A human short open reading frame (sORF)-encoded polypeptide that stimulates DNA end joining

J Biol Chem. 2014 Apr 18;289(16):10950-10957. doi: 10.1074/jbc.C113.533968. Epub 2014 Mar 7.


The recent discovery of numerous human short open reading frame (sORF)-encoded polypeptides (SEPs) has raised important questions about the functional roles of these molecules in cells. Here, we show that a 69-amino acid SEP, MRI-2, physically interacts with the Ku heterodimer to stimulate DNA double-strand break ligation via nonhomologous end joining. The characterization of MRI-2 suggests that this SEP may participate in DNA repair and underscores the potential of SEPs to serve important biological functions in mammalian cells.

Keywords: DNA Repair; Peptide Interactions; Peptides; Protein-Protein Interactions; Proteomics; Short ORF.

Publication types

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

MeSH terms

  • Cell Line
  • DNA Breaks, Double-Stranded*
  • DNA End-Joining Repair / physiology*
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • Humans
  • Ku Autoantigen
  • Open Reading Frames / physiology*


  • DNA Helicases
  • XRCC5 protein, human
  • Ku Autoantigen