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.
Brockdorff
Neil
N
X Inactivation Group, MRC Clinical Sciences Centre, ICSM, Hammersmith Hospital, DuCane Road, W12 0NN, London, UK. neil.brockdorff@hgmp.mrc.ac.uk
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