C4A

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Complement component 4A (Rodgers blood group)
Protein C4A PDB 1hzf.png
PDB rendering based on 1hzf.
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols C4A ; C4; C4A2; C4A3; C4A4; C4A6; C4AD; C4S; CO4; CPAMD2; RG
External IDs OMIM120810 MGI88228 HomoloGene36030 GeneCards: C4A Gene
RNA expression pattern
PBB GE C4A 208451 s at tn.png
PBB GE C4A 214428 x at tn.png
More reference expression data
Orthologs
Species Human Mouse
Entrez 720 12268
Ensembl ENSG00000206340 ENSMUSG00000073418
UniProt P0C0L4 P01029
RefSeq (mRNA) NM_001252204 NM_009780
RefSeq (protein) NP_001239133 NP_033910
Location (UCSC) Chr 6:
31.95 – 31.97 Mb
Chr 17:
34.73 – 34.74 Mb
PubMed search [1] [2]

Complement C4-A is a protein that in humans is encoded by the C4A gene.[1]

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.[2][3][4][5][6][7] 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.[1]

See also[edit]

References[edit]

  1. ^ a b "Entrez Gene: C4A complement component 4A (Rodgers blood group)". 
  2. ^ Dawkins RL, Uko G, Christiansen FT, Kay PH (1983). "Low C4 concentrations in insulin dependent diabetes mellitus.". Br Med J (Clin Res Ed) 287 (6395): 839. doi:10.1136/bmj.287.6395.839-b. PMC 1549128. PMID 6412852. 
  3. ^ Vergani D, Johnston C, B-Abdullah N, Barnett AH (1983). "Low serum C4 concentrations: an inherited predisposition to insulin dependent diabetes?". Br Med J (Clin Res Ed) 286 (6369): 926–8. doi:10.1136/bmj.286.6369.926. PMC 1547358. PMID 6403137. 
  4. ^ Mijovic CH, Fletcher JA, Bradwell AR, Barnett AH (1987). "Low C4 levels in type 1 (insulin-dependent) diabetes". Diabetologia 30 (10): 824. doi:10.1007/bf00275752. PMID 3428499. 
  5. ^ Thomsen M, Mølvig J, Zerbib A, et al. (1988). "The susceptibility to insulin-dependent diabetes mellitus bis associated with C4 allotypes independently of the association with HLA-DQ alleles in HLA-DR3, 4 heterozygotes". Immunogenetics 28 (5): 320–327. doi:10.1007/BF00364230. PMID 3139557. 
  6. ^ Jenhani F, Bardi R, Gorgi Y, Ayed K, Jeddi M (1992). "C4 polymorphism in multiplex families with insulin dependent diabetes in the Tunisian population: standard C4 typing methods and RFLP analysis.". J Autoimmun 5 (2): 149–60. doi:10.1016/0896-8411(92)90196-w. PMID 1352685. 
  7. ^ Lhotta K, Auinger M, Kronenberg F, Irsigler K, König P (1996). "Polymorphism of complement C4 and susceptibility to IDDM and microvascular complications". Diabetes Care 19 (1): 53–55. doi:10.2337/diacare.19.1.53. 

Further reading[edit]