TY - JOUR
T1 - The chromatin remodeling complex NuRD establishes the poised state of rRNA genes characterized by bivalent histone modifications and altered nucleosome positions
AU - Xie, Wenbing
AU - Ling, Te
AU - Zhou, Yonggang
AU - Feng, Weijun
AU - Zhu, Qiaoyun
AU - Stunnenberg, Henk G.
AU - Grummt, Ingrid
AU - Tao, Wei
PY - 2012/5/22
Y1 - 2012/5/22
N2 - 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 growtharrested and differentiated cells correlateswith 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.
AB - 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 growtharrested and differentiated cells correlateswith 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.
KW - Cell differentiation
KW - Epigenetic dynamics
KW - NoRC
KW - Poised chromatin
UR - http://www.scopus.com/inward/record.url?scp=84861419777&partnerID=8YFLogxK
U2 - 10.1073/pnas.1201262109
DO - 10.1073/pnas.1201262109
M3 - Article
C2 - 22570494
AN - SCOPUS:84861419777
SN - 0027-8424
VL - 109
SP - 8161
EP - 8166
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 21
ER -