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Symbol JAK2 contributors: mct/shn - updated : 20-06-2016
HGNC name Janus kinase 2
HGNC id 6192
Corresponding disease
MPD Ph1-negative myeloproliferative disorders, JAK2 mutated
PRV polycythemia rubra vera
Location 9p24.1      Physical location : 4.985.244 - 5.128.182
Synonym name
  • Janus kinase 2 (a protein tyrosine kinase)
  • tyrosine-protein kinase JAK2
  • Synonym symbol(s) EVI139, JTK10
    TYPE functioning gene
    STRUCTURE 142.94 kb     25 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked N status provisional
    Map pter - D9S1686 - D9S1810 - JAK2 - D9S1681 - D9S1852 - cen
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    25 - 5285 - 1132 - 2009 19181784
    Type widely
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Cardiovascularheart   highly Homo sapiens
    Digestiveintestinesmall intestine  moderately Homo sapiens
     intestinelarge intestinecolon moderately Homo sapiens
    Endocrinepancreas   lowly Homo sapiens
    Lymphoid/Immunespleen   highly Homo sapiens
     thymus   moderately Homo sapiens
    Nervousbrain   lowly Homo sapiens
    Reproductivefemale systemplacenta  moderately Homo sapiens
     female systemovary  moderately Homo sapiens
     male systemtestis  highly Homo sapiens
     male systemprostate  lowly Homo sapiens
    Respiratorylung   lowly Homo sapiens
    Urinarykidney   lowly Homo sapiens
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    Muscularstriatum  highly Homo sapiens
    SystemCellPubmedSpeciesStageRna symbol
    Blood/Hematopoieticleukocyte Homo sapiens
    cell lineage
    cell lines
    at STAGE
  • a C terminal kinase domain
  • a JH2 pseudokinase domain tandemly linked to the N site of the former and seven JAK homology (JH), and functioning as a negative regulator and is presumed to be a catalytically inactive pseudokinase
  • N terminus region (JH6, JH7) critical for receptor binding domains
  • two phosphotransferase domains
  • one SH2 domain
  • a FERM domain and a kinase domain binding to CDKN1B
    interspecies ortholog to Jak2, Mus musculus
    ortholog to Jak2, Rattus norvegicus
    ortholog to JAK2, Pan troglodytes
    ortholog to jak2b, Danio rerio
  • protein kinase superfamily
  • Tyr protein kinase family
  • JAK subfamily
  • CATEGORY enzyme
    SUBCELLULAR LOCALIZATION     plasma membrane
    basic FUNCTION
  • cytokine receptor signaling pathways, playing pivotal functions for signal transduction from hematopoietic cytokine receptors
  • involved in GH induced activation of the GH receptor
  • involved in c-Myc protein induction by Bcr-Abl (
  • required in definitive erythropoiesis and has a nonredundant role in the function of a specific group of cytokines receptors (
  • mediating an increase of c-MYC RNA expression by BCR-ABL but also interfering with proteasome-dependent degradation of c-Myc protein
  • stimulates homologous recombination and genetic instability, and a single mutation can give rise to different myeloproliferative disorders
  • regulates BCR-ABL signaling in chronic myeloid leukemia
  • essential role signaling in GnRH neurons for normal reproductive development and fertility (
  • could enhance SLC5A1 protein abundance by influencing transcription of SLC5A1 or a regulator thereof
  • enhances the SLC5A1 protein abundance in the cell membrane and thus stimulates electrogenic glucose uptake by this carrier
  • may modify SLC5A1 activity by direct interaction with the carrier or by phosphorylating other signaling molecules regulating SLC5A1
  • up-regulates SLC6A19 activity which may foster amino acid uptake into JAK2 expressing cells
  • could enhance SLC6A19 protein abundance by either accelerating carrier insertion into the cell membrane or delaying the carrier retrieval from the cell membrane
  • JAK2 is a critical factor that stabilizes IFNGR2 surface expression in Th17 cells from active multiple sclerosis (AMS) patients, making them sensitive to IFNG
  • EPOR and/or JAK2 deliver signals crucial to EPO-dependent proliferation, differentiation, and cell survival
  • contributes to the regulation of phosphate transporter SLC34A1
  • is a powerful stimulator of the Na+, coupled phosphate transporter SLC34A1
    signaling signal transduction
    a component
    small molecule nucleotide,
  • ATP
  • protein
  • IFN-gamma (
  • IFN-gamma receptor, IFN-gamma R (
  • synaptophysin, Syp (
  • AT1 receptor (
  • beta c chain of the GM-CSF receptor (
  • erythropoietin receptor, EPOR (
  • c-kit proto-oncogene (
  • PP2A, P13K, and Yes (
  • interleukin-12 receptor subunits beta1 and beta2 (
  • signal transducer and activator of transcription 5, STAT5 (
  • SHC (Src homology 2 domain containing) transforming protein, Shc (
  • signal transducer and activator of transcription 3, STAT3 (
  • SH2-Bbeta (
  • midkine-receptor (
  • tec protein tyrosine kinase, TEC (
  • insulin receptor, IR and the insulin-like growth factor-1 receptor, IGF1 (
  • tumor necrosis factor receptor 1, TNFR1 (
  • interleukin-5 (IL-5) receptor alpha and betac (
  • p125 focal adhesion kinase, FAK (
  • growth factor receptor-bound protein 10, Grb10 (
  • interleukin-12 receptor beta 2, IL-12R beta 2 (
  • cytokine-inducible SH2 protein 3, CIS3 (
  • growth hormone receptor, GHR (
  • chemokine (C-X-C motif) receptor 4, CXCR4 (
  • Skb1 and Hsl7p (
  • SH2-Containing protein tyrosine phosphatase-1, SHP-1 (
  • thyroid stimulating hormone receptor, TSHR (
  • SIRPalpha (
  • box 1-like motif in the cytoplasmic tail of CTLA-4 molecule (
  • cytokine receptor-like molecule 2, CRLM-2 (
  • signal transducing adaptor molecule (SH3 domain and ITAM motif) 1, STAM1 and signal transducing adaptor molecule (SH3 domain and ITAM motif) 2, STAM2 (
  • hTid-1(S) or hTid-1(L) (
  • protein tyrosine phosphatase, non-receptor type 1B, PTP1B (
  • protein tyrosine phosphatase-PEST, PTP-PEST (
  • G protein-coupled AngII type 1, AT(1) and protein tyrosine kinase 2 beta, PYK2B (
  • v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, neuro/glioblastoma derived oncogene homolog (avian), ERBB2 (
  • suppressor of cytokine signaling 1, SOCS1 (
  • Hes1 and Hes5 (
  • FABP4 in a fatty acid-dependent manner
  • beta subunit of IFNgamma receptor and PKCepsilon
  • VHL is a SOCS1-cooperative negative regulator of JAK2
  • oncogenic LCK and JAK2 may utilize different mechanisms to upregulate LMO2 levels during oncogenic transformation
  • is a novel regulator of the GABA transporter SLC6A12 (the kinase up-regulates the carrier presumably by enhancing the insertion of carrier protein into the cell membrane)
  • JAK2 is a mediator of FIP1L1-PDGFRA-induced eosinophil growth and function in chronic eosinophilic leukemia (CEL) (pMID: 22523564)
  • JAK2 down-regulates CLCN2 activity and thus counteracts Cl(-) exit, an effect which may impact on cell volume regulation
  • contributes to the regulation of the inositol transporter (SLC5A3)
  • may similarly contribute to the stimulating effect of Angiotensin II on Na+ coupled phosphate transport and insertion of SLC34A1 protein into the proximal renal tubular brush border membrane
  • CCDC80 is a JAK2-binding partner
  • JAK2 tyrosine kinase phosphorylates and is negatively regulated by centrosomal protein NIN
  • NK cell activation and secretion of IFNG1 results in activation of JAK1, JAK2 and STAT1 in tumor cells, resulting in rapid up-regulation of CD274 expression
  • SOCS1 negatively regulates IFNG1 signaling pathway (and other pathways) by directly inhibiting JAK1, JAK2
  • cell & other
    activated by cytokine receptors
    monocyte chemotactic protein SCYA2 (MCP)
    BRCA1 (
    IL-13 in colon carcinoma cell lines (
    Other regulated by phosphorylation of tyrosine residues in the putative activation loop of the kinase domains
    corresponding disease(s) PRV , MPD
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    tumoral   translocation    
    in acute lymphoblastic leukemia
    tumoral fusion     gain of function
    in leukemia or constitutively expressed in acute lymphoblastic leukemia with t(9;12) (p24;p13) and a chimeric fusion protein, 5' - ETV6 -JAK2 - 3'
    tumoral fusion      
    BCR-JAK2 fusion, result of a t(9;22)(p24;q11.2) translocation in a chronic myeloid leukemia
    tumoral   translocation    
    t(8;9)(p22;p24), in in atypical chronic myeloid leukaemia with a PCM1-JAK2 fusion
    tumoral fusion      
    with RPN1, in t(3;9)(q21;p24) in a patient with chronic idiopathic myelofibrosis (CIMF), a chronic myeloproliferative disorder
    constitutional germinal mutation      
    V617F mutation is associated with thrombosis and pregnancy loss
    tumoral fusion      
    with SSBP2 in a t(5;9)(q14.1;p24.1) in pre-B acute lymphocytic leukemia
    tumoral   amplification    
    V617F activating mutation in addition to KIT and FLT3 mutations is associated with clinical outcome in patients with t(8;21)(q22;q22) acute myeloid leukemia
    tumoral somatic mutation      
    somatic activating mutation in 18p 100 of Down syndrome acute lymphoblastic leukaemia
    tumoral somatic mutation      
    in pediatric acute lymphoblastic leukemia
    tumoral   translocation    
    t(4;9)(q21;p24) leading to a novel SEC31A-JAK2 fusion, in classical Hodgkin lymphoma
    constitutional       loss of function
    JAK2 deficiency leaves NK cell numbers and maturation unaltered
    Susceptibility to Budd-Chiari syndrome and portal vein thrombosis
    Variant & Polymorphism other
  • JAK2 46/1 haplotype associated with Budd-Chiari syndrome and portal vein thrombosis
  • Candidate gene
    Therapy target
  • a possible therapeutic target for compounds with anti-tyrosine kinase activity
  • inhibition of JAK signaling is a logical target for therapeutic intervention in JAK mutated ALL
  • inhibition of CRLF2/JAK2 signaling may represent a therapeutic approach for high-risk B-ALL patients )
  • SystemTypeDisorderPubmed
    JAK2-targeted therapy in individuals with Chuvash polycythemia
  • Jak2-deficient mice are lethal at embryonic stage due to the absence of definitive erythropoiesis (
  • Jak2-/- mouse embryos are anemic and die around day 12.5 postcoitum because of absence of definitive erythropoiesis (
  • GnRH neuron-specific Jak2 conditional knock-out mice display reduced GnRH mRNA levels, reduced secretion of GnRH and basal serum luteinizing hormone (LH) levels are ignificantly lower in female. Female Jak2 G(-/-) mice exhibit significantly delayed puberty and first estrus, abnormal estrous cyclicity, and impaired fertility (