FIGURE 2.

PDEγ N-terminal peptides PDEγ(1–61)and PDEγ(10–30) abrogate label transfer from PDEγ to RGS9·β5. Experiments were performed as described in Fig. 1. Shown in each panel is one of two similar experiments. Prior to UV photolysis, BBM-PDEγ was incubated with RGS9·β5 and αt-GDP-AlF₄⁻ in the absence (lanes 1, 4, and 7) or presence of PDEγ peptides in a 500 × molar excess over BBM-PDEγ. The following peptides were preincubated in the reactions prior to adding BBM-PDEγ: PDEγ(62–87), lanes 2 and 5; PDEγ(1–61), lanes 3 and 6; PDEγ(10–30), lane 8; PDEγ(15–26), lane 9.