1
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Rinaldi F, Girotto S. Structure-based approaches in synthetic lethality strategies. Curr Opin Struct Biol 2024; 88:102895. [PMID: 39137490 DOI: 10.1016/j.sbi.2024.102895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 08/15/2024]
Abstract
Evolution has fostered robust DNA damage response (DDR) mechanisms to combat DNA lesions. However, disruptions in this intricate machinery can render cells overly reliant on the remaining functional but often less accurate DNA repair pathways. This increased dependence on error-prone pathways may result in improper repair and the accumulation of mutations, fostering genomic instability and facilitating the uncontrolled cell proliferation characteristic of cancer initiation and progression. Strategies based on the concept of synthetic lethality (SL) leverage the inherent genomic instability of cancer cells by targeting alternative pathways, thereby inducing selective death of cancer cells. This review emphasizes recent advancements in structural investigations of pivotal SL targets. The significant contribution of structure-based methodologies to SL research underscores their potential impact in characterizing the growing number of SL targets, largely due to advances in next-generation sequencing. Harnessing these approaches is essential for advancing the development of precise and personalized SL therapeutic strategies.
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Affiliation(s)
- Francesco Rinaldi
- Computational and Chemical Biology, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Stefania Girotto
- Structural Biophysics Facility, Istituto Italiano di Tecnologia, 16163 Genoa, Italy.
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2
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Maiuri T, Bazan CB, Harding RJ, Begeja N, Kam TI, Byrne LM, Rodrigues FB, Warner MM, Neuman K, Mansoor M, Badiee M, Dasovich M, Wang K, Thompson LM, Leung AKL, Andres SN, Wild EJ, Dawson TM, Dawson VL, Arrowsmith CH, Truant R. Poly ADP-ribose signaling is dysregulated in Huntington disease. Proc Natl Acad Sci U S A 2024; 121:e2318098121. [PMID: 39331414 PMCID: PMC11459172 DOI: 10.1073/pnas.2318098121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 08/18/2024] [Indexed: 09/28/2024] Open
Abstract
Huntington disease (HD) is a genetic neurodegenerative disease caused by cytosine, adenine, guanine (CAG) expansion in the Huntingtin (HTT) gene, translating to an expanded polyglutamine tract in the HTT protein. Age at disease onset correlates to CAG repeat length but varies by decades between individuals with identical repeat lengths. Genome-wide association studies link HD modification to DNA repair and mitochondrial health pathways. Clinical studies show elevated DNA damage in HD, even at the premanifest stage. A major DNA repair node influencing neurodegenerative disease is the PARP pathway. Accumulation of poly adenosine diphosphate (ADP)-ribose (PAR) has been implicated in Alzheimer and Parkinson diseases, as well as cerebellar ataxia. We report that HD mutation carriers have lower cerebrospinal fluid PAR levels than healthy controls, starting at the premanifest stage. Human HD induced pluripotent stem cell-derived neurons and patient-derived fibroblasts have diminished PAR response in the context of elevated DNA damage. We have defined a PAR-binding motif in HTT, detected HTT complexed with PARylated proteins in human cells during stress, and localized HTT to mitotic chromosomes upon inhibition of PAR degradation. Direct HTT PAR binding was measured by fluorescence polarization and visualized by atomic force microscopy at the single molecule level. While wild-type and mutant HTT did not differ in their PAR binding ability, purified wild-type HTT protein increased in vitro PARP1 activity while mutant HTT did not. These results provide insight into an early molecular mechanism of HD, suggesting possible targets for the design of early preventive therapies.
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Affiliation(s)
- Tamara Maiuri
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
| | - Carlos Barba Bazan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
| | - Rachel J. Harding
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, TorontoONM5S 3M2, Canada
- Structural Genomics Consortium, University of Toronto, Toronto, ONM5G 1L7, Canada
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Nola Begeja
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
| | - Tae-In Kam
- Neurodegeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore,MD21205
| | - Lauren M. Byrne
- University College London Huntington Disease Centre, University College London Queen Square Institute of Neurology, University College London, LondonWC1N 3BG, United Kingdom
| | - Filipe B. Rodrigues
- University College London Huntington Disease Centre, University College London Queen Square Institute of Neurology, University College London, LondonWC1N 3BG, United Kingdom
| | - Monica M. Warner
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4L8, Canada
| | - Kaitlyn Neuman
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
| | - Muqtasid Mansoor
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
| | - Mohsen Badiee
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21205
| | - Morgan Dasovich
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21205
| | - Keona Wang
- Department of Neurobiology and Behavior, University of California, Irvine, CA92697
| | - Leslie M. Thompson
- Department of Neurobiology and Behavior, University of California, Irvine, CA92697
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA92868
| | - Anthony K. L. Leung
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21205
- Department of Molecular Biology and Genetics, School of Medicine, Johns Hopkins University, Baltimore,MD21205
- Department of Genetic Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD21205
- Department of Oncology, School of Medicine, Johns Hopkins University, Baltimore, MD21205
| | - Sara N. Andres
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4L8, Canada
| | - Edward J. Wild
- University College London Huntington Disease Centre, University College London Queen Square Institute of Neurology, University College London, LondonWC1N 3BG, United Kingdom
| | - Ted M. Dawson
- Neurodegeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore,MD21205
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Valina L. Dawson
- Neurodegeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore,MD21205
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD21205
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD21205
| | - Cheryl H. Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, ONM5G 1L7, Canada
- Princess Margaret Cancer Centre, University of Toronto, Toronto, ONM5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 1L7, Canada
| | - Ray Truant
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 3Z5, Canada
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3
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Jenni R, Klaa H, Khamessi O, Chikhaoui A, Najjar D, Ghedira K, Kraoua I, Turki I, Yacoub-Youssef H. Clinical and genetic spectrum of Ataxia Telangiectasia Tunisian patients: Bioinformatic analysis unveil mechanisms of ATM variants pathogenicity. Int J Biol Macromol 2024; 278:134444. [PMID: 39098699 DOI: 10.1016/j.ijbiomac.2024.134444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/28/2024] [Accepted: 08/01/2024] [Indexed: 08/06/2024]
Abstract
Ataxia Telangiectasia (AT) is a rare multisystemic neurodegenerative disease caused by biallelic mutations in the ATM gene. Few clinical studies on AT disease have been conducted in Tunisia, however, the mutational landscape is still undefined. Our aim is to determine the clinical and genetic spectrum of AT Tunisian patients and to explore the potential underlying mechanism of variant pathogenicity. Sanger sequencing was performed for nine AT patients. A comprehensive computational analysis was conducted to evaluate the possible pathogenic effect of ATM identified variants. Genetic screening of ATM gene has identified nine different variants from which six have not been previously reported. In silico analysis has predicted a pathogenic effect of identified mutations. This was corroborated by a structural bioinformatics study based on molecular modeling and docking for novel missense mutations. Our findings suggest a profound impact of identified mutations not only on the ATM protein stability, but also on the ATM-ligand interactions. Our study characterizes the mutational landscape of AT Tunisian patients which will allow to set up genetic counseling and prenatal diagnosis for families at risk and expand the spectrum of ATM variants worldwide. Furthermore, understanding the mechanism that underpin variant pathogenicity could provide further insights into disease pathogenesis.
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Affiliation(s)
- Rim Jenni
- Laboratory of Biomedical Genomics and Oncogenetics (LR16IPT05), Institut Pasteur de Tunis, University Tunis El Manar, Tunis 1002, Tunisia.
| | - Hedia Klaa
- LR18SP04 and Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, 1007 Tunis, Tunisia.
| | - Oussema Khamessi
- Laboratory of Bioinformatics, Biomathematics and Biostatistics (BIMS), Institut Pasteur de Tunis (IPT), University of Tunis El Manar, Tunis, Tunisia; Institut de Biotechnologie de Sidi Thabet, Université de la Manouba, Ariana BP-66, Manouba 2010, Tunisia.
| | - Asma Chikhaoui
- Laboratory of Biomedical Genomics and Oncogenetics (LR16IPT05), Institut Pasteur de Tunis, University Tunis El Manar, Tunis 1002, Tunisia.
| | - Dorra Najjar
- Laboratory of Biomedical Genomics and Oncogenetics (LR16IPT05), Institut Pasteur de Tunis, University Tunis El Manar, Tunis 1002, Tunisia.
| | - Kais Ghedira
- Laboratory of Bioinformatics, Biomathematics and Biostatistics (BIMS), Institut Pasteur de Tunis (IPT), University of Tunis El Manar, Tunis, Tunisia.
| | - Ichraf Kraoua
- LR18SP04 and Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, 1007 Tunis, Tunisia.
| | - Ilhem Turki
- LR18SP04 and Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, 1007 Tunis, Tunisia.
| | - Houda Yacoub-Youssef
- Laboratory of Biomedical Genomics and Oncogenetics (LR16IPT05), Institut Pasteur de Tunis, University Tunis El Manar, Tunis 1002, Tunisia.
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4
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Richardson ME, Holdren M, Brannan T, de la Hoya M, Spurdle AB, Tavtigian SV, Young CC, Zec L, Hiraki S, Anderson MJ, Walker LC, McNulty S, Turnbull C, Tischkowitz M, Schon K, Slavin T, Foulkes WD, Cline M, Monteiro AN, Pesaran T, Couch FJ. Specifications of the ACMG/AMP variant curation guidelines for the analysis of germline ATM sequence variants. Am J Hum Genet 2024:S0002-9297(24)00332-X. [PMID: 39317201 DOI: 10.1016/j.ajhg.2024.08.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 08/29/2024] [Accepted: 08/29/2024] [Indexed: 09/26/2024] Open
Abstract
The ClinGen Hereditary Breast, Ovarian, and Pancreatic Cancer (HBOP) Variant Curation Expert Panel (VCEP) is composed of internationally recognized experts in clinical genetics, molecular biology, and variant interpretation. This VCEP made specifications for the American College of Medical Genetics and Association for Molecular Pathology (ACMG/AMP) guidelines for the ataxia telangiectasia mutated (ATM) gene according to the ClinGen protocol. These gene-specific rules for ATM were modified from the ACMG/AMP guidelines and were tested against 33 ATM variants of various types and classifications in a pilot curation phase. The pilot revealed a majority agreement between the HBOP VCEP classifications and the ClinVar-deposited classifications. Six pilot variants had conflicting interpretations in ClinVar, and re-evaluation with the VCEP's ATM-specific rules resulted in four that were classified as benign, one as likely pathogenic, and one as a variant of uncertain significance (VUS) by the VCEP, improving the certainty of interpretations in the public domain. Overall, 28 of the 33 pilot variants were not VUS, leading to an 85% classification rate. The ClinGen-approved, modified rules demonstrated value for improved interpretation of variants in ATM.
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Affiliation(s)
| | - Megan Holdren
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Miguel de la Hoya
- Molecular Oncology Laboratory, Hospital Clínico San Carlos, IdISSC, 28040 Madrid, Spain
| | - Amanda B Spurdle
- Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia
| | - Sean V Tavtigian
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | | | | | | | | | - Logan C Walker
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Shannon McNulty
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Clare Turnbull
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Marc Tischkowitz
- Department of Medical Genetics, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Katherine Schon
- Department of Medical Genetics, National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Thomas Slavin
- City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - William D Foulkes
- Departments of Human Genetics, McGill University, Montreal, QC, Canada
| | - Melissa Cline
- UC Santa Cruz Genomics Institute, Mail Stop: Genomics, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Alvaro N Monteiro
- Department of Cancer Epidemiology, H Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA
| | | | - Fergus J Couch
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
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5
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Lee JH. Oxidative stress and the multifaceted roles of ATM in maintaining cellular redox homeostasis. Redox Biol 2024; 75:103269. [PMID: 39018798 PMCID: PMC11301354 DOI: 10.1016/j.redox.2024.103269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/12/2024] [Accepted: 07/13/2024] [Indexed: 07/19/2024] Open
Abstract
The ataxia telangiectasia mutated (ATM) protein kinase is best known as a master regulator of the DNA damage response. However, accumulating evidence has unveiled an equally vital function for ATM in sensing oxidative stress and orchestrating cellular antioxidant defenses to maintain redox homeostasis. ATM can be activated through a non-canonical pathway involving intermolecular disulfide crosslinking of the kinase dimers, distinct from its canonical activation by DNA double-strand breaks. Structural studies have elucidated the conformational changes that allow ATM to switch into an active redox-sensing state upon oxidation. Notably, loss of ATM function results in elevated reactive oxygen species (ROS) levels, altered antioxidant profiles, and mitochondrial dysfunction across multiple cell types and tissues. This oxidative stress arising from ATM deficiency has been implicated as a central driver of the neurodegenerative phenotypes in ataxia-telangiectasia (A-T) patients, potentially through mechanisms involving oxidative DNA damage, PARP hyperactivation, and widespread protein aggregation. Moreover, defective ATM oxidation sensing disrupts transcriptional programs and RNA metabolism, with detrimental impacts on neuronal homeostasis. Significantly, antioxidant therapy can ameliorate cellular and organismal abnormalities in various ATM-deficient models. This review synthesizes recent advances illuminating the multifaceted roles of ATM in preserving redox balance and mitigating oxidative insults, providing a unifying paradigm for understanding the complex pathogenesis of A-T disease.
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Affiliation(s)
- Ji-Hoon Lee
- Department of Biological Sciences, Research Center of Ecomimetics, Chonnam National University, Gwangju, 61186, Republic of Korea.
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6
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Li Z, Gu J, Huang X, Lu Z, Feng Y, Xu X, Yang J. Transcriptome-based network analysis reveals hub immune genes and pathways of hepatopancreas against LPS in Amphioctopus fangsiao. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109696. [PMID: 38871144 DOI: 10.1016/j.fsi.2024.109696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/13/2024] [Accepted: 06/11/2024] [Indexed: 06/15/2024]
Abstract
The hepatopancreas is the biggest digestive organ in Amphioctopus fangsiao (A. fangsiao), but also undertakes critical functions like detoxification and immune defense. Generally, pathogenic bacteria or endotoxin from the gut microbiota would be arrested and detoxified in the hepatopancreas, which could be accompanied by the inevitable immune responses. In recent years, studies related to cephalopods immune have been increasing, but the molecular mechanisms associated with the hepatopancreatic immunity are still unclear. In this study, lipopolysaccharide (LPS), a major component of the cell wall of Gram-negative bacteria, was used for imitating bacteria infection to stimulate the hepatopancreas of A. fangsiao. To investigate the immune process happened in A. fangsiao hepatopancreas, we performed transcriptome analysis of hepatopancreas tissue after LPS injection, and identified 2615 and 1943 differentially expressed genes (DEGs) at 6 and 24 h post-injection, respectively. GO and KEGG enrichment analysis showed that these DEGs were mainly involved in immune-related biological processes and signaling pathways, including ECM-receptor interaction signaling pathway, Phagosome signaling pathway, Lysosome signaling pathway, and JAK-STAT signaling pathways. The function relationships between these DEGs were further analyzed through protein-protein interaction (PPI) networks. It was found that Mtor, Mapk14 and Atm were the three top interacting DEGs under LPS stimulation. Finally, 15 hub genes involving multiple KEGG signaling pathways and PPI relationships were selected for qRT-PCR validation. In this study, for the first time we explored the molecular mechanisms associated with hepatopancreatic immunity in A. fangsiao using a PPI networks approach, and provided new insights for understanding hepatopancreatic immunity in A. fangsiao.
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Affiliation(s)
- Zan Li
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Jingjing Gu
- Binzhou Testing Center, Binzhou 256600, China
| | - Xiaolan Huang
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Zhengcai Lu
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Yanwei Feng
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Xiaohui Xu
- School of Agriculture, Ludong University, Yantai, 264025, China.
| | - Jianmin Yang
- School of Agriculture, Ludong University, Yantai, 264025, China
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7
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Richardson ME, Holdren M, Brannan T, de la Hoya M, Spurdle AB, Tavtigian SV, Young CC, Zec L, Hiraki S, Anderson MJ, Walker LC, McNulty S, Turnbull C, Tischkowitz M, Schon K, Slavin T, Foulkes WD, Cline M, Monteiro AN, Pesaran T, Couch FJ. Specifications of the ACMG/AMP variant curation guidelines for the analysis of germline ATM sequence variants. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.28.24307502. [PMID: 38854136 PMCID: PMC11160822 DOI: 10.1101/2024.05.28.24307502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The ClinGen Hereditary Breast, Ovarian and Pancreatic Cancer (HBOP) Variant Curation Expert Panel (VCEP) is composed of internationally recognized experts in clinical genetics, molecular biology and variant interpretation. This VCEP made specifications for ACMG/AMP guidelines for the ataxia telangiectasia mutated (ATM) gene according to the Food and Drug Administration (FDA)-approved ClinGen protocol. These gene-specific rules for ATM were modified from the American College of Medical Genetics and Association for Molecular Pathology (ACMG/AMP) guidelines and were tested against 33 ATM variants of various types and classifications in a pilot curation phase. The pilot revealed a majority agreement between the HBOP VCEP classifications and the ClinVar-deposited classifications. Six pilot variants had conflicting interpretations in ClinVar and reevaluation with the VCEP's ATM-specific rules resulted in four that were classified as benign, one as likely pathogenic and one as a variant of uncertain significance (VUS) by the VCEP, improving the certainty of interpretations in the public domain. Overall, 28 the 33 pilot variants were not VUS leading to an 85% classification rate. The ClinGen-approved, modified rules demonstrated value for improved interpretation of variants in ATM.
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Affiliation(s)
| | - Megan Holdren
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Miguel de la Hoya
- Molecular Oncology Laboratory, Hospital Clínico San Carlos, IdISSC, 28040 Madrid, Spain
| | - Amanda B Spurdle
- Population Health, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia
| | - Sean V Tavtigian
- Department of Oncological Sciences and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | | | | | | | | | - Logan C Walker
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Shannon McNulty
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Clare Turnbull
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Marc Tischkowitz
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Katherine Schon
- Division of Genetics and Epidemiology, Institute of Cancer Research, London, UK
| | - Thomas Slavin
- City of Hope Comprehensive Cancer Center, Duarte, CA, USA
| | - William D Foulkes
- Departments of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Melissa Cline
- UC Santa Cruz Genomics Institute, Mail Stop: Genomics, University of California, Santa Cruz, CA, USA
| | - Alvaro N Monteiro
- Department of Cancer Epidemiology, H Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA
| | | | - Fergus J Couch
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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8
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Xu J, Bradley N, He Y. Structure and function of the apical PIKKs in double-strand break repair. Curr Opin Struct Biol 2023; 82:102651. [PMID: 37437397 PMCID: PMC10530350 DOI: 10.1016/j.sbi.2023.102651] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 07/14/2023]
Abstract
Members of the phosphatidylinositol 3' kinase (PI3K)-related kinases (PIKKs) family, including DNA-dependent protein kinase catalytic subunit (DNA-PKcs), ataxia telangiectasia mutated (ATM), ataxia-telangiectasia mutated and Rad3-related (ATR), mammalian target of rapamycin (mTOR), suppressor with morphological effect on genitalia 1 (SMG1), and transformation/transcription domain-associated protein 1 (TRRAP/Tra1), participate in a variety of physiological processes, such as cell-cycle control, metabolism, transcription, replication, and the DNA damage response. In eukaryotic cells, DNA-PKcs, ATM, and ATR-ATRIP are the main sensors and regulators of DNA double-strand break repair. The purpose of this review is to describe recent structures of DNA-PKcs, ATM, and ATR, as well as their functions in activation and phosphorylation in different DNA repair pathways.
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Affiliation(s)
- Jingfei Xu
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Noah Bradley
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
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9
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Howes AC, Perisic O, Williams RL. Structural insights into the activation of ataxia-telangiectasia mutated by oxidative stress. SCIENCE ADVANCES 2023; 9:eadi8291. [PMID: 37756394 PMCID: PMC10530080 DOI: 10.1126/sciadv.adi8291] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023]
Abstract
Ataxia-telangiectasia mutated (ATM) is a master kinase regulating DNA damage response that is activated by DNA double-strand breaks. However, ATM is also directly activated by reactive oxygen species, but how oxidative activation is achieved remains unknown. We determined the cryo-EM structure of an H2O2-activated ATM and showed that under oxidizing conditions, ATM formed an intramolecular disulfide bridge between two protomers that are rotated relative to each other when compared to the basal state. This rotation is accompanied by release of the substrate-blocking PRD region and twisting of the N-lobe relative to the C-lobe, which greatly optimizes catalysis. This active site remodeling enabled us to capture a substrate (p53) bound to the enzyme. This provides the first structural insights into how ATM is activated during oxidative stress.
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Affiliation(s)
| | - Olga Perisic
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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10
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Li S, Wang L, Wang Y, Zhang C, Hong Z, Han Z. The synthetic lethality of targeting cell cycle checkpoints and PARPs in cancer treatment. J Hematol Oncol 2022; 15:147. [PMID: 36253861 PMCID: PMC9578258 DOI: 10.1186/s13045-022-01360-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
Continuous cell division is a hallmark of cancer, and the underlying mechanism is tumor genomics instability. Cell cycle checkpoints are critical for enabling an orderly cell cycle and maintaining genome stability during cell division. Based on their distinct functions in cell cycle control, cell cycle checkpoints are classified into two groups: DNA damage checkpoints and DNA replication stress checkpoints. The DNA damage checkpoints (ATM-CHK2-p53) primarily monitor genetic errors and arrest cell cycle progression to facilitate DNA repair. Unfortunately, genes involved in DNA damage checkpoints are frequently mutated in human malignancies. In contrast, genes associated with DNA replication stress checkpoints (ATR-CHK1-WEE1) are rarely mutated in tumors, and cancer cells are highly dependent on these genes to prevent replication catastrophe and secure genome integrity. At present, poly (ADP-ribose) polymerase inhibitors (PARPi) operate through “synthetic lethality” mechanism with mutant DNA repair pathways genes in cancer cells. However, an increasing number of patients are acquiring PARP inhibitor resistance after prolonged treatment. Recent work suggests that a combination therapy of targeting cell cycle checkpoints and PARPs act synergistically to increase the number of DNA errors, compromise the DNA repair machinery, and disrupt the cell cycle, thereby increasing the death rate of cancer cells with DNA repair deficiency or PARP inhibitor resistance. We highlight a combinational strategy involving PARP inhibitors and inhibition of two major cell cycle checkpoint pathways, ATM-CHK2-TP53 and ATR-CHK1-WEE1. The biological functions, resistance mechanisms against PARP inhibitors, advances in preclinical research, and clinical trials are also reviewed.
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Affiliation(s)
- Shuangying Li
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Liangliang Wang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Yuanyuan Wang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Changyi Zhang
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Zhenya Hong
- Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
| | - Zhiqiang Han
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
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11
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Structures of Mec1/ATR kinase endogenously stimulated by different genotoxins. Cell Discov 2022; 8:98. [PMID: 36175395 PMCID: PMC9523049 DOI: 10.1038/s41421-022-00461-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/20/2022] [Indexed: 11/16/2022] Open
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12
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Bueno‐Martínez E, Sanoguera‐Miralles L, Valenzuela‐Palomo A, Esteban‐Sánchez A, Lorca V, Llinares‐Burguet I, Allen J, García‐Álvarez A, Pérez‐Segura P, Durán M, Easton DF, Devilee P, Vreeswijk MPG, de la Hoya M, Velasco‐Sampedro EA. Minigene-based splicing analysis and ACMG/AMP-based tentative classification of 56 ATM variants. J Pathol 2022; 258:83-101. [PMID: 35716007 PMCID: PMC9541484 DOI: 10.1002/path.5979] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/11/2022] [Accepted: 06/08/2022] [Indexed: 12/29/2022]
Abstract
The ataxia telangiectasia-mutated (ATM) protein is a major coordinator of the DNA damage response pathway. ATM loss-of-function variants are associated with 2-fold increased breast cancer risk. We aimed at identifying and classifying spliceogenic ATM variants detected in subjects of the large-scale sequencing project BRIDGES. A total of 381 variants at the intron-exon boundaries were identified, 128 of which were predicted to be spliceogenic. After further filtering, we ended up selecting 56 variants for splicing analysis. Four functional minigenes (mgATM) spanning exons 4-9, 11-17, 25-29, and 49-52 were constructed in the splicing plasmid pSAD. Selected variants were genetically engineered into the four constructs and assayed in MCF-7/HeLa cells. Forty-eight variants (85.7%) impaired splicing, 32 of which did not show any trace of the full-length (FL) transcript. A total of 43 transcripts were identified where the most prevalent event was exon/multi-exon skipping. Twenty-seven transcripts were predicted to truncate the ATM protein. A tentative ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular Pathology)-based classification scheme that integrates mgATM data allowed us to classify 29 ATM variants as pathogenic/likely pathogenic and seven variants as likely benign. Interestingly, the likely pathogenic variant c.1898+2T>G generated 13% of the minigene FL-transcript due to the use of a noncanonical GG-5'-splice-site (0.014% of human donor sites). Circumstantial evidence in three ATM variants (leakiness uncovered by our mgATM analysis together with clinical data) provides some support for a dosage-sensitive expression model in which variants producing ≥30% of FL-transcripts would be predicted benign, while variants producing ≤13% of FL-transcripts might be pathogenic. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Elena Bueno‐Martínez
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
| | - Lara Sanoguera‐Miralles
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
| | - Alberto Valenzuela‐Palomo
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
| | - Ada Esteban‐Sánchez
- Molecular Oncology Laboratory CIBERONC, Hospital Clínico San Carlos, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos)MadridSpain
| | - Víctor Lorca
- Molecular Oncology Laboratory CIBERONC, Hospital Clínico San Carlos, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos)MadridSpain
| | - Inés Llinares‐Burguet
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
| | - Jamie Allen
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary CareUniversity of CambridgeCambridgeUK
| | - Alicia García‐Álvarez
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
| | - Pedro Pérez‐Segura
- Molecular Oncology Laboratory CIBERONC, Hospital Clínico San Carlos, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos)MadridSpain
| | - Mercedes Durán
- Cancer Genetics, Instituto de Biología y Genética MolecularValladolidSpain
| | - Douglas F Easton
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary CareUniversity of CambridgeCambridgeUK
| | - Peter Devilee
- Department of Human GeneticsLeiden University Medical CenterLeidenThe Netherlands
| | - Maaike PG Vreeswijk
- Department of Human GeneticsLeiden University Medical CenterLeidenThe Netherlands
| | - Miguel de la Hoya
- Molecular Oncology Laboratory CIBERONC, Hospital Clínico San Carlos, IdISSC (Instituto de Investigación Sanitaria del Hospital Clínico San Carlos)MadridSpain
| | - Eladio A Velasco‐Sampedro
- Splicing and Genetic Susceptibility to Cancer, Unidad de Excelencia Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC‐UVa)ValladolidSpain
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13
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Roemer A, Mohammed L, Strickfaden H, Underhill DA, Hendzel MJ. Mechanisms governing the accessibility of DNA damage proteins to constitutive heterochromatin. Front Genet 2022; 13:876862. [PMID: 36092926 PMCID: PMC9458887 DOI: 10.3389/fgene.2022.876862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/18/2022] [Indexed: 12/05/2022] Open
Abstract
Chromatin is thought to regulate the accessibility of the underlying DNA sequence to machinery that transcribes and repairs the DNA. Heterochromatin is chromatin that maintains a sufficiently high density of DNA packing to be visible by light microscopy throughout the cell cycle and is thought to be most restrictive to transcription. Several studies have suggested that larger proteins and protein complexes are attenuated in their access to heterochromatin. In addition, heterochromatin domains may be associated with phase separated liquid condensates adding further complexity to the regulation of protein concentration within chromocenters. This provides a solvent environment distinct from the nucleoplasm, and proteins that are not size restricted in accessing this liquid environment may partition between the nucleoplasm and heterochromatin based on relative solubility. In this study, we assessed the accessibility of constitutive heterochromatin in mouse cells, which is organized into large and easily identifiable chromocenters, to fluorescently tagged DNA damage response proteins. We find that proteins larger than the expected 10 nm size limit can access the interior of heterochromatin. We find that the sensor proteins Ku70 and PARP1 enrich in mouse chromocenters. At the same time, MRE11 shows variability within an asynchronous population that ranges from depleted to enriched but is primarily homogeneously distribution between chromocenters and the nucleoplasm. While larger downstream proteins such as ATM, BRCA1, and 53BP1 are commonly depleted in chromocenters, they show a wide range of concentrations, with none being depleted beyond approximately 75%. Contradicting exclusively size-dependent accessibility, many smaller proteins, including EGFP, are also depleted in chromocenters. Our results are consistent with minimal size-dependent selectivity but a distinct solvent environment explaining reduced concentrations of diffusing nucleoplasmic proteins within the volume of the chromocenter.
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14
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Jiang B, Wang J, Liu W, Cheng J, Xu J, Cao M, Li Y. Comparative transcriptome analysis of MDBK cells reveals that BoIFN-γ augmented host immune responses to bovine herpesvirus 1 infection. Front Microbiol 2022; 13:973278. [PMID: 36016774 PMCID: PMC9396027 DOI: 10.3389/fmicb.2022.973278] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Bovine herpesvirus 1 (BoHV-1) is an alphaherpesvirus that causes infectious bovine rhinotracheitis and infectious pustular vulvovaginitis in cattle. Ιnterferon-gamma (IFN-γ) is a pleiotropic cytokine with antiviral activity that modulates the innate and adaptive immune responses. In this study, we prepared high-purity bovine interferon gamma (BoIFN-γ) dimer protein using prokaryotic expression system and affinity chromatography. We subsequently investigated the effect of BoIFN-γ on BoHV-1 infection in Madin-Darby bovine kidney (MDBK) cells. The results showed that BoIFN-γ pre-treament not only decreased the production of BoHV-1 but also reduced the cytopathic effect of the virus. Differential gene expression profiles of BoHV-1 infected MDBK cells were then analysed through high-throughput RNA sequencing. The data showed that BoIFN-γ pre-treatment reduced lipid metabolism disorder and DNA damage caused by BoHV-1 infection. Furthermore, BoIFN-γ treatment upregulated the transcription of interferon regulatory transcription factors (IRF1 and GBP5) and interferon-stimulated genes (ISGs) of MDBK cells. Additionally, BoIFN-γ promotes expression of cellular protein involved in complement activation and coagulation cascades response as well as antigen processing and presentation process, while BoHV-1 infection dramatically downregulates transcription of these immune components including C3, C1r, C1s, PLAT, ITGB2, PROCR, BoLA, CD74, B2M, PA28, BoLA-DRA, and TAPBP. Collectively, our findings revealed that BoIFN-γ pre-treatment can improve host resistance to BoHV-1 infection and regulate transcription or expression of host protein associated with cellular metabolism and innate immune response. This provides insights into the development of prophylactic agents for prevention and control of BoHV-1 infection.
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Affiliation(s)
- Bo Jiang
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Jing Wang
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Wenxiao Liu
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Jing Cheng
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
| | - Jian Xu
- Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Mengyao Cao
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
- Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Yongqing Li
- Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China
- *Correspondence: Yongqing Li,
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15
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Dimitrov T, Anli C, Moschopoulou AA, Kronenberger T, Kudolo M, Geibel C, Schwalm MP, Knapp S, Zender L, Forster M, Laufer S. Development of novel urea-based ATM kinase inhibitors with subnanomolar cellular potency and high kinome selectivity. Eur J Med Chem 2022; 235:114234. [DOI: 10.1016/j.ejmech.2022.114234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022]
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16
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Warren C, Pavletich NP. Structure of the human ATM kinase and mechanism of Nbs1 binding. eLife 2022; 11:74218. [PMID: 35076389 PMCID: PMC8828054 DOI: 10.7554/elife.74218] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 01/24/2022] [Indexed: 11/27/2022] Open
Abstract
DNA double-strand breaks (DSBs) can lead to mutations, chromosomal rearrangements, genome instability, and cancer. Central to the sensing of DSBs is the ATM (Ataxia-telangiectasia mutated) kinase, which belongs to the phosphatidylinositol 3-kinase-related protein kinase (PIKK) family. In response to DSBs, ATM is activated by the MRN (Mre11-Rad50-Nbs1) protein complex through a poorly understood process that also requires double-stranded DNA. Previous studies indicate that the FxF/Y motif of Nbs1 directly binds to ATM, and is required to retain active ATM at sites of DNA damage. Here, we report the 2.5 Å resolution cryo-EM structures of human ATM and its complex with the Nbs1 FxF/Y motif. In keeping with previous structures of ATM and its yeast homolog Tel1, the dimeric human ATM kinase adopts a symmetric, butterfly-shaped structure. The conformation of the ATM kinase domain is most similar to the inactive states of other PIKKs, suggesting that activation may involve an analogous realigning of the N and C lobes along with relieving the blockage of the substrate-binding site. We also show that the Nbs1 FxF/Y motif binds to a conserved hydrophobic cleft within the Spiral domain of ATM, suggesting an allosteric mechanism of activation. We evaluate the importance of these structural findings with mutagenesis and biochemical assays.
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Affiliation(s)
- Christopher Warren
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Nikola P Pavletich
- Memorial Sloan Kettering Cancer Center, Howard Hughes Medical Institute, New York, United States
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17
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Papageorgiou GI, Fergadis E, Skouteris N, Christakos E, Tsakatikas SA, Lianos E, Kosmas C. Case Report: Combination of Olaparib With Chemotherapy in a Patient With ATM-Deficient Colorectal Cancer. Front Oncol 2022; 11:788809. [PMID: 35004311 PMCID: PMC8728007 DOI: 10.3389/fonc.2021.788809] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/01/2021] [Indexed: 12/18/2022] Open
Abstract
Poly-ADP ribose polymerase (PARP) inhibitors are constantly increasing in their indications for use as anti-cancer treatment in various neoplasms, the majority of which are linked with BRCA deficiency. Preclinical data support the investigation of PARP inhibitors in other neoplasms exhibiting “BRCAness” or homologous recombination deficiency (HRD) as monotherapy as well as in combination with chemotherapy. With the current report we present the case of a heavily pretreated 55-year-old male patient diagnosed with stage IV ATM-deficient CRC, who was effectively treated with an off-label olaparib-irinotecan combination after exhaustion of all available treatment choices; furthermore, we discuss the existing data providing evidence for the use of PARP inhibitors in ATM-deficient CRC and encourage the implementation of next-generation sequencing (NGS) in patients with no other available treatment options.
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Affiliation(s)
- Georgios I Papageorgiou
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Evangelos Fergadis
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Nikos Skouteris
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Evridiki Christakos
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Sergios A Tsakatikas
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Evangelos Lianos
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
| | - Christos Kosmas
- Division of Medical Oncology & Hematopoietic Cell Transplant Unit, Department of Medicine, ''Metaxa'' Cancer Hospital, Piraeus, Greece
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18
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Ueno S, Sudo T, Hirasawa A. ATM: Functions of ATM Kinase and Its Relevance to Hereditary Tumors. Int J Mol Sci 2022; 23:523. [PMID: 35008949 PMCID: PMC8745051 DOI: 10.3390/ijms23010523] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 02/04/2023] Open
Abstract
Ataxia-telangiectasia mutated (ATM) functions as a key initiator and coordinator of DNA damage and cellular stress responses. ATM signaling pathways contain many downstream targets that regulate multiple important cellular processes, including DNA damage repair, apoptosis, cell cycle arrest, oxidative sensing, and proliferation. Over the past few decades, associations between germline ATM pathogenic variants and cancer risk have been reported, particularly for breast and pancreatic cancers. In addition, given that ATM plays a critical role in repairing double-strand breaks, inhibiting other DNA repair pathways could be a synthetic lethal approach. Based on this rationale, several DNA damage response inhibitors are currently being tested in ATM-deficient cancers. In this review, we discuss the current knowledge related to the structure of the ATM gene, function of ATM kinase, clinical significance of ATM germline pathogenic variants in patients with hereditary cancers, and ongoing efforts to target ATM for the benefit of cancer patients.
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Affiliation(s)
- Sayaka Ueno
- Section of Translational Research, Hyogo Cancer Center, 13-70 Kita-Oji-cho, Akashi-shi 673-8558, Japan;
- Department of Clinical Genomic Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan;
| | - Tamotsu Sudo
- Section of Translational Research, Hyogo Cancer Center, 13-70 Kita-Oji-cho, Akashi-shi 673-8558, Japan;
| | - Akira Hirasawa
- Department of Clinical Genomic Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan;
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19
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Structure of the Human TELO2-TTI1-TTI2 Complex. J Mol Biol 2021; 434:167370. [PMID: 34838521 DOI: 10.1016/j.jmb.2021.167370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 11/21/2022]
Abstract
Phosphatidylinositol 3-kinase-related protein kinases (PIKKs) play critical roles in various metabolic pathways related to cell proliferation and survival. The TELO2-TTI1-TTI2 (TTT) complex has been proposed to recognize newly synthesized PIKKs and to deliver them to the R2TP complex (RUVBL1-RUVBL2-RPAP3-PIH1D1) and the heat shock protein 90 chaperone, thereby supporting their folding and assembly. Here, we determined the cryo-EM structure of the TTT complex at an average resolution of 4.2 Å. We describe the full-length structures of TTI1 and TELO2, and a partial structure of TTI2. All three proteins form elongated helical repeat structures. TTI1 provides a platform on which TELO2 and TTI2 bind to its central region and C-terminal end, respectively. The TELO2 C-terminal domain (CTD) is required for the interaction with TTI1 and recruitment of Ataxia-telangiectasia mutated (ATM). The N- and C-terminal segments of TTI1 recognize the FRAP-ATM-TRRAP (FAT) domain and the N-terminal HEAT repeats of ATM, respectively. The TELO2 CTD and TTI1 N- and C-terminal segments are required for cell survival in response to ionizing radiation.
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20
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Langer LM, Bonneau F, Gat Y, Conti E. Cryo-EM reconstructions of inhibitor-bound SMG1 kinase reveal an autoinhibitory state dependent on SMG8. eLife 2021; 10:72353. [PMID: 34698635 PMCID: PMC8592573 DOI: 10.7554/elife.72353] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/25/2021] [Indexed: 12/31/2022] Open
Abstract
The PI3K-related kinase (PIKK) SMG1 monitors the progression of metazoan nonsense-mediated mRNA decay (NMD) by phosphorylating the RNA helicase UPF1. Previous work has shown that the activity of SMG1 is impaired by small molecule inhibitors, is reduced by the SMG1 interactors SMG8 and SMG9, and is downregulated by the so-called SMG1 insertion domain. However, the molecular basis for this complex regulatory network has remained elusive. Here, we present cryo-electron microscopy reconstructions of human SMG1-9 and SMG1-8-9 complexes bound to either a SMG1 inhibitor or a non-hydrolyzable ATP analog at overall resolutions ranging from 2.8 to 3.6 Å. These structures reveal the basis with which a small molecule inhibitor preferentially targets SMG1 over other PIKKs. By comparison with our previously reported substrate-bound structure (Langer et al.,2020), we show that the SMG1 insertion domain can exert an autoinhibitory function by directly blocking the substrate-binding path as well as overall access to the SMG1 kinase active site. Together with biochemical analysis, our data indicate that SMG1 autoinhibition is stabilized by the presence of SMG8. Our results explain the specific inhibition of SMG1 by an ATP-competitive small molecule, provide insights into regulation of its kinase activity within the NMD pathway, and expand the understanding of PIKK regulatory mechanisms in general.
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Affiliation(s)
- Lukas M Langer
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Fabien Bonneau
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Yair Gat
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Elena Conti
- Max Planck Institute of Biochemistry, Martinsried, Germany
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21
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Biagiotti S, Barone A, Aliano MP, Federici G, Malatesta M, Caputi C, Soddu S, Leuzzi V, Chessa L, Magnani M. Functional Classification of the ATM Variant c.7157C>A and In Vitro Effects of Dexamethasone. Front Genet 2021; 12:759467. [PMID: 34759960 PMCID: PMC8573154 DOI: 10.3389/fgene.2021.759467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Most of the ATM variants associated with Ataxia Telangiectasia are still classified as variants with uncertain significance. Ataxia Telangiectasia is a multisystemic disorder characterized by "typical" and "atypical" phenotypes, with early-onset and severe symptoms or with late-onset and mild symptoms, respectively. Here we classified the c.7157C > A ATM variant found in homozygosity in two brothers of Lebanese ethnicity. The brothers presented with an atypical phenotype, showing less than 50% of the positive criteria considered for classification. We performed several in silico analyses to predict the effect of c.7157C > A at the DNA, mRNA and protein levels, revealing that the alteration causes a missense substitution in a highly conserved alpha helix in the FAT domain. 3D structural analyses suggested that the variant might be pathogenic due to either loss of activity or to a structural damage affecting protein stability. Our subsequent in vitro studies showed that the second hypothesis is the most likely, as indicated by the reduced protein abundance found in the cells carrying the variant. Moreover, two different functional assays showed that the mutant protein partially retains its kinase activity. Finally, we investigated the in vitro effect of Dexamethasone showing that the drug is able to increase both protein abundance and activity. In conclusion, our results suggest that the c.7157C > A variant is pathogenic, although it causes an atypical phenotype, and that dexamethasone could be therapeutically effective on this and possibly other missense ATM variants.
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Affiliation(s)
- Sara Biagiotti
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | - Ambra Barone
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
| | | | - Giulia Federici
- Department of Research and Advanced Technologies, IRCCS Regina Elena National Cancer Institute, Roma, Italy
| | - Marco Malatesta
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Caterina Caputi
- Department of Human Neuroscience, Sapienza University of Rome, Roma, Italy
| | - Silvia Soddu
- Department of Research and Advanced Technologies, IRCCS Regina Elena National Cancer Institute, Roma, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Roma, Italy
| | | | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
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22
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Molecular basis of human ATM kinase inhibition. Nat Struct Mol Biol 2021; 28:789-798. [PMID: 34556870 DOI: 10.1038/s41594-021-00654-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022]
Abstract
Human checkpoint kinase ataxia telangiectasia-mutated (ATM) plays a key role in initiation of the DNA damage response following DNA double-strand breaks. ATM inhibition is a promising approach in cancer therapy, but, so far, detailed insights into the binding modes of known ATM inhibitors have been hampered due to the lack of high-resolution ATM structures. Using cryo-EM, we have determined the structure of human ATM to an overall resolution sufficient to build a near-complete atomic model and identify two hitherto unknown zinc-binding motifs. We determined the structure of the kinase domain bound to ATPγS and to the ATM inhibitors KU-55933 and M4076 at 2.8 Å, 2.8 Å and 3.0 Å resolution, respectively. The mode of action and selectivity of the ATM inhibitors can be explained by structural comparison and provide a framework for structure-based drug design.
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23
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ATM's Role in the Repair of DNA Double-Strand Breaks. Genes (Basel) 2021; 12:genes12091370. [PMID: 34573351 PMCID: PMC8466060 DOI: 10.3390/genes12091370] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022] Open
Abstract
Ataxia telangiectasia mutated (ATM) is a central kinase that activates an extensive network of responses to cellular stress via a signaling role. ATM is activated by DNA double strand breaks (DSBs) and by oxidative stress, subsequently phosphorylating a plethora of target proteins. In the last several decades, newly developed molecular biological techniques have uncovered multiple roles of ATM in response to DNA damage-e.g., DSB repair, cell cycle checkpoint arrest, apoptosis, and transcription arrest. Combinational dysfunction of these stress responses impairs the accuracy of repair, consequently leading to dramatic sensitivity to ionizing radiation (IR) in ataxia telangiectasia (A-T) cells. In this review, we summarize the roles of ATM that focus on DSB repair.
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24
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Structural basis of the (in)activity of the apical DNA damage response kinases ATM, ATR and DNA-PKcs. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 163:120-129. [DOI: 10.1016/j.pbiomolbio.2020.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/19/2020] [Accepted: 10/29/2020] [Indexed: 12/15/2022]
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25
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Tannous EA, Burgers PM. Novel insights into the mechanism of cell cycle kinases Mec1(ATR) and Tel1(ATM). Crit Rev Biochem Mol Biol 2021; 56:441-454. [PMID: 34151669 DOI: 10.1080/10409238.2021.1925218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA replication is a highly precise process which usually functions in a perfect rhythm with cell cycle progression. However, cells are constantly faced with various kinds of obstacles such as blocks in DNA replication, lack of availability of precursors and improper chromosome alignment. When these problems are not addressed, they may lead to chromosome instability and the accumulation of mutations, and even cell death. Therefore, the cell has developed response mechanisms to keep most of these situations under control. Of the many factors that participate in this DNA damage response, members of the family of phosphatidylinositol 3-kinase-related protein kinases (PIKKs) orchestrate the response landscape. Our understanding of two members of the PIKK family, human ATR (yeast Mec1) and ATM (yeast Tel1), and their associated partner proteins, has shown substantial progress through recent biochemical and structural studies. Emerging structural information of these unique kinases show common features that reveal the mechanism of kinase activity.
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Affiliation(s)
- Elias A Tannous
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, USA
| | - Peter M Burgers
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, USA
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26
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Cancer genome datamining and functional genetic analysis implicate mechanisms of ATM/ATR dysfunction underpinning carcinogenesis. Commun Biol 2021; 4:363. [PMID: 33742106 PMCID: PMC7979806 DOI: 10.1038/s42003-021-01884-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 02/17/2021] [Indexed: 12/16/2022] Open
Abstract
ATM and ATR are conserved regulators of the DNA damage response linked to cancer. Comprehensive DNA sequencing efforts identified ~4,000 cancer-associated mutations in ATM/ATR; however, their cancer implications remain largely unknown. To gain insights, we identify functionally important conserved residues in ATM, ATR and budding yeast Mec1ATR via cancer genome datamining and a functional genetic analysis, respectively. Surprisingly, only a small fraction of the critical residues is in the active site of the respective enzyme complexes, implying that loss of the intrinsic kinase activity is infrequent in carcinogenesis. A number of residues are solvent accessible, suggestive of their involvement in interacting with a protein-partner(s). The majority, buried inside the respective enzyme complexes, might play a structural or regulatory role. Together, these findings identify evolutionarily conserved ATM, ATR, and Mec1ATR residues involved in diverse aspects of the enzyme function and provide fresh insights into the elusive genotype-phenotype relationships in ATM/ATR and their cancer-associated variants. Waskiewicz et al. identify functionally important and evolutionarily conserved residues of ATM/ATR via data mining and a functional genetic analysis, finding that loss of the intrinsic kinase activity occurs infrequently in carcinogenesis. This study provides insights into the genotype-phenotype relationships in ATM/ATR and their cancer-associated variants.
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27
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Almarzooqi F, Souid AK, Vijayan R, Al-Hammadi S. Novel genetic variants of inborn errors of immunity. PLoS One 2021; 16:e0245888. [PMID: 33481921 PMCID: PMC7822508 DOI: 10.1371/journal.pone.0245888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 01/10/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Inborn errors of immunity (IEI) are prevalent in tribal cultures due to frequent consanguineous marriages. Many of these disorders are autosomal recessive, resulting from founder mutations; hence they are amenable to prevention. The primary objective of this study was to evaluate the pathogenicity of novel variants of IEI found among Emiratis. METHODS This retrospective data collection study reports novel variants of IEI detected by diagnostic exome sequencing. Pathogenicity prediction was based on scoring tools, amino acid alignment, and Jensen-Shannon divergence values. RESULTS Twenty-one novel variants were identified; nine were frameshift, three nonsense, four intronic (one pathogenic), and five missense (two pathogenic). Fifteen variants were likely pathogenic, of which 13 were autosomal recessive and two uncertain inheritance. Their clinical spectra included combined immunodeficiency, antibody deficiency, immune dysregulation, defects in intrinsic/innate immunity, and bone marrow failure. CONCLUSION The described novel pathogenic variants are core to a planned national screening program that aims toward IEI prevention. Future studies, however, are needed to confirm their natural history in individual patients and estimate their prevalence in the community.
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Affiliation(s)
- Farida Almarzooqi
- Department of Pediatrics, College of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
- * E-mail:
| | - Abdul-Kader Souid
- Department of Pediatrics, College of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Ranjit Vijayan
- Department of Biology, College of Science, UAE University, Al Ain, United Arab Emirates
| | - Suleiman Al-Hammadi
- Department of Pediatrics, College of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
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28
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Panigrahi R, Glover JNM. Structural insights into DNA double-strand break signaling. Biochem J 2021; 478:135-156. [PMID: 33439989 DOI: 10.1042/bcj20200066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 12/14/2022]
Abstract
Genomic integrity is most threatened by double-strand breaks, which, if left unrepaired, lead to carcinogenesis or cell death. The cell generates a network of protein-protein signaling interactions that emanate from the DNA damage which are now recognized as a rich basis for anti-cancer therapy development. Deciphering the structures of signaling proteins has been an uphill task owing to their large size and complex domain organization. Recent advances in mammalian protein expression/purification and cryo-EM-based structure determination have led to significant progress in our understanding of these large multidomain proteins. This review is an overview of the structural principles that underlie some of the key signaling proteins that function at the double-strand break site. We also discuss some plausible ideas that could be considered for future structural approaches to visualize and build a more complete understanding of protein dynamics at the break site.
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Affiliation(s)
- Rashmi Panigrahi
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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29
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Williams RM, Yates LA, Zhang X. Structures and regulations of ATM and ATR, master kinases in genome integrity. Curr Opin Struct Biol 2020; 61:98-105. [PMID: 31924595 DOI: 10.1016/j.sbi.2019.12.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/27/2019] [Accepted: 12/07/2019] [Indexed: 12/24/2022]
Abstract
Homologous recombination (HR) is a faithful repair mechanism for double stranded DNA breaks. Two highly homologous master kinases, the tumour suppressors ATM and ATR (Tel1 and Mec1 in yeast), coordinate cell cycle progression with repair during HR. Despite their importance, our molecular understanding of these apical coordinators has been limited, in part due to their large sizes. With the recent development in cryo-electron microscopy, significant advances have been made in structural characterisation of these proteins in the last two years. These structures, combined with new biochemical studies, now provide a more detailed understanding of how a low basal activity is maintained and how activation may occur. In this review, we summarize recent advances in the structural and molecular understanding of these key components in HR, compare the common and distinct features of these kinases and suggest aspects of structural components that are likely to be involved in regulating its activity.
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Affiliation(s)
- Rhys M Williams
- Section of Structural Biology, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Luke A Yates
- Section of Structural Biology, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Xiaodong Zhang
- Section of Structural Biology, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK.
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30
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Jansma M, Linke-Winnebeck C, Eustermann S, Lammens K, Kostrewa D, Stakyte K, Litz C, Kessler B, Hopfner KP. Near-Complete Structure and Model of Tel1ATM from Chaetomium thermophilum Reveals a Robust Autoinhibited ATP State. Structure 2019; 28:83-95.e5. [PMID: 31740028 DOI: 10.1016/j.str.2019.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/02/2019] [Accepted: 10/21/2019] [Indexed: 11/18/2022]
Abstract
Tel1 (ATM in humans) is a large kinase that resides in the cell in an autoinhibited dimeric state and upon activation orchestrates the cellular response to DNA damage. We report the structure of an endogenous Tel1 dimer from Chaetomium thermophilum. Major parts are at 2.8 Å resolution, including the kinase active site with ATPγS bound, and two different N-terminal solenoid conformations are at 3.4 Å and 3.6 Å, providing a side-chain model for 90% of the Tel1 polypeptide. We show that the N-terminal solenoid has DNA binding activity, but that its movements are not coupled to kinase activation. Although ATPγS and catalytic residues are poised for catalysis, the kinase resides in an autoinhibited state. The PIKK regulatory domain acts as a pseudo-substrate, blocking direct access to the site of catalysis. The structure allows mapping of human cancer mutations and defines mechanisms of autoinhibition at near-atomic resolution.
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Affiliation(s)
- Marijke Jansma
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Christian Linke-Winnebeck
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Sebastian Eustermann
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Katja Lammens
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Dirk Kostrewa
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Kristina Stakyte
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Claudia Litz
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Brigitte Kessler
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
| | - Karl-Peter Hopfner
- Department of Biochemistry, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany; Gene Center, Ludwig-Maximilians-Universität, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
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31
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Cryo-EM Structure of Nucleotide-Bound Tel1 ATM Unravels the Molecular Basis of Inhibition and Structural Rationale for Disease-Associated Mutations. Structure 2019; 28:96-104.e3. [PMID: 31740029 PMCID: PMC6945111 DOI: 10.1016/j.str.2019.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/05/2019] [Accepted: 10/18/2019] [Indexed: 01/20/2023]
Abstract
Yeast Tel1 and its highly conserved human ortholog ataxia-telangiectasia mutated (ATM) are large protein kinases central to the maintenance of genome integrity. Mutations in ATM are found in ataxia-telangiectasia (A-T) patients and ATM is one of the most frequently mutated genes in many cancers. Using cryoelectron microscopy, we present the structure of Tel1 in a nucleotide-bound state. Our structure reveals molecular details of key residues surrounding the nucleotide binding site and provides a structural and molecular basis for its intrinsically low basal activity. We show that the catalytic residues are in a productive conformation for catalysis, but the phosphatidylinositol 3-kinase-related kinase (PIKK) regulatory domain insert restricts peptide substrate access and the N-lobe is in an open conformation, thus explaining the requirement for Tel1 activation. Structural comparisons with other PIKKs suggest a conserved and common allosteric activation mechanism. Our work also provides a structural rationale for many mutations found in A-T and cancer.
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