Differential histone H3 Lys-9 and Lys-27 methylation profiles on the X chromosome.
Histone H3 tail modifications are among the earliest chromatin changes in the X-chromosome inactivation process. In this study we investigated the relative profiles of two important repressive marks on the X chromosome: methylation of H3 lysine 9 (K9) and 27 (K27). We found that both H3K9 dimethylation and K27 trimethylation characterize the inactive X in somatic cells and that their relative kinetics of enrichment on the X chromosome as it undergoes inactivation are similar. However, dynamic changes of H3K9 and H3K27 methylation on the inactivating X chromosome compared to the rest of the genome are distinct, suggesting that these two modifications play complementary and perhaps nonredundant roles in the establishment and/or maintenance of X inactivation. Furthermore, we show that a hotspot of H3K9 dimethylation 5' to Xist also displays high levels of H3 tri-meK27. However, analysis of this region in G9a mutant embryonic stem cells shows that these two methyl marks are dependent on different histone methyltransferases.
Rougeulle
Claire
C
CNRS URA 2578, Unité de Génétique Moléculaire Murine, Pasteur Institute, Paris 75015, France. rougeull@pasteur.fr
Chaumeil
Julie
J
Sarma
Kavitha
K
Allis
C David
CD
Reinberg
Danny
D
Avner
Philip
P
Heard
Edith
E
D000818:Animals; D002478:Cells, Cultured; D004303:Dosage Compensation, Genetic; D005260:Female; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000737:chemistry; D008297:Male; D008745:Methylation; D051379:Mice; D009154:Mutation; D011496:Protein Methyltransferases; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism; D014960:X Chromosome / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D006657:Histones; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; C077885:XIST non-coding RNA; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D008239:Lysine