RRC ID 31846
Author Kojima K, Amano Y, Yoshino K, Tanaka N, Sugamura K, Takeshita T.
Title ESCRT-0 protein hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) is targeted to endosomes independently of signal-transducing adaptor molecule (STAM) and the complex formation with STAM promotes its endosomal dissociation.
Journal J Biol Chem
Abstract The ESCRT-0 complex, consisting of the hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) and the signal-transducing adaptor molecule (STAM) proteins, recognizes ubiquitylated cargo during the initial step of endosomal sorting. The endosomal accumulation of overexpressed Hrs has been reported previously to be associated with endosome enlargement. In this study, we have found that co-expressing exogenous STAM1 in Hrs-overexpressing cells leads to a diffuse localization for a large part of the Hrs accumulated on endosomes and a recovery of the impaired cargo protein degradation process, thus suggesting that exogenous STAM abrogates the abnormalities of the Hrs-positive endosomes. A fluorescently labeled Hrs, introduced into the cells by membrane permeabilization, exhibited endosomal localization in the absence of STAM1 and gradually dissociated from the endosomes upon the sequential addition of recombinant STAM1. Furthermore, when microinjected into cells, the fluorescently labeled Hrs also showed endosomal accumulation; however, ESCRT-0 complexes formed prior to the microinjection did not. Analysis of the state of the complex in HeLa cells using blue-native PAGE revealed that the membrane-associated Hrs exists partly as a monomer and not only in the STAM1-bound form. Thus, our data suggest that the membrane binding and dissociation cycle of the ESCRT-0 proteins on the endosomal membrane is a critical step during the cargo sorting process.
Volume 289(48)
Pages 33296-310
Published 2014-11-28
DOI 10.1074/jbc.M114.578245
PII M114.578245
PMID 25296754
PMC PMC4246087
MeSH Adaptor Proteins, Signal Transducing / genetics Adaptor Proteins, Signal Transducing / metabolism* Animals Endosomal Sorting Complexes Required for Transport / genetics Endosomal Sorting Complexes Required for Transport / metabolism* Endosomes / genetics Endosomes / metabolism* HeLa Cells Humans Mice Mice, Knockout Phosphoproteins / genetics Phosphoproteins / metabolism* Protein Transport / physiology
IF 4.238
Times Cited 5
DNA material pco12 EGFR (RDB01276) CSII-EF-MCS (RDB04378).