Complement pathway regulator

Complement pathway regulators comprise a heterogeneous group of proteins—including both soluble and membrane-bound forms—that tightly control the activation, amplification, and resolution of the complement cascade, a crucial component of innate immunity[3][4][6][8]. These regulators prevent damage to host tissues while allowing effective defense against pathogens. Major members include Factor H (soluble inhibitor of the alternative pathway), Factor I (a serine protease that inactivates C3b and C4b), Decay-accelerating factor (CD55), Membrane cofactor protein (CD46), Complement receptor 1 (CD35), and CD59 (which inhibits the membrane attack complex)[3][4][6][7][8]. Complement dysregulation is implicated in a spectrum of diseases—autoimmune, inflammatory, infectious, degenerative, and neoplastic—making these regulators, as a group, both biomarkers and emerging therapeutic targets. Therapies may target the regulators themselves or the balance they keep in the complement cascade, but individual targeting is complex due to their diversity and essential roles in homeostasis[8][3][4].

Other names

Complement regulatory proteinComplement regulatorComplement control proteinCRP (should not be confused with C-reactive protein)Factor HProperdinFactor IDecay-accelerating factor (DAF/CD55)Membrane cofactor protein (MCP/CD46)Complement receptor 1 (CR1/CD35)CD59C1-inhibitorC4b-binding protein

Inhibition of complement activation (by blocking or mimicking complement regulators), Enhancement of regulatory protein activity (rare), Decay-acceleration, Cofactor-mediated proteolytic inactivation, Blockade of membrane attack complex formation