title: Endoplasmic reticulum-associated inactivation of the hormone jasmonoyl-L-isoleucine by multiple members of the cytochrome P450 94 family in Arabidopsis.
abstract: The plant hormone jasmonate (JA) controls diverse aspects of plant immunity, growth, and development. The amplitude and duration of JA responses are controlled in large part by the intracellular level of jasmonoyl-L-isoleucine (JA-Ile). In contrast to detailed knowledge of the JA-Ile biosynthetic pathway, little is known about enzymes involved in JA-Ile metabolism and turnover. Cytochromes P450 (CYP) 94B3 and 94C1 were recently shown to sequentially oxidize JA-Ile to hydroxy (12OH-JA-Ile) and dicarboxy (12COOH-JA-Ile) derivatives. Here, we report that a third member (CYP94B1) of the CYP94 family also participates in oxidative turnover of JA-Ile in Arabidopsis. In vitro studies showed that recombinant CYP94B1 converts JA-Ile to 12OH-JA-Ile and lesser amounts of 12COOH-JA-Ile. Consistent with this finding, metabolic and physiological characterization of CYP94B1 loss-of-function and overexpressing plants demonstrated that CYP94B1 and CYP94B3 coordinately govern the majority (>95%) of 12-hydroxylation of JA-Ile in wounded leaves. Analysis of CYP94-promoter-GUS reporter lines indicated that CYP94B1 and CYP94B3 serve unique and overlapping spatio-temporal roles in JA-Ile homeostasis. Subcellular localization studies showed that CYP94s involved in conversion of JA-Ile to 12COOH-JA-Ile reside on endoplasmic reticulum (ER). In vitro studies further showed that 12COOH-JA-Ile, unlike JA-Ile, fails to promote assembly of COI1-JAZ co-receptor complexes. The double loss-of-function mutant of CYP94B3 and ILL6, a JA-Ile amidohydrolase, displayed a JA profile consistent with the collaborative action of the oxidative and the hydrolytic pathways in JA-Ile turnover. Collectively, our results provide an integrated view of how multiple ER-localized CYP94 and JA amidohydrolase enzymes attenuate JA signaling during stress responses.
authors.affiliation: From the Department of Energy-Plant Research Laboratory and the Division of Biochemistry, Interdisciplinary Plant Group, and kooaj@missouri.edu.
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Koo
authors.affiliation: From the Department of Energy-Plant Research Laboratory and.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Thireault
authors.affiliation: From the Department of Energy-Plant Research Laboratory and.
authors.forename: Starla
authors.initials: S
authors.lastname: Zemelis
authors.affiliation: the Division of Biochemistry, Interdisciplinary Plant Group, and Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211.
authors.forename: Arati N
authors.initials: AN
authors.lastname: Poudel
authors.affiliation: the Division of Biochemistry, Interdisciplinary Plant Group, and.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan, and.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kitaoka
authors.affiliation: From the Department of Energy-Plant Research Laboratory and.
authors.forename: Federica
authors.initials: F
authors.lastname: Brandizzi
authors.affiliation: Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan, and.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsuura
authors.affiliation: From the Department of Energy-Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824.
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Howe
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism; D055162:Biocatalysis; D003517:Cyclopentanes / Q000737:chemistry / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006706:Homeostasis; D006868:Hydrolysis; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D005810:Multigene Family; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D010084:Oxidation-Reduction; D054883:Oxylipins / Q000378:metabolism; D010641:Phenotype; D030821:Plants, Genetically Modified; D011485:Protein Binding; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D004269:DNA, Bacterial; D054883:Oxylipins; C036483:T-DNA; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; C011006:jasmonic acid; D003577:Cytochrome P-450 Enzyme System
keywords: Cytochrome P450; Fatty Acid Oxidation; Jasmonate; Plant Biochemistry; Plant Hormone; Stress Response