Post-translational decrease in respiratory chain proteins in the Polg mutator mouse brain

PLoS One. 2014 Apr 10;9(4):e94646. doi: 10.1371/journal.pone.0094646. eCollection 2014.


Mitochondrial DNA damage is thought to be a causal contributor to aging as mice with inactivating mutations in polymerase gamma (Polg) develop a progeroid phenotype. To further understand the molecular mechanisms underlying this phenotype, we used iTRAQ and RNA-Seq to determine differences in protein and mRNA abundance respectively in the brains of one year old Polg mutator mice compared to control animals. We found that mitochondrial respiratory chain proteins are specifically decreased in abundance in the brains of the mutator mice, including several nuclear encoded mitochondrial components. However, we found no evidence that the changes we observed in protein levels were the result of decreases in mRNA expression. These results show that there are post-translational effects associated with mutations in Polg.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Brain / metabolism*
  • DNA Polymerase gamma
  • DNA, Mitochondrial / genetics
  • DNA-Directed DNA Polymerase / genetics*
  • DNA-Directed DNA Polymerase / metabolism
  • Electron Transport / genetics*
  • Mice
  • Mitochondria / genetics
  • Mitochondria / metabolism
  • Mutation
  • Phenotype
  • Protein Biosynthesis / physiology*


  • DNA, Mitochondrial
  • DNA Polymerase gamma
  • DNA-Directed DNA Polymerase
  • Polg protein, mouse