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Reichlmeir M, Duecker RP, Röhrich H, Key J, Schubert R, Abell K, Possemato AP, Stokes MP, Auburger G. The ataxia-telangiectasia disease protein ATM controls vesicular protein secretion via CHGA and microtubule dynamics via CRMP5. Neurobiol Dis 2024; 203:106756. [PMID: 39615799 DOI: 10.1016/j.nbd.2024.106756] [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: 06/24/2024] [Revised: 11/25/2024] [Accepted: 11/25/2024] [Indexed: 12/16/2024] Open
Abstract
The autosomal recessive disease ataxia-telangiectasia (A-T) presents with cerebellar degeneration, immunodeficiency, radiosensitivity, capillary dilatations, and pulmonary infections. Most symptoms outside the nervous system can be explained by failures of the disease protein ATM as a Ser/Thr-kinase to coordinate DNA damage repair. However, ATM in adult neurons has cytoplasmic localization and vesicle association, where its roles remain unclear. Here, we defined novel ATM protein targets in human neuroblastoma cells, and filtered initial pathogenesis events in ATM-null mouse cerebellum. Profiles of global proteome and phosphoproteomics - both direct ATM/ATR substrates and overall phosphorylation changes - confirmed previous findings for NBN, MRE11, MDC1, CHEK1, EIF4EBP1, AP3B2, PPP2R5C, SYN1 and SLC2A1. Even stronger downregulation of ATM/ATR substrate phosphopeptides after ATM-depletion was documented for CHGA, EXPH5, NBEAL2 and CHMP6 as key factors of protein secretion and endosome dynamics, as well as for CRMP5, DISP2, PHACTR1, PLXNC1, INA and TPX2 as neurite extension factors. Prominent effects on semaphorin-CRMP5-microtubule signals and ATM association with CRMP5 were validated. As a functional consequence, microtubules were stabilized, and neurite retraction ensued. The impact of ATM on secretory granules confirms previous ATM-null cerebellar transcriptome findings. This study provides the first link of A-T neural atrophy to growth cone collapse and aberrant microtubule dynamics.
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Affiliation(s)
- Marina Reichlmeir
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany.
| | - Ruth Pia Duecker
- Division for Allergy, Pneumatology and Cystic Fibrosis, Department for Children and Adolescence, Goethe-University, Frankfurt am Main, Germany.
| | - Hanna Röhrich
- Institute for Experimental Pediatric Hematology and Oncology, Medical Faculty, Goethe-University Frankfurt, Komturstrasse 3a, 60528 Frankfurt am Main, Germany.
| | - Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany.
| | - Ralf Schubert
- Division for Allergy, Pneumatology and Cystic Fibrosis, Department for Children and Adolescence, Goethe-University, Frankfurt am Main, Germany.
| | - Kathryn Abell
- Cell Signaling Technology, Inc., Danvers, MA 01923, USA.
| | | | | | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany.
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Derby SJ, Dutton L, Strathdee KE, Stevenson K, Koessinger A, Jackson M, Tian Y, Yu W, Mclay K, Misquitta J, Alsharif S, Clarke CJ, Gilmour L, Thomason P, McGhee E, McGarrity-Cottrell CL, Vanderlinden A, Collis SJ, Rominyi O, Lemgruber L, Solecki G, Olson M, Winkler F, Carlin LM, Heiland DH, Inman GJ, Chalmers AJ, Norman JC, Carruthers R, Birch JL. Inhibition of ATR opposes glioblastoma invasion through disruption of cytoskeletal networks and integrin internalization via macropinocytosis. Neuro Oncol 2024; 26:625-639. [PMID: 37936324 PMCID: PMC10995506 DOI: 10.1093/neuonc/noad210] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Indexed: 11/09/2023] Open
Abstract
BACKGROUND Glioblastomas have highly infiltrative growth patterns that contribute to recurrence and poor survival. Despite infiltration being a critical therapeutic target, no clinically useful therapies exist that counter glioblastoma invasion. Here, we report that inhibition of ataxia telangiectasia and Rad 3 related kinase (ATR) reduces invasion of glioblastoma cells through dysregulation of cytoskeletal networks and subsequent integrin trafficking. METHODS Glioblastoma motility and invasion were assessed in vitro and in vivo in response to ATR inhibition (ATRi) and ATR overexpression using time-lapse microscopy, two orthotopic glioblastoma models, and intravital imaging. Disruption to cytoskeleton networks and endocytic processing were investigated via high-throughput, super-resolution and intravital imaging. RESULTS High ATR expression was associated with significantly poorer survival in clinical datasets while histological, protein expression, and spatial transcriptomics using glioblastoma tumor specimens revealed higher ATR expression at infiltrative margins. Pharmacological inhibition with two different compounds and RNAi targeting of ATR opposed the invasion of glioblastoma, whereas overexpression of ATR drove migration. Subsequent investigation revealed that cytoskeletal dysregulation reduced macropinocytotic internalization of integrins at growth-cone-like structures, resulting in a tumor microtube retraction defect. The biological relevance and translational potential of these findings were confirmed using two orthotopic in vivo models of glioblastoma and intravital imaging. CONCLUSIONS We demonstrate a novel role for ATR in determining invasion in glioblastoma cells and propose that pharmacological targeting of ATR could have far-reaching clinical benefits beyond radiosensitization.
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Affiliation(s)
- Sarah J Derby
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Louise Dutton
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Karen E Strathdee
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Katrina Stevenson
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Anna Koessinger
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
- CRUK Scotland Institute, Glasgow, UK
| | - Mark Jackson
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Yuling Tian
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Wenxi Yu
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Kathy Mclay
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Josette Misquitta
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Sama Alsharif
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | - Lesley Gilmour
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | | | | | - Aurelie Vanderlinden
- Department of Oncology and Metabolism, The University of Sheffield Medical School, Sheffield, UK
| | - Spencer J Collis
- Department of Oncology and Metabolism, The University of Sheffield Medical School, Sheffield, UK
| | - Ola Rominyi
- Department of Oncology and Metabolism, The University of Sheffield Medical School, Sheffield, UK
| | - Leandro Lemgruber
- Cellular Analysis Facility, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Gergely Solecki
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Olson
- Department of Chemistry and Biology, Ryeson University, Toronto, Ontario, Canada
| | - Frank Winkler
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Leo M Carlin
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
- CRUK Scotland Institute, Glasgow, UK
| | | | - Gareth J Inman
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
- CRUK Scotland Institute, Glasgow, UK
| | - Anthony J Chalmers
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Jim C Norman
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
- CRUK Scotland Institute, Glasgow, UK
| | - Ross Carruthers
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Joanna L Birch
- Wolfson Wohl Translational Cancer Research Centre, School of Cancer Sciences, University of Glasgow, Glasgow, UK
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Chuang CN, Liu HC, Woo TT, Chao JL, Chen CY, Hu HT, Hsueh YP, Wang TF. Noncanonical usage of stop codons in ciliates expands proteins with structurally flexible Q-rich motifs. eLife 2024; 12:RP91405. [PMID: 38393970 PMCID: PMC10942620 DOI: 10.7554/elife.91405] [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] [Indexed: 02/25/2024] Open
Abstract
Serine(S)/threonine(T)-glutamine(Q) cluster domains (SCDs), polyglutamine (polyQ) tracts and polyglutamine/asparagine (polyQ/N) tracts are Q-rich motifs found in many proteins. SCDs often are intrinsically disordered regions that mediate protein phosphorylation and protein-protein interactions. PolyQ and polyQ/N tracts are structurally flexible sequences that trigger protein aggregation. We report that due to their high percentages of STQ or STQN amino acid content, four SCDs and three prion-causing Q/N-rich motifs of yeast proteins possess autonomous protein expression-enhancing activities. Since these Q-rich motifs can endow proteins with structural and functional plasticity, we suggest that they represent useful toolkits for evolutionary novelty. Comparative Gene Ontology (GO) analyses of the near-complete proteomes of 26 representative model eukaryotes reveal that Q-rich motifs prevail in proteins involved in specialized biological processes, including Saccharomyces cerevisiae RNA-mediated transposition and pseudohyphal growth, Candida albicans filamentous growth, ciliate peptidyl-glutamic acid modification and microtubule-based movement, Tetrahymena thermophila xylan catabolism and meiosis, Dictyostelium discoideum development and sexual cycles, Plasmodium falciparum infection, and the nervous systems of Drosophila melanogaster, Mus musculus and Homo sapiens. We also show that Q-rich-motif proteins are expanded massively in 10 ciliates with reassigned TAAQ and TAGQ codons. Notably, the usage frequency of CAGQ is much lower in ciliates with reassigned TAAQ and TAGQ codons than in organisms with expanded and unstable Q runs (e.g. D. melanogaster and H. sapiens), indicating that the use of noncanonical stop codons in ciliates may have coevolved with codon usage biases to avoid triplet repeat disorders mediated by CAG/GTC replication slippage.
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Affiliation(s)
| | - Hou-Cheng Liu
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
| | - Tai-Ting Woo
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
| | - Ju-Lan Chao
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
| | - Chiung-Ya Chen
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
| | - Hisao-Tang Hu
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
- Department of Biochemical Science and Technology, National Chiayi UniversityChiayiTaiwan
| | - Ting-Fang Wang
- Institute of Molecular Biology, Academia SinicaTaipeiTaiwan
- Department of Biochemical Science and Technology, National Chiayi UniversityChiayiTaiwan
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Stubbins RJ, Korotev S, Godley LA. Germline CHEK2 and ATM Variants in Myeloid and Other Hematopoietic Malignancies. Curr Hematol Malig Rep 2022; 17:94-104. [PMID: 35674998 DOI: 10.1007/s11899-022-00663-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE OF REVIEW An intact DNA damage response is crucial to preventing cancer development, including in myeloid and lymphoid malignancies. Deficiencies in the homologous recombination (HR) pathway can lead to defective DNA damage responses, and this can occur through inherited germline mutations in HR pathway genes, such as CHEK2 and ATM. We now understand that germline mutations can be identified frequently (~ 5-10%) in patients with myeloid and lymphoid malignancies, and among the most common of these are CHEK2 and ATM. We review the role that deleterious germline CHEK2 and ATM variants play in the development of hematopoietic malignancies, and how this influences clinical practice, including cancer screening, hematopoietic stem cell transplantation, and therapy choice. RECENT FINDINGS In recent large cohorts of patients diagnosed with myeloid or lymphoid malignancies, deleterious germline loss of function variants in CHEK2 and ATM are among the most common identified. Germline CHEK2 variants predispose to a range of myeloid malignancies, most prominently myeloproliferative neoplasms and myelodysplastic syndromes (odds ratio range: 2.1-12.3), and chronic lymphocytic leukemia (odds ratio 14.83). Deleterious germline ATM variants have been shown to predispose to chronic lymphocytic leukemia (odds ratio range: 1.7-10.1), although additional studies are needed to demonstrate the risk they confer for myeloid malignancies. Early studies suggest there may also be associations between deleterious germline CHEK2 and ATM variants and development of clonal hematopoiesis. Identifying CHEK2 and ATM variants is crucial for the optimal management of patients and families affected by hematopoietic malignancies. OPENING CLINICAL CASE: "A 45 year-old woman presents to your clinic with a history of triple-negative breast cancer diagnosed five years ago, treated with surgery, radiation, and chemotherapy. About six months ago, she developed cervical lymphadenopathy, and a biopsy demonstrated small lymphocytic leukemia. Peripheral blood shows a small population of lymphocytes with a chronic lymphocytic leukemia immunophenotype, and FISH demonstrates a complex karyotype: gain of one to two copies of IGH and FGFR3; gain of two copies of CDKN2C at 1p32.3; gain of two copies of CKS1B at 1q21; tetrasomy for chromosome 3; trisomy and tetrasomy for chromosome 7; tetrasomy for chromosome 9; tetrasomy for chromosome 12; gain of one to two copies of ATM at 11q22.3; deletion of chromosome 13 deletion positive; gain of one to two copies of TP53 at 17p13.1). Given her history of two cancers, you arrange for germline genetic testing using DNA from cultured skin fibroblasts, which demonstrates pathogenic variants in ATM [c.1898 + 2 T > G] and CHEK2 [p.T367Metfs]. Her family history is significant for multiple cancers. (Fig. 1)." Fig. 1 Representative pedigree from a patient with germline pathogenic ATM and CHEK2 variants who was affected by early onset breast cancer and chronic lymphocytic leukemia. Arrow indicates proband. Colors indicate cancer type/disease: purple, breast cancer; blue, lymphoma; brown, melanoma; yellow, colon cancer; and green, autoimmune disease.
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Affiliation(s)
- Ryan J Stubbins
- Section of Hematology Oncology, Department of Medicine, The University of Chicago, 5841 S. Maryland Ave., MC 2115, Chicago, IL, 60637, USA.,Leukemia/BMT Program of BC, BC Cancer, Vancouver, BC, Canada
| | - Sophia Korotev
- Section of Hematology Oncology, Department of Medicine, The University of Chicago, 5841 S. Maryland Ave., MC 2115, Chicago, IL, 60637, USA
| | - Lucy A Godley
- Section of Hematology Oncology, Department of Medicine, The University of Chicago, 5841 S. Maryland Ave., MC 2115, Chicago, IL, 60637, USA.
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5
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Reuter AS, Stern D, Bernard A, Goossens C, Lavergne A, Flasse L, Von Berg V, Manfroid I, Peers B, Voz ML. Identification of an evolutionarily conserved domain in Neurod1 favouring enteroendocrine versus goblet cell fate. PLoS Genet 2022; 18:e1010109. [PMID: 35286299 PMCID: PMC8959185 DOI: 10.1371/journal.pgen.1010109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 03/28/2022] [Accepted: 02/17/2022] [Indexed: 12/16/2022] Open
Abstract
ARP/ASCL transcription factors are key determinants of cell fate specification in a wide variety of tissues, coordinating the acquisition of generic cell fates and of specific subtype identities. How these factors, recognizing highly similar DNA motifs, display specific activities, is not yet fully understood. To address this issue, we overexpressed different ARP/ASCL factors in zebrafish ascl1a-/- mutant embryos to determine which ones are able to rescue the intestinal secretory lineage. We found that Ascl1a/b, Atoh1a/b and Neurod1 factors are all able to trigger the first step of the secretory regulatory cascade but distinct secretory cells are induced by these factors. Indeed, Neurod1 rescues the enteroendocrine lineage while Ascl1a/b and Atoh1a/b rescue the goblet cells. Gain-of-function experiments with Ascl1a/Neurod1 chimeric proteins revealed that the functional divergence is encoded by a 19-aa ultra-conserved element (UCE), present in all Neurod members but absent in the other ARP/ASCL proteins. Importantly, inserting the UCE into the Ascl1a protein reverses the rescuing capacity of this Ascl1a chimeric protein that cannot rescue the goblet cells anymore but can efficiently rescue the enteroendocrine cells. This novel domain acts indeed as a goblet cell fate repressor that inhibits gfi1aa expression, known to be important for goblet cell differentiation. Deleting the UCE domain of the endogenous Neurod1 protein leads to an increase in the number of goblet cells concomitant with a reduction of the enteroendocrine cells, phenotype also observed in the neurod1 null mutant. This highlights the crucial function of the UCE domain for NeuroD1 activity in the intestine. As Gfi1 acts as a binary cell fate switch in several tissues where Neurod1 is also expressed, we can envision a similar role of the UCE in other tissues, allowing Neurod1 to repress Gfi1 to influence the balance between cell fates. It is not yet clear how highly related factors like the ARP/Ascl factors display specific activities even though they recognize the same consensus DNA motif. This specificity could be provided by their cellular environment or by intrinsic properties of the factors themselves. To distinguish between these two possibilities, we have expressed several ARP/Ascl factors in the ascl1a-/- mutant to determine which ones are able to rescue the intestinal secretory defects. We found that Ascl1a/b and Atoh1a/b are able to rescue the goblet cells while Neurod1 rescues the enteroendocrine lineage. Furthermore, we show that the specific Neurod1 activity is conferred by the presence of a 19-aa ultra-conserved element (UCE), present in all vertebrate Neurod members but absent in all the other ARP/ASCL proteins. This UCE domain, so far uncharacterized, acts as a goblet cell fate repressor and inhibits gfi1aa expression, known to be important for goblet cell differentiation. Inserting the UCE into Ascl1a protein reverses the rescuing capacity of this chimeric protein that cannot rescue the goblet cells anymore but can efficiently rescue the enteroendocrine cells. This study therefore highlights an unique intrinsic property of Neurod1 allowing it to repress Gfi1 to influence the balance between cell fates. As Gfi1 acts as a binary cell fate switch in several tissues where Neurod1 is also expressed, we can envision a similar role of the UCE in other tissues, allowing Neurod1 to repress Gfi1 to influence the balance between cell fates.
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Affiliation(s)
- Anne Sophie Reuter
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - David Stern
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Alice Bernard
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Chiara Goossens
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Arnaud Lavergne
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Lydie Flasse
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Virginie Von Berg
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Isabelle Manfroid
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Bernard Peers
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
| | - Marianne L. Voz
- Laboratory of Zebrafish Development and Disease Models (ZDDM), GIGA, University of Liège, Liège, Belgium
- * E-mail:
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Lazebny OE, Kulikov AM, Butovskaya PR, Proshakov PA, Fokin AV, Butovskaya ML. Analysis of Aggressive Behavior in Young Russian Males Using 250 SNP Markers. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420080098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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DNA damage causes rapid accumulation of phosphoinositides for ATR signaling. Nat Commun 2017; 8:2118. [PMID: 29242514 PMCID: PMC5730617 DOI: 10.1038/s41467-017-01805-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 10/13/2017] [Indexed: 12/11/2022] Open
Abstract
Phosphoinositide lipids (PPIs) are enriched in the nucleus and are accumulated at DNA damage sites. Here, we investigate roles of nuclear PPIs in DNA damage response by sequestering specific PPIs with the expression of nuclear-targeted PH domains, which inhibits recruitment of Ataxia telangiectasia and Rad3-related protein (ATR) and reduces activation of Chk1. PPI-binding domains rapidly (< 1 s) accumulate at damage sites with local enrichment of PPIs. Accumulation of PIP3 in complex with the nuclear receptor protein, SF1, at damage sites requires phosphorylation by inositol polyphosphate multikinase (IPMK) and promotes nuclear actin assembly that is required for ATR recruitment. Suppressed ATR recruitment/activation is confirmed with latrunculin A and wortmannin treatment as well as IPMK or SF1 depletion. Other DNA repair pathways involving ATM and DNA-PKcs are unaffected by PPI sequestration. Together, these findings reveal that nuclear PPI metabolism mediates an early damage response through the IPMK-dependent pathway to specifically recruit ATR. Phosphoinositides are enriched in the nucleus and accumulate upon DNA damage but their role in responding to DNA damage is poorly defined. Here, the authors show that phosphoinositides rapidly accumulate at DNA damage sites and are required for ATR recruitment and subsequent Chk1 activation.
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Guénolé A, Legube G. A meeting at risk: Unrepaired DSBs go for broke. Nucleus 2017; 8:589-599. [PMID: 29099269 PMCID: PMC5788565 DOI: 10.1080/19491034.2017.1380138] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/06/2017] [Accepted: 09/12/2017] [Indexed: 12/17/2022] Open
Abstract
Translocations are dramatic genomic rearrangements due to aberrant rejoining of distant DNA ends that can trigger cancer onset and progression. Translocations frequently occur in genes, yet the mechanisms underlying their formation remain poorly understood. One potential mechanism involves DNA Double Strand Break mobility and juxtaposition (i.e. clustering), an event that has been intensively debated over the past decade. Using Capture Hi-C, we recently found that DSBs do in fact cluster in human nuclei but only when induced in transcriptionally active genes. Notably, we found that clustering of damaged genes is regulated by cell cycle progression and coincides with damage persistency. Here, we discuss the mechanisms that could sustain clustering and speculate on the functional consequences of this seemingly double edge sword mechanism that may well stand at the heart of translocation biogenesis.
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Affiliation(s)
- Aude Guénolé
- LBCMCP, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
| | - Gaëlle Legube
- LBCMCP, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, UT3, Toulouse, France
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