complement component 4A (Rodgers blood group)
Symbol
Organism
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 |
---|---|---|---|---|---|---|---|
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 | |
DAA2146 | complement component 4A increases with age | Molecular | temporal lobe | Human | C4A | 115.3% 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 ID | GO Term | GO 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 | |