Sterol Δ14 reductase
| Sterol Δ14 reductase | ||
|---|---|---|
| Secondary to quaternary structure | Membrane protein | |
| Cofactor | NADP | |
| Identifier | ||
| Gene name (s) | TM7SF2 , LBR | |
| Enzyme classification | ||
| EC, category | 1.3.1.70 , oxidoreductase | |
| Response type | Hydrogenation | |
| Substrate | 4,4-dimethyl-5α-cholesta-8,14,24-trien-3β-ol + NADPH / H + | |
| Products | 14-demethyllanosterol + NADP + | |
| Occurrence | ||
| Parent taxon | Eukaryotes | |
Sterol-Δ14-reductase (also: C14-sterol-reductase, C14SR) are called enzymes in cholesterol biosynthesis . The enzymes catalyze the hydrogenation of 4,4-dimethyl-5α-cholesta-8,14,24-trien-3β-ol, after which 14-demethyllanosterol is formed. It takes place in most eukaryotes . In humans, there are two enzymes with Δ14 sterol reductase activity: TM7SF2 ( gene name: TM7SF2 ) is located in the membrane of the endoplasmic reticulum (ER), while the lamin B receptor (gene name: LBR ) is located on the Inner membrane of the cell nucleus can be found. In humans, TM7SF2 is mainly formed in the heart , brain , pancreas , lungs , liver , muscles , kidneys , ovaries , prostate and testes . LBR also appears to be involved in chromatin organization and nucleus import.
C14SR is redundant in cholesterol biosynthesis; Knockout mice without the TM7SF2 gene show normal metabolic values. In contrast, mutations in the LBR gene can lead to rare hereditary diseases such as the Pelger-Huët anomaly or Greenberg dysplasia .
Catalyzed reaction
+ NADPH / H + ⇔ 
+ NADP +
4,4-Dimethyl-5α-cholesta-8,14,24-trien-3β-ol is hydrogenated, 14-demethyllanosterol is formed.
Individual evidence
- ↑ Homologues at OMA
- ↑ InterPro: Lamin-B-Receptor
- ↑ UniProt O76062
- ↑ a b UniProt Q14739
- ↑ Bennati AM, Schiavoni G, Franken S, et al. : Disruption of the gene encoding 3beta-hydroxysterol Delta-reductase (Tm7sf2) in mice does not impair cholesterol biosynthesis . In: FEBS J . . 275, No. 20, October 2008, pp. 5034-47. doi : 10.1111 / j.1742-4658.2008.06637.x . PMID 18785926 .
Web links
- D'Eustachio / reactome: 4,4-dimethylcholesta-8 (9), 14,24-trien-3beta-ol is reduced to 4,4-dimethylcholesta-8 (9), 24-dien-3beta-ol (TM7SF2)
- D'Eustachio / reactome: 4,4-dimethylcholesta-8 (9), 14,24-trien-3beta-ol is reduced to 4,4-dimethylcholesta-8 (9), 24-dien-3beta-ol (LBR)
- OrphaNet: Greenberg dysplasia