PT  - JOURNAL ARTICLE
AU  - William Conway
AU  - Won-Ki Cho
AU  - Namrata Jayanth
AU  - Susan Mullen
AU  - Ibrahim I Cissé
TI  - Cell-cycle dependent organization and dynamics of RNA Polymerase I in live human cells
AID  - 10.1101/133082
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 133082
4099  - http://biorxiv.org/content/early/2017/05/01/133082.short
4100  - http://biorxiv.org/content/early/2017/05/01/133082.full
AB  - RNA Polymerase I (Pol I) is responsible for over 60% of transcriptional output in human cells, yet basic questions concerning the spatial and temporal organization of the polymerase remain unanswered. Here we investigate how mammalian cells rely on Pol I organization throughout the cell cycle to balance different needs, from complete transcription shut down to massive increase in protein synthesis (and thus ribosomal RNA synthesis) before cell division. In contrast to our previous reports on RNA Polymerase II, Pol I clusters are stable with active transcription, and the presence of transient Pol I clusters correlates with inactive ribosomal transcription. Our results suggest that both stable and transient populations Pol I clusters co-exist in individual living cells, and their relative fraction may directly reflect the global gene expression need of the cell.