Type:Protein
SpeciesReactivity:R
B=Bovine;Ca=Cat;Ch=Chicken;D=Dog;EQ=Equine;GP=GuineaPig;H=Human;M=Mouse;P=Porcine;Pr=Primate;R=Rat;Rb=Rabbit;Y=Yeast;Xe=Xenopus;Ze=Zebrafish;;;;NA-NotApplicable;STP=Step-TactinProteins;All
Image:Neurofascininducedneuriteoutgrowth.A)RecombinantratNeurofascinimmobilizedonamicroplatepromotesneuriteoutgrowthinE18primaryratcorticalneurons. B).Inabsenceoftheprotein,outgrowthisless.
Neurofascin155(NF155)isatypeItransmembraneglycoproteinthatbelongstotheL1CAMfamilyofcelladhesionproteins.1,2TheratNF155CDNAencodesa1240aminoacid(aa)precursorthatcontainsa24aasignalsequence,a1086aaextracellulardomain(ECD),a21aatransmembranesegment,anda109aacytoplasmicdomain.TheECDconsistsofsixIg-likedomainsandfourfibronectintypeIIIrepeats,thesecondofwhichhasanRGDmotif.AsplicevariantofNeurofascin,NF186,lackstheRGD-containingfibronectintypeIIIdomainbutinsteadhasamucin-likedomainandanadditionalnon-RGDfibronectintypeIIIdomain.3WithinsharedregionsoftheECD,ratNF155shares45%and39%aasequenceidentitywithratNr-CAMandL1CAM,respectively,and98%aasequenceidentitywithhumanandmouseNF155.NF155istransientlyexpressedbyoligodendrocytesattheonsetofaxonmyelination,whereasNF186isneuronallyexpressedinnodesofRanvier.4-6ClusteringofNF155inparanodaloligodengroglialipidraftdomainsisstABIlizedbydimerizationofitscytoplasmicdomainsandassociationwithintracellularankyrin.(6-9)NF155interactswithaxonalcontactinandplaysaroleinnodeofRanvierformationandtheestablishmentofsaltatoryconduction.(5,9-12)TheECDofNF155iscleavedfromoligodengrogliamembranesbymetalloproteases,aprocesswhichisrequiredforNF155transportfromtheglialcellbodytotheaxoglialjunction.(13)Inadditiontodistinctexpressionpatterns,Neurofascinisoformshavedifferentfunctionalproperties.NF155promotesneuronaladhesionandneuriteoutgrowth,whereasNF186inhibitsneuronaladhesion.(4,7,13).
