Regulation of a Golgi flippase by phosphoinositides and an ArfGEF.

ABSTRACT: The essential role for phosphatidylinositol-4-phosphate (PtdIns(4)P) in vesicle-mediated protein transport from the trans-Golgi network (TGN) was first described in the budding yeast Saccharomyces cerevisiae. However, the identity of downstream effectors of PtdIns(4)P in this system has been elusive. Here, we show that Drs2p, a type IV P-type ATPase required for phospholipid translocase (flippase) activity and transport vesicle budding from the TGN, is an effector of PtdIns(4)P. Drs2p-dependent flip of a fluorescent phosphatidylserine analogue across purified TGN membranes requires synthesis of PtdIns(4)P by the phosphatidylinositol-4-kinase (PI(4)K) Pik1p. PtdIns(4)P binds to a regulatory domain in the C-terminal tail of Drs2p that has homology to a split PH domain and is required for Drs

SUBMITTER: Natarajan P 

PROVIDER: S-EPMC2787759 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature