Binding of IL-10 leads to activation of the receptor-associated Janus tyrosine kinases, JAK1 and TYK2 (Finbloom & Winestock 1995), leading to phosphorylation of IL10RA at two conserved intracellular tyrosine residues (Y446 and Y496) that serve as docking sites for STAT molecules (Ho et al. 1995, Weber-Nordt et al. 1996).
The details of receptor phosphorylation are unclear. Most descriptions of IL10 receptor tyrosine phosphorylation (Donnelly et al. 1999, Carey et al. 2012) suggest that JAK1 and TYK2 are responsible for IL10RA phosphorylation but it is not clear whether one or both kinases are responsible for phosphorylating IL10RA.