title: Systems-wide analysis of ubiquitylation dynamics reveals a key role for PAF15 ubiquitylation in DNA-damage bypass.
abstract: Protein ubiquitylation has emerged as a key regulatory mechanism in DNA-damage signalling and repair pathways. We report a proteome-wide, site-specific survey of ubiquitylation changes after ultraviolet irradiation, identifying numerous upregulated and downregulated ubiquitylation sites on known components of DNA-damage signalling, as well as on proteins not previously implicated in this process. Our results uncover a critical role for PCNA-associated factor PAF15 (p15(PAF)/KIAA0101) ubiquitylation during DNA replication. During unperturbed S phase, chromatin-associated PAF15 is modified by double mono-ubiquitylation of Lys 15 and 24 templated through PCNA binding. Replication blocks trigger rapid, proteasome-dependent removal of Lys 15/24-ubiquitylated PAF15 from PCNA, facilitating bypass of replication-fork-blocking lesions by allowing recruitment of translesion DNA synthesis polymerase polη to mono-ubiquitylated PCNA at stalled replisomes. Our findings demonstrate widespread involvement of ubiquitin signalling in genotoxic-stress responses and identify a critical function for dynamic PAF15 ubiquitylation in safeguarding genome integrity when DNA replication is challenged.
authors.affiliation: Ubiquitin Signaling Group, Department of Disease Biology, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark.
authors.forename: Lou K
authors.initials: LK
authors.lastname: Povlsen
authors.forename: Petra
authors.initials: P
authors.lastname: Beli
authors.forename: Sebastian A
authors.initials: SA
authors.lastname: Wagner
authors.forename: Sara L
authors.initials: SL
authors.lastname: Poulsen
authors.forename: Kathrine B
authors.initials: KB
authors.lastname: Sylvestersen
authors.forename: Jon W
authors.initials: JW
authors.lastname: Poulsen
authors.forename: Michael L
authors.initials: ML
authors.lastname: Nielsen
authors.forename: Simon
authors.initials: S
authors.lastname: Bekker-Jensen
authors.forename: Niels
authors.initials: N
authors.lastname: Mailand
authors.forename: Chunaram
authors.initials: C
authors.lastname: Choudhary
mesh_terms: D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D004249:DNA Damage / Q000502:physiology*; D004260:DNA Repair / Q000502:physiology*; D004261:DNA Replication / Q000502:physiology; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D016196:S Phase / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D054875:Ubiquitination; D014466:Ultraviolet Rays / Q000009:adverse effects*; D000099270:Y-Family DNA Polymerases
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase; D008239:Lysine; D046988:Proteasome Endopeptidase Complex; C425208:PCLAF protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases