Journal Article

Arabidopsis Contains Nine Long-Chain Acyl-Coenzyme A Synthetase Genes That Participate in Fatty Acid and Glycerolipid Metabolism

Martin S. Fulda, Jay M. Shockey, Browse, John A.

2002

Overview

Long-chain acyl-coenzyme A (CoA) synthetases (LACSs) activate free fatty acids to acyl-CoA thioesters and as such play critical roles in fatty acid metabolism. This important class of enzymes factors prominently in several fatty acid-derived metabolic pathways, including phospholipid, triacylglycerol, and jasmonate biosynthesis and fatty acid β-oxidation. In an effort to better understand the factors that control fatty acid metabolism in oilseeds, we have sought to identify and characterize genes that encode LACSs in Arabidopsis. Nine cDNAs were identified, cloned, and tested for their ability to complement a LACS-deficient strain of yeast (Saccharomyces cerevisiae). Seven of the nine successfully restored growth, whereas two cDNAs encoding putative peroxisomal isoforms did not. Lysates from yeast cells overexpressing each of the nine cDNAs were active in LACS enzyme assays using oleic acid as a substrate. The substrate specificities of the enzymes were determined after overexpression in LACS-deficient Escherichia coli. Most of the LACS enzymes displayed highest levels of activity with the fatty acids that make up the common structural and storage lipids in Arabidopsis tissues. Analysis of the tissue-specific expression profiles for these genes revealed one flower-specific isoform, whereas all others were expressed in various tissues throughout the plant. These nine cDNAs are thought to constitute the entire LACS family in Arabidopsis, and as such, will serve as powerful tools in the study of acyl-CoA metabolism in oilseeds.

• Publisher: American Society of Plant Biologists,American Society of Plant Physiologists
• Subject: acetate-CoA ligase / Agronomy. Soil science and plant productions / Amino Acid Sequence / amino acid sequences / Amino acids / Arabidopsis / Arabidopsis - enzymology / Arabidopsis - genetics / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / Biochemical Processes and Macromolecular Structures / Biological and medical sciences / Biosynthesis / chemical constituents of plants / Cloning, Molecular / Coenzyme A Ligases / Coenzyme A Ligases - genetics / Coenzyme A Ligases - metabolism / Complementary DNA / E coli / Economic plant physiology / enzyme activity / Enzyme substrates / Enzymes / enzymology / Escherichia coli / Fatty acids / Fatty Acids - metabolism / Fundamental and applied biological sciences. Psychology / gene expression / Gene Expression Regulation, Enzymologic / Gene Expression Regulation, Plant / Genes / Genetic Complementation Test / genetics / Glycerides / Glycerides - metabolism / Isoenzymes / Isoenzymes - genetics / Isoenzymes - metabolism / Lipid metabolism / Lipids / long-chain-fatty-acid-CoA ligase / lyases / Metabolism / Metabolism. Physicochemical requirements / Molecular Sequence Data / Multigene Family / Multigene Family - genetics / Mutation / Nitrogen metabolism and other ones (excepting carbon metabolism) / Nutrition. Photosynthesis. Respiration. Metabolism / oilseeds / Phylogeny / plant development / Plant physiology and development / plant proteins / plant tissues / Saccharomyces cerevisiae / Saccharomyces cerevisiae - genetics / seedlings / Seeds / sequence analysis / Sequence Homology, Amino Acid / Substrate Specificity / Yeasts