Identification, expression, and functional analyses of a thylakoid ATP/ADP carrier from Arabidopsis

Research output: Contribution to journalArticle


In plants the chloroplast thylakoid membrane is the site of light-dependent photosynthetic reactions coupled to ATP synthesis. The ability of the plant cell to build and alter this membrane system is essential for efficient photosynthesis. A nucleotide translocator homologous to the bovine mitochondrial ADP/ATP carrier (AAC) was previously found in spinach thylakoids. Here we have identified and characterized a thylakoid ATP/ADP carrier (TAAC) from Arabidopsis.(i) Sequence homology with the bovine AAC and the prediction of chloroplast transit peptides indicated a putative carrier encoded by the At5g01500 gene, as a TAAC. (ii) Transiently expressed TAAC-green fluorescent protein fusion construct was targeted to the chloroplast. Western blotting using a peptide-specific antibody together with immunogold electron microscopy revealed a major location of TAAC in the thylakoid membrane. Previous proteomic analyses identified this protein in chloroplast envelope preparations. (iii) Recombinant TAAC protein specifically imports ATP in exchange for ADP across the cytoplasmic membrane of Escherichia coli. Studies on isolated thylakoids from Arabidopsis confirmed these observations. (iv) The lack of TAAC in an Arabidopsis T-DNA insertion mutant caused a 30-40% reduction in the thylakoid ATP transport and metabolism. (v) TAAC is readily expressed in dark-grown Arabidopsis seedlings, and its level remains stable throughout the greening process. Its expression is highest in developing green tissues and in leaves undergoing senescence or abiotic stress. We propose that the TAAC protein supplies ATP for energy-dependent reactions during thylakoid biogenesis and turnover in plants.


  • Sophie Thuswaldner
  • Jens O Lagerstedt
  • Marc Rojas-Stütz
  • Karim Bouhidel
  • Christophe Declercq
  • Nathalie Leborgne-Castel
  • Arti Mishra
  • Francis Marty
  • Benoît Schoefs
  • Iwona Adamska
  • Bengt L Persson
  • Cornelia Spetea
External organisations
  • University of Kalmar
Research areas and keywords


  • Amino Acid Sequence, Animals, Antiporters, Arabidopsis, Arabidopsis Proteins, Cattle, Chloroplasts, Escherichia coli, Green Fluorescent Proteins, Models, Molecular, Molecular Sequence Data, Mutation, Oxidative Stress, Protein Conformation, Recombinant Proteins, Sequence Homology, Amino Acid, Thylakoids, Journal Article, Research Support, Non-U.S. Gov't
Original languageEnglish
Pages (from-to)8848-59
JournalJournal of Biological Chemistry
Issue number12
Publication statusPublished - 2007 Mar 23
Publication categoryResearch
Externally publishedYes