Recombinant Human Acyl-CoA 6-desaturase (FADS2), partial

Function

Involved in the biosynthesis of highly unsaturated fatty acids (HUFA) from the essential polyunsaturated fatty acids (PUFA) linoleic acid (LA) (18:2n-6) and alpha-linolenic acid (ALA) (18:3n-3) precursors, acting as a fatty acyl-coenzyme A (CoA) desaturase that introduces a cis double bond at carbon 6 of the fatty acyl chain. Catalyzes the first and rate limiting step in this pathway which is the desaturation of LA (18:2n-6) and ALA (18:3n-3) into gamma-linoleate (GLA) (18:3n-6) and stearidonate (18:4n-3), respectively (PubMed:12713571). Subsequently, in the biosynthetic pathway of HUFA n-3 series, it desaturates tetracosapentaenoate (24:5n-3) to tetracosahexaenoate (24:6n-3), which is then converted to docosahexaenoate (DHA)(22:6n-3), an important lipid for nervous system function (By similarity). Desaturates hexadecanate (palmitate) to produce 6Z-hexadecenoate (sapienate), a fatty acid unique to humans and major component of human sebum, that has been implicated in the development of acne and may have potent antibacterial activity (PubMed:12713571). It can also desaturate (11E)-octadecenoate (trans-vaccenoate, the predominant trans fatty acid in human milk) at carbon 6 generating (6Z,11E)-octadecadienoate (By similarity). In addition to Delta-6 activity, this enzyme exhibits Delta-8 activity with slight biases toward n-3 fatty acyl-CoA substrates (By similarity)

Subcellular Location

Endoplasmic reticulum membrane (Multi-pass membrane protein)

Tissue Specificity

Expressed in a wide array of tissues, highest expression is found in liver followed by brain, lung, heart, and retina. A lower level is found in breast tumor when compared with normal tissues; lowest levels were found in patients with poor prognostic index

Pathway

Lipid metabolism; polyunsaturated fatty acid biosynthesis

• Cho H.P. et al. Cloning, expression, and nutritional regulation of the mammalian Delta-6 desaturase. — J. Biol. Chem. (1999)
• Marquardt A. et al. cDNA cloning, genomic structure, and chromosomal localization of three members of the human fatty acid desaturase family. — Genomics (2000)
• Zhang J.S.S. et al. PubMed: CI-88LR473M9JQL2 (NOV-)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• Otsuki T. et al. Signal sequence and keyword trap in silico for selection of full-length human cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries. — DNA Res. (2005)
• Taylor T.D. et al. Human chromosome 11 DNA sequence and analysis including novel gene identification. — Nature (2006)
• Mural R.J. et al. PubMed: CI-5GBDQ6B103N1E (JUL-)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)