JAK3

The protein encoded by this gene is a member of the Janus kinase (JAK) family of tyrosine kinases involved in cytokine receptor-mediated intracellular signal transduction. It is predominantly expressed in immune cells and transduces a signal in response to its activation via tyrosine phosphorylation by interleukin receptors. Mutations in this gene are associated with autosomal SCID (severe combined immunodeficiency disease).

Janus kinase 3

Non-receptor tyrosine kinase involved in various processes such as cell growth, development, or differentiation. Mediates essential signaling events in both innate and adaptive immunity and plays a crucial role in hematopoiesis during T-cells development. In the cytoplasm, plays a pivotal role in signal transduction via its association with type I receptors sharing the common subunit gamma such as IL2R, IL4R, IL7R, IL9R, IL15R and IL21R. Following ligand binding to cell surface receptors, phosphorylates specific tyrosine residues on the cytoplasmic tails of the receptor, creating docking sites for STATs proteins. Subsequently, phosphorylates the STATs proteins once they are recruited to the receptor. Phosphorylated STATs then form homodimer or heterodimers and translocate to the nucleus to activate gene transcription. For example, upon IL2R activation by IL2, JAK1 and JAK3 molecules bind to IL2R beta (IL2RB) and gamma chain (IL2RG) subunits inducing the tyrosine phosphorylation of both receptor subunits on their cytoplasmic domain. Then, STAT5A AND STAT5B are recruited, phosphorylated and activated by JAK1 and JAK3. Once activated, dimerized STAT5 translocates to the nucleus and promotes the transcription of specific target genes in a cytokine-specific fashion.

Adaptive immune responseIEA:UniProtKB-KW
B cell differentiationISS:BHF-UCL
Cytokine-mediated signaling pathwayManual Assertion Based On ExperimentIBA:GO_Central
Enzyme linked receptor protein signaling pathwayISS:BHF-UCL
Erythrocyte differentiationManual Assertion Based On ExperimentIBA:GO_Central
Growth hormone receptor signaling pathway via JAK-STATManual Assertion Based On ExperimentTAS:UniProtKB
Innate immune responseIEA:UniProtKB-KW
Interleukin-2-mediated signaling pathwayTAS:Reactome
Interleukin-4-mediated signaling pathwayManual Assertion Based On ExperimentIDA:BHF-UCL
Intracellular signal transductionISS:BHF-UCL
Negative regulation of dendritic cell cytokine productionISS:BHF-UCL
Negative regulation of FasL productionISS:BHF-UCL
Negative regulation of interleukin-10 productionISS:BHF-UCL
Negative regulation of interleukin-12 productionISS:BHF-UCL
Negative regulation of T cell activationISS:BHF-UCL
Negative regulation of T-helper 1 cell differentiationISS:BHF-UCL
Negative regulation of thymocyte apoptotic processISS:BHF-UCL
Peptidyl-tyrosine phosphorylationISS:BHF-UCL
Positive regulation of activated T cell proliferationIEA:Ensembl
Positive regulation of calcium ion transportIEA:Ensembl
Positive regulation of cytosolic calcium ion concentrationIEA:Ensembl
Positive regulation of nitric-oxide synthase biosynthetic processIEA:Ensembl
Positive regulation of T cell proliferationManual Assertion Based On ExperimentIBA:GO_Central
Protein phosphorylationManual Assertion Based On ExperimentTAS:ProtInc
Regulation of apoptotic processManual Assertion Based On ExperimentIBA:GO_Central
Regulation of receptor signaling pathway via JAK-STATManual Assertion Based On ExperimentTAS:UniProtKB
Regulation of T cell apoptotic processISS:BHF-UCL
Response to interleukin-15Manual Assertion Based On ExperimentTAS:BHF-UCL
Response to interleukin-2Manual Assertion Based On ExperimentTAS:BHF-UCL
Response to interleukin-4Manual Assertion Based On ExperimentIDA:BHF-UCL
Response to interleukin-9Manual Assertion Based On ExperimentTAS:BHF-UCL
T cell homeostasisISS:BHF-UCL
Tyrosine phosphorylation of STAT proteinManual Assertion Based On ExperimentIBA:GO_Central

Endomembrane system; Cytoplasm

Severe combined immunodeficiency autosomal recessive T-cell-negative/B-cell-positive/NK-cell-negative (T(-)B(+)NK(-) SCID):
A form of severe combined immunodeficiency (SCID), a genetically and clinically heterogeneous group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. Patients present in infancy recurrent, persistent infections by opportunistic organisms. The common characteristic of all types of SCID is absence of T-cell-mediated cellular immunity due to a defect in T-cell development.

Tyrosine phosphorylated in response to IL-2 and IL-4. Dephosphorylation of Tyr-980 and Tyr-981 by PTPN2 negatively regulates cytokine-mediated signaling (Probable).