1994 Fiscal Year Final Research Report Summary
Formation of Cell-like liposome encapsulated cytoskeletons.
| Project/Area Number |
05454637
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biophysics
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| Research Institution | Nagoya University |
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Principal Investigator |
HOTANI Hirokazu Nagoya Univ., Dept.Mol.Boil., Professor, 理学部, 教授 (80025444)
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| Co-Investigator(Kenkyū-buntansha) |
ITOH Tomohiko Nagoya Univ., Dept.Mol.Biol., Assist.Professor, 理学部, 助手 (30183742)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Cytoskeleton / Liposome / Microtubule / Cell model / Actin / Dark-field Microscopy |
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| Research Abstract |
To study whether the cytoskeleton can determine the shape of cells, we constructed the liposome which contained subunit proteins of microtubules or microfilaments. Liposome are single or multi-layred vesicles of lipid bilayr.
By raising the temperature, the encapsulated tubulin or G-actin was polymerized to microtubules or actin filaments (F-actin), respectively. As the encapsulated tubulin polymerized forming microtubules, the liposome transformed into a lemon shape. Two tubular membrane projections then developed from both sides of the lemon-shaped liposome and the projections grew longer. Both of the projections were straight, rigid, uniform in diameter and aligned on a line. Finally, the liposome transformed into a dipolar-shaped liposome, which had a central sphere and two straight tubes.
When the encapsulated actin polymerized into actin filaments, the liposome transformed into a disk or dumbbell shape which has geometrical symmetry. The actin filaments polymerized in the liposome spontaneously aligned along the periphery of the liposome to form bundles. Elongation of microtubules or actin filaments caused morphological changes of the liposomes, indicating that the self-assembly process of the cytoskeletons itself can generate the mechanical force strong enough to deform membranes. Microtubule and actin filament are quite different in their rigidity. They may generate mechanical force in different amount with each other, when they self-assemble. These characteristics mighy cause the difference in the liposome shape.
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