The chromatin remodeling complex NuRD establishes the poised state of rRNA genes characterized by bivalent histone modifications and altered nucleosome positions
The chromatin remodeling complex NuRD establishes the poised state of rRNA genes characterized by bivalent histone modifications and altered nucleosome positions
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染色质重塑复合体 NuRD 建立 rRNA 基因的平衡状态，其特征是二价组蛋白修饰和核小体位置改变
DOI：
10.1073/pnas.1201262109
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发表时间：
2012-05-22
影响因子：
11.1
通讯作者：
Tao, Wei
中科院分区：
文献类型：
--
作者：
Xie, Wenbing;Ling, Te;Tao, Wei
rRNA genes (rDNA) exist in two distinct epigenetic states, active promoters being unmethylated and marked by euchromatic histone modifications, whereas silent ones are methylated and exhibit heterochromatic features. Here we show that the nucleosome remodeling and deacetylation (NuRD) complex establishes a specific chromatin structure at rRNA genes that are poised for transcription activation. The promoter of poised rRNA genes is unmethylated, associated with components of the preinitiation complex, marked by bivalent histone modifications and covered by a nucleosome in the “off” position, which is refractory to transcription initiation. Repression of rDNA transcription in growth-arrested and differentiated cells correlates with elevated association of NuRD and increased levels of poised rRNA genes. Reactivation of transcription requires resetting the promoter-bound nucleosome into the “on” position by the DNA-dependent ATPase CSB (Cockayne syndrome protein B). The results uncover a unique mechanism by which ATP-dependent chromatin remodeling complexes with opposing activities establish a specific chromatin state and regulate transcription.
