Intracellular events following engagement of interferon gamma with its heterodimeric receptor

All 4 receptor chains (2 IFN-gamma-R1 and 2 IFN-gamma-R2) approximate and form docking sites for JAKs, which are transphosphorylated, leading to recruitment of STAT1 from the cytosol. STAT1 becomes transactivated and phosphorylated. Once phosphorylated, STAT1 homodimerizes and forms GAF. GAF translocates to the nucleus and binds to GAS, initiating transcription of response genes.