XIST RNA Associates with Specific Regions of the Inactive X Chromatin

• Published in: The Journal of biological chemistry 2000-11, Vol.275 (47), p.36491-36494
• Main Authors: Gilbert, Sandra L., Pehrson, John R., Sharp, Phillip A.
• Format: Article
• Language: English
• Subjects: Animals; Antibody Specificity; Cells, Cultured; Chromatin - chemistry; Dosage Compensation, Genetic; Fibronectins - genetics; Histones - genetics; Immune Sera; Mice; Promoter Regions, Genetic; RNA, Long Noncoding; RNA, Untranslated - genetics; RNA, Untranslated - immunology; Transcription Factors - genetics; Transcription Factors - immunology; X Chromosome; XIST gene
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.C000409200

Microscopy studies have shown thatXIST RNA colocalizes with the inactive X chromosome (Xi). However, the molecular basis for this colocalization is unknown. Here we provide two lines of evidence from chromatin immunoprecipitation experiments that XIST RNA physically associates with the Xi chromatin. First, XIST RNA can be co-precipitated by antiserum against macroH2A, a histone H2A variant enriched in the Xi. Second, XIST RNA can be co-precipitated by antisera that recognize unacetylated, but not acetylated, isoforms of histones H3 and H4. The specificity ofXIST RNA association with hypoacetylated chromatin, together with the previous finding that hypoacetylated histone H4 is enriched at promoters of X-inactivated genes, raises the possibility that XIST RNA may contribute to the hypoacetylation of specific regions of the Xi so as to alter the expression of X-linked genes.