17α-hydroxylase

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Cytochrome P450, family 17, subfamily A, polypeptide 1
Identifiers
Symbols CYP17A1; CPT7; CYP17; P450C17; S17AH
External IDs OMIM: 609300 MGI88586 HomoloGene73875
RNA expression pattern

More reference expression data

Orthologs
Human Mouse
Entrez 1586 13074
Ensembl ENSG00000148795 ENSMUSG00000003555
Uniprot P05093 Q3UYU1
Refseq NM_000102 (mRNA)
NP_000093 (protein)
NM_007809 (mRNA)
NP_031835 (protein)
Location Chr 10: 104.58 - 104.59 Mb Chr 19: 46.72 - 46.73 Mb
Pubmed search [1] [2]

CYP17A1 (also known as 17α-hydroxylase/17,20 lyase/17,20 desmolase[1]) is a cytochrome P450 enzyme which acts upon pregnenolone and progesterone to add a hydroxyl (-OH) group at carbon 17 of the steroid D ring (the hydroxylase activity), or acts upon 17-hydroxyprogesterone and 17-hydroxypregnenolone to split the side chain off the steroid nucleus (the lyase activity).

17α-hydroxylase converts pregnenolone and progesterone to their 17-hydroxy forms, and converts 17-hydroxypregnenolone and 17-hydroxyprogesterone to DHEA and androstenedione, respectively. It corresponds to the downward arrows in this reaction scheme.
17α-hydroxylase converts pregnenolone and progesterone to their 17-hydroxy forms, and converts 17-hydroxypregnenolone and 17-hydroxyprogesterone to DHEA and androstenedione, respectively. It corresponds to the downward arrows in this reaction scheme.

This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum. It has both 17alpha-hydroxylase and 17,20-lyase activities and is a key enzyme in the steroidogenic pathway that produces progestins, mineralocorticoids, glucocorticoids, androgens, and estrogens. Mutations in this gene are associated with isolated steroid-17 alpha-hydroxylase deficiency, 17-alpha-hydroxylase/17,20-lyase deficiency, pseudohermaphroditism, and adrenal hyperplasia.[2]

Contents

Additional images

Steroidogenesis, showing, at left side, both reactions of 17-alpha hydroxylase, and both actions of 17, 20 lyase.
Steroidogenesis, showing, at left side, both reactions of 17-alpha hydroxylase, and both actions of 17, 20 lyase.


See also

External links

References

  1. ^ Medical Physiology, Boron & Boulpaep, ISBN 1-4160-2328-3, Elsevier Saunders 2005. Updated edition. Page 1180.
  2. ^ "Entrez Gene: CYP17A1 cytochrome P450, family 17, subfamily A, polypeptide 1".

Further reading

  • Miura K, Yasuda K, Yanase T, et al. (1996). "Mutation of cytochrome P-45017 alpha gene (CYP17) in a Japanese patient previously reported as having glucocorticoid-responsive hyperaldosteronism: with a review of Japanese patients with mutations of CYP17.". J. Clin. Endocrinol. Metab. 81 (10): 3797–801. PMID 8855840. 
  • Miller WL, Geller DH, Auchus RJ (1999). "The molecular basis of isolated 17,20 lyase deficiency.". Endocr. Res. 24 (3-4): 817–25. PMID 9888582. 
  • Strauss JF (2004). "Some new thoughts on the pathophysiology and genetics of polycystic ovary syndrome.". Ann. N. Y. Acad. Sci. 997: 42–8. PMID 14644808. 

Wikipedia content modification information:

  • This page was last modified on 4 October 2008, at 13:32.

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