Synaptojanin 1-mediated PI(4,5)P2 hydrolysis is modulated by membrane curvature and facilitates membrane fission.

ABSTRACT: Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P₂] plays a fundamental role in clathrin-mediated endocytosis. However, precisely how PI(4,5)P₂ metabolism is spatially and temporally regulated during membrane internalization and the functional consequences of endocytosis-coupled PI(4,5)P₂ dephosphorylation remain to be explored. Using cell-free assays with liposomes of varying diameters, we show that the major synaptic phosphoinositide phosphatase, synaptojanin 1 (Synj1), acts with membrane curvature generators/sensors, such as the BAR protein endophilin, to preferentially remove PI(4,5)P₂ from curved membranes as opposed to relatively flat ones. Moreover, in vivo recruitment of Synj1's inositol 5-phosphatase domain to endophilin-induced membrane tubules results in fragmentation and condensa

SUBMITTER: Chang-Ileto B 

PROVIDER: S-EPMC3058127 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature