Diferenciación celular: Diferenzas entre revisións
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Alternately, upon receiving differentiation signals, PcG proteins are recruited to promoters of pluripotency transcription factors. PcG-deficient ES cells can begin differentiation but cannot maintain the differentiated phenotype.<ref name= "Christophersen"/> Simultaneously, differentiation and development-promoting genes are activated by Trithorax group (TrxG) chromatin regulators and lose their repression.<ref name= "Christophersen"/><ref name = "Guenther"/> TrxG proteins are recruited at regions of high transcriptional activity, where they catalyze the trimethylation of histone H3 lysine 4 (H3K4me3) and promote gene activation through histone acetylation.<ref name = "Guenther"/> PcG and TrxG complexes engage in direct competition and are thought to be functionally antagonistic, creating at differentiation and development-promoting loci what is termed a “bivalent domain” and rendering these genes sensitive to rapid induction or repression.<ref name = "Meissner">{{cite journal |pmid=20944600 |doi=10.1038/nbt.1684 |author=Meissner A |title=Epigenetic modifications in pluripotent and differentiated cells |journal=Nat Biotechnol |year= 2010 |volume=28 |issue=10 |pages=1079–88}}</ref>
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=====Posicionamento de nucleosomas=====
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