MRE11 deacetylation by SIRT2 promotes DNA binding to facilitate DNA end resection and ATM-dependent signaling
Fatmata Sesay, Hui Zhang, Priya Kapoor-Vazirani, Andrew T. Jung, Mark E. Essien, Amanda J. Bastien, Nho C. Luong, Xu Liu, PamelaSara E. Head, Duc M. Duong, Xiaofeng Yang, Zachary S. Buchwald, Xingming Deng, Nicholas T. Seyfried, David S. Yu
Fatmata Sesay, Hui Zhang, Priya Kapoor-Vazirani, Andrew T. Jung, Mark E. Essien, Amanda J. Bastien, Nho C. Luong, Xu Liu, PamelaSara E. Head, Duc M. Duong, Xiaofeng Yang, Zachary S. Buchwald, Xingming Deng, Nicholas T. Seyfried, David S. Yu
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Research Article Cell biology Oncology

MRE11 deacetylation by SIRT2 promotes DNA binding to facilitate DNA end resection and ATM-dependent signaling

Abstract

MRE11, a breast tumor suppressor and component of the MRE11-RAD50-NBS1 complex, plays a critical role in DNA end resection and initiation of ataxia-telangiectasia mutation–dependent (ATM-dependent) DNA damage signaling. However, the precise mechanisms governing MRE11 function in the DNA damage response (DDR) remain incompletely understood. Here, we found that MRE11 is deacetylated by the SIRT2 sirtuin deacetylase and breast tumor suppressor, which promotes DNA binding to facilitate DNA end resection and ATM-dependent signaling. SIRT2 deacetylase activity promoted DNA end resection. SIRT2 further complexed with and deacetylated MRE11 at conserved lysine 393 (K393) in response to DNA double-stranded breaks (DSBs), which promoted MRE11 localization and DNA binding at DSBs but not interaction with RAD50, NBS1, or CtIP. Moreover, MRE11 K393 deacetylation by SIRT2 promoted ATM-dependent signaling. Our findings define a mechanism regulating MRE11 binding to DNA through SIRT2 deacetylation, elucidating a critical upstream signaling event directing MRE11 function in the DDR and providing insight into how SIRT2 dysregulation leads to genomic instability and tumorigenesis.

Authors

Fatmata Sesay, Hui Zhang, Priya Kapoor-Vazirani, Andrew T. Jung, Mark E. Essien, Amanda J. Bastien, Nho C. Luong, Xu Liu, PamelaSara E. Head, Duc M. Duong, Xiaofeng Yang, Zachary S. Buchwald, Xingming Deng, Nicholas T. Seyfried, David S. Yu

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Figure 5

MRE11 K393 deacetylation by SIRT2 in response to DNA damage promotes its binding to dsDNA.

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MRE11 K393 deacetylation by SIRT2 in response to DNA damage promotes its...
(A) Structural model depicting the impact of K393 acetylation on binding with DNA. Human MRE11 aa 1–411 (PDB: 3T1I) were aligned with the structure of Pyrococcus furiosus MRE11-DNA complex (PDB: 3DSC). The distance between K393 and the phosphate group in the DNA was measured using PyMOL (version 2.5.4). Residue K393 was mutated to Q and R, respectively, in PyMOL. (B) MRE11 was purified from HCT116 SIRT2 WT and KO cells treated with or without 6 Gy IR with a 4 hour recovery, incubated with biotin-labeled dsDNA oligos (bio-dsDNA), and pulled down with agarose-streptavidin beads. Pull-downs were separated by SDS-PAGE and immunoblotted with the indicated antibodies. (C) GFP-MRE11 WT, K393Q, and K393R mutants were purified from HCT116 cells and incubated with bio-dsDNA as described in B. (D) Quantitative analysis of MRE11-binding to FokI-induced DSBs using ChIP-qPCR. Quantification from 3 independent experiments is shown as the mean ± SD. Western blots shown are representative, and each experiment was conducted at least 3 independent times. Statistical significance was determined using 1-way ANOVA followed by Dunnett’s post hoc test for multiple comparisons. **P < 0.01.