1
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Xu X, Chang CW, Li M, Omabe K, Le N, Chen YH, Liang F, Liu Y. DNA replication initiation factor RECQ4 possesses a role in antagonizing DNA replication initiation. Nat Commun 2023; 14:1233. [PMID: 36871012 PMCID: PMC9985596 DOI: 10.1038/s41467-023-36968-1] [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: 12/08/2021] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Deletion of the conserved C-terminus of the Rothmund-Thomson syndrome helicase RECQ4 is highly tumorigenic. However, while the RECQ4 N-terminus is known to facilitate DNA replication initiation, the function of its C-terminus remains unclear. Using an unbiased proteomic approach, we identify an interaction between the RECQ4 N-terminus and the anaphase-promoting complex/cyclosome (APC/C) on human chromatin. We further show that this interaction stabilizes APC/C co-activator CDH1 and enhances APC/C-dependent degradation of the replication inhibitor Geminin, allowing replication factors to accumulate on chromatin. In contrast, the function is blocked by the RECQ4 C-terminus, which binds to protein inhibitors of APC/C. A cancer-prone, C-terminal-deleted RECQ4 mutation increases origin firing frequency, accelerates G1/S transition, and supports abnormally high DNA content. Our study reveals a role of the human RECQ4 C-terminus in antagonizing its N-terminus, thereby suppressing replication initiation, and this suppression is impaired by oncogenic mutations.
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Affiliation(s)
- Xiaohua Xu
- Thermo Fisher Scientific, 5781 Van Allen Way, Carlsbad, CA, 92008, USA
| | - Chou-Wei Chang
- Vesigen Therapeutics, 790 Memorial Drive, Suite 103, Cambridge, MA, 02139, USA
| | - Min Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Kenneth Omabe
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Nhung Le
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA
| | - Yi-Hsuan Chen
- Department of Computer Science, University of Southern California, Los Angeles, CA, 90089, USA
| | - Feng Liang
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, 90089, USA
| | - Yilun Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, 91010-3000, USA.
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2
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Capasso M, Montella A, Tirelli M, Maiorino T, Cantalupo S, Iolascon A. Genetic Predisposition to Solid Pediatric Cancers. Front Oncol 2020; 10:590033. [PMID: 33194750 PMCID: PMC7656777 DOI: 10.3389/fonc.2020.590033] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/08/2020] [Indexed: 12/15/2022] Open
Abstract
Progresses over the past years have extensively improved our capacity to use genome-scale analyses—including high-density genotyping and exome and genome sequencing—to identify the genetic basis of pediatric tumors. In particular, exome sequencing has contributed to the evidence that about 10% of children and adolescents with tumors have germline genetic variants associated with cancer predisposition. In this review, we provide an overview of genetic variations predisposing to solid pediatric tumors (medulloblastoma, ependymoma, astrocytoma, neuroblastoma, retinoblastoma, Wilms tumor, osteosarcoma, rhabdomyosarcoma, and Ewing sarcoma) and outline the biological processes affected by the involved mutated genes. A careful description of the genetic basis underlying a large number of syndromes associated with an increased risk of pediatric cancer is also reported. We place particular emphasis on the emerging view that interactions between germline and somatic alterations are a key determinant of cancer development. We propose future research directions, which focus on the biological function of pediatric risk alleles and on the potential links between the germline genome and somatic changes. Finally, the importance of developing new molecular diagnostic tests including all the identified risk germline mutations and of considering the genetic predisposition in screening tests and novel therapies is emphasized.
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Affiliation(s)
- Mario Capasso
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | | | - Matilde Tirelli
- CEINGE Biotecnologie Avanzate, Naples, Italy.,European School of Molecular Medicine, Università Degli Studi di Milano, Milan, Italy
| | - Teresa Maiorino
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Sueva Cantalupo
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
| | - Achille Iolascon
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Naples, Italy.,CEINGE Biotecnologie Avanzate, Naples, Italy
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3
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Miller DB, Piccolo SR. Compound Heterozygous Variants in Pediatric Cancers: A Systematic Review. Front Genet 2020; 11:493. [PMID: 32508881 PMCID: PMC7249936 DOI: 10.3389/fgene.2020.00493] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/20/2020] [Indexed: 12/21/2022] Open
Abstract
A compound heterozygous (CH) variant is a type of germline variant that occurs when each parent donates one alternate allele and these alleles are located at different loci within the same gene. Pathogenic germline variants have been identified for some pediatric cancer types but in most studies, CH variants are overlooked. Thus, the prevalence of pathogenic CH variants in most pediatric cancer types is unknown. We identified 26 studies (published between 1999 and 2019) that identified a CH variant in at least one pediatric cancer patient. These studies encompass 21 cancer types and have collectively identified 25 different genes in which a CH variant occurred. However, the sequencing methods used and the number of patients and genes evaluated in each study were highly variable across the studies. In addition, methods for assessing pathogenicity of CH variants varied widely and were often not reported. In this review, we discuss technologies and methods for identifying CH variants, provide an overview of studies that have identified CH variants in pediatric cancer patients, provide insights into future directions in the field, and give a summary of publicly available pediatric cancer sequencing data. Although considerable insights have been gained over the last 20 years, much has yet to be learned about the involvement of CH variants in pediatric cancers. In future studies, larger sample sizes, more pediatric cancer types, and better pathogenicity assessment and filtering methods will be needed to move this field forward.
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Affiliation(s)
- Dustin B Miller
- Department of Biology, Brigham Young University, Provo, UT, United States
| | - Stephen R Piccolo
- Department of Biology, Brigham Young University, Provo, UT, United States
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4
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Abstract
Many recent advances have emerged in the telomere and telomerase fields. This Timeline article highlights the key advances that have expanded our views on the mechanistic underpinnings of telomeres and telomerase and their roles in ageing and disease. Three decades ago, the classic view was that telomeres protected the natural ends of linear chromosomes and that telomerase was a specific telomere-terminal transferase necessary for the replication of chromosome ends in single-celled organisms. While this concept is still correct, many diverse fields associated with telomeres and telomerase have substantially matured. These areas include the discovery of most of the key molecular components of telomerase, implications for limits to cellular replication, identification and characterization of human genetic disorders that result in premature telomere shortening, the concept that inhibiting telomerase might be a successful therapeutic strategy and roles for telomeres in regulating gene expression. We discuss progress in these areas and conclude with challenges and unanswered questions in the field.
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Affiliation(s)
- Jerry W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Woodring E Wright
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
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5
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Fang H, Niu K, Mo D, Zhu Y, Tan Q, Wei D, Li Y, Chen Z, Yang S, Balajee AS, Zhao Y. RecQL4-Aurora B kinase axis is essential for cellular proliferation, cell cycle progression, and mitotic integrity. Oncogenesis 2018; 7:68. [PMID: 30206236 PMCID: PMC6134139 DOI: 10.1038/s41389-018-0080-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/06/2018] [Accepted: 04/28/2018] [Indexed: 01/22/2023] Open
Abstract
Human RecQL4 helicase plays critical roles in the maintenance of genomic stability. Mutations in RecQL4 helicase results in three clinically related autosomal recessive disorders: Rothmund–Thomson syndrome (RTS), RAPADILINO, and Baller–Gerold syndrome. In addition to several premature aging features, RTS patients are characterized by aneuploidy involving either loss or gain of a single chromosome. Chromosome mosaicism and isochromosomes involving chromosomes 2, 7, and 8 have been reported in RecQL4-deficient RTS patients, but the precise role of RecQL4 in chromosome segregation/stability remains to be elucidated. Here, we demonstrate that RecQL4 physically and functionally interacts with Aurora B kinase (AURKB) and stabilizes its expression by inhibiting its ubiquitination process. Our study indicates that the N-terminus of RecQL4 interacts with the catalytic domain of AURKB. Strikingly, RecQL4 suppression reduces the expression of AURKB leading to mitotic irregularities and apoptotic cell death. RecQL4 suppression increases the proportion of cells at the G2/M phase followed by an extensive cell death, presumably owing to the accumulation of mitotic irregularities. Both these defects (accumulation of cells at G2/M phase and an improper mitotic exit to sub-G1) are complemented by the ectopic expression of AURKB. Finally, evidence is provided for the requirement of both human telomerase reverse transcriptase and RecQL4 for stable immortalization and longevity of RTS fibroblasts. Collectively, our study suggests that the RecQL4–AURKB axis is essential for cellular proliferation, cell cycle progression, and mitotic stability in human cells.
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Affiliation(s)
- Hongbo Fang
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Kaifeng Niu
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Dongliang Mo
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yuqi Zhu
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Qunsong Tan
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Di Wei
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yueyang Li
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zixiang Chen
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shuchen Yang
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Adayabalam S Balajee
- Cytogenetics Biodosimetry Laboratory, REACTS, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, 1299 Bethel Valley Road, Oak Ridge, TN, 37830, USA.
| | - Yongliang Zhao
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, 100101, Beijing, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
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6
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Telomere-associated aging disorders. Ageing Res Rev 2017; 33:52-66. [PMID: 27215853 PMCID: PMC9926533 DOI: 10.1016/j.arr.2016.05.009] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 01/25/2023]
Abstract
Telomeres are dynamic nucleoprotein-DNA structures that cap and protect linear chromosome ends. Several monogenic inherited diseases that display features of human premature aging correlate with shortened telomeres, and are referred to collectively as telomeropathies. These disorders have overlapping symptoms and a common underlying mechanism of telomere dysfunction, but also exhibit variable symptoms and age of onset, suggesting they fall along a spectrum of disorders. Primary telomeropathies are caused by defects in the telomere maintenance machinery, whereas secondary telomeropathies have some overlapping symptoms with primary telomeropathies, but are generally caused by mutations in DNA repair proteins that contribute to telomere preservation. Here we review both the primary and secondary telomeropathies, discuss potential mechanisms for tissue specificity and age of onset, and highlight outstanding questions in the field and future directions toward elucidating disease etiology and developing therapeutic strategies.
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7
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Elmakky A, Stanghellini I, Landi A, Percesepe A. Role of Genetic Factors in the Pathogenesis of Radial Deficiencies in Humans. Curr Genomics 2016; 16:264-78. [PMID: 26962299 PMCID: PMC4765521 DOI: 10.2174/1389202916666150528000412] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/20/2015] [Accepted: 05/27/2015] [Indexed: 01/09/2023] Open
Abstract
Radial deficiencies (RDs), defined as under/abnormal development or absence of any of the
structures of the forearm, radial carpal bones and thumb, occur with a live birth incidence ranging
from 1 out of 30,000 to 1 out 6,000 newborns and represent about one third/one fourth of all the congenital
upper limb anomalies. About half of radial disorders have a mendelian cause and pattern of
inheritance, whereas the remaining half appears sporadic with no known gene involved. In sporadic
forms certain anomalies, such as thumb or radial hypoplasia, may occur either alone or in association
with systemic conditions, like vertebral abnormalities or renal defects. All the cases with a mendelian inheritance are syndromic
forms, which include cardiac defects (in Holt-Oram syndrome), bone marrow failure (in Fanconi anemia), platelet
deficiency (in thrombocytopenia-absent-radius syndrome), ocular motility impairment (in Okihiro syndrome). The
genetics of radial deficiencies is complex, characterized by genetic heterogeneity and high inter- and intra-familial clinical
variability: this review will analyze the etiopathogenesis and the genotype/phenotype correlations of the main radial deficiency
disorders in humans.
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Affiliation(s)
- Amira Elmakky
- Medical Genetics, Department of Medical and Surgical Sciences, University Hospital of Modena, Italy
| | - Ilaria Stanghellini
- Medical Genetics, Department of Medical and Surgical Sciences, University Hospital of Modena, Italy
| | - Antonio Landi
- Hand Surgery and Microsurgery, Department of Locomotor System Diseases, University Hospital of Modena, Modena, Italy
| | - Antonio Percesepe
- Medical Genetics, Department of Medical and Surgical Sciences, University Hospital of Modena, Italy
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8
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Zhang C. Involvement of Iron-Containing Proteins in Genome Integrity in Arabidopsis Thaliana. Genome Integr 2015; 6:2. [PMID: 27330736 PMCID: PMC4911903 DOI: 10.4103/2041-9414.155953] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 03/12/2015] [Indexed: 01/03/2023] Open
Abstract
The Arabidopsis genome encodes numerous iron-containing proteins such as iron-sulfur (Fe-S) cluster proteins and hemoproteins. These proteins generally utilize iron as a cofactor, and they perform critical roles in photosynthesis, genome stability, electron transfer, and oxidation-reduction reactions. Plants have evolved sophisticated mechanisms to maintain iron homeostasis for the assembly of functional iron-containing proteins, thereby ensuring genome stability, cell development, and plant growth. Over the past few years, our understanding of iron-containing proteins and their functions involved in genome stability has expanded enormously. In this review, I provide the current perspectives on iron homeostasis in Arabidopsis, followed by a summary of iron-containing protein functions involved in genome stability maintenance and a discussion of their possible molecular mechanisms.
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Affiliation(s)
- Caiguo Zhang
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado, Aurora, Colorado, USA
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9
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Keller H, Kiosze K, Sachsenweger J, Haumann S, Ohlenschläger O, Nuutinen T, Syväoja JE, Görlach M, Grosse F, Pospiech H. The intrinsically disordered amino-terminal region of human RecQL4: multiple DNA-binding domains confer annealing, strand exchange and G4 DNA binding. Nucleic Acids Res 2014; 42:12614-27. [PMID: 25336622 PMCID: PMC4227796 DOI: 10.1093/nar/gku993] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/20/2014] [Accepted: 10/06/2014] [Indexed: 01/01/2023] Open
Abstract
Human RecQL4 belongs to the ubiquitous RecQ helicase family. Its N-terminal region represents the only homologue of the essential DNA replication initiation factor Sld2 of Saccharomyces cerevisiae, and also participates in the vertebrate initiation of DNA replication. Here, we utilized a random screen to identify N-terminal fragments of human RecQL4 that could be stably expressed in and purified from Escherichia coli. Biophysical characterization of these fragments revealed that the Sld2 homologous RecQL4 N-terminal domain carries large intrinsically disordered regions. The N-terminal fragments were sufficient for the strong annealing activity of RecQL4. Moreover, this activity appeared to be the basis for an ATP-independent strand exchange activity. Both activities relied on multiple DNA-binding sites with affinities to single-stranded, double-stranded and Y-structured DNA. Finally, we found a remarkable affinity of the N-terminus for guanine quadruplex (G4) DNA, exceeding the affinities for other DNA structures by at least 60-fold. Together, these findings suggest that the DNA interactions mediated by the N-terminal region of human RecQL4 represent a central function at the replication fork. The presented data may also provide a mechanistic explanation for the role of elements with a G4-forming propensity identified in the vicinity of vertebrate origins of DNA replication.
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Affiliation(s)
- Heidi Keller
- Research Group Biochemistry, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Kristin Kiosze
- Research Group Biochemistry, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Juliane Sachsenweger
- Research Group Biochemistry, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Sebastian Haumann
- Research Group Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Oliver Ohlenschläger
- Research Group Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Tarmo Nuutinen
- Department of Biology, University of Eastern Finland, PO Box 111, FI-80101 Joensuu, Finland
| | - Juhani E Syväoja
- Institute of Biomedicine, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland
| | - Matthias Görlach
- Research Group Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Frank Grosse
- Research Group Biochemistry, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany Center for Molecular Biomedicine, Friedrich-Schiller University, Jena, Germany
| | - Helmut Pospiech
- Research Group Biochemistry, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany Faculty of Biochemistry and Molecular Medicine, PO Box 5000, FI-90014 University of Oulu, Finland
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10
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Ohlenschläger O, Kuhnert A, Schneider A, Haumann S, Bellstedt P, Keller H, Saluz HP, Hortschansky P, Hänel F, Grosse F, Görlach M, Pospiech H. The N-terminus of the human RecQL4 helicase is a homeodomain-like DNA interaction motif. Nucleic Acids Res 2012; 40:8309-24. [PMID: 22730300 PMCID: PMC3458545 DOI: 10.1093/nar/gks591] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The RecQL4 helicase is involved in the maintenance of genome integrity and DNA replication. Mutations in the human RecQL4 gene cause the Rothmund–Thomson, RAPADILINO and Baller–Gerold syndromes. Mouse models and experiments in human and Xenopus have proven the N-terminal part of RecQL4 to be vital for cell growth. We have identified the first 54 amino acids of RecQL4 (RecQL4_N54) as the minimum interaction region with human TopBP1. The solution structure of RecQL4_N54 was determined by heteronuclear liquid–state nuclear magnetic resonance (NMR) spectroscopy (PDB 2KMU; backbone root-mean-square deviation 0.73 Å). Despite low-sequence homology, the well-defined structure carries an overall helical fold similar to homeodomain DNA-binding proteins but lacks their archetypical, minor groove-binding N-terminal extension. Sequence comparison indicates that this N-terminal homeodomain-like fold is a common hallmark of metazoan RecQL4 and yeast Sld2 DNA replication initiation factors. RecQL4_N54 binds DNA without noticeable sequence specificity yet with apparent preference for branched over double-stranded (ds) or single-stranded (ss) DNA. NMR chemical shift perturbation observed upon titration with Y-shaped, ssDNA and dsDNA shows a major contribution of helix α3 to DNA binding, and additional arginine side chain interactions for the ss and Y-shaped DNA.
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Affiliation(s)
- Oliver Ohlenschläger
- Research Group Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstr. 11, Jena, Germany
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11
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Su Y, Meador JA, Calaf GM, Proietti De-Santis L, Zhao Y, Bohr VA, Balajee AS. Human RecQL4 helicase plays critical roles in prostate carcinogenesis. Cancer Res 2010; 70:9207-17. [PMID: 21045146 DOI: 10.1158/0008-5472.can-10-1743] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Prostate cancer is the second leading cause of cancer-associated deaths among men in the western countries. Here, we report that human RecQL4 helicase, which is implicated in the pathogenesis of a subset of cancer-prone Rothmund-Thomson syndrome, is highly elevated in metastatic prostate cancer cell lines. Increased RecQL4 expression was also detected in human prostate tumor tissues as a function of tumor grade with the highest expression level in metastatic tumor samples, suggesting that RecQL4 may be a potential prognostic factor for advanced stage of prostate cancer. Transient and stable suppression of RecQL4 by small interfering RNA and short hairpin RNA vectors drastically reduced the growth and survival of metastatic prostate cancer cells, indicating that RecQL4 is a prosurvival factor for prostate cancer cells. RecQL4 suppression led to increased poly(ADP-ribose) polymerase (PARP) synthesis and RecQL4-suppressed prostate cancer cells underwent an extensive apoptotic death in a PARP-1-dependent manner. Most notably, RecQL4 knockdown in metastatic prostate cancer cells drastically reduced their cell invasiveness in vitro and tumorigenicity in vivo, showing that RecQL4 is essential for prostate cancer promotion. Observation of a direct interaction of retinoblastoma (Rb) and E2F1 proteins with RecQL4 promoter suggests that Rb-E2F1 pathway may regulate RecQL4 expression. Collectively, our study shows that RecQL4 is an essential factor for prostate carcinogenesis.
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Affiliation(s)
- Yanrong Su
- Center for Radiological Research, Department of Radiation Oncology, Columbia University Medical Center, New York, New York 10032, USA
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12
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Chun SG, Yee NS. Werner syndrome as a hereditary risk factor for exocrine pancreatic cancer: potential role of WRN in pancreatic tumorigenesis and patient-tailored therapy. Cancer Biol Ther 2010; 10:430-7. [PMID: 20657174 DOI: 10.4161/cbt.10.5.12763] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Advanced age is considered a risk factor for pancreatic cancer, but this relationship at the molecular and genetic level remains unclear. We present a clinical case series focusing on an association between pancreatic adenocarcinoma and Werner syndrome (WS) that is an autosomal recessive genetic disorder characterized by accelerated aging and cancer predisposition, and is caused by loss-of-function mutations in the WS RecQ helicase gene (WRN). Although pancreatic adenocarcinoma mostly occurs in a sporadic fashion, a minority of cases occurs in the context of susceptible individuals with hereditary syndromes. While WS has not been previously recognized as a risk factor for developing malignant tumors of the exocrine pancreas, the clinicopathologic features of three reported patients suggest a contributory role of WRN deficiency in pancreatic carcinogenesis. Molecular genetic analyses support the role of WRN as a tumor suppressor gene, although recent evidence reveals that WRN can alternatively promote oncogenicity depending on the molecular context. Based upon the clinico-pathologic features of these patients and the role of WRN in experimental models, we propose that its loss-of-function predisposes the development of pancreatic adenocarcinoma through epigenetic silencing or loss-of-heterozygosity of WRN. To test this hypothesis, we are investigating the mechanistic role of WRN in pancreatic cancer models including a pancreatic adenocarcinoma cell line generated from a human with WS. These studies are expected to provide new insight into the relationship between aging and pancreatic tumorigenesis, and facilitate development of novel strategies for patient-tailored interventions in this deadly malignancy.
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Affiliation(s)
- Stephen G Chun
- Department of Surgery, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, USA
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13
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Simon T, Kohlhase J, Wilhelm C, Kochanek M, De Carolis B, Berthold F. Multiple malignant diseases in a patient with Rothmund-Thomson syndrome with RECQL4 mutations: Case report and literature review. Am J Med Genet A 2010; 152A:1575-9. [PMID: 20503338 DOI: 10.1002/ajmg.a.33427] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
RECQL4 mutations cause genetic instability and increase the risk of malignant disease. We report on a patient with compound heterozygosity for two novel RECQL4 mutations: mutation c.1919_1924delTCACAG, p.L640_A642delinsP in exon 12 of the RECQL4 gene and mutation c.1704+1G>A in intron 10 of the RECQL4 gene. He subsequently developed large cell anaplastic T cell lymphoma at the age of 9 years, diffuse large cell B lymphoma and osteosarcoma when he was 14 years old, and finally acute lymphatic leukemia when he was 21 years old. The most remarkable clinical features are young age, spontaneous remission of diffuse large cell lymphoma, and severe CNS and skin toxicity of cytotoxic treatment.
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Affiliation(s)
- T Simon
- Department of Pediatric Oncology and Hematology, Children's Hospital, University of Cologne, Cologne, Germany.
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14
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Tahmaseb K, Matson SW. Rapid purification of helicase proteins and in vitro analysis of helicase activity. Methods 2010; 51:322-8. [PMID: 20153831 DOI: 10.1016/j.ymeth.2010.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 02/08/2010] [Accepted: 02/09/2010] [Indexed: 11/29/2022] Open
Abstract
Most processes involving an organism's genetic material, including replication, repair and recombination, require access to single-stranded DNA as a template or reaction intermediate. To disrupt the hydrogen bonds between the two strands in double-stranded DNA, organisms utilize proteins called DNA helicases. DNA helicases use duplex DNA as a substrate to create single-stranded DNA in a reaction that requires ATP hydrolysis. Due to their critical role in cellular function, understanding the reaction catalyzed by helicases is essential to understanding DNA metabolism. Helicases are also important in many disease processes due to their role in DNA maintenance and replication. Here we discuss ways to rapidly purify helicases in sufficient quantity for biochemical analysis. We also briefly discuss potential substrates to use with helicases to establish some of their critical biochemical parameters. Through the use of methods that simplify the study of helicases, our understanding of these essential proteins can be accelerated.
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Affiliation(s)
- Kambiz Tahmaseb
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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15
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Rossi ML, Ghosh AK, Bohr VA. Roles of Werner syndrome protein in protection of genome integrity. DNA Repair (Amst) 2010; 9:331-44. [PMID: 20075015 DOI: 10.1016/j.dnarep.2009.12.011] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Werner syndrome protein (WRN) is one of a family of five human RecQ helicases implicated in the maintenance of genome stability. The conserved RecQ family also includes RecQ1, Bloom syndrome protein (BLM), RecQ4, and RecQ5 in humans, as well as Sgs1 in Saccharomyces cerevisiae, Rqh1 in Schizosaccharomyces pombe, and homologs in Caenorhabditis elegans, Xenopus laevis, and Drosophila melanogaster. Defects in three of the RecQ helicases, RecQ4, BLM, and WRN, cause human pathologies linked with cancer predisposition and premature aging. Mutations in the WRN gene are the causative factor of Werner syndrome (WS). WRN is one of the best characterized of the RecQ helicases and is known to have roles in DNA replication and repair, transcription, and telomere maintenance. Studies both in vitro and in vivo indicate that the roles of WRN in a variety of DNA processes are mediated by post-translational modifications, as well as several important protein-protein interactions. In this work, we will summarize some of the early studies on the cellular roles of WRN and highlight the recent findings that shed some light on the link between the protein with its cellular functions and the disease pathology.
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Affiliation(s)
- Marie L Rossi
- Laboratory of Molecular Gerontology, National Institute on Aging, Baltimore, MD 21224, USA
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16
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Debeljak M, Zver A, Jazbec J. A patient with Baller-Gerold syndrome and midline NK/T lymphoma. Am J Med Genet A 2009; 149A:755-9. [PMID: 19291770 DOI: 10.1002/ajmg.a.32736] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Three autosomal recessive disorders are associated with mutations in the RECQL4 gene: Rothmund-Thomson syndrome (RTS), Baller-Gerold syndrome (BGS), and RAPADILINO syndrome. BGS is characterized by two major clinical abnormalities: craniosynostosis and preaxial limb anomalies but not cancer development. We performed RECQL4 mutation detection in a patient with BGS and several clinical signs of RTS who developed a midline NK/T-cell lymphoma. Sequencing was used to identify RECQL4 mutations, and RNA analysis was used to examine expression of mRNA in leukocytes. The patient was found to be compound heterozygous for two mutations in exon 15, namely c.[2492_2493delAT] + c.[2506_2518del13bp]. We found that only the allele with 13 bp deletion was expressed in blood leukocytes. Our patient showed severe phenotypic abnormalities, with clinical signs of both BGS and RTS. She developed an extranodal NK/T-cell lymphoma, which is extremely rare in children of her age and is the first described case of BGS with development of a cancer. This case of a RECQL4-related disorder highlights the significant phenotypic overlap between the classically delineated RECQL4-associated syndromes and questions the need to redefine or combine these clinical entities.
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Affiliation(s)
- Marusa Debeljak
- Center for Medical Genetics, University Children's Hospital, University Medical Center, Ljubljana, Slovenia
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17
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Affiliation(s)
- Richard Kellermayer
- Section of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030-2399, USA.
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