Taking it off: regulation of H3 K56 acetylation by Hst3 and Hst4

Cell Cycle. 2006 Nov;5(22):2561-5. doi: 10.4161/cc.5.22.3501. Epub 2006 Nov 15.


Histone modifications have been implicated in both DNA repair and checkpoint-mediated responses to DNA damage. Recently much attention has focused on the acetylation of H3 K56. Indeed, this modification is cell cycle-regulated, maintained upon replicative damage in a checkpoint-dependent manner, and is essential for surviving DNA damage. We and others have discovered that two members of the HDAC Sirtuin family, Hst3 and Hst4, negatively regulate H3 K56 acetylation in budding yeast. Additionally, we have shown that these two HDACs are targeted for repression by the DNA damage checkpoint, which is vital for DNA damage tolerance. Discovery that two HDACs are negative regulators of the cellular response to DNA damage and that they target the acetylation of H3 K56 reveals a complex relationship between histone modifications, HDACs, and the DNA damage response. Here, we discuss the recent reports of the regulation of H3 K56-Ac by Hst3 and Hst4 and put forth the critical questions that remain for understanding the intimate, though poorly characterized, connection between chromatin states and genomic maintenance.

Publication types

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

MeSH terms

  • Acetylation
  • Animals
  • Gene Expression Regulation
  • Genomic Instability
  • Histone Deacetylases / genetics
  • Histone Deacetylases / metabolism*
  • Histones / metabolism*
  • Humans
  • Models, Biological
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Sirtuins / metabolism*


  • Histones
  • Saccharomyces cerevisiae Proteins
  • Hst3 protein, S cerevisiae
  • Hst4 protein, S cerevisiae
  • Sirtuins
  • Histone Deacetylases