title: Gene characterized for membrane desaturase that produces (E)-11 isomers of mono- and diunsaturated fatty acids.
abstract: Moth species have evolved integral membrane desaturases that exhibit a wide diversity in substrate specificity, as well as in regiospecificity and stereospecificity of the unsaturated products. We report here the cloning and expression of a single desaturase from the sex pheromone gland of the light brown apple moth, Epiphyas postvittana, that makes E11 isomers of monounsaturated (E11-16 and E11-14) fatty acids and a diunsaturated (E9,E11-14) fatty acid. In the pheromone gland, the monoene precursor is made available by beta oxidation of E11-16 acid with a subsequent two-carbon loss to E9-14 acid. A functional assay using a baculovirus expression system required addition of myristic acid and E9-14 acid precursors to demonstrate the unusual regiospecificity and stereospecificity of this desaturase. The amino acid sequence of this desaturase has approximately 61% identity to that of Z11-desaturases from two other insect species, and only approximately 48% identity to the metabolic Z9-desaturases in those species. A pheromone-gland Z9-desaturase gene also was found with the light brown apple moth that differed in its deduced amino acid sequence (66% identity) with the metabolic Z9-desaturase from fat body in this species.
authors.affiliation: Department of Entomology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456, USA.
authors.forename: Weitian
authors.initials: W
authors.lastname: Liu
authors.forename: Hongmei
authors.initials: H
authors.lastname: Jiao
authors.forename: Nancy C
authors.initials: NC
authors.lastname: Murray
authors.forename: Marion
authors.initials: M
authors.lastname: O'Connor
authors.forename: Wendell L
authors.initials: WL
authors.lastname: Roelofs
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005216:Fat Body / Q000201:enzymology; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000737:chemistry; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect; D008969:Molecular Sequence Data; D009036:Moths / Q000201:enzymology* / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012724:Sex Attractants / Q000096:biosynthesis; D013237:Stereoisomerism
chemical_list: D018076:DNA, Complementary; D005231:Fatty Acids, Unsaturated; D011994:Recombinant Proteins; D012724:Sex Attractants; D044943:Fatty Acid Desaturases