FIGURE 9.

Stimulation of cAMP production in LGR7- and LGR8-expressing cells by mutant peptides with residue substitution at the Lys^A17 position. A, stimulation of cAMP production in LGR7- and LGR8-expressing cells by K^A17A, K^A17G, K^A17D, and K^A17Q mutants. Unlike the K^A17A peptide, mutants with an aspartic acid, glycine, or glutamine at the Lys^A17 position did not exhibit an enhanced LGR8-activation activity. Each data point represents the mean ± S.E. of quadruplicate samples. B, LGR7- and LGR8-binding activities of K^A17A, K^A17G, K^A17D, and K^A17Q mutants. Each data point represents the mean ± S.E. of triplicate samples.