The function of C5AR1 (complement C5a receptor 1, Ensembl gene identifier ENSG00000197405) is as follows. Receptor for the chemotactic and inflammatory peptide anaphylatoxin C5a, stimulating chemotaxis, granule enzyme release, intracellular calcium release and superoxide anion production (PubMed:10636859, PubMed:15153520, PubMed:1847994, PubMed:29300009, PubMed:36806352, PubMed:7622471, PubMed:8182049, PubMed:9553099). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase (PubMed:36806352, PubMed:37852260). C5AR1 is coupled to G(i)/G(o) (GNAI1 or GNAO1) G alpha proteins and mediates inhibition of adenylate cyclase (PubMed:36806352, PubMed:37852260). The ligand interacts with at least two sites on the receptor: a high-affinity site on the extracellular N-terminus, and a second site in the transmembrane region which activates downstream signaling events (PubMed:7622471, PubMed:8182049, PubMed:9553099). {ECO:0000269|PubMed:10636859, ECO:0000269|PubMed:15153520, ECO:0000269|PubMed:1847994, ECO:0000269|PubMed:29300009, ECO:0000269|PubMed:36806352, ECO:0000269|PubMed:37852260, ECO:0000269|PubMed:7622471, ECO:0000269|PubMed:8182049, ECO:0000269|PubMed:9553099}.