The chromatin remodeling complex NuRD establishes the poised state of rRNA genes characterized by bivalent histone modifications and altered nucleosome positions.

ABSTRACT: 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 r

SUBMITTER: Xie W 

PROVIDER: S-EPMC3361413 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature