Drosophila Reptin and other TIP60 complex components promote generation of silent chromatin

Genetics. 2006 Sep;174(1):241-51. doi: 10.1534/genetics.106.059980. Epub 2006 Jul 2.

Abstract

Histone acetyltransferase (HAT) complexes have been linked to activation of transcription. Reptin is a subunit of different chromatin-remodeling complexes, including the TIP60 HAT complex. In Drosophila, Reptin also copurifies with the Polycomb group (PcG) complex PRC1, which maintains genes in a transcriptionally silent state. We demonstrate genetic interactions between reptin mutant flies and PcG mutants, resulting in misexpression of the homeotic gene Scr. Genetic interactions are not restricted to PRC1 components, but are also observed with another PcG gene. In reptin homozygous mutant cells, a Polycomb response-element-linked reporter gene is derepressed, whereas endogenous homeotic gene expression is not. Furthermore, reptin mutants suppress position-effect variegation (PEV), a phenomenon resulting from spreading of heterochromatin. These features are shared with three other components of TIP60 complexes, namely Enhancer of Polycomb, Domino, and dMRG15. We conclude that Drosophila Reptin participates in epigenetic processes leading to a repressive chromatin state as part of the fly TIP60 HAT complex rather than through the PRC1 complex. This shows that the TIP60 complex can promote the generation of silent chromatin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology*
  • Chromatin / metabolism*
  • Crosses, Genetic
  • DNA Helicases / genetics
  • DNA Helicases / physiology*
  • Drosophila / genetics*
  • Drosophila / metabolism
  • Drosophila Proteins / genetics
  • Drosophila Proteins / physiology*
  • Embryo, Nonmammalian
  • Epigenesis, Genetic / physiology
  • Female
  • Gene Expression Regulation, Developmental
  • Gene Order
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / physiology*
  • Male
  • Multiprotein Complexes / physiology
  • Mutation
  • Polycomb-Group Proteins
  • Regulatory Elements, Transcriptional
  • Repressor Proteins / genetics
  • Suppression, Genetic

Substances

  • Carrier Proteins
  • Chromatin
  • Drosophila Proteins
  • Multiprotein Complexes
  • Polycomb-Group Proteins
  • Repressor Proteins
  • rept protein, Drosophila
  • Histone Acetyltransferases
  • Tip60 protein, Drosophila
  • DNA Helicases