STRUCTURE, FUNCTION, AND DIETARY REGULATION OF Δ6, Δ5, AND Δ9 DESATURASES
Top Cited Papers
- 14 July 2004
- journal article
- review article
- Published by Annual Reviews in Annual Review of Nutrition
- Vol. 24 (1), 345-376
- https://doi.org/10.1146/annurev.nutr.24.121803.063211
Abstract
▪ Abstract Fatty acid desaturases introduce a double bond in a specific position of long-chain fatty acids, and are conserved across kingdoms. Degree of unsaturation of fatty acids affects physical properties of membrane phospholipids and stored triglycerides. In addition, metabolites of polyunsaturated fatty acids are used as signaling molecules in many organisms. Three desaturases, Δ9, Δ6, and Δ5, are present in humans. Delta-9 catalyzes synthesis of monounsaturated fatty acids. Oleic acid, a main product of Δ9 desaturase, is the major fatty acid in mammalian adipose triglycerides, and is also used for phospholipid and cholesteryl ester synthesis. Delta-6 and Δ5 desaturases are required for the synthesis of highly unsaturated fatty acids (HUFAs), which are mainly esterified into phospholipids and contribute to maintaining membrane fluidity. While HUFAs may be required for cold tolerance in plants and fish, the primary role of HUFAs in mammals is cell signaling. Arachidonic acid is required as substrates for eicosanoid synthesis, while docosahexaenoic acid is required in visual and neuronal functions. Desaturases in mammals are regulated at the transcriptional level. Reflecting overlapping functions, three desaturases share a common mechanism of a feedback regulation to maintain products in membrane phospholipids. At the same time, regulation of Δ9 desaturase differs from Δ6 and Δ5 desaturases because its products are incorporated into more diverse lipid groups. Combinations of multiple transcription factors achieve this sophisticated differential regulation.Keywords
This publication has 87 references indexed in Scilit:
- Transcription regulation and animal diversityNature, 2003
- The E-box like sterol regulatory element mediates the suppression of human Δ-6 desaturase gene by highly unsaturated fatty acidsBiochemical and Biophysical Research Communications, 2002
- Mga2p Is a Putative Sensor for Low Temperature and Oxygen to Induce OLE1 Transcription in Saccharomyces cerevisiaeBiochemical and Biophysical Research Communications, 2002
- Cloning and Characterization of the Human Stearoyl-CoA Desaturase Gene Promoter: Transcriptional Activation by Sterol Regulatory Element Binding Protein and Repression by Polyunsaturated Fatty Acids and CholesterolBiochemical and Biophysical Research Communications, 2001
- Effects of Diabetes and Insulin on Hepatic Δ6 Desaturase Gene ExpressionBiochemical and Biophysical Research Communications, 2001
- A Palmitoyl-CoA-Specific Δ9 Fatty Acid Desaturase from Caenorhabditis elegansBiochemical and Biophysical Research Communications, 2000
- A Model Cell Line to Study Regulation of Stearoyl-CoA Desaturase Gene 1 Expression by Insulin and Polyunsaturated Fatty AcidsBiochemical and Biophysical Research Communications, 1996
- In vivo cholesterol removal from liver microsomes induces changes in fatty acid desaturase activitiesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1988
- Cholesterol-induced microsomal changes modulate desaturase activitiesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1987
- Linoleic acid desaturation activity of liver microsomes of essential fatty acid deficient and sufficient ratsBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1976