CD46
Description
The CD46 (CD46 molecule) is a protein-coding gene located on chromosome 1.
CD46, also known as Membrane Cofactor Protein (MCP) and cluster of differentiation 46 (CD46), is a protein encoded by the CD46 gene in humans. It is a crucial part of the complement system, acting as an inhibitory complement receptor. CD46 is a type I membrane protein and has cofactor activity for the inactivation of complement components C3b and C4b through cleavage by serum factor I. This protects host cells from damage by the complement system. CD46 may also play a role in the fusion of sperm and egg during fertilization.
CD46 serves as a receptor for several pathogens, including the Edmonston strain of measles virus, human herpesvirus-6 (HHV-6), group B adenoviruses, and type IV pili of pathogenic Neisseria. Its extracellular region contains four short consensus repeats (SCR) that are believed to linearize upon binding to HHV-6, as seen with other ligands.
CD46 acts as a cofactor for complement factor I, a serine protease that protects cells from damage by the complement system. It does this by cleaving C3b and C4b, components of the complement system that are deposited on host tissue. CD46 may also be involved in the fusion of sperm and egg during fertilization. Additionally, CD46 acts as a costimulatory factor for T-cells, inducing the differentiation of CD4+ T-cells into T-regulatory 1 cells. These T-regulatory 1 cells suppress immune responses by secreting interleukin-10, which is thought to prevent autoimmunity.
CD46 is also known as AHUS2, MCP, MIC10, TLX, TRA2.10.
