Phosphorylation of the linker histone H1 by CDK regulates its binding to HP1alpha

Mol Cell. 2006 Jun 9;22(5):693-9. doi: 10.1016/j.molcel.2006.04.016.


Two key components of mammalian heterochromatin that play a structural role in higher order chromatin organization are the heterochromatin protein 1alpha (HP1alpha) and the linker histone H1. Here, we show that these proteins interact in vivo and in vitro through their hinge and C-terminal domains, respectively. The phosphorylation of H1 by CDK2, which is required for efficient cell cycle progression, disrupts this interaction. We propose that phosphorylation of H1 provides a signal for the disassembly of higher order chromatin structures during interphase, independent of histone H3-lysine 9 (H3-K9) methylation, by reducing the affinity of HP1alpha for heterochromatin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Chromatin / genetics
  • Chromatin / metabolism
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Cyclin-Dependent Kinase 2 / genetics
  • Cyclin-Dependent Kinase 2 / metabolism*
  • Fluorescent Antibody Technique
  • Gene Expression Regulation
  • Histones / metabolism*
  • Humans
  • Interphase
  • Mice
  • NIH 3T3 Cells
  • Phosphorylation
  • Protein Binding
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Tumor Cells, Cultured


  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Histones
  • Recombinant Fusion Proteins
  • heterochromatin-specific nonhistone chromosomal protein HP-1
  • Cyclin-Dependent Kinase 2