protein_function: High-affinity receptor for interleukin-15. Can signalboth in cis and trans where IL15R from one subset of cellspresents IL15 to neighboring IL2RG-expressing cells. Signaltransduction involves SYK (By similarity)..
Interleukin 15 receptor, alpha subunit is a subunit of the interleukin 15 receptor which is encoded by the gene IL15RA in humans. The human IL15RA gene was mapped to chromosome 10p15-p14 by FISH and the mouse Il15ra gene was mapped to chromosome 2. The cytoplasmic domain of IL15R-alpha, like that of IL2R-alpha, was dispensable for mitogenic signaling, suggesting that the primary role of the alpha chains is to confer high-affinity binding. At high concentrations, IL15, like IL2, was able to signal through a complex of IL2R-beta and -gamma in the absence of the alpha subunit. The soluble receptor displayed high affinity for IL15 and inhibited both binding of IL15 to the membrane receptor and IL15-induced cell proliferation.