IL-4 binds to a cell surface receptor complex that consists of the IL-4-binding protein (IL-4Rα) and the γ chain of the IL-2 receptor complex (γc). The receptors for IL-4 and IL-2 have several features in common; both use the γc as a receptor component, and both activate the Janus kinases JAK-1 and JAK-3. In spite of these similarities, IL-4 evokes specific responses, including the tyrosine phosphorylation of 4PS/IRS-2 and the induction of CD23. To determine whether sequences within the cytoplasmic domain of the IL-4Rα specify these IL-4-specific responses, we transplanted the insulin IL-4 receptor motif (I4R motif) of the huIL-4Rα to the cytoplasmic domain of a truncated IL-2Rβ. In addition, we transplanted a region that contains peptide sequences shown to block Stat6 binding to DNA. We analyzed the ability of cells expressing these IL-2R-IL-4R chimeric constructs to respond to IL-2. We found that IL-4 function could be transplanted to the IL-2 receptor by these regions and that proliferative and differentiative functions can be induced by different receptor sequences.
Wang, H. Y., Paul, W. E., & Keegan, A. D. (1996). IL-4 function can be transferred to the IL-2 receptor by tyrosine containing sequences found in the IL-4 receptor α chain. Immunity, 4(2), 113–121. https://doi.org/10.1016/S1074-7613(00)80676-7