Mutation in TACO1, encoding a translational activator of COX I, results in cytochrome c oxidase deficiency and late-onset Leigh syndrome.

Defects in mitochondrial translation are among the most common causes of mitochondrial disease, but the mechanisms that regulate mitochondrial translation remain largely unknown. In the yeast Saccharomyces cerevisiae, all mitochondrial mRNAs require specific translational activators, which recognize sequences in 5' UTRs and mediate translation. As mammalian mitochondrial mRNAs do not have significant 5' UTRs, alternate mechanisms must exist to promote translation. We identified a specific defect in the synthesis of the mitochondrial DNA (mtDNA)-encoded COX I subunit in a pedigree segregating late-onset Leigh syndrome and cytochrome c oxidase (COX) deficiency. We mapped the defect to chromosome 17q by functional complementation and identified a homozygous single-base-pair insertion in CCDC44, encoding a member of a large family of hypothetical proteins containing a conserved DUF28 domain. CCDC44, renamed TACO1 for translational activator of COX I, shares a notable degree of structural similarity with bacterial homologs, and our findings suggest that it is one of a family of specific mammalian mitochondrial translational activators.

Citation

Woranontee Weraarpachai, Hana Antonicka, Florin Sasarman, Jürgen Seeger, Bertold Schrank, Jill E Kolesar, Hanns Lochmüller, Mario Chevrette, Brett A Kaufman, Rita Horvath, Eric A Shoubridge. Mutation in TACO1, encoding a translational activator of COX I, results in cytochrome c oxidase deficiency and late-onset Leigh syndrome. Nature genetics. 2009 Jul;41(7):833-7

Mesh Tags

Substances

PMID: 19503089

search → result