The inositol polyphosphate 5-phosphatase Ocrl associates with endosomes that are partially coated with clathrin.
The subcellular localization of Ocrl, the inositol polyphosphate 5-phosphatase that is mutated in Lowe syndrome, was investigated by fluorescence microscopy. Ocrl was localized to endosomes and Golgi membranes along with clathrin, giantin, the mannose 6-phosphate receptor, transferrin, and the early endosomal antigen 1 endosomal marker in fixed cells. The endosomal localization of Ocrl was confirmed by live-cell time-lapse microscopy in which we monitored the dynamics of Ocrl on endosomes. GST binding assays show that Ocrl interacts with the clathrin terminal domain and the clathrin adaptor protein AP-2. Our findings suggest a role for Ocrl in endosomal receptor trafficking and sorting.
Ungewickell
Alexander
A
Division of Hematology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Ward
Michael E
ME
Ungewickell
Ernst
E
Majerus
Philip W
PW
D033962:Adaptor Protein Complex 2 / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002460:Cell Line; D002966:Clathrin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011992:Endosomes / Q000201:enzymology / Q000378:metabolism*; D005456:Fluorescent Dyes; D006056:Golgi Apparatus / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D007425:Intracellular Membranes / Q000201:enzymology / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017527:Receptor, IGF Type 2 / Q000235:genetics / Q000378:metabolism
D033962:Adaptor Protein Complex 2; D002966:Clathrin; D005456:Fluorescent Dyes; D017527:Receptor, IGF Type 2; D010744:Phosphoric Monoester Hydrolases; C075695:OCRL protein, human