Complement component 4B

C4B
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesC4B, C4B1, C4B12, C4B2, C4B3, C4B5, C4BD, C4B_2, C4F, CH, CO4, CPAMD3, Complement component 4B, complement component 4B (Chido blood group), complement C4B (Chido blood group)
External IDsOMIM: 120820; MGI: 88228; HomoloGene: 36030; GeneCards: C4B; OMA:C4B - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001002029

NM_009780

RefSeq (protein)

NP_001239133
NP_009224
NP_001229752

NP_033910

Location (UCSC)Chr 6: 32.01 – 32.04 MbChr 17: 34.95 – 34.96 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Complement component 4B (Chido blood group) is a kind of the Complement component 4 protein that in humans is encoded by the C4B gene.[5]

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 RCCX locus within the major histocompatibility complex (MHC) class III region on chromosome 6.[6][7] 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].[5] Each copy of the gene, due to five adjacent nucleotide substitutions cause four amino acid changes and immunological subfunctionalization,[8] can be of one of two types: C4A and C4B.[9] Each gene contains 41 exons and has a dichotomous size variation between approximately 22 kb and 16 kb, with the longer variant being the result of the integration of the endogenous retrovirus HERV-K(C4) into intron 9.[7]

  1. ^ a b c ENSG00000236625, ENSG00000224389, ENSG00000228454, ENSG00000224639 GRCh38: Ensembl release 89: ENSG00000228267, ENSG00000236625, ENSG00000224389, ENSG00000228454, ENSG00000224639Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000073418Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ a b "Entrez Gene: Complement component 4B (Chido blood group)". Retrieved 2012-01-27.
  6. ^ Zhou D, Rudnicki M, Chua GT, Lawrance SK, Zhou B, Drew JL, Barbar-Smiley F, Armstrong TK, Hilt ME, Birmingham DJ, Passler W, Auletta JJ, Bowden SA, Hoffman RP, Wu YL, Jarjour WN, Mok CC, Ardoin SP, Lau YL, Yu CY (2021). "Human Complement C4B Allotypes and Deficiencies in Selected Cases With Autoimmune Diseases". Front Immunol. 12: 739430. doi:10.3389/fimmu.2021.739430. PMC 8577214. PMID 34764957.
  7. ^ a b Carrozza C, Foca L, De Paolis E, Concolino P (2021). "Genes and Pseudogenes: Complexity of the RCCX Locus and Disease". Front Endocrinol (Lausanne). 12: 709758. doi:10.3389/fendo.2021.709758. PMC 8362596. PMID 34394006.
  8. ^ Bánlaki Z, Szabó JA, Szilágyi Á, Patócs A, Prohászka Z, Füst G, Doleschall M (2013). "Intraspecific evolution of human RCCX copy number variation traced by haplotypes of the CYP21A2 gene". Genome Biol Evol. 5 (1): 98–112. doi:10.1093/gbe/evs121. PMC 3595039. PMID 23241443.
  9. ^ Doleschall M, Luczay A, Koncz K, Hadzsiev K, Erhardt É, Szilágyi Á, Doleschall Z, Németh K, Török D, Prohászka Z, Gereben B, Fekete G, Gláz E, Igaz P, Korbonits M, Tóth M, Rácz K, Patócs A (June 2017). "A unique haplotype of RCCX copy number variation: from the clinics of congenital adrenal hyperplasia to evolutionary genetics". Eur J Hum Genet. 25 (6): 702–710. doi:10.1038/ejhg.2017.38. PMC 5477366. PMID 28401898.