Role of polycomb proteins Ring1A and Ring1B in the epigenetic regulation of gene expression.
Generation of cell diversity depends on epigenetic regulatory mechanisms. Polycomb group (PcG) proteins are central components of epigenetic regulation in metazoans. The system, initially associated with transcriptional program stability during development, is also involved in the regulation of other processes, such as maintenance of stem cell pluripotency and cell proliferation. PcG regulation involves chromatin modifications through covalent histone modifications. One of these modifications, the monoubiquitylation of the H2A histone, depends on Ring1 proteins, which are essential for development in insects and mammals. In murine embryonic stem cells, Ring1A and Ring1B-dependent ubiquitylation of H2A is linked to repression of transcriptional initiation. Studies in mammalian cells have found a multiplicity of protein complexes containing Ring1A and Ring1B, suggesting an expanded regulatory role for Ring1A, Ring1B proteins in the epigenetic regulation of gene expression.
Department of Developmental and Cell Biology, Centro de Investigaciones Biologicas, CSIC, Madrid, Spain. mvidal@cib.csic.es
Miguel
M
Vidal
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D004268:DNA-Binding Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D010802:Phylogeny; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D063150:Polycomb Repressive Complex 1; D012097:Repressor Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D044767:Ubiquitin-Protein Ligases
D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1; C489840:Ring1 protein, mouse; C489842:Rnf2 protein, mouse; D044767:Ubiquitin-Protein Ligases