords | cell-substratum adhesion / cell movement / actin |
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| Research Abstract |
Exhaustive research of feet protein genes
We investigated this research by two approaches. After making mutants that can not adhere to the substratum by chemical mutagens, the phenotypes were rescued by cDNAlibrary. Byisolatng the cDNA form the rescued cells, we found new genes relating feet of Dictyostelium cells. Second, from the genome project, estimating possible genes relating feet proteins, we found 2 genes in Dictyostelium. We made GFP-fused genes and observed the dynamics of the proteins.
Observation of dynamics of feet during cell movement
WE observed dynamics of ‘actin foci', which we refer to as feet of Dictyostelium by evanescence microscope, simultaneously observing the distance between the cell membrane and the substratum by reflection interference microscope. Each actin focus showed rapid turnover with 20 sec. The number of actin foci decreased as the cell migrate faser. We found also other feet than actin foci. During cell division, dynamic actin structures formed underbeneath the nucei, which we refer to as ‘MDAS', mitotic phase-specific dymanic actin structure. When MDAS was eliminated artificially, the cell failed to divide.
Visualization of force of the cell
We used gelatin as new substratum in place of silicone, which was previously used. We could more reproducible measurement of local area. The order of the force was nano-Newton level. We could visualize the force as pseudo-color.
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