X-chromosome inactivation: closing in on proteins that bind Xist RNA.
X inactivation is the developmentally regulated silencing of a single X chromosome in XX female mammals. In recent years, the Xist gene has been revealed as the master regulatory switch controlling this process. Parental imprinting and/or counting mechanisms ensure that Xist is expressed only on the inactive X chromosome. Chromosome silencing then results from the accumulation of the Xist RNA silencing signal, in cis, over the entire length of the X chromosome. A key issue has been to identify the factors that interact with Xist RNA to initiate heritable gene silencing. This review discusses recent progress that has put this goal in sight.
X Inactivation Group, MRC Clinical Sciences Centre, ICSM, Hammersmith Hospital, DuCane Road, W12 0NN, London, UK. neil.brockdorff@hgmp.mrc.ac.uk
Neil
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Brockdorff
D000818:Animals; D004303:Dosage Compensation, Genetic; D005260:Female; D020868:Gene Silencing; D006657:Histones / Q000378:metabolism; D006801:Humans; D063151:Polycomb Repressive Complex 2; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014960:X Chromosome
C491488:EED protein, human; D006657:Histones; D011506:Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D012097:Repressor Proteins; D014157:Transcription Factors; C077885:XIST non-coding RNA; D063151:Polycomb Repressive Complex 2