An ATR-dependent function for the Ddx19 RNA helicase in nuclear R-loop metabolism.
Coordination between transcription and replication is crucial in the maintenance of genome integrity. Disturbance of these processes leads to accumulation of aberrant DNA:RNA hybrids (R-loops) that, if unresolved, generate DNA damage and genomic instability. Here we report a novel, unexpected role for the nucleopore-associated mRNA export factor Ddx19 in removing nuclear R-loops formed upon replication stress or DNA damage. We show, in live cells, that Ddx19 transiently relocalizes from the nucleopore to the nucleus upon DNA damage, in an ATR/Chk1-dependent manner, and that Ddx19 nuclear relocalization is required to clear R-loops. Ddx19 depletion induces R-loop accumulation, proliferation-dependent DNA damage and defects in replication fork progression. Further, we show that Ddx19 resolves R-loopsin vitrovia its helicase activity. Furthermore, mutation of a residue phosphorylated by Chk1 in Ddx19 disrupts its interaction with Nup214 and allows its nuclear relocalization. Finally, we show that Ddx19 operates in resolving R-loops independently of the RNA helicase senataxin. Altogether these observations put forward a novel, ATR-dependent function for Ddx19 in R-loop metabolism to preserve genome integrity in mammalian cells.
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France.|Genomics and Health Laboratory, Biology Department, Faculty of Sciences, R. Hariri Campus, Lebanese University, Hadath, Lebanon.
Dana
0000-0002-5674-8312
D
Hodroj
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France.
Bénédicte
B
Recolin
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France.
Kamar
K
Serhal
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France.
Susan
S
Martinez
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France.
Nikolay
N
Tsanov
Genomics and Health Laboratory, Biology Department, Faculty of Sciences, R. Hariri Campus, Lebanese University, Hadath, Lebanon.
Raghida
R
Abou Merhi
Genome Surveillance and Stability Laboratory, Institute of Human Genetics, UMR9002, CNRS-UM, University of Montpellier, Montpellier Cedex 5, France domenico.maiorano@igh.cnrs.fr.
Domenico
0000-0003-4229-5903
D
Maiorano
D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D000071877:Checkpoint Kinase 1 / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D012313:RNA / Q000378:metabolism*; D014981:Xenopus / Q000378:metabolism*; D029867:Xenopus Proteins / Q000378:metabolism
D029867:Xenopus Proteins; D012313:RNA; C576898:Atr protein, Xenopus; D064007:Ataxia Telangiectasia Mutated Proteins; D000071877:Checkpoint Kinase 1; C000605875:Chek1 protein, Xenopus; D053487:DEAD-box RNA Helicases

Xenopus
; Chk1; DNA damage; camptothecin; replication stress