CRL4(Cdt2)-mediated destruction of the histone methyltransferase Set8 prevents premature chromatin compaction in S phase

Mol Cell. 2010 Oct 8;40(1):22-33. doi: 10.1016/j.molcel.2010.09.015.

Abstract

The proper coordination between DNA replication and mitosis during cell-cycle progression is crucial for genomic stability. During G2 and mitosis, Set8 catalyzes monomethylation of histone H4 on lysine 20 (H4K20me1), which promotes chromatin compaction. Set8 levels decline in S phase, but why and how this occurs is unclear. Here, we show that Set8 is targeted for proteolysis in S phase and in response to DNA damage by the E3 ubiquitin ligase, CRL4(Cdt2). Set8 ubiquitylation occurs on chromatin and is coupled to DNA replication via a specific degron in Set8 that binds PCNA. Inactivation of CRL4(Cdt2) leads to Set8 stabilization and aberrant H4K20me1 accumulation in replicating cells. Transient S phase expression of a Set8 mutant lacking the degron promotes premature H4K20me1 accumulation and chromatin compaction, and triggers a checkpoint-mediated G2 arrest. Thus, CRL4(Cdt2)-dependent destruction of Set8 in S phase preserves genome stability by preventing aberrant chromatin compaction during DNA synthesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation* / drug effects
  • Cell Proliferation* / radiation effects
  • Chromatin Assembly and Disassembly* / drug effects
  • Chromatin Assembly and Disassembly* / radiation effects
  • Cullin Proteins / genetics
  • Cullin Proteins / metabolism*
  • DNA Damage
  • DNA Replication
  • Down-Regulation
  • Genomic Instability
  • HeLa Cells
  • Histone-Lysine N-Methyltransferase / genetics
  • Histone-Lysine N-Methyltransferase / metabolism*
  • Histones / genetics
  • Histones / metabolism*
  • Humans
  • Methylation
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Proliferating Cell Nuclear Antigen / metabolism
  • Protein Binding
  • Protein Processing, Post-Translational* / drug effects
  • Protein Processing, Post-Translational* / radiation effects
  • S Phase* / drug effects
  • S Phase* / radiation effects
  • Time Factors
  • Ubiquitin-Protein Ligases
  • Ubiquitination
  • Xenopus

Substances

  • Cullin Proteins
  • DTL protein, human
  • Histones
  • Nuclear Proteins
  • Proliferating Cell Nuclear Antigen
  • Histone-Lysine N-Methyltransferase
  • KMT5A protein, human
  • Ubiquitin-Protein Ligases