Identification of Mitochondrial Coenzyme A Transporters from Maize and Arabidopsis

• Published in: Plant physiology (Bethesda) 2013-06, Vol.162 (2), p.581-588
• Main Authors: Zallot, Rémi, Agrimi, Gennaro, Lerma-Ortiz, Claudia, Teresinski, Howard J., Frelin, Océane, Ellens, Kenneth W., Castegna, Alessandra, Russo, Annamaria, de Crécy-Lagard, Valérie, Mullen, Robert T., Palmieri, Ferdinando, Hanson, Andrew D.
• Format: Article
• Language: English
• Subjects: Antiporters - genetics; Antiporters - metabolism; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; BIOCHEMISTRY AND METABOLISM; Biological and medical sciences; Carrier Proteins - genetics; Carrier Proteins - metabolism; Chloroplasts; Chloroplasts - metabolism; Coenzyme A - metabolism; Coenzymes; Corn; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genetic Complementation Test; Genomes; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Mitochondria; Mitochondria - genetics; Mitochondria - metabolism; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Molecular Sequence Data; Phylogenetics; Pisum sativum - genetics; Pisum sativum - metabolism; Plant cells; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plants; Proteins; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Yeasts; Zea mays - genetics; Zea mays - metabolism
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.113.218081

Plants make coenzyme A (CoA) in the cytoplasm but use it for reactions in mitochondria, chloroplasts, and peroxisomes, implying that these organelles have CoA transporters. A plant peroxisomal CoA transporter is already known, but plant mitochondrial or chloroplastic CoA transporters are not. Mitochondrial CoA transporters belonging to the mitochondrial carrier family, however, have been identified in yeast (Saccharomyces cerevisiae; Leu-5p) and mammals (SLC25A42). Comparative genomic analysis indicated that angiosperms have two distinct homologs of these mitochondrial CoA transporters, whereas nonflowering plants have only one. The homologs from maize (Zea mays; GRMZM2G161299 and GRMZM2G420119) and Arabidopsis (Arabidopsis thaliana; Atlgl4560 and At4g26180) all complemented the growth defect of the yeast leu5A mitochondrial CoA carrier mutant and substantially restored its mitochondrial CoA level, confirming that these proteins have CoA transport activity. Dual-import assays with purified pea (Pisum sativum) mitochondria and chloroplasts, and subcellular localization of green fluorescent protein fusions in transiently transformed tobacco (Nicotiana tabacum) Bright Yellow-2 cells, showed that the maize and Arabidopsis proteins are targeted to mitochondria. Consistent with the ubiquitous importance of CoA, the maize and Arabidopsis mitochondrial CoA transporter genes are expressed at similar levels throughout the plant. These data show that representatives of both monocotyledons and eudicotyledons have twin, mitochondrially located mitochondrial carrier family carriers for CoA. The highly conserved nature of these carriers makes possible their reliable annotation in other angiosperm genomes.