Tyrosine-protein kinase JAK1(JAK1) and Tyrosine-protein kinase JAK3 (JAK3) are believed to be phosphorylated after stimulation of the Interleukin-15 receptor complex by Interleukin-15 (IL15) (Johnston et al. 1995), though it has been reported that only JAK3 phosphorylation increases in response to IL15 (Krolopp et al. 2016). The Interleukin-15 receptor complex consists of IL15, Interleukin-15 receptor alpha subunit (IL15RA, IL15Rα), Interleukin-2 receptor beta subunit (IL2RB, IL2Rβ), which is associated with JAK1 and Interleukin receptor gamma subunit, which is associated with JAK3 (Johnston et al. 1995). This is a black box event since the mechanism by which IL15 promotes JAK phosphorylation is unclear.
transmembrane receptor protein tyrosine kinase activity of IL15RA:IL15:IL2RB:JAK1:IL2RG:JAK3 [plasma membrane]