Polycomb purification by in vivo biotinylation tagging reveals cohesin and Trithorax group proteins as interaction partners
Open Access
- 17 March 2011
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 108 (14), 5572-5577
- https://doi.org/10.1073/pnas.1007916108
Abstract
The maintenance of specific gene expression patterns during cellular proliferation is crucial for the identity of every cell type and the development of tissues in multicellular organisms. Such a cellular memory function is conveyed by the complex interplay of the Polycomb and Trithorax groups of proteins (PcG/TrxG). These proteins exert their function at the level of chromatin by establishing and maintaining repressed (PcG) and active (TrxG) chromatin domains. Past studies indicated that a core PcG protein complex is potentially associated with cell type or even cell stage-specific sets of accessory proteins. In order to better understand the dynamic aspects underlying PcG composition and function we have established an inducible version of the biotinylation tagging approach to purify Polycomb and associated factors from Drosophila embryos. This system enabled fast and efficient isolation of Polycomb containing complexes under near physiological conditions, thereby preserving substoichiometric interactions. Novel interacting proteins were identified by highly sensitive mass spectrometric analysis. We found many TrxG related proteins, suggesting a previously unrecognized extent of molecular interaction of the two counteracting chromatin regulatory protein groups. Furthermore, our analysis revealed an association of PcG protein complexes with the cohesin complex and showed that Polycomb-dependent silencing of a transgenic reporter depends on cohesin function.Keywords
This publication has 40 references indexed in Scilit:
- Polycomb Group Proteins Set the Stage for Early Lineage CommitmentCell Stem Cell, 2010
- Cohesin, gene expression and development: Lessons from DrosophilaChromosome Research, 2009
- The Drosophila cohesin subunit Rad21 is a trithorax group (trxG) proteinProceedings of the National Academy of Sciences of the United States of America, 2008
- An Extended Transcriptional Network for Pluripotency of Embryonic Stem CellsCell, 2008
- Cell-Type-Specific TEV Protease Cleavage Reveals Cohesin Functions in Drosophila NeuronsDevelopmental Cell, 2008
- A protein interaction network for pluripotency of embryonic stem cellsNature, 2006
- Control of Developmental Regulators by Polycomb in Human Embryonic Stem CellsCell, 2006
- Polycomb complexes repress developmental regulators in murine embryonic stem cellsNature, 2006
- Genome-scale profiling of histone H3.3 replacement patternsNature Genetics, 2005
- Stabilization of Chromatin Structure by PRC1, a Polycomb ComplexCell, 1999