Complement component C3a receptor (C3aR)

Complement component C3a receptor is a seven-transmembrane G protein-coupled receptor specifically recognizing the C3a anaphylatoxin, a cleavage product of complement component C3[1][2]. Upon binding to C3a, C3aR activates intracellular signaling cascades that mediate pro-inflammatory, chemotactic, and immune-regulatory effects on granulocytes, monocytes, mast cells, activated lymphocytes, and nervous tissue[1][2][4]. C3aR plays a central role in innate and adaptive immunity, balancing inflammation and immune suppression, and is implicated in host defense, tissue homeostasis, and multiple disease processes[1][3][4]. Structural studies have elucidated both active and inactive conformations of C3aR, guiding the development of targeted small-molecule therapeutics like JR14a[2]. Its activity is tightly regulated and linked to receptor internalization and phosphorylation status, underscoring the therapeutic complexity and importance of this target in complement-mediated immune modulation[2][4].

Other names

C3a receptorC3aRComplement component 3a receptor

Agonism: Activation of C3aR signaling, leading to immune cell activation, chemotaxis, and inflammatory mediator release. Antagonism: Inhibition of C3aR activity to reduce inflammatory signaling (important for the management of complement-mediated inflammatory diseases).