Enzymes
| UniProtKB help_outline | 392 proteins |
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- Name help_outline androst-4-ene-3,17-dione Identifier CHEBI:16422 (Beilstein: 2059239; CAS: 63-05-8) help_outline Charge 0 Formula C19H26O2 InChIKeyhelp_outline AEMFNILZOJDQLW-QAGGRKNESA-N SMILEShelp_outline [H][C@@]12CCC3=CC(=O)CC[C@]3(C)[C@@]1([H])CC[C@]1(C)C(=O)CC[C@@]21[H] 2D coordinates Mol file for the small molecule Search links Involved in 19 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADPH Identifier CHEBI:57783 (Beilstein: 10411862) help_outline Charge -4 Formula C21H26N7O17P3 InChIKeyhelp_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,279 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 5α-androstan-3,17-dione Identifier CHEBI:15994 (CAS: 846-46-8) help_outline Charge 0 Formula C19H28O2 InChIKeyhelp_outline RAJWOBJTTGJROA-WZNAKSSCSA-N SMILEShelp_outline [H][C@@]12CC[C@@]3([H])[C@]4([H])CCC(=O)[C@@]4(C)CC[C@]3([H])[C@@]1(C)CCC(=O)C2 2D coordinates Mol file for the small molecule Search links Involved in 9 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADP+ Identifier CHEBI:58349 Charge -3 Formula C21H25N7O17P3 InChIKeyhelp_outline XJLXINKUBYWONI-NNYOXOHSSA-K SMILEShelp_outline NC(=O)c1ccc[n+](c1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,285 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:50816 | RHEA:50817 | RHEA:50818 | RHEA:50819 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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| MetaCyc help_outline |
Related reactions help_outline
More general form(s) of this reaction
Publications
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Characterization of 5alpha-reductase activity and isoenzymes in human abdominal adipose tissues.
Fouad Mansour M., Pelletier M., Tchernof A.
<h4>Introduction</h4>The substrate for the generation of 5α-dihydrotestosterone (DHT) is either androstenedione (4-dione) which is first converted to androstanedione and then to DHT through 17-oxoreductase activity, or testosterone, which is directly converted to DHT. Three 5α-reductase isoenzymes ... >> More
<h4>Introduction</h4>The substrate for the generation of 5α-dihydrotestosterone (DHT) is either androstenedione (4-dione) which is first converted to androstanedione and then to DHT through 17-oxoreductase activity, or testosterone, which is directly converted to DHT. Three 5α-reductase isoenzymes have been characterized and designated as types 1, 2 and 3 (SRD5A1, 2 and 3).<h4>Objective</h4>To define the predominant source of local DHT production in human adipose tissues, identify 5α-reductase isoenzymes and test their impact on preadipocyte differentiation.<h4>Methods</h4>Cultures of omental (OM) and subcutaneous (SC) preadipocytes were treated for 0, 6 or 24h with 30nM (14)C-4-dione or (14)C-testosterone, with and without 500nM 5α-reductase inhibitors 17-N,N-diethylcarbamoyl-4-methyl-4-aza-5-androstan-3-one (4-MA) or finasteride. Protein level and mRNA abundance of 5α-reductase isoenzymes/transcripts were examined in whole SC and OM adipose tissue. HEK-293 cells stably transfected with 5α-reductase type 1, 2 or 3 were used to test 5α-reductase inhibitors. We also assessed the impact of 5α-reductase inhibitors on preadipocyte differentiation.<h4>Results</h4>Over 24h, DHT formation from 4-dione increased gradually (p<0.05) and was significantly higher compared to that generated from testosterone (p<0.001). DHT formation from both 4-dione and testosterone was blocked by both 5α-reductase inhibitors. In whole adipose tissue from both fat compartments, SRD5A3 was the most highly expressed isoenzyme followed by SRD5A1 (p<0.001). SRD5A2 was not expressed. In HEK-293 cells, 4-MA and finasteride inhibited activity of 5α-reductases types 2 and 3 but not type 1. In preadipocyte cultures where differentiation was inhibited by 4-dione (p<0.05, n=7) or testosterone (p<0.05, n=5), the inhibitors 4-MA and finasteride abolished these effects.<h4>Conclusion</h4>Although 4-dione is the main source of DHT in human preadipocytes, production of this steroid by 5α-reductase isoenzymes mediates the inhibitory effect of both 4-dione and testosterone on preadipocyte differentiation. << Less
J. Steroid Biochem. Mol. Biol. 161:45-53(2016) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Structural and biochemical properties of cloned and expressed human and rat steroid 5 alpha-reductases.
Andersson S., Russell D.W.
The microsomal enzyme steroid 5 alpha-reductase is responsible for the conversion of testosterone into the more potent androgen dihydrotestosterone. In man, this steroid acts on a variety of androgen-responsive target tissues to mediate such diverse endocrine processes as male sexual differentiati ... >> More
The microsomal enzyme steroid 5 alpha-reductase is responsible for the conversion of testosterone into the more potent androgen dihydrotestosterone. In man, this steroid acts on a variety of androgen-responsive target tissues to mediate such diverse endocrine processes as male sexual differentiation in the fetus and prostatic growth in men. Here we describe the isolation, structure, and expression of a cDNA encoding the human steroid 5 alpha-reductase. A rat cDNA was used as a hybridization probe to screen a human prostate cDNA library. A 2.1-kilobase cDNA was identified and DNA sequence analysis indicated that the human steroid 5 alpha-reductase was a hydrophobic protein of 259 amino acids with a predicted molecular weight of 29,462. A comparison of the human and rat protein sequences revealed a 60% identity. Transfection of expression vectors containing the human and rat cDNAs into simian COS cells resulted in the synthesis of high levels of steroid 5 alpha-reductase enzyme activity. Both enzymes expressed in COS cells showed similar substrate specificities for naturally occurring steroid hormones. However, synthetic 4-azasteroids demonstrated marked differences in their abilities to inhibit the human and rat steroid 5 alpha-reductases. << Less
Proc. Natl. Acad. Sci. U.S.A. 87:3640-3644(1990) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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5alpha-reductases in human physiology: an unfolding story.
Traish A.M.
<h4>Objective</h4>5α-reductases are a family of isozymes expressed in a wide host of tissues including the central nervous system (CNS) and play a pivotal role in male sexual differentiation, development and physiology.<h4>Methods</h4>A comprehensive literature search from 1970 to 2011 was made th ... >> More
<h4>Objective</h4>5α-reductases are a family of isozymes expressed in a wide host of tissues including the central nervous system (CNS) and play a pivotal role in male sexual differentiation, development and physiology.<h4>Methods</h4>A comprehensive literature search from 1970 to 2011 was made through PubMed and the relevant information was summarized.<h4>Results</h4>5α reductases convert testosterone, progesterone, deoxycorticosterone, aldosterone and corticosterone into their respective 5α-dihydro-derivatives, which serve as substrates for 3α-hydroxysteroid dehydrogenase enzymes. The latter transforms these 5α-reduced metabolites into a subclass of neuroactive steroid hormones with distinct physiological functions. The neuroactive steroid hormones modulate a multitude of functions in human physiology encompassing regulation of sexual differentiation, neuroprotection, memory enhancement, anxiety, sleep and stress, among others. In addition, 5α -reductase type 3 is also implicated in the N-glycosylation of proteins via formation of dolichol phosphate. The family of 5α-reductases was targeted for drug development to treat pathophysiological conditions, such as benign prostatic hyperplasia and androgenetic alopecia. While the clinical use of 5α-reductase inhibitors was well established, the scope and the magnitude of the adverse side effects of such drugs, especially on the CNS, is still unrecognized due to lack of knowledge of the various physiological functions of this family of enzymes, especially in the CNS.<h4>Conclusion</h4>There is an urgent need to better understand the function of 5α-reductases and the role of neuroactive steroids in human physiology in order to minimize the potential adverse side effects of inhibitors targeting 5α-reductases to treat benign prostatic hyperplasia and androgenic alopecia. << Less
Endocr Pract 18:965-975(2012) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.