FIGURE 6.

IP responses of wild-type and Phe^178(4.64) mutant receptors. GnRH I- (A), GnRH II- (B), and [Phe³]GnRH I (C)-stimulated IP responses of Phe^178(4.64) receptors mutated to Ala ▴, Leu ●, or Trp ⧫ compared with wild-type receptors ■. COS-7 cells were transiently transfected with the wild-type or mutant receptors, and IP accumulation was measured after stimulation with GnRH ligands for 60 min. Results are representative experiments repeated at least three times with essentially the same results. Points are mean ± S.E. of triplicate measurements.