No complex formation between Tip110 and P-TEFb.
A, 293T cells were transfected with pTip110.HA (lane 1) or pcDNA3 (lane 2). Whole cell extracts (WCE) were prepared and immunoprecipitated (IP) with α-HA, α-cyclin T1 (CycT1), or α-CDK9 antibody, followed by Western blot analysis (WB) with α-HA, α-CycT1, or α-CDK9 antibody. B, WCE were prepared from 293T cells and immunoprecipitated with α-Tip110 antibody or an isotype-matched IgG, followed by Western blot analysis with α-CycT1, α-CDK9, or α-Tip110 antibody. C, WCE were prepared from 293T cells and immunoprecipitated with α-CycT1 antibody or an isotype-matched IgG, followed by Western blot analysis with α-Tip110 or α-CycT1 antibody. D, WCE were prepared from 293T cells and immunoprecipitated with α-CDK9 antibody or an isotype-matched IgG, followed by Western blot analysis with α-Tip110 or α-CDK9 antibody.