共查询到20条相似文献,搜索用时 218 毫秒
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Philipp A. Steffen Jo?o Pedro Fonseca Cornelia G?nger Eva Dworschak Tobias Kockmann Christian Beisel Leonie Ringrose 《Nucleic acids research》2013,41(10):5235-5250
The Polycomb (PcG) and Trithorax (TrxG) group proteins work antagonistically on several hundred developmentally important target genes, giving stable mitotic memory, but also allowing flexibility of gene expression states. How this is achieved in quantitative terms is poorly understood. Here, we present a quantitative kinetic analysis in living Drosophila of the PcG proteins Enhancer of Zeste, (E(Z)), Pleiohomeotic (PHO) and Polycomb (PC) and the TrxG protein absent, small or homeotic discs 1 (ASH1). Fluorescence recovery after photobleaching and fluorescence correlation spectroscopy reveal highly dynamic chromatin binding behaviour for all proteins, with exchange occurring within seconds. We show that although the PcG proteins substantially dissociate from mitotic chromatin, ASH1 remains robustly associated with chromatin throughout mitosis. Finally, we show that chromatin binding by ASH1 and PC switches from an antagonistic relationship in interphase, to a cooperative one during mitosis. These results provide quantitative insights into PcG and TrxG chromatin-binding dynamics and have implications for our understanding of the molecular nature of epigenetic memory. 相似文献
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The Polycomb (PcG) and Trithorax (TrxG) group proteins are essential for development in all multicellular organisms. Mutations
of the PcG and TrxG genes act as early embryonic lethals, while their overexpression correlates with malignancies. Comparative
genomic analysis showed that PcG and TrxG form a binary regulatory system that functions as an epigenetic rheostat to determine
the threshold levels of extracellular signals affecting the expression levels of key developmental genes. 相似文献
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The Polycomb (PcG) and Trithorax (TrxG) group proteins are essential for development in all multicellular organisms. Mutations of the PcG and TrxG genes act as early embryonic lethals, while their overexpression correlates with malignancies. Comparative genome analysis showed that PcG and TrxG form a binary regulatory system that functions as an epigenetic rheostat to determine the threshold levels of extracellular signals affecting the expression levels of key developmental genes. 相似文献
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Developmental genetic studies in Drosophila unraveled the importance of Polycomb group (PcG) and Trithorax group (TrxG) genes in controlling cellular identity.PcG and TrxG proteins form histone modifying complexes that catalyze repressive or activating histone modifications,respectively,and thus maintaining the expression status of homeotic genes.Human orthologs of PcG and TrxG genes are implicated in tumorigenesis as well as in determining the prognosis of individual cancers.Recent whole genome analyses of cancers also highlighted the importance of histone modifying proteins in controlling tumorigenesis.Comprehensive understanding of the mechanistic relationship between histone regulation and tumorigenesis holds the promise of significantly advancing our understanding and management of cancer.It is anticipated that Drosophila melanogaster,the model organism that contributed significantly to our understanding of the functional role of histone regulation in development,could also provide unique insight for our understanding of how histone dysregulation can lead to cancer.In this review,we will discuss several recent advances in this regard. 相似文献
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《遗传学报》2011,38(1)
Developmental genetic studies in Drosophila unraveled the importance of Polycomb group (PcG) and Trithorax group (TrxG) genes in controlling cellular identity.PcG and TrxG proteins form histone modifying complexes that catalyze repressive or activating histone modifications,respectively,and thus maintaining the expression status of homeotic genes.Human orthologs of PcG and TrxG genes are implicated in tumorigenesis as well as in determining the prognosis of individual cancers.Recent whole genome analyses of cancers also highlighted the importance of histone modifying proteins in controlling tumorigenesis.Comprehensive understanding of the mechanistic relationship between histone regulation and tumorigenesis holds the promise of significantly advancing our understanding and management of cancer.It is anticipated that Drosophila melanogaster,the model organism that contributed significantly to our understanding of the functional role of histone regulation in development,could also provide unique insight for our understanding of how histone dysregulation can lead to cancer.In this review,we will discuss several recent advances in this regard. 相似文献
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Environmentally coordinated epigenetic silencing of FLC by protein and long noncoding RNA components 总被引:1,自引:0,他引:1
In Arabidopsis, the role of the vernalization pathway is to repress expression of a potent floral repressor, FLOWERING LOCUS C (FLC), after a sufficient period of winter cold has been perceived. Following winter, the lack of FLC expression allows unimpeded operation of the photoperiod pathway and hence rapid flowering of vernalized plants in spring via the activation of floral integrator genes. Molecular studies revealed that regulation of the key floral repressor, FLC, is under the control of the interplay between Trithorax group (TrxG)-mediated activation and Polycomb group (PcG)-mediated repression. On-off switch of genes by TrxG and PcG is an evolutionarily conserved mechanism to coordinate cellular identity in eukaryotes. Regulation of FLC by external cues provides an excellent model system to study mechanisms in which cell identity is influenced by environment. In this review, we discuss coordinated contributions by protein and long noncoding RNA components to this environmentally induced epigenetic switch of a developmental program in plants. 相似文献
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O. Lamiable M. Rabhi F. Peronnet D. Locker M. Decoville 《Genesis (New York, N.Y. : 2000)》2010,48(4):244-253
Two main classes of proteins, Polycomb group (PcG) and Trithorax group (TrxG), play a key role in the regulation of homeotic genes. These proteins act in multimeric complexes to remodel chromatin. A third class of proteins named Enhancers of Trithorax and Polycomb (ETP) modulates the activity of TrxG and PcG, but their role remains largely unknown. We previously identified an HMGB‐like protein, DSP1 (Dorsal Switch Protein 1), which was classified as an ETP. Preliminary studies have revealed that DSP1 is involved in multimeric complexes. Here we identify a DEAD‐box RNA helicase, Rm62, as partner of DSP1 in a 250‐kDa complex. Coimmunoprecipitation assays performed on embryo extracts indicate that DSP1 and Rm62 are associated in 3‐ to 12‐h embryos. Furthermore, DSP1 and Rm62 colocalize on polytene chromosomes. Consistent with these results, a mutation in Rm62 enhances a null mutation of dsp1 and also mutations of trxG or PcG, suggesting that Rm62 has characteristics of an ETP. We show here for the first time that an RNA helicase is involved in the maintenance of homeotic genes. genesis 48:244–253, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
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