Signal transducer and activator of transcription that mediates signaling by type I IFNs (IFN-alpha and IFN-beta). Following type I IFN binding to cell surface receptors, Jak kinases (TYK2 and JAK1) are activated, leading to tyrosine phosphorylation of STAT1 and STAT2. The phosphorylated STATs dimerize, associate with ISGF3G/IRF-9 to form a complex termed ISGF3 transcription factor, that enters the nucleus. ISGF3 binds to the IFN stimulated response element (ISRE) to activate the transcription of interferon stimulated genes, which drive the cell in an antiviral state.
Specificity
Natural and recombinant Human Signal transducer and activator of transcription 2
Subcellular Location
Cytoplasm Nucleus Translocated into the nucleus upon activation by IFN-alpha/beta.
Interacts with ISGF3G/IRF-9 in the cytoplasm. Heterodimer with STAT1 upon IFN-alpha/beta induced phosphorylation. Interacts with CRSP2 and CRSP6. Interacts with Simian virus 5 protein V and rabies virus phosphoprotein (By similarity). Can form a homodimer upon IFN-alpha induced phosphorylation. Interacts with IFNAR1; the interaction requires the phosphorylation of IFNAR1 at 'Tyr-466'. Interacts with IFNAR2. Interacts with dengue virus NS5; this interaction inhibits the phosphorylation of STAT2, and, when all viral proteins are present (polyprotein), targets STAT2 for degradation.