Complement C3a receptor 1 (C3aR1)

Complement C3a receptor 1 (C3aR1) is a member of the G protein-coupled receptor (GPCR) family, specifically class A, and serves as the primary receptor for the complement anaphylatoxin C3a[1][2][3]. It is expressed on a range of immune and non-immune cell types, including macrophages, mast cells, endothelial cells, and adipocytes[3]. C3aR1 mediates both pro-inflammatory and anti-inflammatory responses through several signaling pathways, predominantly coupling to Gi/o/z G proteins and recruiting β-arrestins. These actions regulate chemotaxis, mast cell degranulation, lipolysis, T cell activation, angiogenesis, and macrophage activation, thereby playing a critical role in immune and inflammatory processes[1][3]. C3aR1 is implicated in a broad array of diseases including inflammatory, metabolic, neurodegenerative, and neoplastic conditions. Pharmacologically, C3aR1 can be targeted by small-molecule agonists (e.g., JR14a) and dual agonist/antagonists (e.g., SB290157), although its high basal activity and signal bias present challenges for drug development[2][3].

Other names

C3a anaphylatoxin chemotactic receptorC3aRAZ3BC3R1HNFAG09C3a-Rcomplement component 3a receptor 1complement component 3 receptor 1C3AR

Agonists or antagonists bind C3aR1 to modulate pro-inflammatory and chemotactic signaling[2][3] Modulation of G protein-dependent (Gi/o/z family) and β-arrestin-dependent pathways, affecting downstream cellular responses[3]