Figure 2.
(A) IRS-1 associates with Bcl-2 and Bcl-XL but not with Bax or Bik. Human Bcl-2, Bcl-XL, Bax, and Bik in the pcDNA3myc vector were cotransfected with IRS-1/pRcCMV in 293 cells. Then lysates were immunoprecipitated (IP) and immunoblotted (WB) with the indicated antibodies. (B) IRS-1 associates with the loop domain of Bcl-2. Upper panel, schematic representation of deletion mutants of Bcl-2. Lower panel, the deletion mutants of Bcl-2, ΔBH4, Δloop, ΔBH3, and ΔBH1-BH2 (ΔBH1–2) in pcDNA3myc vector were cotransfected with IRS-1/pRcCMV in 293 cells. Then lysates were immunoprecipitated and immunoblotted with the indicated antibodies. (C) Bcl-2 associates with the carboxyl half-region of IRS-1. Upper panel, schematic representation of deletion mutants of IRS-1. PH, pleckstrin homology domain; PTB, phosphotyrosine binding domain. Lower panel, the deletion mutants of IRS-1 (C-1, -2, -3, and 4) and IRS-3 tagged with the FLAG sequence in pUC-CAGGS were cotransfected with Bcl-2/pcDNA3myc in 293 cells. Then lysates were immunoprecipitated and immunoblotted with the indicated antibodies.