title: Mitochondrial tricarboxylate and dicarboxylate-tricarboxylate carriers: from animals to plants.
abstract: The citrate carrier (CiC), characteristic of animals, and the dicarboxylate-tricarboxylate carrier (DTC), characteristic of plants and protozoa, belong to the mitochondrial carrier protein family whose members are responsible for the exchange of metabolites, cofactors, and nucleotides between the cytoplasm and the mitochondrial matrix. Most of the functional data on these transporters are obtained from the studies performed with the protein purified from rat, eel yeast, and maize mitochondria or recombinant proteins from different sources incorporated into phospholipid vesicles (liposomes). The functional data indicate that CiC is responsible for the efflux of acetyl-CoA from the mitochondria to the cytosol in the form of citrate, the primer for fatty acid, cholesterol synthesis, and histone acetylation. Like the CiC, the citrate exported by DTC from the mitochondria to the cytosol in exchange for oxaloacetate can be cleaved by citrate lyase to acetyl-CoA and oxaloacetate and used for fatty acid elongation and isoprenoid synthesis. In addition to its role in fatty acid synthesis, CiC is involved in other processes such as gluconeogenesis, insulin secretion, inflammation, and cancer progression, whereas DTC is involved in the production of glycerate, nitrogen assimilation, ripening of fruits, ATP synthesis, and sustaining of respiratory flux in fruit cells. This review provides an assessment of the current understanding of CiC and DTC structural and biochemical characteristics, underlying the structure-function relationship of these carriers. Furthermore, a phylogenetic relationship between CiC and DTC is proposed.
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende Cosenza, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Dolce
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Cappello
authors.forename: Loredana
authors.initials: L
authors.lastname: Capobianco
mesh_terms: D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000502:physiology*; D029382:Dicarboxylic Acid Transporters / Q000502:physiology*; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000502:physiology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D011401:Promoter Regions, Genetic
chemical_list: D002352:Carrier Proteins; D029382:Dicarboxylic Acid Transporters; D024101:Mitochondrial Proteins; C020723:citrate-binding transport protein
keywords: citrate carrier; dicarboxylate-tricarboxylate carrier; gene expression regulation; mitochondrial carrier; phylogenetic analysis; substrate specificity.