RT Journal Article SR Electronic T1 Real-time chromatin dynamics at the single gene level during transcription activation JF bioRxiv FD Cold Spring Harbor Laboratory SP 111179 DO 10.1101/111179 A1 Thomas Germier A1 Silvia Kocanova A1 Nike Walther A1 Aurélien Bancaud A1 Haitham Ahmed Shaban A1 Hafida Sellou A1 Antonio Zaccaria Politi A1 Jan Ellenberg A1 Franck Gallardo A1 Kerstin Bystricky YR 2017 UL http://biorxiv.org/content/early/2017/02/23/111179.abstract AB Genome dynamics relate to regulation of gene expression, the most fundamental process in biology. Yet we still do not know whether the very process of transcription drives spatial organization and chromatin conformation at specific gene loci. To address this issue, we have optimized the ANCHOR/ParB DNA labeling system for real-time imaging and quantitative analysis of the dynamics of a single-copy transgene in human cells. Transcription of the transgene under the control of the endogenous Cyclin D1 promoter was induced by addition of 17β-estradiol. Motion of the ANCHOR3-tagged DNA locus was recorded in the same cell prior to and during appearance of nascent mRNA visualized using the MS2 system. We found that transcription initiation resulted in rapid confinement of the mRNA-producing gene. The confinement was maintained even upon inhibition of pol2 elongation. It did not occur when recruitment of pol2 or transcription initiation was blocked by anti-estrogens or Triptolide. These results suggest that preinitiation complex formation and concomitant reorganization of the chromatin domain constrains freedom of movement of an induced gene’s promoter within minutes. Confined diffusion reflects assembly of functional protein hubs and DNA processing during the rate-limiting steps of transcription.