Jasmonate response locus JAR1 and several related Arabidopsis genes encode enzymes of the firefly luciferase superfamily that show activity on jasmonic, salicylic, and indole-3-acetic acids in an assay for adenylation.
Jasmonic acid (JA) and related cyclopentanones are critical plant signaling molecules, but their mode of action at the molecular level is unclear. A map-based approach was used to identify the defective gene in the Arabidopsis JA response mutant jar1-1. JAR1 is 1 of 19 closely related Arabidopsis genes that are similar to the auxin-induced soybean GH3 gene. Analysis of fold predictions for this protein family suggested that JAR1 might belong to the acyl adenylate-forming firefly luciferase superfamily. These enzymes activate the carboxyl groups of a variety of substrates for their subsequent biochemical modification. An ATP-PPi isotope exchange assay was used to demonstrate adenylation activity in a glutathione S-transferase-JAR1 fusion protein. Activity was specific for JA, suggesting that covalent modification of JA is important for its function. Six other Arabidopsis genes were specifically active on indole-3-acetic acid (IAA), and one was active on both IAA and salicylic acid. These findings suggest that the JAR1 gene family is involved in multiple important plant signaling pathways.
Staswick
Paul E
PE
Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE 68583, USA.
Tiryaki
Iskender
I
Rowe
Martha L
ML
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001517:Coleoptera; D003517:Cyclopentanes / Q000494:pharmacology*; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008156:Luciferases / Q000235:genetics*; D009713:Nucleotidyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D054883:Oxylipins; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D010453:Peptide Synthases
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D007210:Indoleacetic Acids; D008156:Luciferases; D009713:Nucleotidyltransferases; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D020156:Salicylic Acid; C011006:jasmonic acid; C030737:indoleacetic acid; C412831:AT2G46370 protein, Arabidopsis; D010453:Peptide Synthases