@article{c3eda77edf7d4fbd88dbe3c23b13ac31,
title = "Involvement of the nuclear proteasome activator PA28γ in the cellular response to DNA double-strand breaks",
abstract = "The DNA damage response (DDR) is a complex signaling network that leads to damage repair while modulating numerous cellular processes. DNA double-strand breaks (DSBs) - a highly cytotoxic DNA lesion-activate this system most vigorously. The DSB response network is orchestrated by the ATM protein kinase, which phosphorylates key players in its various branches. Proteasome-mediated protein degradation plays an important role in the proteome dynamics following DNA damage induction. Here, we identify the nuclear proteasome activator PA28γ (REGγ; PSME3) as a novel DDR player. PA28γ depletion leads to cellular radiomimetic sensitivity and a marked delay in DSB repair. Specifically, PA28γ deficiency abrogates the balance between the two major DSB repair pathways - nonhomologous end-joining and homologous recombination repair. Furthermore, PA28γ is found to be an ATM target, being recruited to the DNA damage sites and required for rapid accumulation of proteasomes at these sites. Our data reveal a novel ATM-PA28γ- proteasome axis of the DDR that is required for timely coordination of DSB repair.",
keywords = "ATM, DNA repair, Double-strand breaks, Genomic stability, PA28γ (PSME3), Proteasome",
author = "Adva Levy-Barda and Yaniv Lerenthal and Davis, {Anthony J.} and Chung, {Young Min} and Jeroen Essers and Zhengping Shao and {Van Vliet}, Nicole and Chen, {David J.} and Hu, {Mickey C T} and Roland Kanaar and Yael Ziv and Yosef Shiloh",
note = "Funding Information: Luciferase: CGU ACG CGG AAU ACU UCG ATT, We are grateful to Olivier Coux and Michael Glickman for RAD51: GAG CUU GAC AAA CUA CUU CUU, useful discussions, Amir Oryan for comments on the manu-GFP: GGA GCG CAC CAT CTT CTT C, script, Thanos Halazonetis for the anti-53BP1 antibody, Niels ATM: NNG ACU UUG GCU GUC AAC UUU CG. Mailand for the anti-RNF8 antibody, Jochem Dahm-Daphi for U2OS cells were grown to 20–50% confluence and trans-the NHEJ assay system and the Smoler Proteomics Center at the fected with siRNA using DharmaFECT1. Technion and the Proteomic Center of the Weizmann Institute DDR assays. Clonogenic survival of cell lines and immunos-of Science for protein identification. This work was supported taining procedures were performed as previously described in by research grants from the Israel Science Foundation, the A-T reference 19. Detection of 53BP1, γH2AX, MDC1 and BRCA1 Medical Research Foundation, the Israel Cancer Research Fund, nuclear foci was performed as previously described in references and the Dr. Miriam and Sheldon G. Adelson Medical Research 39 and 62. Induction of localized DNA damage and monitor-Foundation (to YS), the National Institutes of Health (NIH ing of protein recruitment were performed according to previous CA 50519) to DJC, and the European Community{\textquoteright}s Seventh protocols.39,40,67 DSB were introduced by irradiating cells with Framework Programme (FP7/2007-2013) under grant agreement α-particles as previously described in references 40 and 68. No. HEALTH-F2-2010-259893 and the Netherlands Genomics DSB repair. NHEJ and HRR assays were performed as previ-Initiative / Netherlands Organization for Scientific Research (to ously described in references 39 and 69–71. siRNAs against the RK). Yosef Shiloh is a Research Professor of the Israel Cancer RAD51 and Ku70 served as controls. The comet assay was per-Research Fund. formed as previously described in references 38 and 39. Immunoblotting, immunoprecipitation, protein identi- fication and chromatin fractionation. Immunoblotting and immunoprecipitation were performed as previously described",
year = "2011",
month = dec,
day = "15",
doi = "10.4161/cc.10.24.18642",
language = "English (US)",
volume = "10",
pages = "4300--4310",
journal = "Cell Cycle",
issn = "1538-4101",
publisher = "Landes Bioscience",
number = "24",
}