PtdIns-specific MPR pathway association of a novel WD40 repeat protein, WIPI49.

ABSTRACT: WIPI49 is a member of a previously undescribed family of WD40-repeat proteins that we demonstrate binds 3-phosphorylated phosphoinositides. Immunofluorescent imaging indicates that WIPI49 is localized to both trans-Golgi and endosomal membranes, organelles between which it traffics in a microtubule-dependent manner. Live cell imaging establishes that WIPI49 traffics through the same set of endosomal membranes as that followed by the mannose-6-phosphate receptor (MPR), and consistent with this, WIPI49 is enriched in clathrin-coated vesicles. Ectopic expression of wild-type WIPI49 disrupts the proper functioning of this MPR pathway, whereas expression of a double point mutant (R221,222AWIPI49) unable to bind phosphoinositides does not disrupt this pathway. Finally, suppression of WIPI49 expr

SUBMITTER: Jeffries TR 

PROVIDER: S-EPMC420090 | biostudies-literature | 2004 Jun

REPOSITORIES: biostudies-literature