SUUR joins separate subsets of PcG, HP1 and B-type lamin targets in Drosophila

J Cell Sci. 2007 Jul 15;120(Pt 14):2344-51. doi: 10.1242/jcs.006007.


Drosophila melanogaster Suppressor of Under-Replication (SuUR) gene encodes a protein that modulates replicative properties of heterochromatin in endocycles of polytene cells. The SuUR mutation abolishes underreplication of intercalary heterochromatin and results in partial underreplication of pericentric heterochromatin. We performed a genome-wide mapping of SUUR target genes in non-polytenic Drosophila Kc cells by using the DamID approach. We show that SUUR preferentially binds genes that are transcriptionally silent and late-replicated. Distinct subsets of SUUR targets are associated with PcG proteins (Pc and Esc; Polycomb and Extra sexcombs), heterochromatic proteins [HP1 and SU(VAR)3-9] and B-type lamin. The SUUR binding profile negatively correlates with the DNA polytenization levels of salivary gland polytene chromosomes. Finally, SUUR target genes are repressed in Drosophila embryos and gradually activated later in development. Together these results suggest that SUUR is a ubiquitous marker of heterochromatin in different cell types.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism
  • Gene Expression Regulation, Developmental
  • Heterochromatin / metabolism
  • Histone-Lysine N-Methyltransferase
  • Lamin Type B / genetics
  • Lamin Type B / metabolism
  • Polycomb Repressive Complex 1
  • Polycomb Repressive Complex 2
  • Protein Binding


  • Chromosomal Proteins, Non-Histone
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Heterochromatin
  • Lamin Type B
  • Pc protein, Drosophila
  • SuUR protein, Drosophila
  • heterochromatin protein 1, Drosophila
  • Histone-Lysine N-Methyltransferase
  • Polycomb Repressive Complex 2
  • esc protein, Drosophila
  • Polycomb Repressive Complex 1