Mouse Polycomb Proteins Bind Differentially to Methylated Histone H3 and RNA and Are Enriched in Facultative Heterochromatin
摘要:
The chromodomain (CD) of the Drosophila Polycomb protein exhibits preferential binding affinity for histone H3 when trimethylated at lysine 27. Here we have investigated the five mouse Polycomb homologs known as Cbx2, Cbx4, Cbx6, Cbx7, and Cbx8. Despite a high degree of conservation, the Cbx chromodomains display significant differences in binding preferences. Not all CDs bind preferentially to K27me3; rather, some display affinity towards both histone H3 trimethylated at K9 and H3K27me3, and one CD prefers K9me3. Cbx7, in particular, displays strong affinity for both H3K9me3 and H3K27me3 and is developmentally regulated in its association with chromatin. Cbx7 associates with facultative heterochromatin and, more specifically, is enriched on the inactive X chromosome. Finally, we find that, in vitro, the chromodomain of Cbx7 can bind RNA and that, in vivo, the interaction of Cbx7 with chromatin, and the inactive X chromosome in particular, depends partly on its association with RNA. We propose that the capacity of this mouse Polycomb homolog to associate with the inactive X chromosome, or any other region of chromatin, depends not only on its chromodomain but also on the combination of histone modifications and RNA molecules present at its target sites.
展开
关键词:
Animals Mice Chromatin Heterochromatin Repressor Proteins RNA Recombinant Fusion Proteins RNA, Untranslated Histones RNA-Binding Proteins
DOI:
10.1128/MCB.26.7.2560-2569.2006
被引量:
年份:
2006




















































通过文献互助平台发起求助,成功后即可免费获取论文全文。
相似文献
参考文献
引证文献
辅助模式
引用
文献可以批量引用啦~
欢迎点我试用!