Adaptor Proteins, Signal Transducing, Animals, COS Cells, Cell Line, Cercopithecus aethiops, Dogs, Endosomal Sorting Complexes Required for Transport, Endosomes, Enzyme Activation, Fluorescent Antibody Technique, HeLa Cells, Humans, Protein Structure, Tertiary, Protein Transport, Saccharomyces cerevisiae Proteins, Subcellular Fractions, Transfection, Transport Vesicles, Vesicular Transport Proteins, rhoB GTP-Binding Protein, Science & Technology, Life Sciences & Biomedicine, Oncology, Cell Biology, rhophilin, RhoB multivesicular bodies, Bro1, MULTIVESICULAR BODY PATHWAY, PROTEIN-KINASE-N, SMALL GTPASE RHO, BINDING-PROTEIN, SACCHAROMYCES-CEREVISIAE, PUTATIVE TARGET, PDZ DOMAINS, YEAST, BRO1, GENE, Chlorocebus aethiops, Hela Cells, Biochemistry & Molecular Biology, 0601 Biochemistry and Cell Biology, 1103 Clinical Sciences
Rhophilin-2 or p76(RBE), a protein whose expression is induced by the cyclic AMP pathway in thyrocytes, contains several protein-protein interaction domains including HR-1, Bro1 and PDZ domains, and is a partner of RhoB in its GTP-bound form (Eur J Biochem, 269(24): 6241-9, 2002). We here define its subcellular localization and dissect the significance of its domains. By subcellular fractionation and colocalization experiments, rhophilin-2 is recruited to subcellular organelles by activated RhoB-GTP. As for its yeast homologue, Npi3/Bro1p, the Bro1 domain of rhophilin-2 is necessary to its recruitment to the vesicular structures, which are not labeled for EEA1 nor Lamp1, but well with the late endosome marker CD63.