Grb2 associated binding protein 2 (Gab2) is phosphorylated in response to Interleukin-2 (Il2) and Interleukin-15 (Il15) stimulation. Its phosphorylation is greatly diminished by mutation of the site in the Interleukin-2 Receptor beta chain (Y338F) (Il2rb, Il2rβ) that recruits SHC transforming protein 1 (Shc1) (Gadina et al. 2000, Wöhrle et al. 2009, Gesbert et al. 1998, Brockdorff et al. 2001). The Il15 receptor complex consists mainly of Il15, Interleukin-15 receptor alpha subunit (Il15ra, Il15rα), IL2rb, which is associated with Jak1 and Interleukin receptor 2 gamma subunit, which is associated with Jak3 (Johnston et al. 1995). In this stage, it also includes a phosphorylated molecule of Shc1, a Grb2 and Gab2. This is a black box event because the kinase responsible for Gab2 phosphorylation has not been demonstrated.
More in detail, human and mouse IL15 have 70.2% amino acid sequence similarity and exhibit similar trans-presentation mechanism, signal transduction machinery and biological activities. Similarly, human IL15 shows cross-reactivity with mouse cells and it was demonstrated that human and mouse IL15 showed similar responses in mouse models (Stoklasek et al. 2006) (Patidar et al. data not published).