FIG. 2.

Importance of the S and A regions of IL-2Rβ for the association of PI 3-K p85 and Jak1. (A) The S and A regions are required for optimal association of IL-2Rβ and p85. 293 T⁺ cells were cotransfected with plasmids expressing Jak1, p85, and either wild-type (βWT) or mutant forms of IL-2Rβ, immunoprecipitated (IP) with hMikβ1, and then Western blotted with anti-p85. (B) The S and A regions are required for optimal association of IL-2Rβ and Jak1. 293 T⁺ cells were cotransfected with plasmids as for panel A, lysed, and immunoprecipitated with hMikβ1 followed by Western blotting with MAb to Jak1. (C) Lysates of the transfected 293T⁺ cells used for panels A and B were blotted with anti-Jak1 (Transduction Laboratories), anti-p85 (UBI), or anti-IL-2Rβ (Santa Cruz).