Publications

• Identification of the delta-6 desaturase of human sebaceous glands: expression and enzyme activity.

  Ge L., Gordon J.S., Hsuan C., Stenn K., Prouty S.M.

  Delta-6 desaturase, also known as fatty acid desaturase-2 (FADS2), is a component of a lipid metabolic pathway that converts the essential fatty acids linoleate and alpha-linolenate into long-chain polyunsaturated fatty acids. Isolation of Delta-6 desaturase/FADS2 cDNA from human skin predicts an ... >> More

  Delta-6 desaturase, also known as fatty acid desaturase-2 (FADS2), is a component of a lipid metabolic pathway that converts the essential fatty acids linoleate and alpha-linolenate into long-chain polyunsaturated fatty acids. Isolation of Delta-6 desaturase/FADS2 cDNA from human skin predicts an identical protein to that expressed in human brain and Southern analysis indicates a single locus, together suggestive of a single Delta-6 desaturase/FADS2 gene. Within human skin, Delta-6 desaturase/FADS2 mRNA and protein expression is restricted to differentiating sebocytes located in the suprabasal layers of the sebaceous gland. Enzymatic analysis using CHO cells overexpressing human Delta-6 desaturase/FADS2 indicates catalysis of a "polyunsaturated fatty acid type" reaction, but also an unexpected "sebaceous-type" reaction, that of converting palmitate into the mono-unsaturated fatty acid sapienate, a 16-carbon fatty acid with a single cis double bond at the sixth carbon from the carboxyl end. Sapienate is the most abundant fatty acid in human sebum, and among hair-bearing animals is restricted to humans. This work identifies Delta-6 desaturase/FADS2 as the major fatty acid desaturase in human sebaceous glands and suggests that the environment of the sebaceous gland permits catalysis of the sebaceous-type reaction and restricts catalysis of the polyunsaturated fatty acid type reaction. << Less

  J. Invest. Dermatol. 120:707-714(2003) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Purification and partial characterization of linoleoyl-CoA desaturase from rat liver microsomes.

  Okayasu T., Nagao M., Ishibashi T., Imai Y.

  Arch Biochem Biophys 206:21-28(1981) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Metabolism of highly unsaturated n-3 and n-6 fatty acids.

  Sprecher H.

  Biochim Biophys Acta 1486:219-231(2000) [PubMed] [EuropePMC]

  This publication is cited by 11 other entries.

• In vivo characterization of the first acyl-CoA Delta6-desaturase from a member of the plant kingdom, the microalga Ostreococcus tauri.

  Domergue F., Abbadi A., Zahringer U., Moreau H., Heinz E.

  Genomic DNA of Ostreococcus tauri, a fully sequenced marine unicellular alga from the phytoplankton, was used to amplify a gene coding for a typical front-end desaturase involved in polyunsaturated fatty acid biosynthesis. Heterologous expression in Saccharomyces cerevisiae revealed very high desa ... >> More

  Genomic DNA of Ostreococcus tauri, a fully sequenced marine unicellular alga from the phytoplankton, was used to amplify a gene coding for a typical front-end desaturase involved in polyunsaturated fatty acid biosynthesis. Heterologous expression in Saccharomyces cerevisiae revealed very high desaturation activity with Delta6-regioselectivity. Short-time kinetic experiments showed that the desaturase product was detected in the acyl-CoA pool 5 min after addition of the exogenous substrate to the yeast medium and long before its appearance in the total fatty acids. When this desaturase was co-expressed with the acyl-CoA Delta6-elongase from Physcomitrella patens and the lipid-linked Delta5-desaturase from Phaeodactylum tricornutum, high proportions of arachidonic or eicosapentaenoic acid were obtained, because nearly all of the Delta6-desaturated products were elongated. Furthermore, the product/educt ratios calculated in each glycerolipid for the Delta6-desaturase or for the acyl-CoA Delta6-elongase were in about the same range, whereas this ratio showed a very uneven profile in the case of the lipid-linked Delta5-desaturase. Finally, a sequence-based comparison of all the functionally characterized Delta6-desaturases showed that this enzyme was not related to any previously described sequence. Altogether, our data suggest that this desaturase from O. tauri is an acyl-CoA Delta6-desaturase, the first one cloned from a photosynthetically active organism. << Less

  Biochem J 389:483-490(2005) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Cloning, expression, and nutritional regulation of the mammalian Delta-6 desaturase.

  Cho H.P., Nakamura M.T., Clarke S.D.

  Arachidonic acid (20:4(n-6)) and docosahexaenoic acid (22:6(n-3)) have a variety of physiological functions that include being the major component of membrane phospholipid in brain and retina, substrates for eicosanoid production, and regulators of nuclear transcription factors. The rate-limiting ... >> More

  Arachidonic acid (20:4(n-6)) and docosahexaenoic acid (22:6(n-3)) have a variety of physiological functions that include being the major component of membrane phospholipid in brain and retina, substrates for eicosanoid production, and regulators of nuclear transcription factors. The rate-limiting step in the production of 20:4(n-6) and 22:6(n-3) is the desaturation of 18:2(n-6) and 18:3(n-3) by Delta-6 desaturase. In this report, we describe the cloning, characterization, and expression of a mammalian Delta-6 desaturase. The open reading frames for mouse and human Delta-6 desaturase each encode a 444-amino acid peptide, and the two peptides share an 87% amino acid homology. The amino acid sequence predicts that the peptide contains two membrane-spanning domains as well as a cytochrome b5-like domain that is characteristic of nonmammalian Delta-6 desaturases. Expression of the open reading frame in rat hepatocytes and Chinese hamster ovary cells instilled in these cells the ability to convert 18:2(n-6) and 18:3(n-3) to their respective products, 18:3(n-6) and 18:4(n-3). When mice were fed a diet containing 10% fat, hepatic enzymatic activity and mRNA abundance for hepatic Delta-6 desaturase in mice fed corn oil were 70 and 50% lower than in mice fed triolein. Finally, Northern analysis revealed that the brain contained an amount of Delta-6 desaturase mRNA that was several times greater than that found in other tissues including the liver, lung, heart, and skeletal muscle. The RNA abundance data indicate that prior conclusions regarding the low level of Delta-6 desaturase expression in nonhepatic tissues may need to be reevaluated. << Less

  J. Biol. Chem. 274:471-477(1999) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.