Abstract
Gene transcription by RNA polymerase II (RNAP II) is a tightly regulated process in the genomic, temporal, and spatial context. Transcriptionally active genes often spatially cluster at RNA Pol II foci, called transcription factories, causing long-range interactions between distal sites of the genome. Recently, we have shown that chromatin exhibits spatially long-range coherently moving regions over the entire nucleus and transcription enhances this long-range correlated DNA movement. Yet, it remains unclear how the mobility of RNA Pol II molecules are affected by transcription regulation and whether this response depends on the coordinated chromatin movement. We applied our Dense Flow reConstruction and Correlation method to analyze nucleus-wide coherent movements of RNA Pol II in living human cancer cells. We quantify the spatial correlation length of RNA Pol II in the context of DNA motion. Like DNA, we observe a spatially coherent movement of RNA Pol II molecules. However, the correlation extends over ∼1 μm, considerably less than for DNA, suggesting that spatially coherent RNA Pol II motion does not solely result from the underlying DNA motion. In contrast to DNA, inducing transcription in quiescent cells decreased the coherent motion of RNA Pol II, while the inhibition of transcription elongation by using DRB slightly increased coherent RNA Pol II motion. The spatially coherent movement of RNA Pol II domains is affected by transcriptional state and largely independent of the underlying chromatin domains. Our results suggest that RNA Pol II domains can cause the emergence of spatially correlated chromatin motion spanning several micrometers.
Competing Interest Statement
The authors have declared no competing interest.
