Biochemical Journal

Research article

3′-Untranslated regions of oxidative phosphorylation mRNAs function in vivo as enhancers of translation

Carlo M. Di LIEGRO, Marianna BELLAFIORE, José M. IZQUIERDO, Anja RANTANEN, José M. CUEZVA

Abstract

Recent findings have indicated that the 3´-untranslated region (3´-UTR) of the mRNA encoding the β-catalytic subunit of the mitochondrial H+-ATP synthase has an in vitro translation-enhancing activity (TEA) [Izquierdo and Cuezva, Mol. Cell. Biol. (1997) 17, 5255–5268; Izquierdo and Cuezva, Biochem. J. (2000) 346, 849–855]. In the present work, we have expressed chimaeric plasmids that encode mRNA variants of green fluorescent protein in normal rat kidney and liver clone 9 cells to determine whether the 3´-UTRs of nuclear-encoded mRNAs involved in the biogenesis of mitochondria have an intrinsic TEA. TEA is found in the 3´-UTR of the mRNAs encoding the α- and β-subunits of the rat H+-ATP synthase complex, as well as in subunit IV of cytochrome c oxidase. No TEA is present in the 3´-UTR of the somatic mRNA encoding rat mitochondrial transcription factor A. Interestingly, the TEA of the 3´-UTR of mRNAs of oxidative phosphorylation is different, depending upon the cell type analysed. These data provide the first in vivo evidence of a novel cell-specific mechanism for the control of the translation of mRNAs required in mitochondrial function.

  • cytochrome c oxidase
  • green fluorescent protein
  • H+-ATP synthase
  • mitochondria
  • mitochondrial transcription factor A