SUMOylation of damaged DNA-binding protein DDB2

Biochem Biophys Res Commun. 2013 Aug 16;438(1):26-31. doi: 10.1016/j.bbrc.2013.07.013. Epub 2013 Jul 13.

Abstract

Damaged DNA-binding protein (DDB) is a heterodimer composed of two subunits, p127 and p48, which have been designated DDB1 and DDB2, respectively. DDB2 recognizes and binds to UV-damaged DNA during nucleotide excision repair. Here, we demonstrated that DDB2 was SUMOylated in a UV-dependent manner, and its major SUMO E3 ligase was PIASy as determined by RNA interference-mediated knockdown. The UV-induced physical interaction between DDB2 and PIASy supported this notion. PIASy knockdown reduced the removal of cyclobutane pyrimidine dimers (CPDs) from total genomic DNA, but did not affect that of 6-4 pyrimidine pyrimidone photoproducts (6-4PPs). Thus, DDB2 plays an indispensable role in CPD repair, but not in 6-4PP repair, which is consistent with the observation that DDB2 was SUMOylated by PIASy. These results suggest that the SUMOylation of DDB2 facilitates CPD repair.

Keywords: DDB2; NER; PIASy; SUMOylation; UV damage.

MeSH terms

  • DNA / physiology*
  • DNA / radiation effects*
  • DNA Damage / physiology*
  • DNA Repair / physiology*
  • DNA Repair / radiation effects
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • HeLa Cells
  • Humans
  • Radiation Dosage
  • SUMO-1 Protein / genetics
  • SUMO-1 Protein / metabolism*
  • Sumoylation / physiology*
  • Sumoylation / radiation effects
  • Ultraviolet Rays

Substances

  • DDB2 protein, human
  • DNA-Binding Proteins
  • SUMO-1 Protein
  • DNA