Fig. 8.

Assessment of constitutive activity (IP production) by the E90K mutation in the presence of combinations of the rat-motif in the human sequence (L112F, Q208E, L300V, and D302E), S217G, and deletion of residue Lys¹⁹¹. Mutants K191A and K191E are shown in the inset. COS-7 cells were transiently transfected with 100 ng of cDNA as described under Materials and Methods. IP production was measured in response to media alone (no agonist added). The dashed horizontal line shows basal level of vector only. In all figures, Means ± S.E.M.s are shown for least three independent experiments, each performed in replicates of four.