21-Hydroxylase

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Cytochrome P450, family 21, subfamily A, polypeptide 2
Identifiers
Symbol(s) CYP21A2; CPS1; CA21H; CAH1; CYP21; CYP21B; MGC150536; MGC150537; P450c21B
External IDs OMIM: 201910 MGI88591 HomoloGene68063
RNA expression pattern

More reference expression data

Orthologs
Human Mouse
Entrez 1589 13079
Ensembl ENSG00000168482 ENSMUSG00000024365
Uniprot P08686 A0JP50
Refseq NM_000500 (mRNA)
NP_000491 (protein)
NM_009995 (mRNA)
NP_034125 (protein)
Location Chr c6_COX: 32.1 - 32.1 Mb Chr 17: 34.41 - 34.41 Mb
Pubmed search [1] [2]

Steroid 21-hydroxylase (or steroid 21-monooxygenase or 21α-Hydroxylase; EC 1.14.99.10) is a cytochrome P450 enzyme which is involved with the biosynthesis of the steroid hormones aldosterone and cortisol.

The CAS number is 9029-68-9.

21-Hydroxylase is encoded by the gene CYP21B.

Contents

[edit] Reaction

It catalyses the hydroxylation of the carbon atom 21 in steroids (adding an "–OH"), which is necessary with the formation of these hormones.

[edit] Pathway

Corticosteroid biosynthetic pathway in rat
Corticosteroid biosynthetic pathway in rat
Steroidogenesis, showing both reactions of 21-Hydroxylase at center top.
Steroidogenesis, showing both reactions of 21-Hydroxylase at center top.

[edit] Clinical significance

A defect within the CYP21B gene causes a disturbance of the development of the enzyme, which leads to congenital adrenal hyperplasia due to 21-hydroxylase deficiency. A related pseudogene is located near this gene; gene conversion events involving the functional gene and the pseudogene are thought account for many cases of steroid 21-hydroxylase deficiency.[1]

[edit] References

[edit] Further reading

  • White PC, Tusie-Luna MT, New MI, Speiser PW (1994). "Mutations in steroid 21-hydroxylase (CYP21).". Hum. Mutat. 3 (4): 373–8. doi:10.1002/humu.1380030408. PMID 8081391. 
  • Helmberg A (1993). "Twin genes and endocrine disease: CYP21 and CYP11B genes.". Acta Endocrinol. 129 (2): 97–108. PMID 8372604. 
  • de-Araujo M, Sanches MR, Suzuki LA, et al. (1996). "Molecular analysis of CYP21 and C4 genes in Brazilian families with the classical form of steroid 21-hydroxylase deficiency.". Braz. J. Med. Biol. Res. 29 (1): 1–13. PMID 8731325. 
  • Yu CY (1999). "Molecular genetics of the human MHC complement gene cluster.". Exp. Clin. Immunogenet. 15 (4): 213–30. PMID 10072631. 
  • Forest MG, Tardy V, Nicolino M, et al. (2005). "21-Hydroxylase deficiency: an exemplary model of the contribution of molecular biology in the understanding and management of the disease.". Ann. Endocrinol. (Paris) 66 (3): 225–32. PMID 15988383. 

[edit] External links

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