FIGURE 6.

MrgX2 is resistant to agonist-induced phosphorylation. A, sequence comparisons of the C termini of C3aR and MrgX2 is shown. B and C, HEK-293T cells transiently expressing HA-C3aR or HA-MrgX2 were incubated with anti-HA antibody followed by PE-conjugated anti-mouse IgG. Representative histograms of expression levels of C3aR (B) and MrgX2 (C) (thick bold lines) in receptor-transfected and mock-transfected cells (dotted lines) are shown. D, HEK-293T cells expressing C3aR were labeled with ³²P and stimulated with C3a (100 nm), and C3aR phosphorylation was determined. Similarly, cells expressing MrgX2 were stimulated with CST (100 nm) or LL-37 (10 μm) for 5 min, and receptor phosphorylation was determined. An autoradiograph from a 3-h exposure is shown. Data shown are representative of three independent experiments.