GUG is an efficient initiation codon to translate the human mitochondrial ATP6 gene

Biochem Biophys Res Commun. 2004 Jan 16;313(3):687-93. doi: 10.1016/j.bbrc.2003.12.013.


A maternally inherited and practically homoplasmic mitochondrial (mtDNA) mutation, 8527A>G, changing the initiation codon AUG into GUG, normally coding for a valine, was observed in the ATP6 gene encoding the ATPase subunit a. No alternate Met codon could replace the normal translational initiator. The patient harboring this mutation exhibited clinical symptoms suggesting a mitochondrial disease but his mother who carried the same mtDNA mutation was healthy. The mutation was absent from 100 controls and occurred once amongst 44 patients suspected of Leber Hereditary Optic Neuropathy (LHON) but devoid of typical LHON mutations. In patient fibroblasts, no effect of 8527A>G mutation could be demonstrated on the biosynthesis of mtDNA-encoded proteins, on size and the content of ATPase subunit a, on ATP hydrolysis and on mitochondrial membrane potential. In addition, ATP synthesis was barely decreased. Therefore, GUG is a functional initiation codon for the human ATP6 gene.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphate / biosynthesis
  • Adenosine Triphosphate / chemistry
  • Adult
  • Blotting, Western
  • Child
  • Codon, Initiator*
  • DNA / metabolism
  • Fibroblasts / metabolism
  • Flow Cytometry
  • Humans
  • Male
  • Mitochondria / metabolism*
  • Mitochondrial Proton-Translocating ATPases
  • Muscles / metabolism
  • Mutation
  • Oxygen / metabolism
  • Phosphorylation
  • Protein Biosynthesis*
  • Skin / metabolism
  • Valine / genetics


  • Codon, Initiator
  • MT-ATP6 protein, human
  • Adenosine Triphosphate
  • DNA
  • Adenosine Triphosphatases
  • Mitochondrial Proton-Translocating ATPases
  • Valine
  • Oxygen