Background
Neuregulin/Heregulinisafamilyofstructurallyrelatedpolypeptidegrowthfactorsderivedfromalternativelysplicedgenes(NRG1,NRG2,NRG3andNRG4).Todate,thereareover14solubleandtransmembraneproteinsderivedfromtheNRG1gene.ProteolyticprocessingoftheextracellulardomainofthetransmembraneNRG1isoformsreleasesolublegrowthfactors.HRG1-B1containsanIgdomainandanEGF-likedomainthatisnecessaryfordirectbindingtoreceptortyrosinekinaseserb3anderb4.Thisbindinginduceserb3anderb4heterodimerizationwitherb2,stimulatingintrinsickinaseactivity,whichleadstotyrosinephosphorylation.AlthoughHRG1-B1BIOLOGicaleffectsisstillunclear,ithasbeenfoundtopromotemotilityandinvasivenessofbreastcancercellswhichmayalsoinvolveup-regulationofexpressionandfunctionoftheautocrinemotility-promotingfactor(AMF).RecombinanthumanHeregulin-B1(HRG1-B1)isa7.5kDapolypeptideconsistingofonlytheEGFdomainofheregulin-B1(65aminoacidresidues).
Specifications