Receptor for the chemotactic and inflammatory C3a, C4a and C5a anaphylatoxin peptides and also for their dearginated forms ASP/C3adesArg, C4adesArg and C5adesArg respectively. Couples weakly to G(i)-mediated signaling pathways. Interacts with C3 (the anaphylatoxin peptide C3a and the adipogenic hormone ASP); the interaction occurs with higher affinity for ASP, enhancing the phosphorylation and activation of GPR77, recruitment of ARRB2 to the cell surface and endocytosis of GRP77. Frontal cortex, hippocampus, hypothalamus, pons and liver. Belongs to the G-protein coupled receptor 1 family.