
Background
PAI-2isaninhibitoryserpinexpressedmainlyinkeratinocytes,activatedmonocytes,andplacentaltrophoblasts.Itexistspredominantlyasa47kDanonglycosylatedintracellularproteinwhichcanbeinducedtobesecretedas60kDaglycoprotein.Thephysiologicalrelevanceofthisproperty,whichisneitheraconsequenceofanymutationinthePAI-2genenorassociatedwithanyknowndisorder,isstillunclear.However,itappearsthattheformationofintracellulardormantpolymersmaybeimportantforthecontrolledreleaseoftheinhibitorfromPAI-2producingcells.PlasmalevelsofPAI-2areusuallyloworundetectable,exceptduringpregnancyandinsomeformsofmonocyticleukemia.SecretionofPAI-2fromtheplacentanormallyoccursduringthethirdtrimesterofpregnancyandaccountsforthedramaticincreaseinPAI-2levels(upto250ng/ml),whicharemaintainedattheselevelsuntilpostpartum,andthenrapidlydecline.InadditiontoitsvitalroleinprotectingtheplacentafromdegradationbyuPAand/oruPA-activatedproteases,PAI-2hasbeenshowntobeessentialforthepreventionofmetastaticspreadofneck,lungandbreastcancers.ThebeneficialeffectofPAI-2seeninthesestudiesispresumedtostemfromitsABIlitytoinhibituPA-dependentcelldissemination.PAI-2hasalsobeenreportedtoinhibitkeratinocyteproliferation,andtoparticipateintheinnateimmuneresponseduringviralinfection.RecombinanthumanPAI-2isa415-residuenonglycosylatedprotein.
Specifications