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DDX17 helicase promotes resolution of R-loop-mediated transcription-replication conflicts in human cells

ABSTRACT: R-loops are three-stranded nucleic acid structures composed of an RNA:DNA hybrid and displaced DNA strand. These structures can halt DNA replication when formed co- transcriptionally in the opposite orientation to replication fork progression. Recent studies have shown that replication forks stalled by co-transcription R-loops can be restarted by a mechanism involving fork cleavage by MUS81 endonuclease, followed by reactivation of transcription, and fork religation by the DNA ligase IV (LIG4)/XRCC4 complex. However, how R-loops are eliminated to allow the sequential restart of transcription and replication in this pathway remains elusive. Here, we identified the human DDX17 helicase as a factor that associates with R-loops and counteracts R-loop-mediated replication stress to preserve genome stability. We show that DDX17 unwinds RNA:DNA hybrids in vitro and promotes MUS81-dependent restart of R-loop-stalled forks in human cells in a manner dependent on its helicase activity. Loss of DDX17 helicase induces accumulation of R-loops and the formation of R-loop-dependent anaphase bridges and micronuclei. These findings establish DDX17 as a component of the MUS81-LIG4 pathway for resolution of R-loop-mediated transcription- replication conflicts, which may be involved in R-loop unwinding.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Pavel Talacko

LAB HEAD: Pavel Janscak

PROVIDER: PXD034331 | Pride | 2022-11-02

REPOSITORIES: Pride

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			Action	DRS
	2a_20181123235655.raw	Raw
	2b_20181124011447.raw	Raw
	2c_20181124023239.raw	Raw
	2d_20181124035032.raw	Raw
	3a.raw	Raw

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