Denigma: Factor

C4B

Symbol: C4B
Name: complement component 4B (Chido blood group)
Alias: CH; C4F; CO4; C4B1; C4B2; C4B3; C4B5; C4BD; C4B12; C4B_2; CPAMD3
Entrez gene ID: 721
Ensembl gene ID: ENSG00000224389
Species: Human (Taxid: 9606)

Function:
This gene encodes the basic 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. 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. In addition, this gene exists as a long form and a short form due to the presence or absence of a 6.4 kb endogenous HERV-K retrovirus in intron 9. [provided by RefSeq, Jul 2008]

Observation:

Genetic variations in C4B are not associated with longevity in Italian [10219002].

Assays: Organismal Lifespan

Longevity Associated Variants:

C4B2 None [10219002]

Classification:

No Age Effect

Type:

Gene

Protein coding

References:

10219002: C4, BF, C3 allele distribution and complement activity in healthy aged people and centenarians.

Aging Relevance Analysis/Source:

GenAge