title: Poly(ADP-ribosyl)ation links the chromatin remodeler SMARCA5/SNF2H to RNF168-dependent DNA damage signaling.
abstract: Ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) arising in native chromatin elicit an RNF8/RNF168-dependent ubiquitylation response, which triggers the recruitment of various repair factors. Precisely how this response is regulated in the context of chromatin remains largely unexplored. Here, we show that SMARCA5/SNF2H, the catalytic subunit of ISWI chromatin remodeling complexes, is recruited to DSBs in a poly(ADP-ribose) polymerase 1 (PARP1)-dependent manner. Remarkably, PARP activity, although dispensable for the efficient spreading of γH2AX into damaged chromatin, selectively promotes spreading of SMARCA5, the E3 ubiquitin ligase RNF168, ubiquitin conjugates and the ubiquitin-binding factors RAD18 and the RAP80-BRCA1 complex throughout DSB-flanking chromatin. This suggests that PARP regulates the spatial organization of the RNF168-driven ubiquitin response to DNA damage. In support of this, we show that SMARCA5 and RNF168 interact in a DNA damage- and PARP-dependent manner. RNF168 became poly(ADP-ribosyl)ated after DNA damage, while RNF168 and poly(ADP-ribose) chains were required for SMARCA5 binding in vivo, explaining how SMARCA5 is linked to the RNF168 ubiquitin cascade. Moreover, SMARCA5 was found to regulate the ubiquitin response by promoting RNF168 accumulation at DSBs, which subsequently facilitates efficient ubiquitin conjugation and BRCA1 assembly. Underlining the importance of these findings, we show that SMARCA5 depletion renders cells sensitive to IR and results in DSB repair defects. Our study unveils a functional link between DNA damage-induced poly(ADP-ribosyl)ation, SMARCA5-mediated chromatin remodeling and RNF168-dependent signaling and repair of DSBs.
authors.affiliation: Department of Toxicogenetics, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands.
authors.forename: Godelieve
authors.initials: G
authors.lastname: Smeenk
authors.forename: Wouter W
authors.initials: WW
authors.lastname: Wiegant
authors.forename: Jurgen A
authors.initials: JA
authors.lastname: Marteijn
authors.forename: Martijn S
authors.initials: MS
authors.lastname: Luijsterburg
authors.forename: Nicholas
authors.initials: N
authors.lastname: Sroczynski
authors.forename: Thomas
authors.initials: T
authors.lastname: Costelloe
authors.forename: Ron J
authors.initials: RJ
authors.lastname: Romeijn
authors.forename: Albert
authors.initials: A
authors.lastname: Pastink
authors.forename: Niels
authors.initials: N
authors.lastname: Mailand
authors.forename: Wim
authors.initials: W
authors.lastname: Vermeulen
authors.forename: Haico
authors.initials: H
authors.lastname: van Attikum
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D042002:Chromatin Assembly and Disassembly / Q000235:genetics / Q000502:physiology*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000235:genetics / Q000502:physiology*; D004260:DNA Repair / Q000235:genetics / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; C535210:RNF168 protein, human; D044767:Ubiquitin-Protein Ligases; D011065:Poly(ADP-ribose) Polymerases; D000251:Adenosine Triphosphatases; C409462:SMARCA5 protein, human