Promiscuity and diversity in 3-ketosteroid reductases

Penning, T.M.; Chen, Mo; Jin, Yi

doi:10.1016/j.jsbmb.2014.12.003

Cited by 32 publications

(12 citation statements)

References 51 publications

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“…The C-4 demethylation reaction is completed by reduction of the C-3 ketone to yield the final sterol product, 4-desmethyllanosterol (IV). Many NAD(P)dependent ketosteroid reductases also catalyze the reverse reaction (26), and therefore, SdmB may affect both the decarboxylative oxidation and the reduction steps at C-3. If so, this would explain why SdmA and SdmB are sufficient for C-4 demethylation and why an ERG27 homolog would not be required in bacteria for the final reduction of the C-3 ketone.…”

Section: Identification Of C-4 Sterol Demethylase Proteins In M Capsmentioning

confidence: 99%

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

Lee

Banta

Wei

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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Sterols are essential eukaryotic lipids that are required for a variety of physiological roles. The diagenetic products of sterol lipids, sterane hydrocarbons, are preserved in ancient sedimentary rocks and are utilized as geological biomarkers, indicating the presence of both eukaryotes and oxic environments throughout Earth's history. However, a few bacterial species are also known to produce sterols, bringing into question the significance of bacterial sterol synthesis for our interpretation of sterane biomarkers. Recent studies suggest that bacterial sterol synthesis may be distinct from what is observed in eukaryotes. In particular, phylogenomic analyses of sterol-producing bacteria have failed to identify homologs of several key eukaryotic sterol synthesis enzymes, most notably those required for demethylation at the C-4 position. In this study, we identified two genes of previously unknown function in the aerobic methanotrophic γ-Proteobacterium that encode sterol demethylase proteins (Sdm). We show that a Rieske-type oxygenase (SdmA) and an NAD(P)-dependent reductase (SdmB) are responsible for converting 4,4-dimethylsterols to 4α-methylsterols. Identification of intermediate products synthesized during heterologous expression of SdmA-SdmB along withC-labeling studies support a sterol C-4 demethylation mechanism distinct from that of eukaryotes. SdmA-SdmB homologs were identified in several other sterol-producing bacterial genomes but not in any eukaryotic genomes, indicating that these proteins are unrelated to the eukaryotic C-4 sterol demethylase enzymes. These findings reveal a separate pathway for sterol synthesis exclusive to bacteria and show that demethylation of sterols evolved at least twice-once in bacteria and once in eukaryotes.

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Section: Identification Of C-4 Sterol Demethylase Proteins In M Capsmentioning

confidence: 99%

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

Lee

Banta

Wei

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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“…Enzymes in grey text will carry out the described conversion but they may not be the principal enzyme involved. Other enzymes, not shown, may also be involved in components of the backdoor pathway (61).…”

Section: Introductionmentioning

confidence: 99%

Alternative (backdoor) androgen production and masculinization in the human fetus

O’Shaughnessy

Antignac

Bizec

et al. 2018

Preprint

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2Masculinization of the external genitalia in humans is dependent on formation of 5α-3 dihydrotestosterone (DHT) through both the canonical androgenic pathway and an alternative 4 (backdoor) pathway. The fetal testes are essential for canonical androgen production but little 5 is known about the synthesis of backdoor androgens despite their known critical role in 6 masculinization. In this study, we have measured plasma and tissue levels of endogenous 7 steroids in second trimester human male fetuses using multi-dimensional and high-resolution formed primarily in non-gonadal tissue with placental progesterone the likely substrate. 16Masculinization of the human fetus depends, therefore, on androgen synthesis by both the 17 fetal testes and non-gonadal tissues leading to DHT formation at the genital tubercle. Our 18 findings provide, for the first time, a solid basis to explain why placental insufficiency is

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“…There are, however, alternative enzymes in the aldo-ketoreductase superfamily (31) , which could possess PGF2α and prostamide F2α synthase activities. AKR1C1, 2, 3, and 4 share more than 86% sequence identity (32). Nevertheless, the marked increase in intraocular pressure in PM/PGFS knock-out mice, about 20%, suggests that the loss of pg.…”

Section: Pg 10mentioning

confidence: 99%

Gene deletion studies reveal a critical role for prostamide/prostaglandin F_2αsynthase in prostamide F_2αformation

Woodward

et al. 2020

Preprint

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Prostamide/prostaglandin F synthase (PM/PGFS) is an enzyme with very narrow substrate specificity and is dedicated to the biosynthesis of prostamide and prostaglandin F2α. The importance of this enzyme, pg. 2 relative to the aldoketoreductase (AKR) series, in providing functional tissue prostamide F2α levels was determined by creating a line of PM/PGFS gene deleted mice. Deletion of the gene encoding PM/PGFS (fam213b) was accomplished by a two exon disruption. Prostamide F2α levels in WT and PM/PGFS KO mice were determined by LC/MS/MS. Intraocular pressure was measured by tonometry and outflow facility was measured by the iPerfusion method in enucleated mouse eyes. Deletion of fam213b had no observed effect on behavior, appetite, or fertility. Intraocular pressure was significantly elevated by approximately 4 mmHg in PM/PGFS KO mice compared to littermate WT mice. No effect on pressure dependent outflow facility occurred, which is consistent with the typically reported prostanoid effect of increasing outflow through the unconventional pathway. The elevation of intraocular pressure caused by deletion of the gene encoding the PM/PGFS enzyme likely results from a diversion of the endoperoxide precursor pathway to provide increased levels of those prostanoids that raise intraocular pressure, namely prostaglandin D2 (PGD2), thromboxane A2 (TxA2). It follows that PM/PGFS may serve an important regulatory role in the eye by providing PGF2α and prostamide F2α to constrain the influence of those prostanoids that raise intraocular pressure. Keywords(a) Expertise key words: prostaglandins, eye, animal models, enzymology, gene expression (b) Free-form key words prostamide/prostaglandin F synthase, fam213b, prostamide F2α, prostaglandin F2α, , intraocular pressure, 13). More recently, a much more substrate specific enzyme and a member of the thioredoxin-like superfamily was discovered and was designated prostamide/prostaglandin F synthase (14,15), PM/PGFS, fam213. This enzyme facilitates a more restricted and targeted formation of PGF2α and prostamide F2α and thereby conferring tighter control of regulatory function(s). Gene deletion is a classical approach for discovering biological functions and the first results of these studies are presented herein, together with the methodology for creating prostamide/prostaglandin F synthase (fam213) knock-out mice. Given the importance of PGF2α and prostamide F2α in the treatment of glaucoma, these present studies focused on regulation of intraocular pressure. pg. 4Methods Creation of prostamide/prostaglandin F synthase (fam213) knock-out mice.The prostamide/prostaglandin F synthase (PM/PGFS) knock-out mouse was generated using the RENKA embryonic stem (ES) cell line, derived from C57BL/6N mice (16). To construct a PM/PGFS targeting vector, a 990 bp DNA fragment carrying exons 2 and 3, containing the enzyme active site of PM/PGFS, was amplified by PCR, and inserted into the targeting vector as described previously (17). In this clone, a DNA fragment of a PGK promoter-driven neo-poly (A...

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Promiscuity and diversity in 3-ketosteroid reductases

Cited by 32 publications

References 51 publications

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

Alternative (backdoor) androgen production and masculinization in the human fetus

Gene deletion studies reveal a critical role for prostamide/prostaglandin F_2αsynthase in prostamide F_2αformation

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Promiscuity and diversity in 3-ketosteroid reductases

Cited by 32 publications

References 51 publications

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

C-4 sterol demethylation enzymes distinguish bacterial and eukaryotic sterol synthesis

Alternative (backdoor) androgen production and masculinization in the human fetus

Gene deletion studies reveal a critical role for prostamide/prostaglandin F2αsynthase in prostamide F2αformation

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Gene deletion studies reveal a critical role for prostamide/prostaglandin F_2αsynthase in prostamide F_2αformation