title: The helicase FBH1 is tightly regulated by PCNA via CRL4(Cdt2)-mediated proteolysis in human cells.
abstract: During replication, DNA damage can challenge replication fork progression and cell viability. Homologous Recombination (HR) and Translesion Synthesis (TLS) pathways appear as major players involved in the resumption and completion of DNA replication. How both pathways are coordinated in human cells to maintain genome stability is unclear. Numerous helicases are involved in HR regulation. Among them, the helicase FBH1 accumulates at sites of DNA damage and potentially constrains HR via its anti-recombinase activity. However, little is known about its regulation in vivo. Here, we report a mechanism that controls the degradation of FBH1 after DNA damage. Firstly, we found that the sliding clamp Proliferating Cell Nuclear Antigen (PCNA) is critical for FBH1 recruitment to replication factories or DNA damage sites. We then showed the anti-recombinase activity of FBH1 is partially dependent on its interaction with PCNA. Intriguingly, after its re-localization, FBH1 is targeted for degradation by the Cullin-ring ligase 4-Cdt2 (CRL4(Cdt2))-PCNA pathway via a PCNA-interacting peptide (PIP) degron. Importantly, expression of non-degradable FBH1 mutant impairs the recruitment of the TLS polymerase eta to chromatin in UV-irradiated cells. Thus, we propose that after DNA damage, FBH1 might be required to restrict HR and then degraded by the Cdt2-proteasome pathway to facilitate TLS pathway.
authors.affiliation: Université Paris-Sud, CNRS-UMR8200 Unit of Genetic Stability and Oncogenesis, Institut de cancérologie Gustave Roussy, Villejuif, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Bacquin
authors.forename: Caroline
authors.initials: C
authors.lastname: Pouvelle
authors.forename: Nicolas
authors.initials: N
authors.lastname: Siaud
authors.forename: Mylène
authors.initials: M
authors.lastname: Perderiset
authors.forename: Sophie
authors.initials: S
authors.lastname: Salomé-Desnoulez
authors.forename: Carine
authors.initials: C
authors.lastname: Tellier-Lebegue
authors.forename: Bernard
authors.initials: B
authors.lastname: Lopez
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Charbonnier
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Kannouche
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002460:Cell Line; D002843:Chromatin / Q000201:enzymology; D004249:DNA Damage; D004265:DNA Helicases / Q000737:chemistry / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D059765:Homologous Recombination; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D059748:Proteolysis; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D014466:Ultraviolet Rays; D000099270:Y-Family DNA Polymerases
chemical_list: D002843:Chromatin; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D046988:Proteasome Endopeptidase Complex; D044767:Ubiquitin-Protein Ligases; C429530:DTL protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases; C464443:FBH1 protein, human