title: Biosynthetic pathway of insect juvenile hormone III in cell suspension cultures of the sedge Cyperus iria.
abstract: In most insect species, juvenile hormones regulate critical physiological processes such as metamorphosis and reproduction. In insects, these sesquiterpenoids are synthesized by retrocerebral endocrine organs, the corpora allata, via the classical mevalonate (MVA) pathway. One of these compounds, juvenile hormone III (JH III), has also been identified in the sedge Cyperus iria. In higher plants, biosynthesis of the sesquiterpenoid backbone may proceed through two distinct pathways: the MVA pathway or the 2C-methyl erythritol 4-phosphate pathway or through a combination of both pathways. Cell suspension cultures of C. iria were used to elucidate the biosynthetic pathway of JH III in the plant. Enzyme inhibition and labeling studies conclusively demonstrated that the biosynthesis of the sesquiterpenoid backbone of JH III proceeds via the MVA pathway. Inhibitor and precursor feeding studies also suggest that later steps of JH III biosynthesis in C. iria are similar to the insect pathway and that the final enzymatic reaction in JH III biosynthesis is catalyzed by a cytochrome P(450) monooxygenase.
authors.affiliation: Department of Zoology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5.
authors.forename: J C
authors.initials: JC
authors.lastname: Bede
authors.forename: P E
authors.initials: PE
authors.lastname: Teal
authors.forename: W G
authors.initials: WG
authors.lastname: Goodman
authors.forename: S S
authors.initials: SS
authors.lastname: Tobe
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000378:metabolism; D000818:Animals; D002250:Carbon Radioisotopes; D002338:Carotenoids / Q000096:biosynthesis; D002478:Cells, Cultured; D029786:Cyperus / Q000378:metabolism*; D065607:Cytochrome P-450 Enzyme Inhibitors; D003576:Electron Transport Complex IV / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004896:Erythritol / Q000031:analogs & derivatives* / Q000096:biosynthesis*; D005578:Fosfomycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D007313:Insecta / Q000378:metabolism*; D007605:Juvenile Hormones / Q000096:biosynthesis* / Q000145:classification; D008148:Lovastatin / Q000494:pharmacology; D008798:Mevalonic Acid / Q000378:metabolism*; D008825:Miconazole / Q000494:pharmacology; D008954:Models, Biological; D008956:Models, Chemical; D009097:Multienzyme Complexes / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*; D013403:Sugar Phosphates / Q000096:biosynthesis*
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D002250:Carbon Radioisotopes; D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D007605:Juvenile Hormones; D009097:Multienzyme Complexes; D012717:Sesquiterpenes; D013403:Sugar Phosphates; D005578:Fosfomycin; D002338:Carotenoids; C024640:fosmidomycin; D008825:Miconazole; D008148:Lovastatin; D010088:Oxidoreductases; C114231:1-deoxy-D-xylulose 5-phosphate reductoisomerase; D003576:Electron Transport Complex IV; D019747:Aldose-Ketose Isomerases; D004896:Erythritol; D008798:Mevalonic Acid