DNA damage-inducible SUMOylation of HERC2 promotes RNF8 binding via a novel SUMO-binding Zinc finger

J Cell Biol. 2012 Apr 16;197(2):179-87. doi: 10.1083/jcb.201106152.

Abstract

Nonproteolytic ubiquitylation of chromatin surrounding deoxyribonucleic acid (DNA) double-strand breaks (DSBs) by the RNF8/RNF168/HERC2 ubiquitin ligases facilitates restoration of genome integrity by licensing chromatin to concentrate genome caretaker proteins near the lesions. In parallel, SUMOylation of so-far elusive upstream DSB regulators is also required for execution of this ubiquitin-dependent chromatin response. We show that HERC2 and RNF168 are novel DNA damage-dependent SUMOylation targets in human cells. In response to DSBs, both HERC2 and RNF168 were specifically modified with SUMO1 at DSB sites in a manner dependent on the SUMO E3 ligase PIAS4. SUMOylation of HERC2 was required for its DSB-induced association with RNF8 and for stabilizing the RNF8-Ubc13 complex. We also demonstrate that the ZZ Zinc finger in HERC2 defined a novel SUMO-specific binding module, which together with its concomitant SUMOylation and T4827 phosphorylation promoted binding to RNF8. Our findings provide novel insight into the regulatory complexity of how ubiquitylation and SUMOylation cooperate to orchestrate protein interactions with DSB repair foci.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Chromatin / metabolism
  • DNA Breaks, Double-Stranded
  • DNA Damage*
  • DNA Repair
  • DNA-Binding Proteins / metabolism*
  • Guanine Nucleotide Exchange Factors / metabolism*
  • HEK293 Cells
  • Humans
  • Poly-ADP-Ribose Binding Proteins
  • Protein Inhibitors of Activated STAT / metabolism
  • RNA Interference
  • RNA, Small Interfering
  • SUMO-1 Protein / metabolism
  • Sumoylation
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Ubiquitin-Protein Ligases / metabolism
  • Zinc Fingers / genetics

Substances

  • Chromatin
  • DNA-Binding Proteins
  • Guanine Nucleotide Exchange Factors
  • HERC2 protein, human
  • PIAS4 protein, human
  • Poly-ADP-Ribose Binding Proteins
  • Protein Inhibitors of Activated STAT
  • RNA, Small Interfering
  • RNF8 protein, human
  • SUMO-1 Protein
  • SUMO1 protein, human
  • UBE2N protein, human
  • Ubiquitin-Conjugating Enzymes
  • RNF168 protein, human
  • Ubiquitin-Protein Ligases