FIGURE 7.

Mutational analysis of the effector interface between Gα₁₃ and p115 RH. A, the T274A and T274S mutations in Gα₁₃ fail to impair Rho activation in cells. HeLa cells were transiently transfected with empty vector or the indicated Gα₁₃ QL construct. The luciferase activity of cell lysates was determined as described under “Experimental Procedures.” Total cell lysate was immunoblotted for either Gα₁₃ or GAPDH. Data are presented as the mean ± S.E. (error bars) of triplicate determinations from a single experiment, representative of three independent experiments with similar results. Data were analyzed by one-way analysis of variance followed by Dunnett's post-test. Statistically significant difference from Gα₁₃ QL is shown as follows. **, p < 0.01; ***, p < 0.001. B, the E273K and R279E mutations in Gα₁₃ impair Rho activation in cells. Assays were performed as in A. Statistically significant difference from Gα₁₃ QL is shown as follows. **, p < 0.01.