Sterol desaturase

K.S. Schweitzer, K.T. Chun, C. Koegel et al. (1996). Cloning and characterization of the Saccharomyces cerevisiae C-22 sterol desaturase gene, encoding a second cytochrome P-450 involved in ergosterol biosynthesis. Gene 169, 105-109. 

Fig. 5.1.2 Cholesterol biosynthesis branch of the isoprenoid biosynthetic pathway. Enzymes are numbered as follows 1 squalene synthase 2 squalene epoxidase 3 2,3-oxidosqua-lene sterol cyclase 4 sterol A24-reductase (desmosterolosis) 5 sterol C-14 demethylase 6 sterol A14-reductase (hydrops-ectopic calcification-moth-eaten, HEM, dysplasia) 7 sterol C-4 demethylase complex (including a 3/ -hydroxysteroid dehydrogenase defective in congenital hemidyspla-sia with ichthyosiform nevus and limb defects, CHILD, syndrome) 8 sterol A8-A7 isomerase (Conradi-Hunermann syndrome CDPX2) 9 sterol A5-desaturase (lathosterolosis) 10 sterol A7-reductase (Smith-Lemli-Opitz syndrome). Enzyme deficiencies are indicated by solid bars across the arrows...

Gachotte, D., Husselstein, T., Bard, M., Lacroute, F. and Benveniste, P. (1996) Isolation and characterization of an Arabidopsis thaliana cDNA encoding a A7-sterol-C-5-desaturase by functional complementation of a defective yeast mutant. Plant., 9, 391-8. 

Taton, M. and Rahier, A. (1996) Plant sterol biosynthesis identification and characterization of higher plant A 7-sterol C5(6)-desaturase. Arch. Biochem. Biophys., 325, 279-88. 

Nara, T. Y., He, W. S., Tang, C., Clarke, S. D., and Nakamura, M. T. The E-box like sterol regulatory element mediates the suppression of human Delta-6 desaturase gene by highly unsaturated fatty acids. Biochem Biophys Res Commun 296 (2002) 111-117. 

Abbreviations a-BFAs anteiso-branched fatty acids AGP acyl carrier protein BHLH active soluble domain of SREBP CNS central nervous system DSD delta 5 desaturase D6D delta 6 desaturase ER endoplasmic reticulum Hik histidine kinase HUFA highly unsaturated fatty acid LXR liver X receptor MUFA monounsaturated fatty add NF-Y nuclear factor Y PLs phospholipids PP peroxisome proliferator PPAR PP-activated receptor PPRE PP response element PUFA polyunsaturated fatty acid PUFA-BP PUFA binding protein PUFA-RE PUFA response element RXR retinoid X receptor SCAP SREBP cleavage-activating protein SCD steraroyl CoA desaturase SFA saturated fatty acid SRE sterol response... 

Tabor, D.E., Kim, J.B., Spiegelman, B.M. and Edwards, P.A. Identification of conserved cis-elements and transcription factors required for sterol-regulated transcription of stearoyl-CoA desaturase 1 and 2. J Biol Chem, 274 (1999) 20603-20610. 

Abbreviations FASN, fatty acid synthase ACC, acetyl-CoA-carboxylase ACL, ATP-citrate lyase NADPH, nicotinamide adenine dinucleotide phosphate MAT, malonyl acetyl transferases KS, ketoacyl synthase KR, p-ketoacyl reductase DH, p-hydroxyacyl dehydratase ER, enoyl reductase TE, thioesterase ACP, acyl carrier protein VLCFA, very long chain fatty acids ELOVL, elongation of very long chain fatty acids SCDl, stearoyl-CoA desaturase-1 AMPK, AMP-activated kinase ME, malic enzyme FASKOL, liver-specific deletion of FAS PPARa, Peroxisome Proliferator-Activating Receptor alpha HMG-CoA, 3-hydroxy-3-methyl-glutaryl-CoA SREBP, sterol response element binding protein SIP, site-one protease S2P, site-two... 

Fig. 6. Coordinated transcriptional regulation of fatty acid desaturases and elongases in mammals. PUFA, polyunsaturated fatty acids +, stimulation inhibition LXR, liver X receptor RXR retinoid X receptor SREBP, sterol regulatory element binding protein ChREBP, carbohydrate response element binding protein Mix, Max-like receptor PPAR-ot, peroxisome proliferator activated receptor alpha LXRE, liver X receptor response element SRE, sterol response element ChoRE, carbohydrate response element PPRE, peroxisome proliferator response element. (See color plate section, plate no. 6.)...

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