title: Identification and characterization of a fatty acyl reductase from a Spodoptera littoralis female gland involved in pheromone biosynthesis.
abstract: Fatty acyl-CoA reductases (FARs), the enzymes that catalyse reduction of a fatty acyl-CoA to the corresponding alcohol in insect pheromone biosynthesis, are postulated to play an important role in determining the proportion of each component in the pheromone blend. For the first time, we have isolated and characterized from the Egyptian cotton leaf worm Spodoptera littoralis (Lepidoptera: Noctuidae) a FAR cDNA (Slit-FAR1), which appeared to be expressed only in the pheromone gland and was undetectable in other female tissues, such as fat body, ovaries, wings, legs or thorax. The encoded protein has been successfully expressed in a recombinant system, and the recombinant enzyme is able to produce the intermediate fatty acid alcohols of the pheromone biosynthesis of S. littoralis from the corresponding acyl-CoA precursors. The kinetic variables Km and Vmax, which have been calculated for each acyl-CoA pheromone precursor, suggest that in S. littoralis pheromone biosynthesis other biosynthetic enzymes (e.g. desaturases, acetyl transferase) should also contribute to the final ratio of components of the pheromone blend. In a phylogenetic analysis, Slit-FAR1 appeared grouped in a cluster of other FARs involved in the pheromone biosynthesis of other insects, with little or non-specificity for the natural pheromone precursors.
authors.affiliation: Department of Biological Chemistry and Molecular Modelling, IQAC (CSIC), Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Carot-Sans
authors.forename: L
authors.initials: L
authors.lastname: Muñoz
authors.forename: M D
authors.initials: MD
authors.lastname: Piulachs
authors.forename: A
authors.initials: A
authors.lastname: Guerrero
authors.forename: G
authors.initials: G
authors.lastname: Rosell
mesh_terms: D042962:Acyl-CoA Oxidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D018076:DNA, Complementary / Q000378:metabolism; D005088:Exocrine Glands / Q000201:enzymology; D005233:Fatty Alcohols / Q000378:metabolism; D005260:Female; D008969:Molecular Sequence Data; D010675:Pheromones / Q000096:biosynthesis*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D018411:Spodoptera / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D005233:Fatty Alcohols; D010675:Pheromones; D042962:Acyl-CoA Oxidase
keywords: Egyptian cotton leaf worm; Spodoptera littoralis; cDNA identification; enzyme kinetics; fatty acyl-CoA reductase; pheromone biosynthesis