Figure 4.

The role of Src-kinase interactions of Tip for SRF activation. (A) Jurkat T cells were transiently transfected with expression plasmids coding for wild-type Tip or its mutants TipΔCSKH, TipmSH3B, TipΔCSKHmSH3, TipY114F, TipY127F and TipY155F. Empty vector (pEF1) served as negative control. Activation of cotransfected p3D.A-Luc displayed as mean values and standard deviation of three independent experiments. Statistical significance, p > 0.05 (ns); p < 0.05 (*). (B) Expression control for Tip and its mutants in total lysates obtained from the cells described in (A). (C) Vector and Tip constructs were cotransfected with p3D.A-Luc into Jurkat T cells, and SFK activity was blocked by PP2 treatment (10 μM) for 40 h. The graph summarizes the reporter activities of six independent experiments. Statistical significance, p > 0.05 (ns); p < 0.001 (***). (D) Total cellular protein tyrosine phosphorylation (pY) and Tip expression in the cells described in (C). Detection of Hsp90α/β served as a loading control