Rap1, a mercenary among the Ras-like GTPases

摘要

ThesmallRas-likeGTPaseRap1isanevolutionaryconservedproteinthatoriginallygainedinterestbecauseofitscapacitytorevertthemorphologicalphenotypeofRas-transformedfibroblasts.Rap1isregulatedbyalargenumberofstimulithatincludegrowthfactorsandcytokines,butalsophysicalforceandosmoticstress.DownstreamofRap1,aplethoraofeffectormoleculeshasbeenproposedonthebasisofbiochemicalstudies.Here,wepresentanoverviewofgeneticstudiesonRap1invariousmodelorganismsandrelatetheobservedphenotypestoeminvitro/emstudies.ThepicturethatemergesisoneinwhichRap1isaversatileregulatorofmorphogenesis,byregulatingdiverseprocessesthatincludeestablishmentofcellularpolarity,cellndash;matrixinteractionsandcellndash;celladhesion.Surprisingly,geneticexperimentsindicatethatinthevariousmodelorganisms,Rap1usesdistincteffectormoleculesthatimpingeupontheactincytoskeletonandadhesionmolecules./p/div