SRD5A1
3-oxo-5-alpha-steroid 4-dehydrogenase 1 is an enzyme that in humans is encoded by the SRD5A1 gene.[1]
Steroid 5-alpha-reductase (EC 1.3.99.5) catalyzes the conversion of testosterone into the more potent androgen, dihydrotestosterone (DHT). There are 2 isoforms of the enzyme: SRD5A1 and SRD5A2.[2]
Regulation
ETV4 family members bind to ETS DNA-binding sites and both regulate their own expression and the transcription of a subset of genes that are dependent upon testicular luminal fluid factors, including Ggt_pr4, SRD5A1, and Gpx5.[3]
6-month dietary vitamin E (VE) deficiency in rats resulted in a twofold increase in the mRNA level of SRD5A1 gene and a twofold decrease in the mRNA level of GCLM gene but is not directly mediated by changes in promoter DNA methylation.[4]
Insulin increases the expression of 5α-reductase type 1 mRNA via Akt signalling suggest that elevated levels of 5α-reduced androgens seen in hyperinsulinemic conditions might be explained on the basis of a stimulatory effect of insulin on 5α-reductase in granulosa cells leading to impaired follicle growth and ovulation.[5]
Clinical signficance
Hyperinsulemia acutely enhances ACTH effects on both the androgen and glucocorticoid pathways leading to changes in steroid metabolites molar ratios that suggest insulin stimulation of 5 α-reductase activity. [6]
PCOS is associated with enhanced androgen and cortisol metabolite excretion and increased 5 alpha-reductase activity that cannot be explained by obesity alone. Increased adrenal corticosteroid production represents an important pathogenic pathway in PCOS. [7]
Progression to castration-resistant prostate cancer (CRPC) is accompanied by increased expression of SRD5A1 over SRD5A2, which is otherwise the dominant isoenzyme expressed in the prostate. The dominant route of DHT synthesis in human CRPC bypasses testosterone, and instead requires 5α-reduction of androstenedione by SRD5A1 to 5α-androstanedione, which is then converted to DHT fuelling cancer growth.[8]
See also
References
- ^ Jenkins EP, Hsieh CL, Milatovich A, Normington K, Berman DM, Francke U, Russell DW (Mar 1992). "Characterization and chromosomal mapping of a human steroid 5 alpha-reductase gene and pseudogene and mapping of the mouse homologue". Genomics 11 (4): 1102–12. doi:10.1016/0888-7543(91)90038-G. PMID 1686016.
- ^ "Entrez Gene: SRD5A1 steroid-5-alpha-reductase, alpha polypeptide 1 (3-oxo-5 alpha-steroid delta 4-dehydrogenase alpha 1)". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=6715.
- ^ Yang, L.; Fox, S. A.; Kirby, J. L.; Troan, B. V.; Hinton, B. T. (2006). "Putative Regulation of Expression of Members of the Ets Variant 4 Transcription Factor Family and Their Downstream Targets in the Rat Epididymis". Biology of Reproduction 74 (4): 714–720. doi:10.1095/biolreprod.105.044354. PMID 16394217. edit
- ^ Fischer, A.; Gaedicke, S.; Frank, J.; Döring, F.; Rimbach, G. (2010). "Dietary vitamin E deficiency does not affect global and specific DNA methylation patterns in rat liver". British Journal of Nutrition 104 (7): 935–940. doi:10.1017/S0007114510001649. PMID 20447326. edit
- ^ Kayampilly, P. P.; Wanamaker, B. L.; Stewart, J. A.; Wagner, C. L.; Menon, K. M. J. (2010). "Stimulatory Effect of Insulin on 5α-Reductase Type 1 (SRD5A1) Expression through an Akt-Dependent Pathway in Ovarian Granulosa Cells". Endocrinology 151 (10): 5030–5037. doi:10.1210/en.2010-0444. PMC 2946143. PMID 20810561. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2946143. edit
- ^ Tosi F, Negri C, Brun E, et al. (February 2011). "Insulin enhances ACTH-stimulated androgen and glucocorticoid metabolism in hyperandrogenic women". Eur. J. Endocrinol. 164 (2): 197–203. doi:10.1530/EJE-10-0782. PMID 21059865.
- ^ Vassiliadi DA, Barber TM, Hughes BA, et al. (September 2009). "Increased 5 alpha-reductase activity and adrenocortical drive in women with polycystic ovary syndrome". J. Clin. Endocrinol. Metab. 94 (9): 3558–66. doi:10.1210/jc.2009-0837. PMID 19567518.
- ^ Chang, K. -H.; Li, R.; Papari-Zareei, M.; Watumull, L.; Zhao, Y. D.; Auchus, R. J.; Sharifi, N. (2011). "Dihydrotestosterone synthesis bypasses testosterone to drive castration-resistant prostate cancer". Proceedings of the National Academy of Sciences 108 (33): 13728–13733. doi:10.1073/pnas.1107898108. PMC 3158152. PMID 21795608. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3158152. edit
Further reading
- Jenkins EP, Andersson S, Imperato-McGinley J, et al. (1992). "Genetic and pharmacological evidence for more than one human steroid 5 alpha-reductase.". J. Clin. Invest. 89 (1): 293–300. doi:10.1172/JCI115574. PMC 442847. PMID 1345916. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=442847.
- Andersson S, Russell DW (1990). "Structural and biochemical properties of cloned and expressed human and rat steroid 5 alpha-reductases.". Proc. Natl. Acad. Sci. U.S.A. 87 (10): 3640–4. doi:10.1073/pnas.87.10.3640. PMC 53958. PMID 2339109. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=53958.
- Moore RJ, Wilson JD (1972). "Localization of the reduced nicotinamide adenine dinucleotide phosphate: 4 -3-ketosteroid 5 -oxidoreductase in the nuclear membrane of the rat ventral prostate.". J. Biol. Chem. 247 (3): 958–67. PMID 4400474.
- Milewich L, Kaimal V, Toews GB (1983). "Androstenedione metabolism in human alveolar macrophages.". J. Clin. Endocrinol. Metab. 56 (5): 920–4. doi:10.1210/jcem-56-5-920. PMID 6833469.
- Thigpen AE, Silver RI, Guileyardo JM, et al. (1993). "Tissue distribution and ontogeny of steroid 5 alpha-reductase isozyme expression.". J. Clin. Invest. 92 (2): 903–10. doi:10.1172/JCI116665. PMC 294929. PMID 7688765. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=294929.
- Antonipillai I, Wahe M, Yamamoto J, Horton R (1995). "Activin and inhibin have opposite effects on steroid 5 alpha-reductase activity in genital skin fibroblasts.". Mol. Cell. Endocrinol. 107 (1): 99–104. doi:10.1016/0303-7207(94)03430-2. PMID 7796940.
- Hirsch KS, Jones CD, Audia JE, et al. (1993). "LY191704: a selective, nonsteroidal inhibitor of human steroid 5 alpha-reductase type 1.". Proc. Natl. Acad. Sci. U.S.A. 90 (11): 5277–81. doi:10.1073/pnas.90.11.5277. PMC 46699. PMID 8389478. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=46699.
- Andersson B, Wentland MA, Ricafrente JY, et al. (1996). "A "double adaptor" method for improved shotgun library construction.". Anal. Biochem. 236 (1): 107–13. doi:10.1006/abio.1996.0138. PMID 8619474.
- Bonkhoff H, Stein U, Aumüller G, Remberger K (1996). "Differential expression of 5 alpha-reductase isoenzymes in the human prostate and prostatic carcinomas.". Prostate 29 (4): 261–7. doi:10.1002/(SICI)1097-0045(199610)29:4<261::AID-PROS7>3.0.CO;2-E. PMID 8876709.
- Yu W, Andersson B, Worley KC, et al. (1997). "Large-scale concatenation cDNA sequencing.". Genome Res. 7 (4): 353–8. doi:10.1101/gr.7.4.353. PMC 139146. PMID 9110174. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=139146.
- Ellis JA, Stebbing M, Harrap SB (1998). "Genetic analysis of male pattern baldness and the 5alpha-reductase genes.". J. Invest. Dermatol. 110 (6): 849–53. doi:10.1046/j.1523-1747.1998.00224.x. PMID 9620288.
- Zhou Z, Shackleton CH, Pahwa S, et al. (1998). "Prominent sex steroid metabolism in human lymphocytes.". Mol. Cell. Endocrinol. 138 (1-2): 61–9. doi:10.1016/S0303-7207(98)00052-5. PMID 9685215.
- Hu RM, Han ZG, Song HD, et al. (2000). "Gene expression profiling in the human hypothalamus-pituitary-adrenal axis and full-length cDNA cloning.". Proc. Natl. Acad. Sci. U.S.A. 97 (17): 9543–8. doi:10.1073/pnas.160270997. PMC 16901. PMID 10931946. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=16901.
- Eminović I, Liović M, Prezelj J, et al. (2002). "New steroid 5alpha-reductase type I (SRD5A1) homologous sequences on human chromosomes 6 and 8.". Pflugers Arch. 442 (6 Suppl 1): R187–9. doi:10.1007/s004240100019. PMID 11678334.
- Ellis JA, Wong ZY, Stebbing M, Harrap SB (2002). "Sex, genes and blood pressure.". Clin. Exp. Pharmacol. Physiol. 28 (12): 1053–5. doi:10.1046/j.1440-1681.2001.03579.x. PMID 11903314.
- Rodríguez-Dorantes M, Lizano-Soberón M, Camacho-Arroyo I, et al. (2002). "Evidence that steroid 5alpha-reductase isozyme genes are differentially methylated in human lymphocytes.". J. Steroid Biochem. Mol. Biol. 80 (3): 323–30. doi:10.1016/S0960-0760(02)00023-7. PMID 11948017.
- Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=139241.
- Ha SJ, Kim JS, Myung JW, et al. (2003). "Analysis of genetic polymorphisms of steroid 5alpha-reductase type 1 and 2 genes in Korean men with androgenetic alopecia.". J. Dermatol. Sci. 31 (2): 135–41. doi:10.1016/S0923-1811(02)00145-7. PMID 12670724.
- Habib FK, Ross M, Bayne CW, et al. (2004). "The loss of 5alpha-reductase type I and type II mRNA expression in metastatic prostate cancer to bone and lymph node metastasis.". Clin. Cancer Res. 9 (5): 1815–9. PMID 12738739.
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1.3.1: NAD/NADP acceptor |
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1.3.3: Oxygen acceptor |
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1.3.5: Quinone |
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1.3.99: Other acceptors |
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B enzm: 1.1/2/3/4/5/6/7/8/10/11/13/14/15-18, 2.1/2/3/4/5/6/7/8, 2.7.10, 2.7.11-12, 3.1/2/3/4/5/6/7, 3.1.3.48, 3.4.21/22/23/24, 4.1/2/3/4/5/6, 5.1/2/3/4/99, 6.1-3/4/5-6
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Mevalonate pathway |
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To cholesterol |
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To Bile acids |
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Steroidogenesis |
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m(A16/C10),i(k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)
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