UniProtSummary | FUNCTION:SwissProt:O60674#Tyrosinekinaseofthenon-receptortype,involvedininterleukin-3andprobablyinterleukin-23signaltransduction. SIZE:1132aminoacids;130674Da SUBUNIT:InteractswithSIRPA(Bysimilarity).InteractswithIL23R,SKB1andSTAM2. SUBCELLULARLOCATION:Intracytoplasmicmembrane;Peripheralmembraneprotein(Bysimilarity).Note=Whollyintracellular,possIBLymembraneassociated(Bysimilarity). TISSUESPECIFICITY:Expressedinblood,bonemarrowandlymphnode. DOMAIN:SwissProt:O60674Possessestwophosphotransferasedomains.Thesecondoneprobablycontainsthecatalyticdomain(Bysimilarity),whilethepresenceofslightdifferencessuggestadifferentrolefordomain1. DISEASE:SwissProt:O60674#ChromosomalaberrationsinvolvingJAK2arefoundinbothchronicandacuteformsofeosinophilic,lymphoblasticandmyeloidleukemia.Translocationt(8;9)(p22;p24)withPCM1linkstheproteinkinasedomainofJAK2tothemajorportionofPCM1.Translocationt(9;12)(p24;p13)withETV6.&DefectsinJAK2areacauseofsusceptibilitytoBudd-Chiarisyndrome[MIM:600880].Budd-Chiarisyndromeisaspectrumofdiseasestates,includinganatomicabnormalitiesandhypercoagulabledisorders,resultinginhepaticvenousoutflowocclusion.Clinicalmanifestationsobservedinthemajorityofpatientsincludehepatomegaly,rightupperquadrantpain,andaBDominalascites.&DefectsinJAK2areassociatedwithpolycythemiavera(PV)[MIM:263300].PV,themostcommonformofprimarypolycythemia,iscausedbysomaticmutationinasinglehematopoieticstemcellleADIngtoclonalhematopoiesis.PVisamyeloproliferativedisordercharacterizedpredominantlybyerythroidhyperplasia,butalsobymyeloidleukocytosis,thrombocytosis,andsplenomegaly.FamilialcasesofPVareveryrareandusuallymanifestinelderlypatients.&DefectsinJAK2genemaybeacauseofessentialthrombocythemia(ET)[MIM:187950].ETischaracterizedbyelevatedplateletlevelsduetosustainedproliferationofmegakaryocytes,andfrequentlyleadtothromboticandhaemorrhagiccomplications.&DefectsinJAK2areassociatedwithfamilialmyelofibrosis[MIM:254450].Myelofibrosiswithmyeloidmetaplasiaisamyeloproliferativediseasewithannualincidenceof0.5-1.5casesper100,000individualsandageatdiagnosisaround60(anincreasedprevalenceisnotedinAshkenaziJews).Clinicalmanifestationsdependonthetypeofbloodcellaffectedandmayincludeanemia,pallor,splenomegaly,hypermetabolicstate,petechiae,ecchymosis,bleeding,lymphadenopathy,hepatomegaly,portalhypertension.&DefectsinJAK2areacauseofacutemyelogenousleukemia(AML)[MIM:601626].AMLisamalignantdiseaseinwhichhematopoieticprecursorsarearrestedinanearlystageofdevelopment. SIMILARITY:Belongstotheproteinkinasesuperfamily.Tyrproteinkinasefamily.JAKsubfamily.&Contains1FERMdomain.&Contains1proteinkinasedomain.&Contains1SH2domain. |