MAPK3 and infection: As shown in Fig. 5A, R. australis-infected BMMs treated with anaphylatoxins demonstrate greater ERK1/2 phosphorylation after 10 min of infection than mock-treated R. australis-infected BMMs, suggesting that anaphylatoxin agonism of anaphylatoxin receptors induces rapid signal transduction resulting in the phosphorylation of ERK1/2.