Characterization of TCL, a new GTPase of the rho family related to TC10 andCcdc42.
GTPases of the Rho family control a wide variety of cellular processes such as cell morphology, motility, proliferation, differentiation, and apoptosis. We report here the characterization of a new Rho member, which shares 85% and 78% amino acid similarity to TC10 and Cdc42, respectively. This GTPase, termed as TC10-like (TCL) is encoded by an unexpectedly large locus, made of five exons spanning over 85 kilobases on human chromosome 14. TCL mRNA is 2.5 kilobases long and is mainly expressed in heart. In vitro, TCL shows rapid GDP/GTP exchange and displays higher GTP dissociation and hydolysis rates than TC10. Using the yeast two-hybrid system and GST pull-down assays, we show that GTP-bound but not GDP-bound TCL protein directly interacts with Cdc42/Rac interacting binding domains, such as those found in PAK and WASP. Despite its overall similarity to TC10 and Cdc42, the constitutively active TCL mutant displays distinct morphogenic activity in REF-52 fibroblasts, producing large and dynamic F-actin-rich ruffles on the dorsal cell membrane. Interestingly, TCL morphogenic activity is blocked by dominant negative Rac1 and Cdc42 mutants, suggesting a cross-talk between these three Rho GTPases.
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Centre de Recherche en Biochimie Macromoléculaire, CNRS-UPR 1086, 1919 Route de Mende, 34293 Montpellier cedex 5, France.
De Toledo
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Comunale
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Ladopoulou
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Gauthier-Rouvière
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Blangy
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Fort
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D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D048429:Cell Size; D003599:Cytoskeleton / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D051316:Wiskott-Aldrich Syndrome Protein; D020764:cdc42 GTP-Binding Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D054462:p21-Activated Kinases; D020741:rho GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D000199:Actins; D011506:Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C485944:Rhoj protein, mouse; C495767:WAS protein, human; C495768:Was protein, mouse; C495769:Was protein, rat; D051316:Wiskott-Aldrich Syndrome Protein; C515903:PAK1 protein, human; C515905:Pak1 protein, mouse; C515906:Pak1 protein, rat; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases; D020558:GTP Phosphohydrolases; C417188:RHOJ protein, human; C503256:RHOQ protein, human; C503260:Rhoq protein, mouse; C503262:Rhoq protein, rat; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins