Publications

• Identification of the mitochondrial ATP-Mg/Pi transporter. Bacterial expression, reconstitution, functional characterization, and tissue distribution.

  Fiermonte G., De Leonardis F., Todisco S., Palmieri L., Lasorsa F.M., Palmieri F.

  The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttle metabolites, nucleotides, and cofactors through this membrane and thereby connect and/or regulate cytoplasm and matrix functions. ATP-Mg is tran ... >> More

  The mitochondrial carriers are a family of transport proteins that, with a few exceptions, are found in the inner membranes of mitochondria. They shuttle metabolites, nucleotides, and cofactors through this membrane and thereby connect and/or regulate cytoplasm and matrix functions. ATP-Mg is transported in exchange for phosphate, but no protein has ever been associated with this activity. We have isolated three human cDNAs that encode proteins of 458, 468, and 489 amino acids with 66-75% similarity and with the characteristic features of the mitochondrial carrier family in their C-terminal domains and three EF-hand Ca(2+)-binding motifs in their N-terminal domains. These proteins have been overexpressed in Escherichia coli and reconstituted into phospholipid vesicles. Their transport properties and their targeting to mitochondria demonstrate that they are isoforms of the ATP-Mg/Pi carrier described in the past in whole mitochondria. The tissue specificity of the three isoforms shows that at least one isoform was present in all of the tissues investigated. Because phosphate recycles via the phosphate carrier in mitochondria, the three isoforms of the ATP-Mg/Pi carrier are most likely responsible for the net uptake or efflux of adenine nucleotides into or from the mitochondria and hence for the variation in the matrix adenine nucleotide content, which has been found to change in many physiopathological situations. << Less

  J. Biol. Chem. 279:30722-30730(2004) [PubMed] [EuropePMC]

  This publication is cited by 11 other entries.

• A novel member of solute carrier family 25 (SLC25A42) is a transporter of coenzyme A and adenosine 3',5'-diphosphate in human mitochondria.

  Fiermonte G., Paradies E., Todisco S., Marobbio C.M., Palmieri F.

  Mitochondrial carriers are a family of proteins that transport metabolites, nucleotides, and cofactors across the inner mitochondrial membrane thereby connecting cytosolic and matrix functions. The essential cofactor coenzyme A (CoA) is synthesized outside the mitochondrial matrix and therefore mu ... >> More

  Mitochondrial carriers are a family of proteins that transport metabolites, nucleotides, and cofactors across the inner mitochondrial membrane thereby connecting cytosolic and matrix functions. The essential cofactor coenzyme A (CoA) is synthesized outside the mitochondrial matrix and therefore must be transported into mitochondria where it is required for a number of fundamental processes. In this work we have functionally identified and characterized SLC25A42, a novel human member of the mitochondrial carrier family. The SLC25A42 gene (Haitina, T., Lindblom, J., Renström, T., and Fredriksson, R., 2006, Genomics 88, 779-790) was overexpressed in Escherichia coli, purified, and reconstituted into phospholipid vesicles. Its transport properties, kinetic parameters, and targeting to mitochondria demonstrate that SLC25A42 protein is a mitochondrial transporter for CoA and adenosine 3',5'-diphosphate. SLC25A42 catalyzed only a counter-exchange transport, exhibited a high transport affinity for CoA, dephospho-CoA, ADP, and adenosine 3',5'-diphosphate, was saturable and inhibited by bongkrekic acid and other inhibitors of mitochondrial carriers to various degrees. The main physiological role of SLC25A42 is to import CoA into mitochondria in exchange for intramitochondrial (deoxy)adenine nucleotides and adenosine 3',5'-diphosphate. This is the first time that a mitochondrial carrier for CoA and adenosine 3',5'-diphosphate has been characterized biochemically. << Less

  J. Biol. Chem. 284:18152-18159(2009) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.

• A fourth ADP/ATP carrier isoform in man: identification, bacterial expression, functional characterization and tissue distribution.

  Dolce V., Scarcia P., Iacopetta D., Palmieri F.

  The mitochondrial ADP/ATP carriers (AACs) catalyze the exchange of cytosolic ADP for matrix ATP. We have identified and characterized a novel member of the AAC subfamily of mitochondrial metabolite transport proteins, termed AAC4. The AAC4 gene maps to human chromosome 4q28.1, and its product AAC4 ... >> More

  The mitochondrial ADP/ATP carriers (AACs) catalyze the exchange of cytosolic ADP for matrix ATP. We have identified and characterized a novel member of the AAC subfamily of mitochondrial metabolite transport proteins, termed AAC4. The AAC4 gene maps to human chromosome 4q28.1, and its product AAC4 is 66-68% identical to human AAC 1-3 and is localized to mitochondria. AAC4 transcripts are exclusively present in liver, testis and brain unlike those of AAC 1-3. Consistent with its belonging to the AAC subfamily, upon heterologous expression and reconstitution into liposomes AAC4 exchanges ADP for ATP by an electrogenic antiport mechanism with high specificity and high sensitivity to carboxyatractyloside and bongkrekic acid. << Less

  FEBS Lett. 579:633-637(2005) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.