complement component 4A (Rodgers blood group)

Symbol

C4A (may also be known as: None)

Organism

Human

Description

This gene encodes the acidic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain may be cleaved to release C4 anaphylatoxin, a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2011]

Links to external resources

Changes associated with this gene

Identifier Name Type Tissues Organism Gene Data Actions
DAA2146 complement component 4A increases with age Molecular temporal lobe Human C4A 115.3% Increase Gene Expression Level
DAA2148 complement component 4A increases with age Molecular hippocampus Human C4A 226.3% Increase Gene Expression Level
DAA2149 complement component 4A increases with age Molecular hippocampus Human C4A 216.4% Increase Gene Expression Level
DAA2151 complement component 4A increases with age Molecular parietal lobe Human C4A 153.8% Increase Gene Expression Level
DAA2153 complement component 4A increases with age Molecular frontal lobe Human C4A 187.3% Increase Gene Expression Level

GO Terms

GO IDGO TermGO Category
GO:0006954 inflammatory response biological_process
GO:0006956 complement activation biological_process
GO:0006958 complement activation, classical pathway biological_process
GO:0045087 innate immune response biological_process
GO:0005576 extracellular region cellular_component
GO:0005615 extracellular space cellular_component
GO:0004866 endopeptidase inhibitor activity molecular_function