Integrinsarecellsurfacereceptorsthatinteractwiththeextracellularmatrixandmediateintracellularsignalsinresponsetotheextracellularmatrixincludingcellularshape,mobility,andprogressionthroughthecellcycle.Integrinsdonotthemselvespossessakinasedomainorenzymaticactivitybutrelyonassociationwithothersignalingmoleculestotransmitsignals.InteractionsbetweentheextracellularmatrixandtheactinCytoskeletoncommonlytakeplaceatfocaladhesionsonthecellsurfacethatcontainlocalizedconcentrationsofintegrins,signalingmolecules,andcytoskeletalelements.Talinformsadirectinteractionwiththeintegrincytoplasmicdomain,andinteractswithcytoskeletalelements(actin)andsignalingfactors.PaxillinandCASalsolocalizeinfocaladhesionsandmayserveasascaffoldforotherintegrinsignalingcomponentslikeFAKandsrc.InteractionofFAK,CASandsrcmayberequiredforintegrinregulationofcellcycleprogression.TheCrkLadaptorproteinmayregulatedownstreamintegrinsignaling.Growthfactorsignalingpathwaysandthecaveolinreceptorexhibitimportantcrosstalkwithintegrinreceptorsincellularresponseslikeactivationofmapkinase,proliferationandmotility. Contributor:GlennCroston,PhD. REFERENCES: