Signal transducer and activator of transcription 3 (STAT3) is believed to bind the Interleukin-22 (IL22) receptor complex, which consists of IL22, phosphorylated Interleukin-22 receptor subunit alpha-1 (IL22RA1), phosphorylated Tyrosine-protein kinase JAK1 (JAK1), Interleukin-10 receptor subunit beta (IL10RB), phosphorylated Non-receptor tyrosine-protein kinase TYK2 (TYK2) and Tyrosine-protein phosphatase non-receptor type 11 (PTPN11 or SHP2) (Meng et al. 2010, Sestito et al. 2011). STAT3 has been reported to pre-associate with IL22RA in the absence of phosphorylated receptor tyrosines (Dumoutier et al. 2009).
This is a black box event because STAT3 binding is represented here as a post-receptor phosphorylation event, inferred from the consensus on interleukin receptor JAK-STAT signaling (Li et al. 2008, Santos et al. 2011).