PHOSPHORYLATION-DEPENDENT ASSOCIATION OF WRN WITH RPA IS REQUIRED FOR RECOVERY OF REPLICATION FORKS STALLED AT SECONDARY DNA STRUCTURES
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ABSTRACT: The WRN protein mutated in the premature aging disorder Werner syndrome is vital for
metabolism of perturbed replication forks. Replication Protein A (RPA) robustly enhances WRN
helicase activity in specific cases when tested in vitro. However, the significance of RPA-binding to
WRN in vivo has remained largely unexplored. We identified several conserved phosphorylation
sites in the acidic domain of WRN targeted by Casein Kinase 2 (CK2). These sites are crucial for
WRN-RPA interaction in vitro and in human cells. Using the CK2-unphosphorylatable WRN
mutant lacking the ability to bind RPA, we determined that the WRN-RPA complex plays a critical
role in fork recovery after replication stress whereas is not necessary for the processing of
replication forks or preventing DNA damage when forks stall or collapse. RPA-binding by WRN
and its helicase activity are crucial for countering the persistence of G4 structures after fork stalling.
Absence of WRN-RPA binding hampers fork recovery, causing single-strand DNA gaps, enlarged
by MRE11, and triggering MUS81-dependent double-strand breaks which requires efficient repair
by RAD51 to prevent excessive DNA damage.
INSTRUMENT(S): Orbitrap Fusion
ORGANISM(S): Homo Sapiens (ncbitaxon:9606)
SUBMITTER: FEDERICA FRATINI
PROVIDER: MSV000095749 | MassIVE |
SECONDARY ACCESSION(S): PXD059007
REPOSITORIES: MassIVE
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