title: Rhophilin-2 is targeted to late-endosomal structures of the vesicular machinery in the presence of activated RhoB.
abstract: 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.
authors.affiliation: Free University of Brussels-Campus Erasme, Institute of Interdisciplinary Research, 808 route de Lennik-1070 Brussels, Belgium. ssteuve@ulb.ac.be
authors.forename: Séverine
authors.initials: S
authors.lastname: Steuve
authors.forename: Thalie
authors.initials: T
authors.lastname: Devosse
authors.forename: Elsa
authors.initials: E
authors.lastname: Lauwers
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Vanderwinden
authors.forename: Bruno
authors.initials: B
authors.lastname: André
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Courtoy
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pirson
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D004285:Dogs; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology; D013347:Subcellular Fractions / Q000378:metabolism*; D014162:Transfection; D022161:Transport Vesicles / Q000201:enzymology / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000502:physiology; D020743:rhoB GTP-Binding Protein / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C480237:Bro1 protein, S cerevisiae; D056827:Endosomal Sorting Complexes Required for Transport; C471419:RHPN2 protein, human; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D020743:rhoB GTP-Binding Protein