Recruitment of Drosophila Polycomb-group proteins by Polycomblike, a component of a novel protein complex in larvae

Development. 2008 Mar;135(5):813-7. doi: 10.1242/dev.016006. Epub 2008 Jan 23.

Abstract

Polycomb-group (PcG) proteins are highly conserved epigenetic transcriptional repressors that play central roles in numerous examples of developmental gene regulation. Four PcG repressor complexes have been purified from Drosophila embryos: PRC1, PRC2, Pcl-PRC2 and PhoRC. Previous studies described a hierarchical recruitment pathway of PcG proteins at the bxd Polycomb Response Element (PRE) of the Ultrabithorax (Ubx) gene in larval wing imaginal discs. The DNA-binding proteins Pho and/or Phol are required for target site binding by PRC2, which in turn is required for chromosome binding by PRC1. Here, we identify a novel larval complex that contains the PcG protein Polycomblike (Pcl) that is distinct from PRC1 and PRC2 and which is also dependent on Pho and/or Phol for binding to the bxd PRE in wing imaginal discs. RNAi-mediated depletion of Pcl in larvae disrupts chromosome binding by E(z), a core component of PRC2, but Pcl does not require E(z) for chromosome binding. These results place the Pcl complex (PCLC) downstream of Pho and/or Phol and upstream of PRC2 and PRC1 in the recruitment hierarchy.

Publication types

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

MeSH terms

  • Animals
  • Cell Nucleus / physiology*
  • Chromatin / isolation & purification
  • Chromatography, Gel
  • Chromosomes / physiology
  • Drosophila / genetics
  • Drosophila / growth & development*
  • Drosophila Proteins / genetics
  • Drosophila Proteins / isolation & purification
  • Drosophila Proteins / physiology*
  • Gene Expression Regulation, Developmental*
  • Genome
  • Larva
  • Polycomb Repressive Complex 1
  • Protein Binding
  • Repressor Proteins / genetics
  • Repressor Proteins / isolation & purification
  • Repressor Proteins / physiology*
  • Wings, Animal / embryology
  • Wings, Animal / growth & development

Substances

  • Chromatin
  • Drosophila Proteins
  • Pc protein, Drosophila
  • Pcl protein, Drosophila
  • Repressor Proteins
  • Polycomb Repressive Complex 1