Overview | Keratinsareagroupofwater-insolubleproteinsthatformmonofilaments,aclassofintermediatefilament.Thesefilamentsformpartofthecytoskeletalcomplexinepidermisandinmostotherepithelialtissues.Nineteenhumanepithelialkeratinsareresolvedwithtwo-dimensionalgelselectrophoresis(Moll,R.,1982).Thesecanbedividedintoacid(pI<5.7) and="" basic="" (pi="">6.0)subfamilies.Theacidickeratinshavemolecularweightsof56.5,55,51,50,50",48,46,45,and40kD.Thebasickeratinshavemolecularweightsof65-67,64,59,58,56,and52kD.Membersoftheacidicandbasicsubfamiliesarefoundtogetherinpairs.Thecompositionofkeratinpairsvarieswiththeepithelialcelltype,stageofdifferentiation,cellulargrowthenvironment,anddiseasestate(Sun,T.T.,1984;Cooper,D.,1985;Sun,T.T.,1985).The56.5/65-67kDpairispresentinkeratinized(differentiated)epidermis.The55/64kDpairischaracteristicofnormal(corneal-type)epithelialdifferentiation(Moll,R.,1982;Sun,T.T,1984).The51/59kDpairischaracteristicofthestratifiedsquamousepithelialofinternalorganismsuchasesophagusandtongue(Moll,R.,1982;Cooper,D.,1985).The51/58kDpairisakeratinocyteMarker;thispairispresentinalmostallstratifiedepitheliairrespectiveofthestateofcellularstratification(Moll,R.,1982;Sun,T.T.,1984).The48/56kDpairischaracteristicofhyper-proliferative(de-differentiated)keratinocytes(Moll,R.,1982;Weiss,R.A.,1984).The45/52kDpairandtoalesserextent,the46/54kDpairarecharacteristicofsimpleepithelia(Moll,R.,1982).The40kDkeratinispresentinmostepitheliaexceptadultepidermis(Moll,R.,1982).5.7)> |