sentences:  Binding of IFN-γ to IFNGR1 induces the rapid dimerization of IFNGR1 chains, thereby forming a site that is recognized by the extracellular domain of IFNGR2.The ligand-induced assembly of the complete receptor complex contains two IFNGR1 and two IFNGR2 subunits, which bring into close juxtaposition the intracellular domains of these proteins together with the inactive Jak1 and Jak2 kinases that they associate with.In this complex, Jak1 and Jak2 transactivate one another and then phosphorylate IFNGR1, thereby forming a paired set of Stat1 docking sites on the ligated receptor.