SUV3 helicase is required for correct processing of mitochondrial transcripts

Nucleic Acids Res. 2015 Sep 3;43(15):7398-413. doi: 10.1093/nar/gkv692. Epub 2015 Jul 7.


Mitochondrial gene expression is largely regulated by post-transcriptional mechanisms that control the amount and translation of each mitochondrial mRNA. Despite its importance for mitochondrial function, the mechanisms and proteins involved in mRNA turnover are still not fully characterized. Studies in yeast and human cell lines have indicated that the mitochondrial helicase SUV3, together with the polynucleotide phosphorylase, PNPase, composes the mitochondrial degradosome. To further investigate the in vivo function of SUV3 we disrupted the homolog of SUV3 in Drosophila melanogaster (Dm). Loss of dmsuv3 led to the accumulation of mitochondrial mRNAs, without increasing rRNA levels, de novo transcription or decay intermediates. Furthermore, we observed a severe decrease in mitochondrial tRNAs accompanied by an accumulation of unprocessed precursor transcripts. These processing defects lead to reduced mitochondrial translation and a severe respiratory chain complex deficiency, resulting in a pupal lethal phenotype. In summary, our results propose that SUV3 is predominantly required for the processing of mitochondrial polycistronic transcripts in metazoan and that this function is independent of PNPase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • DEAD-box RNA Helicases / physiology
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism
  • Drosophila Proteins / physiology*
  • Drosophila melanogaster / genetics
  • Electron Transport
  • Genes, Lethal
  • HeLa Cells
  • Humans
  • Mitochondria / genetics
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism
  • Mitochondrial Proteins / physiology*
  • Polyribonucleotide Nucleotidyltransferase / genetics
  • Protein Biosynthesis
  • RNA / metabolism*
  • RNA Helicases / genetics
  • RNA Helicases / metabolism
  • RNA Helicases / physiology*
  • RNA Processing, Post-Transcriptional*
  • RNA Stability
  • RNA, Messenger / metabolism
  • RNA, Mitochondrial
  • RNA, Ribosomal / metabolism
  • RNA, Transfer / metabolism


  • Drosophila Proteins
  • Mitochondrial Proteins
  • RNA, Messenger
  • RNA, Mitochondrial
  • RNA, Ribosomal
  • RNA
  • RNA, Transfer
  • Polyribonucleotide Nucleotidyltransferase
  • DEAD-box RNA Helicases
  • RNA Helicases
  • SUV3 protein, Drosophila