title: A putative farnesoic acid O-methyltransferase (FAMeT) orthologue in Drosophila melanogaster (CG10527): relationship to juvenile hormone biosynthesis?
abstract: Juvenile hormones (JHs) are key regulators of both metamorphosis and adult reproductive processes. Farnesoic acid O-methyltransferase (FAMeT) is thought to be an important enzyme in the JH biosynthetic pathway, catalyzing methylation of farnesoic acid (FA) to methyl farnesoate (MF). Previous evidence in other insects suggested that FAMeT is rate limiting and regulated by a neuropeptide family, the allatostatins. A full-length cDNA encoding a 296 amino acid putative FAMeT has been isolated. A recombinant (r)FAMeT was cloned, expressed and a specific antiserum generated. rFAMeT was assayed for enzymatic activity using a radiochemical assay. In this assay, no activity was detected either with rFAMeT alone or when added to a corpus allatum CA extract. Immunohistochemical analysis was used to confirm the presence of FAMeT in the CA of Drosophila melanogaster ring gland. Analysis of MF, JHIII and JHB3 release in wild type and mutant stocks in the presence and absence of Drome AST (PISCF-type) suggest that Drosophila FAMeT has little if any effect on sesquiterpenoid biosynthesis. Drome AST appears to have a select effect on JH bisepoxide biosynthesis and not MF or JHIII. Additional analysis of MF, JHIII and JHB3 release in strains with a deficiency or decrease of FAMeT compared to wild type shows no significant decrease in MF, JHIII or JH bisepoxide synthesis. Deficiency strains that reduce the level of FAMeT showed reduced longevity relative to wildtype but this result may be due to other genetic influences.
authors.affiliation: Department of Biology, Queen's University, Kingston, Ont. K7L 3N6, Canada.
authors.forename: S M
authors.initials: SM
authors.lastname: Burtenshaw
authors.forename: P P
authors.initials: PP
authors.lastname: Su
authors.forename: J R
authors.initials: JR
authors.lastname: Zhang
authors.forename: S S
authors.initials: SS
authors.lastname: Tobe
authors.forename: L
authors.initials: L
authors.lastname: Dayton
authors.forename: W G
authors.initials: WG
authors.lastname: Bendena
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003335:Corpora Allata / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000378:metabolism; D005260:Female; D017353:Gene Deletion; D007605:Juvenile Hormones / Q000096:biosynthesis*; D007814:Larva / Q000378:metabolism; D008136:Longevity / Q000235:genetics; D008297:Male; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000494:pharmacology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029721:Drosophila Proteins; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D007605:Juvenile Hormones; D009479:Neuropeptides; D011994:Recombinant Proteins; C032429:methyl farnesoate; C076523:allatostatin; C058633:methyl 6,7-10,11-bis(epoxy)-3,7,11-trimethyl-2-dodecenoate; C007702:farnesoic acid; D008780:Methyltransferases; C032433:farnesoic acid O-methyltransferase