Functional anatomy of phospholipid binding and regulation of phosphoinositide homeostasis by proteins of the sec14 superfamily.

ABSTRACT: Sec14, the major yeast phosphatidylinositol (PtdIns)/phosphatidylcholine (PtdCho) transfer protein, regulates essential interfaces between lipid metabolism and membrane trafficking from the trans-Golgi network (TGN). How Sec14 does so remains unclear. We report that Sec14 binds PtdIns and PtdCho at distinct (but overlapping) sites, and both PtdIns- and PtdCho-binding activities are essential Sec14 activities. We further show both activities must reside within the same molecule to reconstitute a functional Sec14 and for effective Sec14-mediated regulation of phosphoinositide homeostasis in vivo. This regulation is uncoupled from PtdIns-transfer activity and argues for an interfacial presentation mode for Sec14-mediated potentiation of PtdIns kinases. Such a regulatory role for Sec14 is a pr

SUBMITTER: Schaaf G 

PROVIDER: S-EPMC7808562 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature