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Transient pausing by RNA polymerase II
- Source :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Year :
- 2018
- Publisher :
- Proceedings of the National Academy of Sciences, 2018.
-
Abstract
- Significance Transcription by RNA Polymerase II (Pol II) is a highly dynamic process that is tightly regulated at each step of the transcription cycle. We generated GFP-RPB1 knockin cells and developed photobleaching of endogenous Pol II combined with computational modeling to study the in vivo dynamics of Pol II in real time. This approach allowed us to dissect promoter-paused Pol II from initiating and elongating Pol II and showed that initiation and promoter proximal pausing are surprisingly dynamic events, due to premature termination of Pol II. Our study provides new insights into Pol II dynamics and suggests that the iterative release and reinitiation of promoter-bound Pol II is an important component of transcriptional regulation.<br />Initiation and promoter-proximal pausing are key regulatory steps of RNA Polymerase II (Pol II) transcription. To study the in vivo dynamics of endogenous Pol II during these steps, we generated fully functional GFP-RPB1 knockin cells. GFP-RPB1 photobleaching combined with computational modeling revealed four kinetically distinct Pol II fractions and showed that on average 7% of Pol II are freely diffusing, while 10% are chromatin-bound for 2.4 seconds during initiation, and 23% are promoter-paused for only 42 seconds. This unexpectedly high turnover of Pol II at promoters is most likely caused by premature termination of initiating and promoter-paused Pol II and is in sharp contrast to the 23 minutes that elongating Pol II resides on chromatin. Our live-cell–imaging approach provides insights into Pol II dynamics and suggests that the continuous release and reinitiation of promoter-bound Pol II is an important component of transcriptional regulation.
- Subjects :
- 0301 basic medicine
Transcription, Genetic
viruses
RNA polymerase II
promoter-proximal pausing
live-cell imaging
03 medical and health sciences
0302 clinical medicine
Transcription (biology)
Initiation factor
Negative elongation factor
Promoter Regions, Genetic
P-TEFb
Multidisciplinary
biology
Chemistry
Fluorescence recovery after photobleaching
DNA-Directed RNA Polymerases
Cell Biology
Biological Sciences
DSIF
Elongation factor
030104 developmental biology
PNAS Plus
biology.protein
Biophysics
RNA Polymerase II
transcription dynamics
transcription
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 115
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....a327b2cdca22beb5f3d11885c9092a88