Compositional and functional diversity of canonical PRC1 complexes in mammals

Biochim Biophys Acta Gene Regul Mech. 2017 Feb;1860(2):233-245. doi: 10.1016/j.bbagrm.2016.12.006. Epub 2016 Dec 20.


The compositional complexity of Polycomb Repressive Complex 1 (PRC1) increased dramatically during vertebrate evolution. What is considered the "canonical" PRC1 complex consists of four subunits originally identified as regulators of body segmentation in Drosophila. In mammals, each of these four canonical subunits consists of two to six paralogs that associate in a combinatorial manner to produce over a hundred possible distinct PRC1 complexes with unknown function. Genetic studies have begun to define the phenotypic roles for different PRC1 paralogs; however, relating these phenotypes to unique biochemical and transcriptional function for the different paralogs has been challenging. In this review, we attempt to address how the compositional diversity of canonical PRC1 complexes relates to unique roles for individual PRC1 paralogs in transcriptional regulation. This review focuses primarily on PRC1 complex composition, genome targeting, and biochemical function.

Keywords: Chromatin; Chromodomain; H2A119Ub; H3K27me3; Polycomb; Transcriptional repression.

Publication types

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

MeSH terms

  • Animals
  • Humans
  • Mammals / genetics*
  • Mammals / metabolism*
  • Phenotype
  • Polycomb Repressive Complex 1 / genetics*
  • Polycomb Repressive Complex 1 / metabolism*
  • Transcription, Genetic / genetics


  • Polycomb Repressive Complex 1