Fig. 10

Local chromatin motion in the cell. A (left) Decondensed chromatin in cells treated with histone deacetylase (HDAC) inhibitor TSA showed increased chromatin movements because of weakening nucleosome–nucleosome interactions and subsequently less local chromatin constraint. (center) The typical state of chromatin: chromatin domains are organized by local nucleosome–nucleosome interactions and global folding by cohesin. (right) Cohesin loss leads to less constraint and a resultant increase in chromatin motion. B (left and center) Cluster/condensate of active RNAPII and transcription factors (blue sphere) can work as a transient hub (green sphere) to weakly connect multiple chromatin domains and to globally constrain chromatin motion. (right) RNAPII inhibition or its rapid depletion releases the chromatin constraints and increases chromatin motion. C–F Cartoons showing how various nuclear condensates are organized with different chromatin substrates. The orange line represents chromatin. Chromatin seems solid at the mesoscale and behaves like a liquid at the nanoscale, which is consistent with its viscoelastic property [216] (G). Black arrow designates active transcription start site, and green squiggled lines show RNA. Schemes in Panels A and B were reproduced from [220] with modifications