The GTPase-activating enzyme Gyp1p is required for recycling of internalized membrane material by inactivation of the Rab/Ypt GTPase Ypt1p.

ABSTRACT: Rab/Ypt GTPases are key regulators of membrane trafficking and together with SNARE proteins mediate selective fusion of vesicles with target compartments. A family of GTPase-activating enzymes (GAPs) specific for Rab/Ypt GTPases has been discovered, but little is known about their function and substrate specificity in vivo. Here we show that the GAP activity of Gyp1p, a yeast member of this family, is specifically required for recycling of the SNARE Snc1p and the membrane dye FM4-64, implying that inactivation of a Rab/Ypt GTPase may be necessary for recycling of membrane material. Interestingly, recycling of GFP-Snc1p in gyp1 Delta cells is partially restored by reducing the activity of Ypt1p. Moreover, GFP-Snc1p accumulated intracellularly in wild-type cells expressing a GTP-locked, muta

SUBMITTER: Lafourcade C 

PROVIDER: S-EPMC387746 | biostudies-literature | 2004 May

REPOSITORIES: biostudies-literature