2010 Fiscal Year Final Research Report
Physiological significance of the fatty acid composition in phosphatidylinositol
| Project/Area Number |
21770133
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional biochemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
INOUE Takao The University of Tokyo, 大学院・薬学系研究科, 助教 (50361605)
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| Project Period (FY) |
2009 – 2010
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| Keywords | 細胞情報伝達機構 |
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| Research Abstract |
Phosphatidylinositol (PI), an important constituent of membranes, contains stearic acid as the major fatty acid at the sn-1 position. This fatty acid is thought to be incorporated into PI through fatty acid remodeling by sequential deacylation and reacylation. However, the genes responsible for the reaction are unknown, and consequently, the physiological significance of the sn-1 fatty acid remains to be elucidated. Here, we identified acl-8, acl-9, acl-10, which are closely related to each other, and ipla-1 as strong candidates for genes involved in fatty acid remodeling at the sn-1 position of PI. In both ipla-1 mutants and acl-8 acl-9 acl-10 triple mutants of C. elegans, the stearic acid content of PI is reduced and asymmetric division of stem cell-like epithelial cells is defective. The defects in asymmetric division of these mutants are suppressed by a mutation of the same genes involved in intracellular retrograde transport, suggesting that ipla-1 and acl genes act in the same pathway. IPLA-1 and ACL-10 have phospholipase A1 and acyltransferase activity, respectively, both of which recognize the sn-1 position of PI as their substrate. We propose that the sn-1 fatty acid of PI is determined by ipla-1 and acl-8, -9, -10 and crucial for asymmetric divisions.
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