The dynamic dimerization of the yeast ADP/ATP carrier in the iunner mitochondrial membrane is affected by conserved cysteine residues

Dyall, S.D., Agius, S.C., De Marcos Lousa, C., Trézéguet, V. and Tokatlidis, K. (2003) The dynamic dimerization of the yeast ADP/ATP carrier in the iunner mitochondrial membrane is affected by conserved cysteine residues. Journal of Biological Chemistry, 278(29), pp. 26757-26764. (doi:10.1074/jbc.M302700200)

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Abstract

The ADP/ATP carrier (AAC) that facilitates the translocation of ATP made in mitochondria is inserted at the inner mitochondrial membrane by the TIM10-TIM22 protein import system. Here we addressed the state of the AAC precursor during insertion (stage IV of import) and identified residues of the carrier important for dimerization. By a combination of (i) import of a mix of His-tagged and untagged versions of AAC either 35S-labeled or unlabeled, (ii) import of a tandem covalent dimer AAC into wild-type mitochondria, and (iii) import of monomeric AAC into mitochondria expressing only the tandem covalent dimer AAC, we found that the stage IV intermediate is a monomer, and this stage is probably the rate-limiting step of insertion in the membrane. Subsequent dimerization occurs extremely rapidly (within less than a minute). The incoming monomer dimerizes with monomeric endogenous AAC suggesting that the AAC dimer is very dynamic. Conserved Cys residues were found not to affect insertion significantly, but they are crucial for the dimerization process to obtain a functional carrier.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Tokatlidis, Professor Kostas
Authors: Dyall, S.D., Agius, S.C., De Marcos Lousa, C., Trézéguet, V., and Tokatlidis, K.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:Journal of Biological Chemistry
Journal Abbr.:J Biol Chem.
Publisher:American Society for Biochemistry and Molecular Biology, Inc.
ISSN:0021-9258
ISSN (Online):1083-351X

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