HP1a: a structural chromosomal protein regulating transcription

Trends Genet. 2014 Mar;30(3):103-10. doi: 10.1016/j.tig.2014.01.002. Epub 2014 Feb 17.


Heterochromatin protein 1 (HP1a in Drosophila) is a conserved eukaryotic chromosomal protein that is prominently associated with pericentric heterochromatin and mediates the concomitant gene silencing. Mechanistic studies implicate HP1 family proteins as 'hub proteins,' able to interact with a variety of chromosomal proteins through the chromo-shadow domain (CSD), as well as to recognize key histone modification sites [primarily histone H3 di/trimethyl Lys9 (H3K9me2/3)] through the chromodomain (CD). Consequently, HP1 has many important roles in chromatin architecture and impacts both gene expression and gene silencing, utilizing a variety of mechanisms. Clearly, HP1 function is altered by context, and potentially by post-translational modifications (PTMs). Here, we report on recent ideas as to how this versatile protein accomplishes its diverse functions.

Keywords: HP1a; chromodomain; gene expression; silencing.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Chromobox Protein Homolog 5
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Chromosomes / metabolism*
  • Gene Silencing
  • Humans
  • Protein Processing, Post-Translational / genetics
  • Transcription, Genetic*
  • Transcriptional Activation


  • Chromosomal Proteins, Non-Histone
  • Chromobox Protein Homolog 5