Pausing sites of RNA polymerase II on actively transcribed genes are enriched in DNA double-stranded breaks
| Autor: | Stefan Bekiranov, Arkadi Manukyan, Sandeep Singh, Yuh-Hwa Wang, Karol Szlachta, Heather M Raimer, Manikarna Dinda |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Transcriptional Activation DNA damage RNA polymerase II Biochemistry 03 medical and health sciences chemistry.chemical_compound Transcription (biology) Gene expression Transcriptional regulation Humans Gene Regulation DNA Breaks Double-Stranded Molecular Biology Gene Etoposide 030102 biochemistry & molecular biology biology Topoisomerase Cell Biology Cell biology 030104 developmental biology DNA Topoisomerases Type II chemistry DNA Topoisomerases Type I biology.protein Camptothecin RNA Polymerase II biological phenomena cell phenomena and immunity Transcription Initiation Site DNA HeLa Cells |
| Zdroj: | J Biol Chem |
| Popis: | DNA double-stranded breaks (DSBs) are strongly associated with active transcription, and promoter-proximal pausing of RNA polymerase II (Pol II) is a critical step in transcriptional regulation. Mapping the distribution of DSBs along actively expressed genes and identifying the location of DSBs relative to pausing sites can provide mechanistic insights into transcriptional regulation. Using genome-wide DNA break mapping/sequencing techniques at single-nucleotide resolution in human cells, we found that DSBs are preferentially located around transcription start sites of highly transcribed and paused genes and that Pol II promoter-proximal pausing sites are enriched in DSBs. We observed that DSB frequency at pausing sites increases as the strength of pausing increases, regardless of whether the pausing sites are near or far from annotated transcription start sites. Inhibition of topoisomerase I and II by camptothecin and etoposide treatment, respectively, increased DSBs at the pausing sites as the concentrations of drugs increased, demonstrating the involvement of topoisomerases in DSB generation at the pausing sites. DNA breaks generated by topoisomerases are short-lived because of the religation activity of these enzymes, which these drugs inhibit; therefore, the observation of increased DSBs with increasing drug doses at pausing sites indicated active recruitment of topoisomerases to these sites. Furthermore, the enrichment and locations of DSBs at pausing sites were shared among different cell types, suggesting that Pol II promoter-proximal pausing is a common regulatory mechanism. Our findings support a model in which topoisomerases participate in Pol II promoter-proximal pausing and indicated that DSBs at pausing sites contribute to transcriptional activation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|