title: Aptamer-derived peptides as potent inhibitors of the oncogenic RhoGEF Tgat.
abstract: Guanine nucleotide exchange factors (GEFs) activate the Rho GTPases by accelerating their GDP/GTP exchange rate. Some RhoGEFs have been isolated based on their oncogenic potency, and strategies to inhibit their activity are therefore actively being sought. In this study we devise a peptide inhibitor screening strategy to target the GEF activity of Tgat, an oncogenic isoform of the RhoGEF Trio, based on random mutations of the Trio inhibitor TRIP alpha, which we previously isolated using a peptide aptamer screen. This identifies one peptide, TRIP(E32G), which specifically inhibits Tgat GEF activity in vitro and significantly reduces Tgat-induced RhoA activation and foci formation. Furthermore, subcutaneous injection of cells expressing Tgat and TRIP(E32G) into nude mice reduces the formation of Tgat-induced tumors. Our approach thus demonstrates that peptide aptamers are potent inhibitors that can be used to interfere with RhoGEF functions in vivo.
authors.affiliation: Université Montpellier 2 et 1, Centre de Recherche en Biochimie Macromoléculaire, IFR 122, Montpellier, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bouquier
authors.forename: Sylvie
authors.initials: S
authors.lastname: Fromont
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Zeeh
authors.forename: Camille
authors.initials: C
authors.lastname: Auziol
authors.forename: Pauline
authors.initials: P
authors.lastname: Larrousse
authors.forename: Bruno
authors.initials: B
authors.lastname: Robert
authors.forename: Mahel
authors.initials: M
authors.lastname: Zeghouf
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cherfils
authors.forename: Anne
authors.initials: A
authors.lastname: Debant
authors.forename: Susanne
authors.initials: S
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D052158:Aptamers, Peptide / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D005260:Female; D020662:Guanine Nucleotide Exchange Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D041681:NIH 3T3 Cells; D019151:Peptide Library; D017354:Point Mutation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D052158:Aptamers, Peptide; D020662:Guanine Nucleotide Exchange Factors; D019151:Peptide Library; D017346:Protein Serine-Threonine Kinases; C099628:TRIO protein, human; D020742:rhoA GTP-Binding Protein