Fig. 6.

Interaction of GPRK1 with PIs. (A) Phospholipid filter binding assay. Purified GST or the indicated fusion proteins were incubated with PIP-Strips, and bound proteins were detected with α-GST antibodies. (B) PIP bead binding assay. Full-length GPRK1 or Gα_q (labeled with ³⁵S-methionine) was incubated with PI(4)P, PI(5)P, PI(4,5)P₂ beads or agarose beads alone (con). The bound probes were eluted, resolved by SDS/PAGE, and exposed to film. (C) Quantification of the bound GPRK1 (from B). The amount of GPRK1 bound to PI(4,5)P₂ beads was set at 100%. SEMs are indicated (n = 3).