IL-12R beta 2

IL-12 receptor is a type I cytokine receptor that binds to IL-12. IL-12 receptor is expressed primarily on NK and T cells and consists of beta 1 and beta 2 subunits and is a member of the gp130 cytokine receptor superfamily. IL-12R beta 2 (abbreviated IL-12R2 or IL-12Rβ2) is a subunit of the IL-12 receptor, and IL-12Rβ2 is its human gene name. Co-expression of IL-12Rβ2 protein and IL-12Rβ1 protein can lead to the formation of high-affinity IL-12 binding sites and the reconstitution of IL-12-dependent signaling. Upon IL-12 binding to the IL-12 receptor, the cytoplasmic protein TYK2, which interacts directly with IL-12Rβ1, and JAK2, which interacts with IL-12Rβ2, are tyrosine phosphorylated. Phosphorylated TYK2 and JAK2 are required for subsequent tyrosine phosphorylation and activation of STAT4 that binds to IL-12Rβ2. STAT4 is a transcription factor that subsequently homodimerizes, translocates to the nucleus and binds to its target DNA to activate transcription of IFN-γ and other target genes^[1].
Expression of the IL-12Rβ2 chain is thought to be a key factor in controlling T cell development and function. It plays an important role in Th1 cell differentiation and deletion results in failure of Th1 differentiation and dysfunctional production of Th1 effector molecules. Up-regulation of this gene has been found to be associated with many infectious diseases, such as Crohn's disease and leprosy, which are thought to contribute to the inflammatory response and host defense^[2].

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