FIGURE 5.

Increased recruitment of P-TEFb to Tat·RNAPII complex by Tip110. 293T cells were transfected with pLTR-Luc, pTat.Myc, and/or pTip110.HA or ΔNT mutant (marked by an asterisk) plasmids as indicated. pcDNA3 was added to equalize the total amounts of plasmid DNA transfected. WCE were prepared from the transfected cells and directly analyzed by Western blot analysis with α-Tip110, α-Myc, α-CycT1, α-CDK9, or α-β-actin antibody (A); immunoprecipitated (IP) with α-Myc antibody, followed by Western blot analysis with α-CycT1 and α-Myc antibody (B); or immunoprecipitated with α-CTDa antibody, followed by Western blot analysis with α-CDK9 or α-CTDa antibody (C). Rel, the relative changes of cyclin T1 (B) or CDK9 (C) induced by Tip110 expression over the recruitment of the cyclin T or CDK9 in the cells without exogenous Tip110. D, quantitative data were obtained from multiple independent experiments. Error bars, S.D.