Abstract
R loops arising during transcription induce genomic instability, but how cells respond to the R loop-associated genomic stress is still poorly understood. Here, we show that cells harboring high levels of R loops rely on the ATR kinase for survival. In response to aberrant R loop accumulation, the ataxia telangiectasia and Rad3-related (ATR)-Chk1 pathway is activated by R loop-induced reversed replication forks. In contrast to the activation of ATR by replication inhibitors, R loop-induced ATR activation requires the MUS81 endonuclease. ATR protects the genome from R loops by suppressing transcription-replication collisions, promoting replication fork recovery, and enforcing a G2/M cell-cycle arrest. Furthermore, ATR prevents excessive cleavage of reversed forks by MUS81, revealing a MUS81-triggered and ATR-mediated feedback loop that fine-tunes MUS81 activity at replication forks. These results suggest that ATR is a key sensor and suppressor of R loop-induced genomic instability, uncovering a signaling circuitry that safeguards the genome against R loops.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 514-527.e4 |
| Journal | Molecular Cell |
| Volume | 77 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 6 2020 |
Bibliographical note
Funding Information:We thank Dr. J.W. Harper for the MUS81 plasmid and Drs. N. Dyson, J. Walter, J.K. Joung, A. Elia, L. Lan, and members of the Zou and Dyson labs for discussions. D.A.M. was partially supported by an NIH F31 fellowship (1F31CA210311). J.-M.Z. is partially supported by the Massachusetts General Hospital Cancer Center Excellence Award. H.D.N. was supported by an NIH T32 postdoctoral training grant (T32 DK007540) and a grant from the Edward P. Evans Foundation. M.-M.G. was partially supported by a postdoctoral fellowship from Fonds de Recherche Sant? Qu?bec (FRQS). L.Z. is the James & Patricia Poitras Endowed Chair in Cancer Research, and was supported by a Jim & Ann Orr Massachusetts General Hospital Research Scholar Award. This work is supported by grants from the NIH (GM076388, CA197779, and CA218856) to L.Z. D.A.M. and L.Z. designed the project. D.A.M. J.-M.Z. J.O. H.D.N. and M.-M.G. performed the experiments and data analysis. L.Z. supervised the experiments and data analysis. D.A.M. and L.Z. wrote the manuscript with help from all of the other authors. L.Z. has consulted for EMD Serono and received research funding from Calico. All of the other authors declare no competing interests.
Funding Information:
We thank Dr. J.W. Harper for the MUS81 plasmid and Drs. N. Dyson, J. Walter, J.K. Joung, A. Elia, L. Lan, and members of the Zou and Dyson labs for discussions. D.A.M. was partially supported by an NIH F31 fellowship ( 1F31CA210311 ). J.-M.Z. is partially supported by the Massachusetts General Hospital Cancer Center Excellence Award . H.D.N. was supported by an NIH T32 postdoctoral training grant ( T32 DK007540 ) and a grant from the Edward P. Evans Foundation . M.-M.G. was partially supported by a postdoctoral fellowship from Fonds de Recherche Santé Québec (FRQS). L.Z. is the James & Patricia Poitras Endowed Chair in Cancer Research, and was supported by a Jim & Ann Orr Massachusetts General Hospital Research Scholar Award . This work is supported by grants from the NIH ( GM076388 , CA197779 , and CA218856 ) to L.Z.
Publisher Copyright:
© 2019 Elsevier Inc.
Keywords
- ATR
- Chk1
- Fork reversal
- Genomic Instability
- MUS81
- R loop
- checkpoint
- Phosphorylation
- Signal Transduction
- Endonucleases/genetics
- Humans
- Cell Cycle Proteins/metabolism
- Checkpoint Kinase 1/genetics
- DNA Replication/genetics
- R-Loop Structures/genetics
- DNA-Binding Proteins/genetics
- DNA Repair
- Protein Kinases/metabolism
- Ataxia Telangiectasia Mutated Proteins/metabolism
- DNA Damage
- Genomic Instability/physiology
- HeLa Cells
PubMed: MeSH publication types
- Research Support, Non-U.S. Gov't
- Journal Article
- Research Support, N.I.H., Extramural