RRC ID 45860
Author Solinger JA, Spang A.
Title Loss of the Sec1/Munc18-family proteins VPS-33.2 and VPS-33.1 bypasses a block in endosome maturation in Caenorhabditis elegans.
Journal Mol Biol Cell
Abstract The end of the life of a transport vesicle requires a complex series of tethering, docking, and fusion events. Tethering complexes play a crucial role in the recognition of membrane entities and bringing them into close opposition, thereby coordinating and controlling cellular trafficking events. Here we provide a comprehensive RNA interference analysis of the CORVET and HOPS tethering complexes in metazoans. Knockdown of CORVET components promoted RAB-7 recruitment to subapical membranes, whereas in HOPS knockdowns, RAB-5 was found also on membrane structures close to the cell center, indicating the RAB conversion might be impaired in the absence of these tethering complexes. Unlike in yeast, metazoans have two VPS33 homologues, which are Sec1/Munc18 (SM)-family proteins involved in the regulation of membrane fusion. We assume that in wild type, each tethering complex contains a specific SM protein but that they may be able to substitute for each other in case of absence of the other. Of importance, knockdown of both SM proteins allowed bypass of the endosome maturation block in sand-1 mutants. We propose a model in which the SM proteins in tethering complexes are required for coordinated flux of material through the endosomal system.
Volume 25(24)
Pages 3909-25
Published 2014-12-1
DOI 10.1091/mbc.E13-12-0710
PII mbc.E13-12-0710
PMID 25273556
PMC PMC4244200
MeSH Animals Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Endocytosis / genetics Endosomes / metabolism* Female Green Fluorescent Proteins / genetics Green Fluorescent Proteins / metabolism Lysosomes / metabolism Membrane Fusion Microscopy, Fluorescence Munc18 Proteins / genetics Munc18 Proteins / metabolism* Mutation Oocytes / metabolism Protein Transport / genetics RNA Interference Transport Vesicles / metabolism Vacuoles / metabolism Vesicular Transport Proteins / genetics Vesicular Transport Proteins / metabolism* rab GTP-Binding Proteins / genetics rab GTP-Binding Proteins / metabolism rab5 GTP-Binding Proteins / genetics rab5 GTP-Binding Proteins / metabolism rab7 GTP-Binding Proteins
IF 3.791
Times Cited 14
C.elegans tm1125