Complement C1qb (C1QB) Antibody – Mouse Polyclonal

This gene encodes a major constituent of the human complement subcomponent C1q. C1q associates with C1r and C1s in order to yield the first component of the serum complement system. Deficiency of C1q has been associated with lupus erythematosus and glomerulonephritis. C1q is composed of 18 polypeptide chains: six A-chains, six B-chains, and six C-chains. Each chain contains a collagen-like region located near the N terminus and a C-terminal globular region. The A-, B-, and C-chains are arranged in the order A-C-B on chromosome 1. This gene encodes the B-chain polypeptide of human complement subcomponent C1q [provided by RefSeq]

C1QB: C1q associates with the proenzymes C1r and C1s to yield C1, the first component of the serum complement system. The collagen-like regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2) proenzyme complex, and efficient activation of C1 takes place on interaction of the globular heads of C1q with the Fc regions of IgG or IgM antibody present in immune complexes. Defects in C1QB are a cause of complement component C1q deficiency (C1QD). A rare defect resulting in C1 deficiency and impaired activation of the complement classical pathway. C1 deficiency generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis.

Protein type: Secreted; Secreted, signal peptide

Chromosomal Location of Human Ortholog: 1p36.12

Cellular Component: collagen; extracellular region; complement component C1 complex

Molecular Function: protein binding; protein homodimerization activity

Biological Process: innate immune response; complement activation, classical pathway; inner ear development; complement activation

Disease: C1q Deficiency