Coimmunoprecipitation studies show that SHC transforming protein 1 (SHC1) associates with Interleukin-2 receptor subunit beta (IL2RB) as part of Interleukin-2 (IL2) receptor complex (Gadina et al. 2000). Similar binding in the IL15 receptor complex can be inferred from IL15 stimulates SHC1 phosphorylation (Zambricki et al. 2005). 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). IL-15 helps in B cell proliferation via two pathways: IL15–STAT5 and IL15–SHC–Ras–Raf–ERK pathway (Patidar et al. 2016).
This is a black box event because there is no direct evidence of SHC1 binding after IL15 stimulation.