FIG. 3.
Muscarinic-M3 receptor activation promotes the nuclear export of GRK5. (A) CHO-M3MR cells were transfected with GRK5 and treated with ACh for the indicated times (min). M3MR and GRK5 in coexpressing cells were visualized by immunofluorescence. Asterisks indicate cotransfected cells. Scale bars, 10 μM. (B) CHO-M3MR cells were transfected with GRK5 (a to f), GRK5, and CaMBP/n (g, h, and i) or GRK5ΔNTPB (j and k). Transfected cells were subsequently left untreated (Control) or treated with ACh for 5 min, and GRK5 and M3MR were detected as previously described. Where indicated (U73122), cells were pretreated with 1 μM U73122 for 1 h prior to agonist treatment. Asterisks indicate cotransfected cells. Scale bars, 10 μm.