Figure 3.

PhLP phosphorylation at serines 18–20 is required for Gβγ dimer assembly. (A) HEK-293 cells were transiently transfected with PhLP-myc, PhLP S18-20A or empty vector as indicated along with Gβ₁ and HA-Gγ₂ and then assayed after 48 h. Levels of overexpressed Gβ_lγ₂ dimer were determined by immunoprecipitation as in Figure 2A. Bars represent the average±s.e. from six separate experiments (^*P<0.01, ^**P<0.001). (B) The rate of nascent Gβ_lγ₂ dimer formation was determined by a pulse–chase assay as in Figure 2B. Symbols represent the average±s.e. from three separate experiments.