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Hailemariam S, Kumar S, Burgers PM. Activation of Tel1 ATM kinase requires Rad50 ATPase and long nucleosome-free DNA but no DNA ends. J Biol Chem 2019; 294:10120-10130. [PMID: 31073030 DOI: 10.1074/jbc.ra119.008410] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/07/2019] [Indexed: 12/13/2022] Open
Abstract
In Saccharomyces cerevisiae, Tel1 protein kinase, the ortholog of human ataxia telangiectasia-mutated (ATM), is activated in response to DNA double-strand breaks. Biochemical studies with human ATM and genetic studies in yeast suggest that recruitment and activation of Tel1ATM depends on the heterotrimeric MRXMRN complex, composed of Mre11, Rad50, and Xrs2 (human Nbs1). However, the mechanism of activation of Tel1 by MRX remains unclear, as does the role of effector DNA. Here we demonstrate that dsDNA and MRX activate Tel1 synergistically. Although minimal activation was observed with 80-mer duplex DNA, the optimal effector for Tel1 activation is long, nucleosome-free DNA. However, there is no requirement for DNA double-stranded termini. The ATPase activity of Rad50 is critical for activation. In addition to DNA and Rad50, either Mre11 or Xrs2, but not both, is also required. Each of the three MRX subunits shows a physical association with Tel1. Our study provides a model of how the individual subunits of MRX and DNA regulate Tel1 kinase activity.
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Affiliation(s)
- Sarem Hailemariam
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Sandeep Kumar
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Peter M Burgers
- From the Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110
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3
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Pavelitz T, Renfro L, Foster NR, Caracol A, Welsch P, Lao VV, Grady WB, Niedzwiecki D, Saltz LB, Bertagnolli MM, Goldberg RM, Rabinovitch PS, Emond M, Monnat RJ, Maizels N. MRE11-deficiency associated with improved long-term disease free survival and overall survival in a subset of stage III colon cancer patients in randomized CALGB 89803 trial. PLoS One 2014; 9:e108483. [PMID: 25310185 PMCID: PMC4195600 DOI: 10.1371/journal.pone.0108483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 08/19/2014] [Indexed: 11/19/2022] Open
Abstract
Purpose Colon cancers deficient in mismatch repair (MMR) may exhibit diminished expression of the DNA repair gene, MRE11, as a consequence of contraction of a T11 mononucleotide tract. This study investigated MRE11 status and its association with prognosis, survival and drug response in patients with stage III colon cancer. Patients and Methods Cancer and Leukemia Group B 89803 (Alliance) randomly assigned 1,264 patients with stage III colon cancer to postoperative weekly adjuvant bolus 5-fluorouracil/leucovorin (FU/LV) or irinotecan+FU/LV (IFL), with 8 year follow-up. Tumors from these patients were analyzed to determine stability of a T11 tract in the MRE11 gene. The primary endpoint was overall survival (OS), and a secondary endpoint was disease-free survival (DFS). Non-proportional hazards were addressed using time-dependent covariates in Cox analyses. Results Of 625 tumor cases examined, 70 (11.2%) exhibited contraction at the T11 tract in one or both MRE11 alleles and were thus predicted to be deficient in MRE11 (dMRE11). In pooled treatment analyses, dMRE11 patients showed initially reduced DFS and OS but improved long-term DFS and OS compared with patients with an intact MRE11 T11 tract. In the subgroup of dMRE11 patients treated with IFL, an unexplained early increase in mortality but better long-term DFS than IFL-treated pMRE11 patients was observed. Conclusions Analysis of this relatively small number of patients and events showed that the dMRE11 marker predicts better prognosis independent of treatment in the long-term. In subgroup analyses, dMRE11 patients treated with irinotecan exhibited unexplained short-term mortality. MRE11 status is readily assayed and may therefore prove to be a useful prognostic marker, provided that the results reported here for a relatively small number of patients can be generalized in independent analyses of larger numbers of samples. Trial Registration ClinicalTrials.gov NCT00003835
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Affiliation(s)
- Thomas Pavelitz
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Lindsay Renfro
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Nathan R. Foster
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Amber Caracol
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Piri Welsch
- Department of Genome Sciences, University of Washington Medical School, Seattle, Washington, United States of America
| | - Victoria Valinluck Lao
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Surgery, University of Washington Medical School, Seattle, Washington, United States of America
| | - William B. Grady
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington Medical School, Seattle, Washington, United States of America
| | - Donna Niedzwiecki
- Cancer and Leukemia Group B Statistical Center, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Leonard B. Saltz
- Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Monica M. Bertagnolli
- Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | | | - Peter S. Rabinovitch
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
| | - Mary Emond
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Raymond J. Monnat
- Department of Genome Sciences, University of Washington Medical School, Seattle, Washington, United States of America
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
| | - Nancy Maizels
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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4
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Mondal NK, Sorensen E, Hiivala N, Feller E, Griffith B, Wu ZJ. Oxidative stress, DNA damage and repair in heart failure patients after implantation of continuous flow left ventricular assist devices. Int J Med Sci 2013; 10:883-93. [PMID: 23781134 PMCID: PMC3675502 DOI: 10.7150/ijms.6219] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 05/05/2013] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE To study the status of oxidative stress and DNA damage repair in circulating blood leukocytes of heart failure patients supported by continuous flow left ventricular assist devices (LVADs). MATERIALS AND METHODS Ten HF patients implanted with LVAD as bridge to transplant or destination therapy were enrolled in the study and 10 age and sex matched volunteers were recruited as the study control. Reactive oxygen species (ROS) in blood leukocytes and superoxide dismutase (SOD) in erythrocytes were measured by flow cytometry/immunofluorescence microscopy and spectrophotometry, respectively. ELISA was used to measure oxidized low density lipoproteins (oxLDL) in plasma. Markers of DNA damage (γ-H2AX) and repairs (Mre11, DNA ligase IV, Ku70, and Ku80) were quantified in blood lymphocytes by immunocytochemistry. RESULTS Levels of ROS and oxLDL were significantly higher in HF patients with LVAD than baseline as well as the control group; moreover, SOD levels were decreased with increasing post-operative periods. All the changes indicated enhanced oxidative stress among LVAD recipients. Significantly higher γ-H2AX foci in lymphocytes confirmed DNA double strand breaks in LVAD recipients. γ-H2AX foci numbers in lymphocytes were positively correlated with the ROS and oxLDL and negatively with SOD levels (p<0.0001). Expressions of DNA ligase IV, Ku70 and Ku80 proteins were highest after one week and Mre11 protein after 3 months of LVAD transplantation; indicated abnormal DNA repair. CONCLUSIONS The study, for the first time shows that, continuous flow LVAD implanted HF patients not only exhibit elevated oxidative stress and DNA damage in blood leukocytes but also have abnormalities in DNA repair pathways.
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Affiliation(s)
- Nandan Kumar Mondal
- Department of Surgery, Artificial Organ Lab, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Wohlbold L, Merrick KA, De S, Amat R, Kim JH, Larochelle S, Allen JJ, Zhang C, Shokat KM, Petrini JHJ, Fisher RP. Chemical genetics reveals a specific requirement for Cdk2 activity in the DNA damage response and identifies Nbs1 as a Cdk2 substrate in human cells. PLoS Genet 2012; 8:e1002935. [PMID: 22927831 PMCID: PMC3426557 DOI: 10.1371/journal.pgen.1002935] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 07/17/2012] [Indexed: 12/20/2022] Open
Abstract
The cyclin-dependent kinases (CDKs) that promote cell-cycle progression are targets for negative regulation by signals from damaged or unreplicated DNA, but also play active roles in response to DNA lesions. The requirement for activity in the face of DNA damage implies that there are mechanisms to insulate certain CDKs from checkpoint inhibition. It remains difficult, however, to assign precise functions to specific CDKs in protecting genomic integrity. In mammals, Cdk2 is active throughout S and G2 phases, but Cdk2 protein is dispensable for survival, owing to compensation by other CDKs. That plasticity obscured a requirement for Cdk2 activity in proliferation of human cells, which we uncovered by replacement of wild-type Cdk2 with a mutant version sensitized to inhibition by bulky adenine analogs. Here we show that transient, selective inhibition of analog-sensitive (AS) Cdk2 after exposure to ionizing radiation (IR) enhances cell-killing. In extracts supplemented with an ATP analog used preferentially by AS kinases, Cdk2(as) phosphorylated the Nijmegen Breakage Syndrome gene product Nbs1-a component of the conserved Mre11-Rad50-Nbs1 complex required for normal DNA damage repair and checkpoint signaling-dependent on a consensus CDK recognition site at Ser432. In vivo, selective inhibition of Cdk2 delayed and diminished Nbs1-Ser432 phosphorylation during S phase, and mutation of Ser432 to Ala or Asp increased IR-sensitivity. Therefore, by chemical genetics, we uncovered both a non-redundant requirement for Cdk2 activity in response to DNA damage and a specific target of Cdk2 within the DNA repair machinery.
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Affiliation(s)
- Lara Wohlbold
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Karl A. Merrick
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, United States of America
- Program in Biochemistry and Program in Cell and Molecular Biology, Weill Cornell Graduate School of Medical Sciences, New York, New York, United States of America
| | - Saurav De
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Ramon Amat
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Jun Hyun Kim
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Stéphane Larochelle
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Jasmina J. Allen
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Chao Zhang
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Kevan M. Shokat
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - John H. J. Petrini
- Molecular Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Robert P. Fisher
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, United States of America
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Abstract
The maintenance of genome stability depends on the DNA damage response (DDR), which is a functional network comprising signal transduction, cell cycle regulation and DNA repair. The metabolism of DNA double-strand breaks governed by the DDR is important for preventing genomic alterations and sporadic cancers, and hereditary defects in this response cause debilitating human pathologies, including developmental defects and cancer. The MRE11 complex, composed of the meiotic recombination 11 (MRE11), RAD50 and Nijmegen breakage syndrome 1 (NBS1; also known as nibrin) proteins is central to the DDR, and recent insights into its structure and function have been gained from in vitro structural analysis and studies of animal models in which the DDR response is deficient.
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Affiliation(s)
- Travis H Stracker
- Institute for Research in Biomedicine Barcelona, C/ Baldiri Reixac 10, 08028 Barcelona, Spain.
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