1
|
Zeng J, Li J, Liu Y, Liang R, Wang L, Zhou Q, Sun J, Liu Z, Wang W, Zhu S. A Chinese patient with Rothmund-Thomson syndrome. Mol Genet Genomic Med 2024; 12:e2347. [PMID: 38131666 PMCID: PMC10767680 DOI: 10.1002/mgg3.2347] [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: 04/20/2023] [Revised: 11/20/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023] Open
Abstract
INTRODUCTION Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder that has been reported in all ethnicities, with several identifiable pathogenic variants. There have been reported cases indicating that RTS may lead to low birth weight in fetuses, but specific data on the fetal period are lacking. Genetic testing for RTS II is currently carried out by identifying pathogenic variants in RECQL4. METHODS In order to determine the cause, we performed whole-genome sequencing (WGS) analysis on the patient and his parents. Variants detected by WGS were confirmed by Sanger sequencing and examined in family members. RESULTS After analyzing the WGS data, we found a heterozygous nonsense mutation c.2752G>T (p.Glu918Ter) and a novel frameshift insertion mutation c.1547dupC (p.Leu517AlafsTer23) of RECQL4, which is a known pathogenic/disease-causing variant of RTS. Further validation indicated these were compound heterozygous mutations from parents. CONCLUSION Our study expands the mutational spectrum of the RECQL4 gene and enriches the phenotype spectrum of Chinese RTS patients. Our information can assist the patient's parents in making informed decisions regarding their future pregnancies. This case offers a new perspective for clinicians to consider whether to perform prenatal diagnosis.
Collapse
Affiliation(s)
- Juan Zeng
- Obstetrics DepartmentShenzhen Maternity and Child Healthcare HospitalShenzhenGuangdong ProvinceChina
| | - Jiayi Li
- BGI‐ShenzhenShenzhenChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Yuwei Liu
- BGI‐ShenzhenShenzhenChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | | | | | | | | | | | | | - Sujun Zhu
- Obstetrics DepartmentShenzhen Maternity and Child Healthcare HospitalShenzhenGuangdong ProvinceChina
| |
Collapse
|
2
|
Xu X, Chang CW, Li M, Liu C, Liu Y. Molecular Mechanisms of the RECQ4 Pathogenic Mutations. Front Mol Biosci 2021; 8:791194. [PMID: 34869606 PMCID: PMC8637615 DOI: 10.3389/fmolb.2021.791194] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/02/2021] [Indexed: 12/03/2022] Open
Abstract
The human RECQ4 gene encodes an ATP-dependent DNA helicase that contains a conserved superfamily II helicase domain located at the center of the polypeptide. RECQ4 is one of the five RECQ homologs in human cells, and its helicase domain is flanked by the unique amino and carboxyl termini with sequences distinct from other members of the RECQ helicases. Since the identification of the RECQ4 gene in 1998, multiple RECQ4 mutations have been linked to the pathogenesis of three clinical diseases, which are Rothmund-Thomson syndrome, Baller-Gerold syndrome, and RAPADILINO. Patients with these diseases show various developmental abnormalities. In addition, a subset of RECQ4 mutations are associated with high cancer risks, especially for osteosarcoma and/or lymphoma at early ages. The discovery of clinically relevant RECQ4 mutations leads to intriguing questions: how is the RECQ4 helicase responsible for preventing multiple clinical syndromes? What are the mechanisms by which the RECQ4 disease mutations cause tissue abnormalities and drive cancer formation? Furthermore, RECQ4 is highly overexpressed in many cancer types, raising the question whether RECQ4 acts not only as a tumor suppressor but also an oncogene that can be a potential new therapeutic target. Defining the molecular dysfunctions of different RECQ4 disease mutations is imperative to improving our understanding of the complexity of RECQ4 clinical phenotypes and the dynamic roles of RECQ4 in cancer development and prevention. We will review recent progress in examining the molecular and biochemical properties of the different domains of the RECQ4 protein. We will shed light on how the dynamic roles of RECQ4 in human cells may contribute to the complexity of RECQ4 clinical phenotypes.
Collapse
Affiliation(s)
- Xiaohua Xu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Chou-Wei Chang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Min Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Chao Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Yilun Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| |
Collapse
|
3
|
Balajee AS. Human RecQL4 as a Novel Molecular Target for Cancer Therapy. Cytogenet Genome Res 2021; 161:305-327. [PMID: 34474412 DOI: 10.1159/000516568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/24/2021] [Indexed: 11/19/2022] Open
Abstract
Human RecQ helicases play diverse roles in the maintenance of genomic stability. Inactivating mutations in 3 of the 5 human RecQ helicases are responsible for the pathogenesis of Werner syndrome (WS), Bloom syndrome (BS), Rothmund-Thomson syndrome (RTS), RAPADILINO, and Baller-Gerold syndrome (BGS). WS, BS, and RTS patients are at increased risk for developing many age-associated diseases including cancer. Mutations in RecQL1 and RecQL5 have not yet been associated with any human diseases so far. In terms of disease outcome, RecQL4 deserves special attention because mutations in RecQL4 result in 3 autosomal recessive syndromes (RTS type II, RAPADILINO, and BGS). RecQL4, like other human RecQ helicases, has been demonstrated to play a crucial role in the maintenance of genomic stability through participation in diverse DNA metabolic activities. Increased incidence of osteosarcoma in RecQL4-mutated RTS patients and elevated expression of RecQL4 in sporadic cancers including osteosarcoma suggest that loss or gain of RecQL4 expression is linked with cancer susceptibility. In this review, current and future perspectives are discussed on the potential use of RecQL4 as a novel cancer therapeutic target.
Collapse
Affiliation(s)
- Adayabalam S Balajee
- Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center/Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| |
Collapse
|
4
|
Zhang J, Lian H, Chen K, Pang Y, Chen M, Huang B, Zhu L, Xu S, Liu M, Zhong C. RECQ1 Promotes Stress Resistance and DNA Replication Progression Through PARP1 Signaling Pathway in Glioblastoma. Front Cell Dev Biol 2021; 9:714868. [PMID: 34381789 PMCID: PMC8350743 DOI: 10.3389/fcell.2021.714868] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022] Open
Abstract
Glioblastoma (GBM) is the most common aggressive primary malignant brain tumor, and patients with GBM have a median survival of 20 months. Clinical therapy resistance is a challenging barrier to overcome. Tumor genome stability maintenance during DNA replication, especially the ability to respond to replication stress, is highly correlated with drug resistance. Recently, we identified a protective role for RECQ1 under replication stress conditions. RECQ1 acts at replication forks, binds PCNA, inhibits single-strand DNA formation and nascent strand degradation in GBM cells. It is associated with the function of the PARP1 protein, promoting PARP1 recruitment to replication sites. RECQ1 is essential for DNA replication fork protection and tumor cell proliferation under replication stress conditions, and as a target of RECQ1, PARP1 effectively protects and restarts stalled replication forks, providing new insights into genomic stability maintenance and replication stress resistance. These findings indicate that tumor genome stability targeting RECQ1-PARP1 signaling may be a promising therapeutic intervention to overcome therapy resistance in GBM.
Collapse
Affiliation(s)
- Jing Zhang
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.,Institute for Advanced Study, Tongji University, Shanghai, China
| | - Hao Lian
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Kui Chen
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Ying Pang
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Mu Chen
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Bingsong Huang
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Lei Zhu
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Siyi Xu
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Min Liu
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Chunlong Zhong
- Department of Neurosurgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| |
Collapse
|
5
|
Checkpoint functions of RecQ helicases at perturbed DNA replication fork. Curr Genet 2021; 67:369-382. [PMID: 33427950 DOI: 10.1007/s00294-020-01147-y] [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: 11/16/2020] [Revised: 12/07/2020] [Accepted: 12/12/2020] [Indexed: 01/17/2023]
Abstract
DNA replication checkpoint is a cell signaling pathway that is activated in response to perturbed replication. Although it is crucial for maintaining genomic integrity and cell survival, the exact mechanism of the checkpoint signaling remains to be understood. Emerging evidence has shown that RecQ helicases, a large family of helicases that are conserved from bacteria to yeasts and humans, contribute to the replication checkpoint as sensors, adaptors, or regulation targets. Here, we highlight the multiple functions of RecQ helicases in the replication checkpoint in four model organisms and present additional evidence that fission yeast RecQ helicase Rqh1 may participate in the replication checkpoint as a sensor.
Collapse
|
6
|
Schnabel F, Kornak U, Wollnik B. Premature aging disorders: A clinical and genetic compendium. Clin Genet 2020; 99:3-28. [PMID: 32860237 DOI: 10.1111/cge.13837] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 12/22/2022]
Abstract
Progeroid disorders make up a heterogeneous group of very rare hereditary diseases characterized by clinical signs that often mimic physiological aging in a premature manner. Apart from Hutchinson-Gilford progeria syndrome, one of the best-investigated progeroid disorders, a wide spectrum of other premature aging phenotypes exist, which differ significantly in their clinical presentation and molecular pathogenesis. Next-generation sequencing (NGS)-based approaches have made it feasible to determine the molecular diagnosis in the early stages of a disease. Nevertheless, a broad clinical knowledge on these disorders and their associated symptoms is still fundamental for a comprehensive patient management and for the interpretation of variants of unknown significance from NGS data sets. This review provides a detailed overview on characteristic clinical features and underlying molecular genetics of well-known as well as only recently identified premature aging disorders and also highlights novel findings towards future therapeutic options.
Collapse
Affiliation(s)
- Franziska Schnabel
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Uwe Kornak
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable cells" (MBExC), University of Göttingen, Göttingen, Germany
| |
Collapse
|
7
|
Qin Z, Bi L, Hou XM, Zhang S, Zhang X, Lu Y, Li M, Modesti M, Xi XG, Sun B. Human RPA activates BLM's bidirectional DNA unwinding from a nick. eLife 2020; 9:54098. [PMID: 32101168 PMCID: PMC7065910 DOI: 10.7554/elife.54098] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/25/2020] [Indexed: 01/12/2023] Open
Abstract
BLM is a multifunctional helicase that plays critical roles in maintaining genome stability. It processes distinct DNA substrates, but not nicked DNA, during many steps in DNA replication and repair. However, how BLM prepares itself for diverse functions remains elusive. Here, using a combined single-molecule approach, we find that a high abundance of BLMs can indeed unidirectionally unwind dsDNA from a nick when an external destabilizing force is applied. Strikingly, human replication protein A (hRPA) not only ensures that limited quantities of BLMs processively unwind nicked dsDNA under a reduced force but also permits the translocation of BLMs on both intact and nicked ssDNAs, resulting in a bidirectional unwinding mode. This activation necessitates BLM targeting on the nick and the presence of free hRPAs in solution whereas direct interactions between them are dispensable. Our findings present novel DNA unwinding activities of BLM that potentially facilitate its function switching in DNA repair.
Collapse
Affiliation(s)
- Zhenheng Qin
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.,Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Lulu Bi
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xi-Miao Hou
- College of Life Sciences, Northwest A&F University, Yangling, China
| | - Siqi Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.,Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xia Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Ying Lu
- Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Ming Li
- University of Chinese Academy of Sciences, Beijing, China.,Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Mauro Modesti
- Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Institut Paoli-Calmettes, Aix-Marseille Université, Marseille, France
| | - Xu-Guang Xi
- The LBPA, Ecole Normale Supérieure Paris-Saclay, CNRS, Université Paris Saclay, Gif-sur-Yvette, France
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| |
Collapse
|
8
|
Gupta SV, Schmidt KH. Maintenance of Yeast Genome Integrity by RecQ Family DNA Helicases. Genes (Basel) 2020; 11:E205. [PMID: 32085395 PMCID: PMC7074392 DOI: 10.3390/genes11020205] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022] Open
Abstract
With roles in DNA repair, recombination, replication and transcription, members of the RecQ DNA helicase family maintain genome integrity from bacteria to mammals. Mutations in human RecQ helicases BLM, WRN and RecQL4 cause incurable disorders characterized by genome instability, increased cancer predisposition and premature adult-onset aging. Yeast cells lacking the RecQ helicase Sgs1 share many of the cellular defects of human cells lacking BLM, including hypersensitivity to DNA damaging agents and replication stress, shortened lifespan, genome instability and mitotic hyper-recombination, making them invaluable model systems for elucidating eukaryotic RecQ helicase function. Yeast and human RecQ helicases have common DNA substrates and domain structures and share similar physical interaction partners. Here, we review the major cellular functions of the yeast RecQ helicases Sgs1 of Saccharomyces cerevisiae and Rqh1 of Schizosaccharomyces pombe and provide an outlook on some of the outstanding questions in the field.
Collapse
Affiliation(s)
- Sonia Vidushi Gupta
- Department of Cell Biology, Microbiology and Molecular Biology, University of South, Florida, Tampa, FL 33620, USA;
| | - Kristina Hildegard Schmidt
- Department of Cell Biology, Microbiology and Molecular Biology, University of South, Florida, Tampa, FL 33620, USA;
- Cancer Biology and Evolution Program, H. Lee Moffitt Cancer Center and Research, Institute, Tampa, FL 33612, USA
| |
Collapse
|
9
|
Yadav S, Thakur S, Kohlhase J, Bhari N, Kabra M, Gupta N. Report of Two Novel Mutations in Indian Patients with Rothmund-Thomson Syndrome. J Pediatr Genet 2019; 8:163-167. [PMID: 31406625 DOI: 10.1055/s-0039-1684017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 02/23/2019] [Indexed: 02/01/2023]
Abstract
Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder caused by mutations in RECQL4 and has characteristic clinical features. We report two unrelated phenotypically diverse patients (cases 1 and 2) with RTS having novel variants in RECQL4 gene . Case-1 was evaluated for poor growth and recurrent fractures and skin lesions. Case-2 presented at 4 months with failure to thrive and radial ray defect and developed poikilodermatous skin lesions after infancy. Both cases were confirmed to have homozygous pathogenic variants in RECQL4 . Both patients have normal intellect and are on supportive therapy. The presence of characteristic poikiloderma lesions with specific distribution and skeletal anomalies in a patient with proportionate short stature is a clue toward the diagnosis of RTS.
Collapse
Affiliation(s)
- Sakshi Yadav
- Division of Genetics, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Thakur
- Division of Genetic and Fetal Medicine, Fortis Hospital, Delhi and Apollo Hospital, New Delhi, India
| | | | - Neetu Bhari
- Department of Skin, All India Institute of Medical Sciences, New Delhi, India
| | - Madhulika Kabra
- Division of Genetics, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Neerja Gupta
- Division of Genetics, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
10
|
Mo D, Zhao Y, Balajee AS. Human RecQL4 helicase plays multifaceted roles in the genomic stability of normal and cancer cells. Cancer Lett 2017; 413:1-10. [PMID: 29080750 DOI: 10.1016/j.canlet.2017.10.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/13/2017] [Accepted: 10/16/2017] [Indexed: 02/06/2023]
Abstract
Human RecQ helicases that share homology with E. coli RecQ helicase play critical roles in diverse biological activities such as DNA replication, transcription, recombination and repair. Mutations in three of the five human RecQ helicases (RecQ1, WRN, BLM, RecQL4 and RecQ5) result in autosomal recessive syndromes characterized by accelerated aging symptoms and cancer incidence. Mutational inactivation of Werner (WRN) and Bloom (BLM) genes results in Werner syndrome (WS) and Bloom syndrome (BS) respectively. However, mutations in RecQL4 result in three human disorders: (I) Rothmund-Thomson syndrome (RTS), (II) RAPADILINO and (III) Baller-Gerold syndrome (BGS). Cells from WS, BS and RTS are characterized by a unique chromosomal anomaly indicating that each of the RecQ helicases performs specialized function(s) in a non-redundant manner. Elucidating the biological functions of RecQ helicases will enable us to understand not only the aging process but also to determine the cause for age-associated human diseases. Recent biochemical and molecular studies have given new insights into the multifaceted roles of RecQL4 that range from genomic stability to carcinogenesis and beyond. This review summarizes some of the existing and emerging knowledge on diverse biological functions of RecQL4 and its significance as a potential molecular target for cancer therapy.
Collapse
Affiliation(s)
- Dongliang Mo
- Chinese Academy of Science, Beijing Institute of Genomics, Beijing CN 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongliang Zhao
- Chinese Academy of Science, Beijing Institute of Genomics, Beijing CN 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Adayabalam S Balajee
- Radiation Emergency Assistance Center and Training Site, Oak Ridge Associated Universities, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA.
| |
Collapse
|
11
|
Yu F, Cai W, Jiang B, Xu L, Liu S, Zhao S. A novel mutation of adenomatous polyposis coli (APC) gene results in the formation of supernumerary teeth. J Cell Mol Med 2017; 22:152-162. [PMID: 28782241 PMCID: PMC5742724 DOI: 10.1111/jcmm.13303] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 05/27/2017] [Indexed: 12/15/2022] Open
Abstract
Supernumerary teeth are teeth that are present in addition to normal teeth. Although several hypotheses and some molecular signalling pathways explain the formation of supernumerary teeth, but their exact disease pathogenesis is unknown. To study the molecular mechanisms of supernumerary tooth‐related syndrome (Gardner syndrome), a deeper understanding of the aetiology of supernumerary teeth and the associated syndrome is needed, with the goal of inhibiting disease inheritance via prenatal diagnosis. We recruited a Chinese family with Gardner syndrome. Haematoxylin and eosin staining of supernumerary teeth and colonic polyp lesion biopsies revealed that these patients exhibited significant pathological characteristics. APC gene mutations were detected by PCR and direct sequencing. We revealed the pathological pathway involved in human supernumerary tooth development and the mouse tooth germ development expression profile by RNA sequencing (RNA‐seq). Sequencing analysis revealed that an APC gene mutation in exon 15, namely 4292‐4293‐Del GA, caused Gardner syndrome in this family. This mutation not only initiated the various manifestations typical of Gardner syndrome but also resulted in odontoma and supernumerary teeth in this case. Furthermore, RNA‐seq analysis of human supernumerary teeth suggests that the APC gene is the key gene involved in the development of supernumerary teeth in humans. The mouse tooth germ development expression profile shows that the APC gene plays an important role in tooth germ development. We identified a new mutation in the APC gene that results in supernumerary teeth in association with Gardner syndrome. This information may shed light on the molecular pathogenesis of supernumerary teeth. Gene‐based diagnosis and gene therapy for supernumerary teeth may become available in the future, and our study provides a high‐resolution reference for treating other syndromes associated with supernumerary teeth.
Collapse
Affiliation(s)
- Fang Yu
- Department of Pediatric Dentistry, School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China
| | - Wenping Cai
- Center for Translational Neurodegeneration and Regenerative Therapy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Beizhan Jiang
- Department of Endodontics, School & Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, Shanghai, China
| | - Laijun Xu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shangfeng Liu
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shouliang Zhao
- Department of Stomatology, Huashan Hospital, Fudan University, Shanghai, China.,Department of Endodontics, School & Hospital of Stomatology, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Tongji University, Shanghai, China
| |
Collapse
|
12
|
Lu X, Yu F, Liu J, Cai W, Zhao Y, Zhao S, Liu S. The epidemiology of supernumerary teeth and the associated molecular mechanism. Organogenesis 2017; 13:71-82. [PMID: 28598258 DOI: 10.1080/15476278.2017.1332554] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Supernumerary teeth are common clinical dental anomalies. Although various studies have provided abundant information regarding genes and signaling pathways involved in tooth morphogenesis, which include Wnt, FGF, BMP, and Shh, the molecular mechanism of tooth formation, especially for supernumerary teeth, is still unclear. In the population, some cases of supernumerary teeth are sporadic, while others are syndrome-related with familial hereditary. The prompt and accurate diagnosis of syndrome related supernumerary teeth is quite important for some distinctive disorders. Mice are the most commonly used model system for investigating supernumerary teeth. The upregulation of Wnt and Shh signaling in the dental epithelium results in the formation of multiple supernumerary teeth in mice. Understanding the molecular mechanism of supernumerary teeth is also a component of understanding tooth formation in general and provides clinical guidance for early diagnosis and treatment in the future.
Collapse
Affiliation(s)
- Xi Lu
- a Department of Stomatology , Huashan Hospital, Fudan University , Shanghai , P.R. China
| | - Fang Yu
- b Department of Pediatric Dentistry , School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration , Shanghai , P. R. China
| | - Junjun Liu
- a Department of Stomatology , Huashan Hospital, Fudan University , Shanghai , P.R. China
| | - Wenping Cai
- a Department of Stomatology , Huashan Hospital, Fudan University , Shanghai , P.R. China
| | - Yumei Zhao
- b Department of Pediatric Dentistry , School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration , Shanghai , P. R. China
| | - Shouliang Zhao
- a Department of Stomatology , Huashan Hospital, Fudan University , Shanghai , P.R. China
| | - Shangfeng Liu
- a Department of Stomatology , Huashan Hospital, Fudan University , Shanghai , P.R. China
| |
Collapse
|
13
|
Walsh MF, Chang VY, Kohlmann WK, Scott HS, Cunniff C, Bourdeaut F, Molenaar JJ, Porter CC, Sandlund JT, Plon SE, Wang LL, Savage SA. Recommendations for Childhood Cancer Screening and Surveillance in DNA Repair Disorders. Clin Cancer Res 2017; 23:e23-e31. [PMID: 28572264 PMCID: PMC5697784 DOI: 10.1158/1078-0432.ccr-17-0465] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/30/2017] [Accepted: 04/20/2017] [Indexed: 01/09/2023]
Abstract
DNA repair syndromes are heterogeneous disorders caused by pathogenic variants in genes encoding proteins key in DNA replication and/or the cellular response to DNA damage. The majority of these syndromes are inherited in an autosomal-recessive manner, but autosomal-dominant and X-linked recessive disorders also exist. The clinical features of patients with DNA repair syndromes are highly varied and dependent on the underlying genetic cause. Notably, all patients have elevated risks of syndrome-associated cancers, and many of these cancers present in childhood. Although it is clear that the risk of cancer is increased, there are limited data defining the true incidence of cancer and almost no evidence-based approaches to cancer surveillance in patients with DNA repair disorders. This article is the product of the October 2016 AACR Childhood Cancer Predisposition Workshop, which brought together experts from around the world to discuss and develop cancer surveillance guidelines for children with cancer-prone disorders. Herein, we focus on the more common of the rare DNA repair disorders: ataxia telangiectasia, Bloom syndrome, Fanconi anemia, dyskeratosis congenita, Nijmegen breakage syndrome, Rothmund-Thomson syndrome, and Xeroderma pigmentosum. Dedicated syndrome registries and a combination of basic science and clinical research have led to important insights into the underlying biology of these disorders. Given the rarity of these disorders, it is recommended that centralized centers of excellence be involved directly or through consultation in caring for patients with heritable DNA repair syndromes. Clin Cancer Res; 23(11); e23-e31. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.
Collapse
Affiliation(s)
| | - Vivian Y Chang
- University of California, Los Angeles, Los Angeles, California
| | - Wendy K Kohlmann
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah
| | - Hamish S Scott
- Department of Genetics and Molecular Pathology, Centre for Cancer Biology, Adelaide, South Australia
| | | | | | - Jan J Molenaar
- Princess Máxima Center for Pediatric Oncology, Amsterdam, the Netherlands
| | | | | | - Sharon E Plon
- Baylor College of Medicine, Texas Children's Hospital, Houston, Texas
| | - Lisa L Wang
- Baylor College of Medicine, Texas Children's Hospital, Houston, Texas
| | | |
Collapse
|
14
|
Abstract
RecQL4, one of the 5 human RecQ helicases, is a key mediator of genomic stability and its deficiency can cause premature aging phenotypes. Here, by using CRISPR/Cas and RNAi technology, we demonstrated that autophagy level was elevated in both RecQL4 knockdown and knockout cells compared with those of the control cells. Surprisingly, mitochondrial content was increased and LC3 co-localization with mitochondria was partially lost in RecQL4 knockout cells compared with the control cells, suggesting that RecQL4 deficiency impaired mitophagic processes in U2OS cells. Furthermore, we found that knockout of RecQL4 destabilized PINK1. In addition, RecQL4 knockout cells were more susceptible to apoptosis under mitochondrial stress than the control cells. In conclusion, our findings indicated a novel role of RecQL4 in the regulation of autophagy/mitophagy in U2OS cells.
Collapse
Affiliation(s)
- Yangmiao Duan
- a Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Hongbo Fang
- a Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
15
|
Mo D, Fang H, Niu K, Liu J, Wu M, Li S, Zhu T, Aleskandarany MA, Arora A, Lobo DN, Madhusudan S, Balajee AS, Chi Z, Zhao Y. Human Helicase RECQL4 Drives Cisplatin Resistance in Gastric Cancer by Activating an AKT-YB1-MDR1 Signaling Pathway. Cancer Res 2016; 76:3057-66. [PMID: 27013200 DOI: 10.1158/0008-5472.can-15-2361] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 03/14/2016] [Indexed: 11/16/2022]
Abstract
Elevation of the DNA-unwinding helicase RECQL4, which participates in various DNA repair pathways, has been suggested to contribute to the pathogenicity of various human cancers, including gastric cancer. In this study, we addressed the prognostic and chemotherapeutic significance of RECQL4 in human gastric cancer, which has yet to be determined. We observed significant increases in RECQL4 mRNA or protein in >70% of three independent sets of human gastric cancer specimens examined, relative to normal gastric tissues. Strikingly, high RECQL4 expression in primary tumors correlated well with poor survival and gastric cancer lines with high RECQL4 expression displayed increased resistance to cisplatin treatment. Mechanistic investigations revealed a novel role for RECQL4 in transcriptional regulation of the multidrug resistance gene MDR1, through a physical interaction with the transcription factor YB1. Notably, ectopic expression of RECQL4 in cisplatin-sensitive gastric cancer cells with low endogenous RECQL4 was sufficient to render them resistant to cisplatin, in a manner associated with YB1 elevation and MDR1 activation. Conversely, RECQL4 silencing in cisplatin-resistant gastric cancer cells with high endogenous RECQL4 suppressed YB1 phosphorylation, reduced MDR1 expression, and resensitized cells to cisplatin. In establishing RECQL4 as a critical mediator of cisplatin resistance in gastric cancer cells, our findings provide a therapeutic rationale to target RECQL4 or the downstream AKT-YB1-MDR1 axis to improve gastric cancer treatment. Cancer Res; 76(10); 3057-66. ©2016 AACR.
Collapse
Affiliation(s)
- Dongliang Mo
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China. University of Chinese Academy of Sciences, Beijing, China
| | - Hongbo Fang
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Kaifeng Niu
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China. University of Chinese Academy of Sciences, Beijing, China
| | - Jing Liu
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China. University of Chinese Academy of Sciences, Beijing, China
| | - Meng Wu
- Biological Institute, Hebei Academy of Sciences, Shijiazhuang, China
| | - Shiyou Li
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Tienian Zhu
- Department of Medical Oncology, Bethune International Peace Hospital, Shijiazhuang, China
| | - Mohammed A Aleskandarany
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, City Hospital Campus, Nottingham, United Kingdom
| | - Arvind Arora
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, City Hospital Campus, Nottingham, United Kingdom
| | - Dileep N Lobo
- Gastrointestinal Surgery, National Institute for Health Research Nottingham Digestive Diseases Centre, Biomedical Research Unit, Nottingham University Hospitals and University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Srinivasan Madhusudan
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham University Hospitals, City Hospital Campus, Nottingham, United Kingdom
| | - Adayabalam S Balajee
- REAC/TS, Oak Ridge Associated Universities, Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee
| | - Zhenfen Chi
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
| | - Yongliang Zhao
- Key Laboratory of Genomic and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
16
|
Rathi NV, Bhattad MS, Thosar N, Baliga S. Dental management of Rothmund-Thomson syndrome with partial anodontia. BMJ Case Rep 2015; 2015:bcr-2015-209994. [PMID: 26032705 DOI: 10.1136/bcr-2015-209994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive trait disease. It is characterised by skin, eye and skeletal abnormalities. Abnormalities associated with teeth include abnormal crown and root formations, rudimentary or hypoplastic teeth, microdontia and multiple missing teeth. In the present case, there were multiple decayed primary teeth and multiple congenitally missing permanent teeth. Mandibular left primary first molar (tooth 74) was pulpally involved and obturated with mineral trioxide ggregate. Follow-up after 2 years revealed successful obturation.
Collapse
Affiliation(s)
- Nilesh Vithaldas Rathi
- Department of Pedodontics and Preventive Dentistry, Sharad Pawar Dental College, Wardha, Maharashtra, India
| | - Mayur Shrigopal Bhattad
- Department of Pedodontics & Preventive Dentistry, HSRSM Dental College and Hospital, Hingoli, Nanded, Maharashtra, India
| | - Nilima Thosar
- Department of Pedodontics and Preventive Dentistry, Sharad Pawar Dental College, Wardha, Maharashtra, India
| | - Sudhindra Baliga
- Department of Pedodontics and Preventive Dentistry, Sharad Pawar Dental College, Wardha, Maharashtra, India
| |
Collapse
|
17
|
Ng AJM, Walia MK, Smeets MF, Mutsaers AJ, Sims NA, Purton LE, Walsh NC, Martin TJ, Walkley CR. The DNA helicase recql4 is required for normal osteoblast expansion and osteosarcoma formation. PLoS Genet 2015; 11:e1005160. [PMID: 25859855 PMCID: PMC4393104 DOI: 10.1371/journal.pgen.1005160] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/19/2015] [Indexed: 12/04/2022] Open
Abstract
RECQL4 mutations are associated with Rothmund Thomson Syndrome (RTS), RAPADILINO Syndrome and Baller-Gerold Syndrome. These patients display a range of benign skeletal abnormalities such as low bone mass. In addition, RTS patients have a highly increased incidence of osteosarcoma (OS). The role of RECQL4 in normal adult bone development and homeostasis is largely uncharacterized and how mutation of RECQL4 contributes to OS susceptibility is not known. We hypothesised that Recql4 was required for normal skeletal development and both benign and malignant osteoblast function, which we have tested in the mouse. Recql4 deletion in vivo at the osteoblastic progenitor stage of differentiation resulted in mice with shorter bones and reduced bone volume, assessed at 9 weeks of age. This was associated with an osteoblast intrinsic decrease in mineral apposition rate and bone formation rate in the Recql4-deficient cohorts. Deletion of Recql4 in mature osteoblasts/osteocytes in vivo, however, did not cause a detectable phenotype. Acute deletion of Recql4 in primary osteoblasts or shRNA knockdown in an osteoblastic cell line caused failed proliferation, accompanied by cell cycle arrest, induction of apoptosis and impaired differentiation. When cohorts of animals were aged long term, the loss of Recql4 alone was not sufficient to initiate OS. We then crossed the Recql4fl/fl allele to a fully penetrant OS model (Osx-Cre p53fl/fl). Unexpectedly, the Osx-Cre p53fl/flRecql4fl/fl (dKO) animals had a significantly increased OS-free survival compared to Osx-Cre p53fl/fl or Osx-Cre p53fl/flRecql4fl/+ (het) animals. The extended survival was explained when the Recql4 status in the tumors that arose was assessed, and in no case was there complete deletion of Recql4 in the dKO OS. These data provide a mechanism for the benign skeletal phenotypes of RECQL4 mutation syndromes. We propose that tumor suppression and osteosarcoma susceptibility are most likely a function of mutant, not null, alleles of RECQL4. Rothmund Thomson Syndrome (RTS), RAPADILINO Syndrome and Baller-Gerold Syndrome are very rare human syndromes associated with mutations in RECQL4. RECQL4 is important for controlling how cells divide and for preventing genome damage. Patients with RECQL4 mutations have problems with bone formation and a low bone mass, similar to osteoporosis. RTS patients have a highly increased risk of developing bone cancer (osteosarcoma). The role of RECQL4 in normal bone development and osteosarcoma formation is largely unknown. We have used mouse models to understand the specific role of Recql4 in bone development. Mice with Recql4 removed specifically from their bone cells have shortened bones and a reduced rate of bone formation. Therefore, RECQL4 is essential for normal bone development. Interestingly, the animals with no Recql4 in bone cells did not develop osteosarcoma. Using mouse models of osteosarcoma, we observed delayed cancer formation when Recql4 was also deleted. Further analysis demonstrated that bone cancer could not arise from Recql4 null cells even with concurrent p53 deletion. These studies clarify the role of RECQL4 in both normal and malignant bone biology and suggest that RECQL4 mutations that cause osteosarcoma most likely result in proteins with reduced, but not absent, function.
Collapse
Affiliation(s)
- Alvin J. M. Ng
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Mannu K. Walia
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Monique F. Smeets
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | | | - Natalie A. Sims
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Louise E. Purton
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
- ACRF Rational Drug Discovery Centre, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
| | - Nicole C. Walsh
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - T. John Martin
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
| | - Carl R. Walkley
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia
- ACRF Rational Drug Discovery Centre, St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- * E-mail:
| |
Collapse
|
18
|
Herrmann NJ, Knoll A, Puchta H. The nuclease FAN1 is involved in DNA crosslink repair in Arabidopsis thaliana independently of the nuclease MUS81. Nucleic Acids Res 2015; 43:3653-66. [PMID: 25779053 PMCID: PMC4402529 DOI: 10.1093/nar/gkv208] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/01/2015] [Indexed: 01/06/2023] Open
Abstract
Fanconi anemia is a severe genetic disorder. Mutations in one of several genes lead to defects in DNA crosslink (CL) repair in human cells. An essential step in CL repair is the activation of the pathway by the monoubiquitination of the heterodimer FANCD2/FANCI, which recruits the nuclease FAN1 to the CL site. Surprisingly, FAN1 function is not conserved between different eukaryotes. No FAN1 homolog is present in Drosophila and Saccharomyces cerevisiae. The FAN1 homolog in Schizosaccharomyces pombe is involved in CL repair; a homolog is present in Xenopus but is not involved in CL repair. Here we show that a FAN1 homolog is present in plants and it is involved in CL repair in Arabidopsis thaliana. Both the virus-type replication-repair nuclease and the ubiquitin-binding ubiquitin-binding zinc finger domains are essential for this function. FAN1 likely acts upstream of two sub-pathways of CL repair. These pathways are defined by the Bloom syndrome homolog RECQ4A and the ATPase RAD5A, which is involved in error-free post-replicative repair. Mutations in both FAN1 and the endonuclease MUS81 resulted in greater sensitivity against CLs than in the respective single mutants. These results indicate that the two nucleases define two independent pathways of CL repair in plants.
Collapse
Affiliation(s)
- Natalie J Herrmann
- Botanical Institute II, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany
| | - Alexander Knoll
- Botanical Institute II, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany
| | - Holger Puchta
- Botanical Institute II, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany
| |
Collapse
|
19
|
Wang S, Qin W, Li JH, Lu Y, Lu KY, Nong DG, Dou SX, Xu CH, Xi XG, Li M. Unwinding forward and sliding back: an intermittent unwinding mode of the BLM helicase. Nucleic Acids Res 2015; 43:3736-46. [PMID: 25765643 PMCID: PMC4402530 DOI: 10.1093/nar/gkv209] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 03/02/2015] [Indexed: 01/11/2023] Open
Abstract
There are lines of evidence that the Bloom syndrome helicase, BLM, catalyzes regression of stalled replication forks and disrupts displacement loops (D-loops) formed during homologous recombination (HR). Here we constructed a forked DNA with a 3′ single-stranded gap and a 5′ double-stranded handle to partly mimic a stalled DNA fork and used magnetic tweezers to study BLM-catalyzed unwinding of the forked DNA. We have directly observed that the BLM helicase may slide on the opposite strand for some distance after duplex unwinding at different forces. For DNA construct with a long hairpin, progressive unwinding of the hairpin is frequently interrupted by strand switching and backward sliding of the enzyme. Quantitative study of the uninterrupted unwinding length (time) has revealed a two-state-transition mechanism for strand-switching during the unwinding process. Mutational studies revealed that the RQC domain plays an important role in stabilizing the helicase/DNA interaction during both DNA unwinding and backward sliding of BLM. Especially, Lys1125 in the RQC domain, a highly conserved amino acid among RecQ helicases, may be involved in the backward sliding activity. We have also directly observed the in vitro pathway that BLM disrupts the mimic stalled replication fork. These results may shed new light on the mechanisms for BLM in DNA repair and homologous recombination.
Collapse
Affiliation(s)
- Shuang Wang
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Wei Qin
- College of Life Science and Technology, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Jing-Hua Li
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ying Lu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ke-Yu Lu
- College of Life Science and Technology, Northwest A & F University, Yangling, Shaanxi 712100, China
| | - Da-Guan Nong
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shuo-Xing Dou
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Chun-Hua Xu
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xu-Guang Xi
- College of Life Science and Technology, Northwest A & F University, Yangling, Shaanxi 712100, China Laboratoire de Biologie et PharmacologieAppliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, 61 Avenue du Président Wilson, 94235 Cachan, France
| | - Ming Li
- Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| |
Collapse
|
20
|
RECQ4 selectively recognizes Holliday junctions. DNA Repair (Amst) 2015; 30:80-9. [PMID: 25769792 DOI: 10.1016/j.dnarep.2015.02.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/20/2015] [Accepted: 02/21/2015] [Indexed: 12/23/2022]
Abstract
The RECQ4 protein belongs to the RecQ helicase family, which plays crucial roles in genome maintenance. Mutations in the RECQ4 gene are associated with three insidious hereditary disorders: Rothmund-Thomson, Baller-Gerold, and RAPADILINO syndromes. These syndromes are characterized by growth deficiency, radial ray defects, red rashes, and higher predisposition to malignancy, especially osteosarcomas. Within the RecQ family, RECQ4 is the least characterized, and its role in DNA replication and repair remains unknown. We have identified several DNA binding sites within RECQ4. Two are located at the N-terminus and one is located within the conserved helicase domain. N-terminal domains probably cooperate with one another and promote the strong annealing activity of RECQ4. Surprisingly, the region spanning 322-400aa shows a very high affinity for branched DNA substrates, especially Holliday junctions. This study demonstrates biochemical activities of RECQ4 that could be involved in genome maintenance and suggest its possible role in processing replication and recombination intermediates.
Collapse
|
21
|
Scollon S, Bergstrom K, McCullough LB, McGuire AL, Gutierrez S, Kerstein R, Parsons DW, Plon SE. Pediatric Cancer Genetics Research and an Evolving Preventive Ethics Approach for Return of Results after Death of the Subject. THE JOURNAL OF LAW, MEDICINE & ETHICS : A JOURNAL OF THE AMERICAN SOCIETY OF LAW, MEDICINE & ETHICS 2015; 43:529-537. [PMID: 26479562 PMCID: PMC4617204 DOI: 10.1111/jlme.12295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The return of genetic research results after death in the pediatric setting comes with unique complexities. Researchers must determine which results and through which processes results are returned. This paper discusses the experience over 15 years in pediatric cancer genetics research of returning research results after the death of a child and proposes a preventive ethics approach to protocol development in order to improve the quality of return of results in pediatric genomic settings.
Collapse
Affiliation(s)
- Sarah Scollon
- Board-certified genetic counselor at Baylor College of Medicine. She received her M.S. in Genetic Counseling from University of Michigan, Ann Arbor, MI
| | - Katie Bergstrom
- Board certified genetic counselor at Baylor College of Medicine. She received her M.S. in Genetic Counseling from the University of Utah in Salt Lake City, UT
| | - Laurence B McCullough
- Professor of Medicine and Medical Ethics and the Associate Director for Education and holder of the Dalton Tomlin Chair in Medical Ethics and Health Policy in the Center for Medical Ethics and Health Policy, Baylor College of Medicine. He received his Ph.D. from University of Texas, Austin, TX
| | - Amy L McGuire
- Leon Jaworski Professor of Biomedical Ethics and Director of the Center for Medical Ethics and Health Policy and a member of the Human Genome Sequencing Center at Baylor College of Medicine. She received her J.D. from the University of Houston, Houston, TX and her Ph.D. from the Institute for Medical Humanities at University of Texas Medical Branch
| | - Stephanie Gutierrez
- Project manager at Baylor College of Medicine. She received her B.S. from Texas State University in San Marcos, TX
| | - Robin Kerstein
- Project coordinator for the Baylor College of Medicine Advancing Sequencing in Childhood Cancer Care (BASIC3) study at Baylor College of Medicine. She received her M.T. from Baylor University, Waco, TX. She holds ASCP and CCRA certifications
| | - D Williams Parsons
- Board-certified pediatric hematologist-oncologist who studies the clinical application of genomic technologies in pediatric cancer care. He is the Director of the Center for Personal Cancer Genomics and Therapeutics and the Co-Director of the Cancer Genetics & Genomics Program at Texas Children's Cancer and Hematology Centers, Baylor College of Medicine. He received his M.D. and Ph.D. from Ohio State University College of Medicine, Columbus, OH
| | - Sharon E Plon
- Board-certified medical geneticist who focuses on laboratory and clinical research related to cancer susceptibility. She is a Professor in the departments of Pediatrics and Molecular and Human Genetics at Baylor College of Medicine. She is the Director of the Cancer Genetics and Genomics Program at Texas Children's Cancer and Hematology Centers. She received her M.D. and Ph.D. from Harvard University, Boston, MA
| |
Collapse
|
22
|
Keijzers G, Maynard S, Shamanna RA, Rasmussen LJ, Croteau DL, Bohr VA. The role of RecQ helicases in non-homologous end-joining. Crit Rev Biochem Mol Biol 2014; 49:463-72. [PMID: 25048400 DOI: 10.3109/10409238.2014.942450] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
DNA double-strand breaks are highly toxic DNA lesions that cause genomic instability, if not efficiently repaired. RecQ helicases are a family of highly conserved proteins that maintain genomic stability through their important roles in several DNA repair pathways, including DNA double-strand break repair. Double-strand breaks can be repaired by homologous recombination (HR) using sister chromatids as templates to facilitate precise DNA repair, or by an HR-independent mechanism known as non-homologous end-joining (NHEJ) (error-prone). NHEJ is a non-templated DNA repair process, in which DNA termini are directly ligated. Canonical NHEJ requires DNA-PKcs and Ku70/80, while alternative NHEJ pathways are DNA-PKcs and Ku70/80 independent. This review discusses the role of RecQ helicases in NHEJ, alternative (or back-up) NHEJ (B-NHEJ) and microhomology-mediated end-joining (MMEJ) in V(D)J recombination, class switch recombination and telomere maintenance.
Collapse
Affiliation(s)
- Guido Keijzers
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen , Copenhagen , Denmark and
| | | | | | | | | | | |
Collapse
|
23
|
Smeets MF, DeLuca E, Wall M, Quach JM, Chalk AM, Deans AJ, Heierhorst J, Purton LE, Izon DJ, Walkley CR. The Rothmund-Thomson syndrome helicase RECQL4 is essential for hematopoiesis. J Clin Invest 2014; 124:3551-65. [PMID: 24960165 DOI: 10.1172/jci75334] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/01/2014] [Indexed: 12/31/2022] Open
Abstract
Mutations within the gene encoding the DNA helicase RECQL4 underlie the autosomal recessive cancer-predisposition disorder Rothmund-Thomson syndrome, though it is unclear how these mutations lead to disease. Here, we demonstrated that somatic deletion of Recql4 causes a rapid bone marrow failure in mice that involves cells from across the myeloid, lymphoid, and, most profoundly, erythroid lineages. Apoptosis was markedly elevated in multipotent progenitors lacking RECQL4 compared with WT cells. While the stem cell compartment was relatively spared in RECQL4-deficent mice, HSCs from these animals were not transplantable and even selected against. The requirement for RECQL4 was intrinsic in hematopoietic cells, and loss of RECQL4 in these cells was associated with increased replicative DNA damage and failed cell-cycle progression. Concurrent deletion of p53, which rescues loss of function in animals lacking the related helicase BLM, did not rescue BM phenotypes in RECQL4-deficient animals. In contrast, hematopoietic defects in cells from Recql4Δ/Δ mice were fully rescued by a RECQL4 variant without RecQ helicase activity, demonstrating that RECQL4 maintains hematopoiesis independently of helicase activity. Together, our data indicate that RECQL4 participates in DNA replication rather than genome stability and identify RECQL4 as a regulator of hematopoiesis with a nonredundant role compared with other RecQ helicases.
Collapse
|
24
|
Nucleases in homologous recombination as targets for cancer therapy. FEBS Lett 2014; 588:2446-56. [DOI: 10.1016/j.febslet.2014.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/02/2014] [Accepted: 06/02/2014] [Indexed: 11/21/2022]
|
25
|
Novel physiological RECQL4 alternative transcript disclosed by molecular characterisation of Rothmund-Thomson Syndrome sibs with mild phenotype. Eur J Hum Genet 2014; 22:1298-304. [PMID: 24518840 DOI: 10.1038/ejhg.2014.18] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 11/15/2013] [Accepted: 01/07/2014] [Indexed: 01/21/2023] Open
Abstract
Rothmund-Thomson syndrome is a rare genodermatosis caused by biallelic mutations of the RECQL4 gene and is characterised by poikiloderma, sparse hair, eyelashes and/or eyebrows, small stature, skeletal and dental abnormalities and cancer predisposition. Mutations predicted to result in the loss of RECQL4 protein have been associated with osteosarcoma risk, but mutation(s)-phenotype correlations are better addressed by combined DNA and RNA analyses. We describe two siblings with a mild phenotype, mainly restricted to the skin, who carry the unreported paternal c.2272C>T alteration in exon 14 and the previously reported maternal exon 15 c.2492_2493delAT, both predicted to result in premature termination codons (p.(Arg758*), p.(His831Argfs*52)). However real-time and transcript analysis showed, in the carrier father and affected daughter, increased levels of a novel RECQL4 physiological alternative transcript with partial in-frame skipping of exon 14, generated by increased usage of a weak cryptic splice site. This alternative transcript is expressed in all controls and tested tissues, its upregulation is specific to the paternal c.2272C>T mutation and depends on the abrogation of the binding motifs for SF2 and SRp55 serine/arginine-rich proteins with bypass of the mutation site located in the skipped exon 14 portion. Moreover, in the proband the increased levels of the alternative transcript, likely encoding a protein isoform with residual activity, may compensate for the dearth of the canonical transcript with the c.2492_2493delAT, accounting for the mild clinical phenotype of the siblings. Our results emphasise the value of RNA analysis to better predict the effects of RECQL4 mutations on the clinical phenotype.
Collapse
|
26
|
Anthonappa RP, King NM, Rabie ABM. Aetiology of supernumerary teeth: a literature review. Eur Arch Paediatr Dent 2013; 14:279-88. [PMID: 24068489 DOI: 10.1007/s40368-013-0082-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 02/14/2013] [Indexed: 02/01/2023]
Abstract
BACKGROUND Supernumerary teeth are teeth, or tooth-like structures that have either erupted or remain unerupted in addition to the 20 primary and 32 permanent teeth. AIMS This paper attempts to (a) provide an overview of the proposed hypotheses and the current understanding of the aetiology of supernumerary teeth, and (b) review the published cases of supernumerary teeth occurring in families. REVIEW No studies have been able to distinguish between different aetiologies for the different locations of supernumerary teeth, while, from a developmental or molecular perspective, the proposed hypotheses may be plausible and explains the origin of different types of supernumerary teeth. CONCLUSION The only clearly evident feature, based on the existing published reports, is that it is logical to state that supernumerary teeth have a genetic component in their aetiology.
Collapse
Affiliation(s)
- R P Anthonappa
- School of Dentistry, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, 17 Monash Avenue Nedlands, Perth, WA, 6009, Australia,
| | | | | |
Collapse
|
27
|
Gupta S, De S, Srivastava V, Hussain M, Kumari J, Muniyappa K, Sengupta S. RECQL4 and p53 potentiate the activity of polymerase γ and maintain the integrity of the human mitochondrial genome. Carcinogenesis 2013; 35:34-45. [PMID: 24067899 DOI: 10.1093/carcin/bgt315] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
UNLABELLED Germline mutations in RECQL4 and p53 lead to cancer predisposition syndromes, Rothmund-Thomson syndrome (RTS) and Li-Fraumeni syndrome (LFS), respectively. RECQL4 is essential for the transport of p53 to the mitochondria under unstressed conditions. Here, we show that both RECQL4 and p53 interact with mitochondrial polymerase (PolγA/B2) and regulate its binding to the mitochondrial DNA (mtDNA) control region (D-loop). Both RECQL4 and p53 bind to the exonuclease and polymerase domains of PolγA. Kinetic constants for interactions between PolγA-RECQL4, PolγA-p53 and PolγB-p53 indicate that RECQL4 and p53 are accessory factors for PolγA-PolγB and PolγA-DNA interactions. RECQL4 enhances the binding of PolγA to DNA, thereby potentiating the exonuclease and polymerization activities of PolγA/B2. To investigate whether lack of RECQL4 and p53 results in increased mitochondrial genome instability, resequencing of the entire mitochondrial genome was undertaken from multiple RTS and LFS patient fibroblasts. We found multiple somatic mutations and polymorphisms in both RTS and LFS patient cells. A significant number of mutations and polymorphisms were common between RTS and LFS patients. These changes are associated with either aging and/or cancer, thereby indicating that the phenotypes associated with these syndromes may be due to deregulation of mitochondrial genome stability caused by the lack of RECQL4 and p53. SUMMARY The biochemical mechanisms by which RECQL4 and p53 affect mtDNA replication have been elucidated. Resequencing of RTS and LFS patients' mitochondrial genome reveals common mutations indicating similar mechanisms of regulation by RECQL4 and p53.
Collapse
Affiliation(s)
- Shruti Gupta
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India and
| | | | | | | | | | | | | |
Collapse
|
28
|
Fradin M, Merklen-Djafri C, Perrigouard C, Aral B, Muller J, Stoetzel C, Frouin E, Flori E, Doray B, Dollfus H, Lipsker D. Long-term follow-up and molecular characterization of a patient with a RECQL4 mutation spectrum disorder. Dermatology 2013; 226:353-7. [PMID: 23899764 DOI: 10.1159/000351311] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/25/2013] [Indexed: 11/19/2022] Open
Abstract
The follow-up of a man from birth to adulthood, presenting with features both of RAPADILINO and Rothmund-Thomson syndrome (RTS), is described. Molecular studies confirmed the presence of two different mutations, c.2767_2768delTT and c.3061C>T, in the RECQL4 gene. This gene is known to be causative of a spectrum including Baller-Gerold syndrome, RAPADILINO syndrome and RTS. New and rare features such as oral leukoplakia and very prominent hyperkeratotic verrucous papules on both soles are shown. This patient has to date no cancer history despite bearing a truncating mutation at the age of 21 years, which is also unusual.
Collapse
Affiliation(s)
- M Fradin
- Service de Génétique Médicale, CHU de Rennes; Rennes, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Fang H, Nie L, Chi Z, Liu J, Guo D, Lu X, Hei TK, Balajee AS, Zhao Y. RecQL4 helicase amplification is involved in human breast tumorigenesis. PLoS One 2013; 8:e69600. [PMID: 23894508 PMCID: PMC3718744 DOI: 10.1371/journal.pone.0069600] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/10/2013] [Indexed: 12/20/2022] Open
Abstract
Breast cancer occur both in hereditary and sporadic forms, and the later one comprises an overwhelming majority of breast cancer cases among women. Numerical and structural alterations involving chromosome 8, with loss of short arm (8p) and gain of long arm (8q), are frequently observed in breast cancer cells and tissues. In this study, we show that most of the human breast tumor cell lines examined display an over representation of 8q24, a chromosomal locus RecQL4 is regionally mapped to, and consequently, a markedly elevated level of RecQL4 expression. An increased RecQL4 mRNA level was also observed in a majority of clinical breast tumor samples (38/43) examined. shRNA-mediated RecQL4 suppression in MDA-MB453 breast cancer cells not only significantly inhibit the in vitro clonogenic survival and in vivo tumorigenicity. Further studies demonstrate that RecQL4 physically interacts with a major survival factor-survivin and its protein level affects survivin expression. Although loss of RecQL4 function due to gene mutations causally linked to occurrence of human RTS with features of premature aging and cancer predisposition, our studies provide the evidence that overexpression of RecQL4 due to gene amplification play a critical role in human breast tumor progression.
Collapse
Affiliation(s)
- Hongbo Fang
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Linghu Nie
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Zhenfen Chi
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jing Liu
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dan Guo
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Xuemei Lu
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Tom K. Hei
- Department of Radiation Oncology, Center for Radiological Research, Columbia University Medical Center, New York, New York, United States of America
| | - Adayabalam S. Balajee
- Department of Radiation Oncology, Center for Radiological Research, Columbia University Medical Center, New York, New York, United States of America
- * E-mail: (ASB); (YZ)
| | - Yongliang Zhao
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- * E-mail: (ASB); (YZ)
| |
Collapse
|
30
|
Kassube SA, Jinek M, Fang J, Tsutakawa S, Nogales E. Structural mimicry in transcription regulation of human RNA polymerase II by the DNA helicase RECQL5. Nat Struct Mol Biol 2013; 20:892-9. [PMID: 23748380 PMCID: PMC3702667 DOI: 10.1038/nsmb.2596] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/25/2013] [Indexed: 11/22/2022]
Abstract
RECQL5 is a member of the highly conserved RecQ family of DNA helicases involved in DNA repair. RECQL5 interacts with RNA polymerase II (Pol II) and inhibits transcription of protein-encoding genes by an unknown mechanism. We show that RECQL5 contacts the Rpb1 jaw domain of Pol II at a site that overlaps with the binding site for the transcription elongation factor TFIIS. Our cryo-EM structure of elongating Pol II arrested in complex with RECQL5 shows that the RECQL5 helicase domain is positioned to sterically block elongation. The crystal structure of the RECQL5 KIX domain reveals similarities with TFIIS, and binding of RECQL5 to Pol II interferes with the ability of TFIIS to promote transcriptional read-through in vitro. Together, our findings reveal a dual mode of transcriptional repression by RECQL5 that includes structural mimicry of the Pol II-TFIIS interaction.
Collapse
Affiliation(s)
- Susanne A. Kassube
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Martin Jinek
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jie Fang
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Susan Tsutakawa
- Life Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
| | - Eva Nogales
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Life Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
| |
Collapse
|
31
|
Jensen MB, Dunn CA, Keijzers G, Kulikowicz T, Rasmussen LJ, Croteau DL, Bohr VA. The helicase and ATPase activities of RECQL4 are compromised by mutations reported in three human patients. Aging (Albany NY) 2013; 4:790-802. [PMID: 23238538 PMCID: PMC3560432 DOI: 10.18632/aging.100506] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
RECQL4 is one of five members of the human RecQ helicase family, and is implicated in three syndromes displaying accelerating aging, developmental abnormalities and a predisposition to cancer. In this study, we purified three variants of RECQL4 carrying previously reported patient mutations. These three mutant proteins were analyzed for the known biochemical activities of RECQL4: DNA binding, unwinding of duplex DNA, ATP hydrolysis and annealing of simplex DNA. Further, the mutant proteins were evaluated for stability and recruitment to sites of laser-induced DNA damage. One mutant was helicase-dead, had marginal ATPase activity and may be structurally compromised, while the other two showed greatly reduced helicase and ATPase activities. The remaining biochemical activities and ability to recruit to damage sites were not significantly impaired for any of the mutants. Our findings demonstrate a consistent pattern of functional deficiency and provide further support for a helicase-dependent cellular function of RECQL4 in addition to its Nterminus-dependent role in initiation of replication, a function that may underlie the phenotype of RECQL4-linked disease.
Collapse
Affiliation(s)
- Martin Borch Jensen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | | | | | | | | | | |
Collapse
|
32
|
Marino F, Vindigni A, Onesti S. Bioinformatic analysis of RecQ4 helicases reveals the presence of a RQC domain and a Zn knuckle. Biophys Chem 2013; 177-178:34-9. [PMID: 23624328 DOI: 10.1016/j.bpc.2013.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 01/10/2023]
Abstract
RecQ helicases play essential roles in the maintenance of genome stability and contain a highly conserved helicase region generally followed by a characteristic RecQ-C-terminal (RQC) domain, plus a number of variable associated domains. Notable exceptions are the RecQ4 helicases, where none of these additional regions have been described. Particularly striking was the fact that no RQC domain had been reported, considering that the RQC domain had been shown to play an essential role in the catalytic mechanism of most RecQ family members. Here we present the results of detailed bioinformatic analyses of RecQ4 proteins that identify, for the first time, the presence of a putative RQC domain, including some of the key residues involved in DNA binding and unwinding. We also describe the presence of a novel "Zn knuckle" domain, as well as an additional Sld2-homology region, providing new insights into the architecture, function and evolution of these enzymes.
Collapse
Affiliation(s)
- Francesca Marino
- Structural Biology Laboratory, Elettra-Sincrotrone Trieste SCpA, Area Science Park, Basovizza, Trieste, Italy.
| | | | | |
Collapse
|
33
|
Chin ELH, da Silva C, Hegde M. Assessment of clinical analytical sensitivity and specificity of next-generation sequencing for detection of simple and complex mutations. BMC Genet 2013; 14:6. [PMID: 23418865 PMCID: PMC3599218 DOI: 10.1186/1471-2156-14-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/08/2013] [Indexed: 09/03/2023] Open
Abstract
Background Detecting mutations in disease genes by full gene sequence analysis is common in clinical diagnostic laboratories. Sanger dideoxy terminator sequencing allows for rapid development and implementation of sequencing assays in the clinical laboratory, but it has limited throughput, and due to cost constraints, only allows analysis of one or at most a few genes in a patient. Next-generation sequencing (NGS), on the other hand, has evolved rapidly, although to date it has mainly been used for large-scale genome sequencing projects and is beginning to be used in the clinical diagnostic testing. One advantage of NGS is that many genes can be analyzed easily at the same time, allowing for mutation detection when there are many possible causative genes for a specific phenotype. In addition, regions of a gene typically not tested for mutations, like deep intronic and promoter mutations, can also be detected. Results Here we use 20 previously characterized Sanger-sequenced positive controls in disease-causing genes to demonstrate the utility of NGS in a clinical setting using standard PCR based amplification to assess the analytical sensitivity and specificity of the technology for detecting all previously characterized changes (mutations and benign SNPs). The positive controls chosen for validation range from simple substitution mutations to complex deletion and insertion mutations occurring in autosomal dominant and recessive disorders. The NGS data was 100% concordant with the Sanger sequencing data identifying all 119 previously identified changes in the 20 samples. Conclusions We have demonstrated that NGS technology is ready to be deployed in clinical laboratories. However, NGS and associated technologies are evolving, and clinical laboratories will need to invest significantly in staff and infrastructure to build the necessary foundation for success.
Collapse
Affiliation(s)
- Ephrem L H Chin
- Department of Human Genetics, Emory University, Michael Street, Atlanta, GA, USA
| | | | | |
Collapse
|
34
|
Parisse P, Vindigni A, Scoles G, Casalis L. In Vitro Enzyme Comparative Kinetics: Unwinding of Surface-Bound DNA Nanostructures by RecQ and RecQ1. JOURNAL OF PHYSICAL CHEMISTRY LETTERS 2012; 3:3532-7. [PMID: 26290984 DOI: 10.1021/jz3018682] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Pietro Parisse
- Sincrotrone Trieste S.C.p.A., s.s.14 km163,5 in Area Science Park, Trieste
34149, Italy
| | - Alessandro Vindigni
- Sincrotrone Trieste S.C.p.A., s.s.14 km163,5 in Area Science Park, Trieste
34149, Italy
- International Centre for Genetic Engineering and Biotechnology, Padriciano
99, Trieste 34149, Italy
- Department of Biochemistry and
Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Giacinto Scoles
- Sincrotrone Trieste S.C.p.A., s.s.14 km163,5 in Area Science Park, Trieste
34149, Italy
- Department of Biological and
Medical Science, University of Udine, Ospedale
della Misericordia, Udine 33100, Italy
| | - Loredana Casalis
- Sincrotrone Trieste S.C.p.A., s.s.14 km163,5 in Area Science Park, Trieste
34149, Italy
| |
Collapse
|
35
|
Ng AJ, Mutsaers AJ, Baker EK, Walkley CR. Genetically engineered mouse models and human osteosarcoma. Clin Sarcoma Res 2012; 2:19. [PMID: 23036272 PMCID: PMC3523007 DOI: 10.1186/2045-3329-2-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/30/2011] [Indexed: 12/19/2022] Open
Abstract
Osteosarcoma is the most common form of bone cancer. Pivotal insight into the genes involved in human osteosarcoma has been provided by the study of rare familial cancer predisposition syndromes. Three kindreds stand out as predisposing to the development of osteosarcoma: Li-Fraumeni syndrome, familial retinoblastoma and RecQ helicase disorders, which include Rothmund-Thomson Syndrome in particular. These disorders have highlighted the important roles of P53 and RB respectively, in the development of osteosarcoma. The association of OS with RECQL4 mutations is apparent but the relevance of this to OS is uncertain as mutations in RECQL4 are not found in sporadic OS. Application of the knowledge or mutations of P53 and RB in familial and sporadic OS has enabled the development of tractable, highly penetrant murine models of OS. These models share many of the cardinal features associated with human osteosarcoma including, importantly, a high incidence of spontaneous metastasis. The recent development of these models has been a significant advance for efforts to improve our understanding of the genetics of human OS and, more critically, to provide a high-throughput genetically modifiable platform for preclinical evaluation of new therapeutics.
Collapse
Affiliation(s)
- Alvin Jm Ng
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine, University of Melbourne, St. Vincent's Hospital, Fitzroy, VIC, 3065, Australia
| | - Anthony J Mutsaers
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine, University of Melbourne, St. Vincent's Hospital, Fitzroy, VIC, 3065, Australia.,Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, ON, N1G 2W1, Canada
| | - Emma K Baker
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine, University of Melbourne, St. Vincent's Hospital, Fitzroy, VIC, 3065, Australia
| | - Carl R Walkley
- St Vincent's Institute of Medical Research, 9 Princes Street, Fitzroy, VIC, 3065, Australia.,Department of Medicine, University of Melbourne, St. Vincent's Hospital, Fitzroy, VIC, 3065, Australia
| |
Collapse
|
36
|
RECQL4 in genomic instability and aging. Trends Genet 2012; 28:624-31. [PMID: 22940096 DOI: 10.1016/j.tig.2012.08.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 07/21/2012] [Accepted: 08/09/2012] [Indexed: 11/21/2022]
Abstract
Helicases are ubiquitous proteins that unwind DNA and participate in DNA metabolism including replication, repair, transcription, and chromatin organization. The highly conserved RecQ helicase family proteins are important in these transactions and have been termed the guardians of the genome. Humans have five members of this family: WRN, BLM, RECQL4, RECQL1, and RECQL5. The first three of are associated with premature aging and cancer prone syndromes, but the latter two proteins have not yet been implicated in any human disease. Although WRN and BLM have been fairly well characterized, RECQL4 has only recently been intensively investigated. The sum of this work to date has shown that RECQL4 has helicase activity and localizes to telomeres and mitochondria. In addition, new protein partners are emerging, implicating RECQL4 in novel processes. Here, we describe these recent findings which place RECQL4 at the crossroads of genomic instability and aging processes.
Collapse
|
37
|
Croteau DL, Rossi ML, Ross J, Dawut L, Dunn C, Kulikowicz T, Bohr VA. RAPADILINO RECQL4 mutant protein lacks helicase and ATPase activity. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1727-34. [PMID: 22885111 DOI: 10.1016/j.bbadis.2012.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 07/17/2012] [Accepted: 07/26/2012] [Indexed: 12/18/2022]
Abstract
The RecQ family of helicases has been shown to play an important role in maintaining genomic stability. In humans, this family has five members and mutations in three of these helicases, BLM, WRN and RECQL4, are associated with disease. Alterations in RECQL4 are associated with three diseases, Rothmund-Thomson syndrome, Baller-Gerold syndrome, and RAPADILINO syndrome. One of the more common mutations found in RECQL4 is the RAPADILINO mutation, c.1390+2delT which is a splice-site mutation leading to an in-frame skipping of exon 7 resulting in 44 amino acids being deleted from the protein (p.Ala420-Ala463del). In order to characterize the RAPADILINO RECQL4 mutant protein, it was expressed in bacteria and purified using an established protocol. Strand annealing, helicase, and ATPase assays were conducted to characterize the protein's activities relative to WT RECQL4. Here we show that strand annealing activity in the absence of ATP is unchanged from that of WT RECQL4. However, the RAPADILINO protein variant lacks helicase and ssDNA-stimulated ATPase activity. These observations help explain the underlying molecular etiology of the disease and our findings provide insight into the genotype and phenotype association among RECQL4 syndromes.
Collapse
Affiliation(s)
- Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, Baltimore, MD 21224, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Chi Z, Nie L, Peng Z, Yang Q, Yang K, Tao J, Mi Y, Fang X, Balajee AS, Zhao Y. RecQL4 cytoplasmic localization: implications in mitochondrial DNA oxidative damage repair. Int J Biochem Cell Biol 2012; 44:1942-51. [PMID: 22824301 DOI: 10.1016/j.biocel.2012.07.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 07/02/2012] [Accepted: 07/15/2012] [Indexed: 10/28/2022]
Abstract
RecQL4, one of the five human RecQ helicases, is crucial for genomic stability and RecQL4 when mutated leads to premature aging phenotypes in humans. Unlike other human RecQ helicases, RecQL4 is found both in the nucleus and the cytoplasm. While the nuclear localization signal (NLS) and the retention domain at the N-terminus are responsible for the nuclear localization of RecQL4, the signal for its cytoplasmic localization is essentially unknown. In this study, two functional nuclear exporting signals (NESs; pNES2 and pNES3) were identified at the C-terminus of RecQL4. Deletion of pNES2 drastically diminished the cytoplasmic localization of RecQL4. Strikingly, addition of ubiquitination tail at the C-terminus of RecQL4 substantially enriched the cytoplasmic fraction of RecQL4 only in the presence of functional pNES2. Immunofluorescence studies revealed that the cytoplasmic RecQL4 was localized in mitochondria. Consistent with its mitochondrial localization, a regulatory role for RecQL4 in the maintenance of mitochondrial DNA (mtDNA) copy number was demonstrated. Elevation of ectopic expression of RecQL4 increased the mtDNA copy number in HEK293 cells while RecQL4 knock down markedly decreased the mtDNA copy number in U2OS cells. Additionally, a substantially increased level of mitochondrial superoxide production, and a markedly decreased repair capacity for oxidative DNA damage were observed in the mitochondria of both RecQL4 deficient human fibroblasts and RecQL4-suppressed cancer cells. These data strongly suggest a regulatory role for RecQL4 in mitochondrial stability and function. Collectively, our study demonstrates that NES-mediated RecQL4 export to the cytoplasm is essential for the maintenance of mitochondrial genome stability.
Collapse
Affiliation(s)
- Zhenfen Chi
- Laboratory of Disease Genomics and Individualized Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
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.
Collapse
Affiliation(s)
- Oliver Ohlenschläger
- Research Group Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstr. 11, Jena, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Chisholm C, Miedler J, Etufugh CN, Ghali F, Cockerell CJ. Unusual and recently described cutaneous atrophic disorders. Int J Dermatol 2012; 50:1506-17. [PMID: 22097997 DOI: 10.1111/j.1365-4632.2011.04938.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cutaneous atrophic conditions are typically caused by changes in the dermis or subcutaneous tissue, sometimes consisting of the loss of a single fiber type. Since a significant decrease of subepidermal tissue is necessary for these lesions to be macroscopically atrophic, many conditions may not be appreciated as atrophy in the clinical setting. Clinicians should be familiar with the common or classic disorders causing cutaneous atrophy; however, there are a few new or rarely described atrophic conditions which are more difficult to identify and may not be atrophic clinically. This paper serves to describe the salient clinical and histological features of these new or rare disorders.
Collapse
|
41
|
Wibom C, Sjöström S, Henriksson R, Brännström T, Broholm H, Rydén P, Johansen C, Collatz-Laier H, Hepworth S, McKinney PA, Bethke L, Houlston RS, Andersson U, Melin BS. DNA-repair gene variants are associated with glioblastoma survival. Acta Oncol 2012; 51:325-32. [PMID: 22017238 DOI: 10.3109/0284186x.2011.616284] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Patient outcome from glioma may be influenced by germline variation. Considering the importance of DNA repair in cancer biology as well as in response to treatment, we studied the relationship between 1458 SNPs, which captured the majority of the common genetic variation in 136 DNA repair genes, in 138 glioblastoma samples from Sweden and Denmark. We confirmed our findings in an independent cohort of 121 glioblastoma patients from the UK. Our analysis revealed nine SNPs annotating MSH2, RAD51L1 and RECQL4 that were significantly (p < 0.05) associated with glioblastoma survival.
Collapse
Affiliation(s)
- Carl Wibom
- Department of Radiation Sciences, Oncology, Umeå University Hospital, Umeå, Sweden.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
De S, Kumari J, Mudgal R, Modi P, Gupta S, Futami K, Goto H, Lindor NM, Furuichi Y, Mohanty D, Sengupta S. RECQL4 is essential for the transport of p53 to mitochondria in normal human cells in the absence of exogenous stress. J Cell Sci 2012; 125:2509-22. [PMID: 22357944 DOI: 10.1242/jcs.101501] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mutations in RECQL4 helicase are associated with Rothmund-Thomson syndrome (RTS). A subset of RTS patients is predisposed to cancer and is sensitive to DNA damaging agents. The enhanced sensitivity of cells from RTS patients correlates with the accumulation of transcriptionally active nuclear p53. We found that in untreated normal human cells these two nuclear proteins, p53 and RECQL4, instead colocalize in the mitochondrial nucleoids. RECQL4 accumulates in mitochondria in all phases of the cell cycle except S phase and physically interacts with p53 only in the absence of DNA damage. p53-RECQL4 binding leads to the masking of the nuclear localization signal of p53. The N-terminal 84 amino acids of RECQL4 contain a mitochondrial localization signal, which causes the localization of RECQL4-p53 complex to the mitochondria. RECQL4-p53 interaction is disrupted after stress, allowing p53 translocation to the nucleus. In untreated normal cells RECQL4 optimizes de novo replication of mtDNA, which is consequently decreased in fibroblasts from RTS patients. Wild-type RECQL4-complemented RTS cells show relocalization of both RECQL4 and p53 to the mitochondria, loss of p53 activation, restoration of de novo mtDNA replication and resistance to different types of DNA damage. In cells expressing Δ84 RECQL4, which cannot translocate to mitochondria, all the above functions are compromised. The recruitment of p53 to the sites of de novo mtDNA replication is also regulated by RECQL4. Thus these findings elucidate the mechanism by which p53 is regulated by RECQL4 in unstressed normal cells and also delineates the mitochondrial functions of the helicase.
Collapse
Affiliation(s)
- Siddharth De
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Pandey N, Govardhan S, Pathak RK. Mobility in the structure of E.coli recQ helicase upon substrate binding as seen from molecular dynamics simulations. Bioinformation 2011; 7:371-4. [PMID: 22347776 PMCID: PMC3280434 DOI: 10.6026/97320630007371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 12/05/2011] [Indexed: 11/23/2022] Open
Abstract
RecQ helicases feature multiple domains in their structure, of which the helicase domain, the RecQ-Ct domain and the HRDC domains are well conserved among the SF2 helicases. The helicase domain and the RecQ-Ct domain constitute the catalytic core of the enzyme. The domain interfaces are the DNA binding sites which display significant conformational changes in our molecular dynamics simulation studies. The preferred conformational states of the DNA bound and unbound forms of RecQ appear to be quite different from each other. DNA binding induces inter-domain flexibility leading to hinge mobility between the domains. The divergence in the dynamics of the two structures is caused by changes in the interactions at the domain interface, which seems to propagate along the whole protein structure. This could be essential in ssDNA binding after strand separation, as well as aiding translocation of the RecQ protein like an inch-worm.
Collapse
Affiliation(s)
- Nishtha Pandey
- School of Biotechnology, Lovely Professional University, Phagwara, Punjab - 144402, India
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad – 500032, India
| | - Savitha Govardhan
- Biosciences group, Birla Institute of Technology and Science – Pilani, Hyderabad Campus, Shamirpet, Andhra Pradesh – 500078, India
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad – 500032, India
| | - Ravi Kant Pathak
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad – 500032, India
| |
Collapse
|
44
|
Machwe A, Karale R, Xu X, Liu Y, Orren DK. The Werner and Bloom syndrome proteins help resolve replication blockage by converting (regressed) holliday junctions to functional replication forks. Biochemistry 2011; 50:6774-88. [PMID: 21736299 DOI: 10.1021/bi2001054] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cells cope with blockage of replication fork progression in a manner that allows DNA synthesis to be completed and genomic instability minimized. Models for resolution of blocked replication involve fork regression to form Holliday junction structures. The human RecQ helicases WRN and BLM (deficient in Werner and Bloom syndromes, respectively) are critical for maintaining genomic stability and thought to function in accurate resolution of replication blockage. Consistent with this notion, WRN and BLM localize to sites of blocked replication after certain DNA-damaging treatments and exhibit enhanced activity on replication and recombination intermediates. Here we examine the actions of WRN and BLM on a special Holliday junction substrate reflective of a regressed replication fork. Our results demonstrate that, in reactions requiring ATP hydrolysis, both WRN and BLM convert this Holliday junction substrate primarily to a four-stranded replication fork structure, suggesting they target the Holliday junction to initiate branch migration. In agreement, the Holliday junction binding protein RuvA inhibits the WRN- and BLM-mediated conversion reactions. Importantly, this conversion product is suitable for replication with its leading daughter strand readily extended by DNA polymerases. Furthermore, binding to and conversion of this Holliday junction are optimal at low MgCl(2) concentrations, suggesting that WRN and BLM preferentially act on the square planar (open) conformation of Holliday junctions. Our findings suggest that, subsequent to fork regression events, WRN and/or BLM could re-establish functional replication forks to help overcome fork blockage. Such a function is highly consistent with phenotypes associated with WRN- and BLM-deficient cells.
Collapse
Affiliation(s)
- Amrita Machwe
- Graduate Center for Toxicology and Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40536, United States
| | | | | | | | | |
Collapse
|
45
|
Mendoza-Maldonado R, Faoro V, Bajpai S, Berti M, Odreman F, Vindigni M, Ius T, Ghasemian A, Bonin S, Skrap M, Stanta G, Vindigni A. The human RECQ1 helicase is highly expressed in glioblastoma and plays an important role in tumor cell proliferation. Mol Cancer 2011; 10:83. [PMID: 21752281 PMCID: PMC3148559 DOI: 10.1186/1476-4598-10-83] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 07/13/2011] [Indexed: 11/21/2022] Open
Abstract
Background RecQ helicases play an essential role in the maintenance of genome stability. In humans, loss of RecQ helicase function is linked with predisposition to cancer and/or premature ageing. Current data show that the specific depletion of the human RECQ1 helicase leads to mitotic catastrophe in cancer cells and inhibition of tumor growth in mice. Results Here, we show that RECQ1 is highly expressed in various types of solid tumors. However, only in the case of brain gliomas, the high expression of RECQ1 in glioblastoma tissues is paralleled by a lower expression in the control samples due to the poor expression of RECQ1 in non-dividing tissues. This conclusion is validated by immunohistochemical analysis of a tissue microarray containing 63 primary glioblastomas and 19 perilesional tissue samples, as control. We also show that acute depletion of RECQ1 by RNAi results in a significant reduction of cellular proliferation, perturbation of S-phase progression, and spontaneous γ-H2AX foci formation in T98G and U-87 glioblastoma cells. Moreover, RECQ1 depleted T98G and U-87 cells are hypersensitive to HU or temozolomide treatment. Conclusions Collectively, these results indicate that RECQ1 has a unique and important role in the maintenance of genome integrity. Our results also suggest that RECQ1 might represent a new suitable target for anti cancer therapies aimed to arrest cell proliferation in brain gliomas.
Collapse
Affiliation(s)
- Ramiro Mendoza-Maldonado
- International Centre for Genetic Engineering and Biotechnology Padriciano 99, 34149 Trieste, Italy.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
The N-terminal region of RECQL4 lacking the helicase domain is both essential and sufficient for the viability of vertebrate cells. Role of the N-terminal region of RECQL4 in cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:473-9. [PMID: 21256165 DOI: 10.1016/j.bbamcr.2011.01.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 12/02/2010] [Accepted: 01/03/2011] [Indexed: 01/29/2023]
Abstract
Rothmund-Thomson syndrome (RTS) is a rare genetic disorder characterized by premature aging, developmental abnormalities, and a predisposition to cancer. RTS is caused by mutations in the RECQL4 gene, which encodes one of the five human RecQ helicases. To identify the cellular functions of RECQL4, we generated a chicken DT40 cell line in which RECQL4 expression could be turned off by doxycycline (Dox). Upon exposure to Dox, cells stopped growing and underwent apoptosis. The cells could be rescued by expression of the N-terminal region of RECQL4 (amino acids 1-496), which lacks the helicase domain and has sequence similarity to yeast Sld2, which plays an essential function in the initiation of DNA replication in Saccharomyces cerevisiae. Smaller fragments of the N-terminal region of RECQL4 did not rescue the cells from lethality. RECQL4 gene knockout cells complemented with RECQL4 (1-496) showed relatively high sensitivity to DNA damaging agents that induce double strand breaks and cross-links, suggesting that the C-terminal region including the helicase domain of RECQL4 is involved in the repair of certain types of DNA lesions.
Collapse
|
47
|
Lucic B, Zhang Y, King O, Mendoza-Maldonado R, Berti M, Niesen FH, Burgess-Brown NA, Pike ACW, Cooper CDO, Gileadi O, Vindigni A. A prominent β-hairpin structure in the winged-helix domain of RECQ1 is required for DNA unwinding and oligomer formation. Nucleic Acids Res 2010; 39:1703-17. [PMID: 21059676 PMCID: PMC3061051 DOI: 10.1093/nar/gkq1031] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
RecQ helicases have attracted considerable interest in recent years due to their role in the suppression of genome instability and human diseases. These atypical helicases exert their function by resolving a number of highly specific DNA structures. The crystal structure of a truncated catalytic core of the human RECQ1 helicase (RECQ149–616) shows a prominent β-hairpin, with an aromatic residue (Y564) at the tip, located in the C-terminal winged-helix domain. Here, we show that the β-hairpin is required for the DNA unwinding and Holliday junction (HJ) resolution activity of full-length RECQ1, confirming that it represents an important determinant for the distinct substrate specificity of the five human RecQ helicases. In addition, we found that the β-hairpin is required for dimer formation in RECQ149–616 and tetramer formation in full-length RECQ1. We confirmed the presence of stable RECQ149–616 dimers in solution and demonstrated that dimer formation favours DNA unwinding; even though RECQ1 monomers are still active. Tetramers are instead necessary for more specialized activities such as HJ resolution and strand annealing. Interestingly, two independent protein–protein contacts are required for tetramer formation, one involves the β-hairpin and the other the N-terminus of RECQ1, suggesting a non-hierarchical mechanism of tetramer assembly.
Collapse
Affiliation(s)
- Bojana Lucic
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
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.
Collapse
Affiliation(s)
- T Simon
- Department of Pediatric Oncology and Hematology, Children's Hospital, University of Cologne, Cologne, Germany.
| | | | | | | | | | | |
Collapse
|
49
|
Vindigni A, Marino F, Gileadi O. Probing the structural basis of RecQ helicase function. Biophys Chem 2010; 149:67-77. [PMID: 20392558 DOI: 10.1016/j.bpc.2010.03.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 01/10/2023]
Abstract
RecQ helicases are a ubiquitous family of DNA unwinding enzymes required to preserve genome integrity, thus preventing premature aging and cancer formation. The five human representatives of this family play non-redundant roles in the suppression of genome instability using a combination of enzymatic activities that specifically characterize each member of the family. These enzymes are in fact not only able to catalyze the transient opening of DNA duplexes, as any other conventional helicase, but can also promote annealing of complementary strands, branch migration of Holliday junctions and, in some cases, excision of ssDNA tails. Remarkably, the balance between these different activities seems to be regulated by protein oligomerization. This review illustrates the recent progress made in the definition of the structural determinants that control the different enzymatic activities of RecQ helicases and speculates on the possible mechanisms that RecQ proteins might use to promote their multiple functions.
Collapse
Affiliation(s)
- Alessandro Vindigni
- International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy.
| | | | | |
Collapse
|
50
|
Thangavel S, Mendoza-Maldonado R, Tissino E, Sidorova JM, Yin J, Wang W, Monnat RJ, Falaschi A, Vindigni A. Human RECQ1 and RECQ4 helicases play distinct roles in DNA replication initiation. Mol Cell Biol 2010; 30:1382-96. [PMID: 20065033 PMCID: PMC2832491 DOI: 10.1128/mcb.01290-09] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 10/26/2009] [Accepted: 12/29/2009] [Indexed: 11/20/2022] Open
Abstract
Cellular and biochemical studies support a role for all five human RecQ helicases in DNA replication; however, their specific functions during this process are unclear. Here we investigate the in vivo association of the five human RecQ helicases with three well-characterized human replication origins. We show that only RECQ1 (also called RECQL or RECQL1) and RECQ4 (also called RECQL4) associate with replication origins in a cell cycle-regulated fashion in unperturbed cells. RECQ4 is recruited to origins at late G(1), after ORC and MCM complex assembly, while RECQ1 and additional RECQ4 are loaded at origins at the onset of S phase, when licensed origins begin firing. Both proteins are lost from origins after DNA replication initiation, indicating either disassembly or tracking with the newly formed replisome. Nascent-origin DNA synthesis and the frequency of origin firing are reduced after RECQ1 depletion and, to a greater extent, after RECQ4 depletion. Depletion of RECQ1, though not that of RECQ4, also suppresses replication fork rates in otherwise unperturbed cells. These results indicate that RECQ1 and RECQ4 are integral components of the human replication complex and play distinct roles in DNA replication initiation and replication fork progression in vivo.
Collapse
Affiliation(s)
- Saravanabhavan Thangavel
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Ramiro Mendoza-Maldonado
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Erika Tissino
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Julia M. Sidorova
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Jinhu Yin
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Weidong Wang
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Raymond J. Monnat
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Arturo Falaschi
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| | - Alessandro Vindigni
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy, Laboratorio di Biologia Molecolare, Scuola Normale Superiore, Via Moruzzi 1, Pisa I-56124, Italy, Departments of Pathology, Genome Sciences, University of Washington, Seattle, Washington 98195-7705, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, Maryland 21224, Istituto di Fisiologia Clinica, CNR, Via Moruzzi 1, I-56124 Pisa, Italy
| |
Collapse
|