P-selectinbelongstotheselectinfamilyofadhesionmolecules.P-selectinactsasareceptorthatsupportsbindingofleukocytestoactivatedplateletsandendothelium.P-selectinmediatedadhesiveinteractionsoperateinconjunctionwithcell-cellinteractionsdirectedbyrelatedmoleculesandarelikelytobeimportantinbothhemostaticandinflammatoryprocesses.P-selectinislocatedinmembranesofagranulesinunstimulatedplateletsandredistributedtothecellsurfaceuponplateletactivation.P-selectinisalsopresentinendothelialcellsinmembranesofWeibel-Paladebodiesandmegakaryocytes.SurfaceappearanceofP-selectinisveryrapid,buttransientdecliningtobasallevelwithinshorttimefollowingstimulation.
ThephysiologicroleofP-selectinmightbethemediationofinitialleukocyteadhesiontoactivatedendotheliumduringacuteinflammation.ItmayworkinconcertwithE-selectintodirectearly,regionallyspecificadherenceofneutrophilsandmonocytesatsitesofacuteinflammation.AsolubleformofP-selectinfoundinserumandplasmahasbeendescribedwhichmightrepresentaproteolyticfragmentormorelikelyasolublesplicevariantlackingthetransmembranedomain.SolubleP-selectinisapotentiallyimportantmoleculetoprovidemoredetailedinsightintopathologicalsituations.ExcessiveaccumulationofneutrophilsontheendothelialsurfaceaccompaniedbyhighexposureofP-selectinhasbeenimplicatedinanumberofinflammatorydisorders,includingadultrespiratorydistresssyndrome,acutelunginjury,ischemia-reperfusioninjury,Gram-negativesepticshock,thromboticdiseasesandrheumatoidarthritis.MalignantcellswereshowntoexpressreceptorsforP-selectinsuggestinganimportantroleforP-selectinintumorformationandmetastasis.Plateletshavealsobeenshowntopromotetumormetastasis.

Synonyms:Plateletalpha-GranuleMembraneProtein,CD62P,GMP-140,LECAM-3,PADGEM