Anti-Complement Receptor C5aR Antibody, clone 20/70 clone 20/70, from rat

C5a anaphylatoxin chemotactic receptor 1 (UniProt: P30993; also known as C5a anaphylatoxin chemotactic receptor, C5a-R, C5aR, CD88) is encoded by the C5ar1 (also known as C5ar, C5r1) gene (Gene ID: 12273) in murine species. C5aR is a multi-pass membrane protein of the G-protein coupled receptor 1 family that serves as a receptor for the chemotactic and inflammatory peptide anaphylatoxin C5a. 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. Receptor activation stimulates chemotaxis, granule enzyme release, intracellular calcium release, and superoxide anion production. C5aR is a homodimer, but can also form higher-order oligomers. C5aR becomes phosphorylated on serine residues in response to C5a binding that results in internalization of the receptor and short-term desensitization to C5a. The phosphorylated receptor is known to Interact with arrestin beta 1 and 2 (ARRB1 and 2) and this interaction is associated with internalization of C5aR. Sulfation is also reported to play a critical role in the association of C5aR with C5a, but it does not alter the ability of the receptor to transduce a signal and mobilize calcium in response to a small peptide agonist.