AAC1/YMR056C Summary Help

Standard Name AAC1 1
Systematic Name YMR056C
Feature Type ORF, Verified
Description Mitochondrial inner membrane ADP/ATP translocator; exchanges cytosolic ADP for mitochondrially synthesized ATP; phosphorylated; Aac1p is a minor isoform while Pet9p is the major ADP/ATP translocator; relocalizes from mitochondrion to cytoplasm upon DNA replication stress (2, 3, 4 and see Summary Paragraph)
Name Description ADP/ATP Carrier 1
Chromosomal Location
ChrXIII:388244 to 387315 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All AAC1 GO evidence and references
  View Computational GO annotations for AAC1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 18 genes
Classical genetics
Large-scale survey
31 total interaction(s) for 27 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 7
  • Affinity Capture-RNA: 2
  • PCA: 1
  • Two-hybrid: 1

Genetic Interactions
  • Negative Genetic: 9
  • Phenotypic Enhancement: 2
  • Positive Genetic: 7
  • Synthetic Lethality: 1
  • Synthetic Rescue: 1

Expression Summary
Length (a.a.) 309
Molecular Weight (Da) 34,120
Isoelectric Point (pI) 10.54
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIII:388244 to 387315 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..930 388244..387315 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004660

PET9, AAC1, and AAC3 are members of a gene family encoding adenine nucleotide translocators of the mitochondrial inner membrane (1, 5). The primary role of the translocators is to pump ADP into the mitochondrion and ATP out of the organelle. However, under certain conditions, such as during exponential growth on glucose under aerobic conditions, they act in the opposite direction, importing ATP into mitochondria (6). Competition experiments suggest that they also import heme into mitochondria, and all three proteins bind to heme (7). Genetic evidence indicates a possible role of the ADP/ATP carriers in apoptosis (8). Pet9p physically interacts with various complexes of the mitochondrial inner membrane, including the TIM23 complex and the cytochrome c oxidase - ubiquinol-cytochrome c reductase supercomplex, and these interactions are dependent on the presence of the phospholipid cardiolipin (9, 10).

PET9 encodes the major isoform of the translocator (11). A pet9 null mutant strain, despite having wild-type copies of AAC1 and AAC3, is unable to respire (i.e., cannot utilize non-fermentable carbon sources such as glycerol or ethanol), and additionally displays a "petite-negative" phenotype, meaning that it cannot survive the loss of the mitochondrial genome (12). AAC1 is expressed at a very low level compared to PET9, and can complement the pet9 mutant phenotypes only if the gene, with its native promoter, is present in multiple copies (1). AAC3 is expressed primarily under anaerobic conditions, and is also capable of complementing the pet9 mutant phenotypes if overexpressed (5). The pet9 aac1 aac3 triple null mutant is viable under standard conditions (growing on fermentable carbon sources such as glucose), but is inviable under anaerobic conditions (13).

All three paralogs are similar to adenine nucleotide translocators in higher organisms. Mutations in the human ANT1 gene (OMIM), encoding the heart and skeletal muscle-specific isoform, are associated with serious diseases. Dominant missense ANT1 mutations are found in patients with progressive external ophthalmoplegia. The equivalent mutations in S. cerevisiae PET9 cause reduction or loss of function, and may lead to the formation of an unregulated channel in the mitochondrial membrane (14, 15). A recessive ANT1 mutation, whose yeast equivalent in PET9 causes a complete loss of function, is associated with hypertrophic cardiomyopathy (16).

Last updated: 2010-05-10 Contact SGD

References cited on this page View Complete Literature Guide for AAC1
1) Lawson JE and Douglas MG  (1988) Separate genes encode functionally equivalent ADP/ATP carrier proteins in Saccharomyces cerevisiae. Isolation and analysis of AAC2. J Biol Chem 263(29):14812-8
2) Gawaz M, et al.  (1990) Structure-function studies of adenine nucleotide transport in mitochondria. II. Biochemical analysis of distinct AAC1 and AAC2 proteins in yeast. J Biol Chem 265(24):14202-8
3) Reinders J, et al.  (2007) Profiling phosphoproteins of yeast mitochondria reveals a role of phosphorylation in assembly of the ATP synthase. Mol Cell Proteomics 6(11):1896-906
4) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
5) Kolarov J, et al.  (1990) A third ADP/ATP translocator gene in yeast. J Biol Chem 265(21):12711-6
6) Traba J, et al.  (2008) Yeast mitochondria import ATP through the calcium-dependent ATP-Mg/Pi carrier Sal1p, and are ATP consumers during aerobic growth in glucose. Mol Microbiol 69(3):570-85
7) Azuma M, et al.  (2008) Adenine nucleotide translocator transports haem precursors into mitochondria. PLoS One 3(8):e3070
8) Pereira C, et al.  (2007) ADP/ATP carrier is required for mitochondrial outer membrane permeabilization and cytochrome c release in yeast apoptosis. Mol Microbiol 66(3):571-82
9) Dienhart MK and Stuart RA  (2008) The Yeast Aac2 Protein Exists in Physical Association with the Cytochrome bc1-COX Supercomplex and the TIM23 Machinery. Mol Biol Cell 19(9):3934-43
10) Claypool SM, et al.  (2008) Cardiolipin defines the interactome of the major ADP/ATP carrier protein of the mitochondrial inner membrane. J Cell Biol 182(5):937-50
11) Smith CP and Thorsness PE  (2008) The Molecular Basis for Relative Physiological Functionality of the ADP/ATP Carrier Isoforms in Saccharomyces cerevisiae. Genetics 179(3):1285-99
12) Chen XJ and Clark-Walker GD  (2000) The petite mutation in yeasts: 50 years on. Int Rev Cytol 194:197-238
13) Drgon T, et al.  (1991) ADP/ATP translocator is essential only for anaerobic growth of yeast Saccharomyces cerevisiae. FEBS Lett 289(2):159-62
14) Fontanesi F, et al.  (2004) Mutations in AAC2, equivalent to human adPEO-associated ANT1 mutations, lead to defective oxidative phosphorylation in Saccharomyces cerevisiae and affect mitochondrial DNA stability. Hum Mol Genet 13(9):923-34
15) Chen XJ  (2002) Induction of an unregulated channel by mutations in adenine nucleotide translocase suggests an explanation for human ophthalmoplegia. Hum Mol Genet 11(16):1835-43
16) Palmieri L, et al.  (2005) Complete loss-of-function of the heart/muscle-specific adenine nucleotide translocator is associated with mitochondrial myopathy and cardiomyopathy. Hum Mol Genet 14(20):3079-88