FIGURE 6.

Comparison of signaling profile of wild type, D282A, and S272A mutant C5aR receptors, co-expressed with C5a and metabolite C5a-des-Arg⁷⁴ in yeast. C5a-des-Arg⁷⁴ stimulates only ∼30% of the signaling in wild type C5aR compared with the signaling stimulated in response to C5a. D282A mutant displays reduced signaling in response to C5a consistent with other studies but displays near-maximal signaling in response to metabolite C5a-des-Arg⁷⁴. The nonfunctional mutant S272A neither responds to C5a nor to the metabolite C5a-des-Arg⁷⁴. Vector represents the β-galactosidase activity of the engineered yeast in the absence of both receptor and ligand. Each bar represents means ± S.D. of signaling activity for three independent transformants, and data are representative of at least two independent experiments.