Complement component 8 gamma chain (C8G)

Complement component 8 gamma chain (C8G) is a 202-amino acid, 22 kDa protein of the lipocalin family and forms one of the three subunits of complement component 8 (C8), participating in the formation of the cytolytic membrane attack complex (MAC) of the complement system[1][3][4]. C8G forms a disulfide bond with C8 alpha and is distinct in structure and function from the alpha and beta subunits, serving as the only lipocalin in the complement system[1][2][3]. It binds small hydrophobic ligands (e.g., retinol, fatty acids), and although not essential for MAC-mediated cell lysis, C8G modulates MAC assembly efficiency and may be involved in ligand transport in plasma[4]. In addition, C8G is expressed by astrocytes in the brain, acting as an endogenous inhibitor of neuroinflammation and contributing to blood-brain barrier integrity through modulation of the S1P-S1PR2 pathway[1][6]. Mutations can cause complement deficiency-associated immunodeficiency and other disease susceptibilities[1][3]. Currently, C8G is not a therapeutic target and no approved drugs specifically target it directly.

Other names

Complement C8 gamma chainComplement component 8, gamma polypeptideC8 gammaC8CComplement component C8 gamma chainComplement component 8 gamma polypeptide

Not directly applicable, as no drugs are known to target C8G specifically