In vivo analysis reveals that ATP-hydrolysis couples remodeling to SWI/SNF release from chromatin

eLife

Ben C Tilly¹  Tsung Wai Kan¹  C Peter Verrijzer¹  Gillian E Chalkley¹  Jan A van der Knaap¹  Yuri M Moshkin¹  Jeroen AA Demmers²  Dick HW Dekkers² 

[1] Department of Biochemistry, Rotterdam, Netherlands;Department of Biochemistry, Rotterdam, Netherlands;Proteomics Center, Erasmus University Medical Center, Rotterdam, Netherlands;

关键词: ATP-dependent chromatin remodeling;    SWI/SNF;    brahma;    live-cell imaging;    polytene chromosomes;    RNA polymerase II;    D. melanogaster;   

DOI  :  10.7554/eLife.69424

来源: eLife Sciences Publications, Ltd

【 摘 要 】

ATP-dependent chromatin remodelers control the accessibility of genomic DNA through nucleosome mobilization. However, the dynamics of genome exploration by remodelers, and the role of ATP hydrolysis in this process remain unclear. We used live-cell imaging of Drosophila polytene nuclei to monitor Brahma (BRM) remodeler interactions with its chromosomal targets. In parallel, we measured local chromatin condensation and its effect on BRM association. Surprisingly, only a small portion of BRM is bound to chromatin at any given time. BRM binds decondensed chromatin but is excluded from condensed chromatin, limiting its genomic search space. BRM-chromatin interactions are highly dynamic, whereas histone-exchange is limited and much slower. Intriguingly, loss of ATP hydrolysis enhanced chromatin retention and clustering of BRM, which was associated with reduced histone turnover. Thus, ATP hydrolysis couples nucleosome remodeling to remodeler release, driving a continuous transient probing of the genome.

【 授权许可】

CC BY