Summary
Performance
Immunogen
Application
Background
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. A deficiency in 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 C-chain polypeptide of human complement subcomponent C1q. Alternatively spliced transcript variants that encode the same protein have been found for this gene. [provided by RefSeq, Jul 2008],disease:Defects in C1QC are a cause of C1q deficiency [MIM:120575]. It is a rare genetic disorder which is associated with recurrent infections and a high prevalence of lupus erythematosus-like symptoms. It is characterized by a loss of activation of the complement classical pathway.,function: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.,online information:C1QC mutation db,PTM:O-linked glycans consist of Glc-Gal disaccharides bound to the oxygen atom of post-translationally added hydroxyl groups.,similarity:Contains 1 C1q domain.,similarity:Contains 1 collagen-like domain.,subunit:C1 is a calcium-dependent trimolecular complex of C1q, R and S in the molar ration of 1:2:2. C1q subcomponent is composed of nine subunits, six of which are disulfide-linked dimers of the A and B chains, and three of which are disulfide-linked dimers of the C chain.,
Research Area
Complement and coagulation cascades;Prion diseases;Systemic lupus erythematosus;
