1
|
Uechi Y, Fujikane R, Morita S, Tamaoki S, Hidaka M. Bloom syndrome DNA helicase mitigates mismatch repair-dependent apoptosis. Biochem Biophys Res Commun 2024; 723:150214. [PMID: 38850810 DOI: 10.1016/j.bbrc.2024.150214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 05/26/2024] [Accepted: 05/31/2024] [Indexed: 06/10/2024]
Abstract
Generation of O6-methylguanine (O6-meG) by DNA-alkylating agents such as N-methyl N-nitrosourea (MNU) activates the multiprotein mismatch repair (MMR) complex and the checkpoint response involving ATR/CHK1 and ATM/CHK2 kinases, which may in turn trigger cell cycle arrest and apoptosis. The Bloom syndrome DNA helicase BLM interacts with the MMR complex, suggesting functional relevance to repair and checkpoint responses. We observed a strong interaction of BLM with MMR proteins in HeLa cells upon treatment with MNU as evidenced by co-immunoprecipitation as well as colocalization in the nucleus as revealed by dual immunofluorescence staining. Knockout of BLM sensitized HeLa MR cells to MNU-induced cell cycle disruption and enhanced expression of the apoptosis markers cleaved caspase-9 and PARP1. MNU-treated BLM-deficient cells also exhibited a greater number of 53BP1 foci and greater phosphorylation levels of H2AX at S139 and RPA32 at S8, indicating the accumulation of DNA double-strand breaks. These findings suggest that BLM prevents double-strand DNA breaks during the MMR-dependent DNA damage response and mitigates O6-meG-induced apoptosis.
Collapse
Affiliation(s)
- Yuka Uechi
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan; Department of Oral Growth and Development, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan
| | - Ryosuke Fujikane
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan; Oral Medicine Research Center, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan.
| | - Sho Morita
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan
| | - Sachio Tamaoki
- Department of Oral Growth and Development, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan
| | - Masumi Hidaka
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan; Oral Medicine Research Center, Fukuoka Dental College, 2-15-1, Tamura, Sawaraku, Fukuoka, 814-0193, Japan
| |
Collapse
|
2
|
Dar A, Godara P, Prusty D, Bashir M. Plasmodium falciparum topoisomerases: Emerging targets for anti-malarial therapy. Eur J Med Chem 2024; 265:116056. [PMID: 38171145 DOI: 10.1016/j.ejmech.2023.116056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 12/12/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024]
Abstract
Different metabolic pathways like DNA replication, transcription, and recombination generate topological constrains in the genome. These topological constraints are resolved by essential molecular machines known as topoisomerases. To bring changes in DNA topology, the topoisomerases create a single or double-stranded nick in the template DNA, hold the nicked ends to let the tangled DNA pass through, and finally re-ligate the breaks. The DNA nicking and re-ligation activities as well as ATPase activities (when present) in topoisomerases are subjected to inhibition by several anticancer and antibacterial drugs, thus establishing these enzymes as successful targets in anticancer and antibacterial therapies. The anti-topoisomerase drugs interfere with the functioning of these enzymes and result in the accumulation of DNA tangles or lethal genomic breaks, thereby promoting host cell (or organism) death. The potential of topoisomerases in the human malarial parasite, Plasmodium falciparum in antimalarial drug development has received little attention so far. Interestingly, the parasite genome encodes orthologs of topoisomerases found in eukaryotes, prokaryotes, and archaea, thus, providing an enormous opportunity for investigating these enzymes for antimalarial therapeutics. This review focuses on the features of Plasmodium falciparum topoisomerases (PfTopos) with respect to their closer counterparts in other organisms. We will discuss overall advances and basic challenges with topoisomerase research in Plasmodium falciparum and our attempts to understand the interaction of PfTopos with classical and new-generation topoisomerase inhibitors using in silico molecular docking approach. The recent episodes of parasite resistance against artemisinin, the only effective antimalarial drug at present, further highlight the significance of investigating new drug targets including topoisomerases in antimalarial therapeutics.
Collapse
Affiliation(s)
- Ashraf Dar
- Department of Biochemistry, University of Kashmir, Srinagar, 190006, India.
| | - Priya Godara
- Central University of Rajasthan, Ajmer, Rajasthan, India
| | | | - Masarat Bashir
- COTS, Sheri-Kashmir University of Agricultural Sciences and Technology, Mirgund, Srinagar, India
| |
Collapse
|
3
|
Lee J, Zhang J, Flanagan M, Martinez JA, Cunniff C, Kucine N, Lu AT, Haghani A, Gordevičius J, Horvath S, Chang VY. Bloom syndrome patients and mice display accelerated epigenetic aging. Aging Cell 2023; 22:e13964. [PMID: 37594403 PMCID: PMC10577546 DOI: 10.1111/acel.13964] [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: 03/20/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/19/2023] Open
Abstract
Bloom syndrome (BSyn) is an autosomal recessive disorder caused by variants in the BLM gene, which is involved in genome stability. Patients with BSyn present with poor growth, sun sensitivity, mild immunodeficiency, diabetes, and increased risk of cancer, most commonly leukemias. Interestingly, patients with BSyn do not have other signs of premature aging such as early, progressive hair loss and cataracts. We set out to determine epigenetic age in BSyn, which can be a better predictor of health and disease over chronological age. Our results show for the first time that patients with BSyn have evidence of accelerated epigenetic aging across several measures in blood lymphocytes, as compared to carriers. Additionally, homozygous Blm mice exhibit accelerated methylation age in multiple tissues, including brain, blood, kidney, heart, and skin, according to the brain methylation clock. Overall, we find that Bloom syndrome is associated with accelerated epigenetic aging effects in multiple tissues and more generally a strong effect on CpG methylation levels.
Collapse
Affiliation(s)
- Jamie Lee
- Division of Pediatric Hematology and OncologyUCLALos AngelesCaliforniaUSA
| | - Joshua Zhang
- Department of Human GeneticsUCLALos AngelesCaliforniaUSA
| | - Maeve Flanagan
- Department of PediatricsWeill Cornell Medical CollegeNew YorkNew YorkUSA
| | - Julian A. Martinez
- Department of Human GeneticsUCLALos AngelesCaliforniaUSA
- Division of Medical GeneticsUCLALos AngelesCaliforniaUSA
- Department of PsychiatryUCLALos AngelesCaliforniaUSA
| | | | - Nicole Kucine
- Department of PediatricsWeill Cornell Medical CollegeNew YorkNew YorkUSA
| | - Ake T. Lu
- Department of Human GeneticsUCLALos AngelesCaliforniaUSA
- Altos LabsSan DiegoCaliforniaUSA
| | - Amin Haghani
- Department of Human GeneticsUCLALos AngelesCaliforniaUSA
- Altos LabsSan DiegoCaliforniaUSA
| | | | - Steve Horvath
- Department of Human GeneticsUCLALos AngelesCaliforniaUSA
- Altos LabsSan DiegoCaliforniaUSA
| | - Vivian Y. Chang
- Division of Pediatric Hematology and OncologyUCLALos AngelesCaliforniaUSA
- Children's Discovery and Innovation InstituteUCLALos AngelesCaliforniaUSA
- Jonsson Comprehensive Cancer CenterUCLALos AngelesCaliforniaUSA
| |
Collapse
|
4
|
Soniat MM, Nguyen G, Kuo HC, Finkelstein IJ. The MRN complex and topoisomerase IIIa-RMI1/2 synchronize DNA resection motor proteins. J Biol Chem 2023; 299:102802. [PMID: 36529288 PMCID: PMC9971906 DOI: 10.1016/j.jbc.2022.102802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 12/08/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
DNA resection-the nucleolytic processing of broken DNA ends-is the first step of homologous recombination. Resection is catalyzed by the resectosome, a multienzyme complex that includes bloom syndrome helicase (BLM), DNA2 or exonuclease 1 nucleases, and additional DNA-binding proteins. Although the molecular players have been known for over a decade, how the individual proteins work together to regulate DNA resection remains unknown. Using single-molecule imaging, we characterized the roles of the MRE11-RAD50-NBS1 complex (MRN) and topoisomerase IIIa (TOP3A)-RMI1/2 during long-range DNA resection. BLM partners with TOP3A-RMI1/2 to form the BTRR (BLM-TOP3A-RMI1/2) complex (or BLM dissolvasome). We determined that TOP3A-RMI1/2 aids BLM in initiating DNA unwinding, and along with MRN, stimulates DNA2-mediated resection. Furthermore, we found that MRN promotes the association between BTRR and DNA and synchronizes BLM and DNA2 translocation to prevent BLM from pausing during resection. Together, this work provides direct observation of how MRN and DNA2 harness the BTRR complex to resect DNA efficiently and how TOP3A-RMI1/2 regulates the helicase activity of BLM to promote efficient DNA repair.
Collapse
Affiliation(s)
- Michael M Soniat
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA.
| | - Giaochau Nguyen
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Hung-Che Kuo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA.
| |
Collapse
|
5
|
Kangethe RT, Winger EM, Settypalli TBK, Datta S, Wijewardana V, Lamien CE, Unger H, Coetzer TH, Cattoli G, Diallo A. Low Dose Gamma Irradiation of Trypanosoma evansi Parasites Identifies Molecular Changes That Occur to Repair Radiation Damage and Gene Transcripts That May Be Involved in Establishing Disease in Mice Post-Irradiation. Front Immunol 2022; 13:852091. [PMID: 35634275 PMCID: PMC9136415 DOI: 10.3389/fimmu.2022.852091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/11/2022] [Indexed: 11/29/2022] Open
Abstract
The protozoan parasite Trypanosoma evansi is responsible for causing surra in a variety of mammalian hosts and is spread by many vectors over a wide geographical area making it an ideal target for irradiation as a tool to study the initial events that occur during infection. Parasites irradiated at the representative doses 100Gy, 140Gy, and 200Gy were used to inoculate BALB/c mice revealing that parasites irradiated at 200Gy were unable to establish disease in all mice. Cytokine analysis of mice inoculated with 200Gy of irradiated parasites showed significantly lower levels of interleukins when compared to mice inoculated with non-irradiated and 100Gy irradiated parasites. Irradiation also differentially affected the abundance of gene transcripts in a dose-dependent trend measured at 6- and 20-hours post-irradiation with 234, 325, and 484 gene transcripts affected 6 hours post-irradiation for 100Gy-, 140Gy- and 200Gy-irradiated parasites, respectively. At 20 hours post-irradiation, 422, 381, and 457 gene transcripts were affected by irradiation at 100Gy, 140Gy, and 200Gy, respectively. A gene ontology (GO) term analysis was carried out for the three representative doses at 6 hours and 20 hours post-irradiation revealing different processes occurring at 20 hours when compared to 6 hours for 100Gy irradiation. The top ten most significant processes had a negative Z score. These processes fall in significance at 140Gy and even further at 200Gy, revealing that they were least likely to occur at 200Gy, and thus may have been responsible for infection in mice by 100Gy and 140Gy irradiated parasites. When looking at 100Gy irradiated parasites 20 hours post-irradiation processes with a positive Z score, we identified genes that were involved in multiple processes and compared their fold change values at 6 hours and 20 hours. We present these genes as possibly necessary for repair from irradiation damage at 6 hours and suggestive of being involved in the establishment of disease in mice at 20 hours post-irradiation. A potential strategy using this information to develop a whole parasite vaccine is also postulated.
Collapse
Affiliation(s)
- Richard T. Kangethe
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
- *Correspondence: Richard T. Kangethe,
| | - Eva M. Winger
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Tirumala Bharani K. Settypalli
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Sneha Datta
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Viskam Wijewardana
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Charles E. Lamien
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Hermann Unger
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Theresa H.T. Coetzer
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Giovanni Cattoli
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
| | - Adama Diallo
- Animal Production and Health Laboratory, FAO/IAEA Agriculture and Biotechnology Laboratory, IAEA Laboratories Seibersdorf, International Atomic Energy Agency (IAEA), Vienna, Austria
- UMR CIRAD INRA, Animal, Santé, Territoires, Risques et Ecosystèmes (ASTRE), Montpellier, France
| |
Collapse
|
6
|
Wei W, Ying X, Chen L, Sun Q, Lu X, Xia Y, Xu R, Zhu Z, Zhang D, Tang Q, Li L, Xie J, Yu H. RecQ mediated genome instability 2 ( RMI2): a potential prognostic and immunological biomarker for pan-cancers. Aging (Albany NY) 2022; 14:4107-4136. [PMID: 35552266 PMCID: PMC9134953 DOI: 10.18632/aging.204076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
Background: RecQ mediated genome instability 2 (RMI2) is an essential component of the BLM-TopoIIIa-RMI1-RMI2 (BTR) complex. However, the mysterious veil of the potential immunological relationship of RMI2 in tumorigenesis and development has not been revealed. Methods: We conducted the differential expression (DE) analysis of the RMI2 in pan-cancer using data onto Oncomine, TIMER, and GEPIA databases. Afterward, survival analysis and clinical-stage correlation analysis were performed via the TCGA database. Subsequently, we used R software to further explore the relationship between the expression level of RMI2 and tumor mutation burden (TMB), microsatellite instability (MSI), tumor microenvironment (TME), tumor immune-infiltrated cells (TILs), immune checkpoints (ICP), mismatch repairs (MMRs) -related genes, m6A-related genes, DNA methylation-related genes. Finally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional networks were also performed for annotation via gene set enrichment analysis (GSEA). Results: The RMI2 expressed remarkably high in most cancer types compared to cancer adjacent normal tissues (P < 0.05). High expression of RMI2 was linked to unfavorable prognosis and advanced stage of disease, especially in LIHC and PAAD. RMI2 expression was related to TMB in 16 cancer types and MSI in 8 cancer types. Furthermore, it is significant positive correlations between RMI2 and stromal and immune cells, ICP-related genes, MMRs-related genes, m6A-related genes, and DNA methylation-related genes. Finally, GSEA analysis revealed that RMI2 was engaged in a variety of signaling pathways in pan-cancers. Conclusions: RMI2 may serve as a potential biological target and probably assume a crucial part in tumorigenesis and progression.
Collapse
Affiliation(s)
- Wei Wei
- Department of General Surgery, Fuyang Hospital of Anhui Medical University, Fuyang 236000, Anhui, China
| | - Xiaomei Ying
- Department of General Surgery, Suzhou Hospital of Anhui Medical University, Suzhou 234000, China
| | - Liang Chen
- Department of General Surgery, Fuyang Hospital of Anhui Medical University, Fuyang 236000, Anhui, China
| | - Qingmei Sun
- Pancreas Center, The First Affiliated Hospital with Nanjing Medical University, Nanjing 210029, Jiangsu, China
| | - Xiaohuan Lu
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, Hubei, China
| | - Yang Xia
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, Anhui, China
| | - Rubin Xu
- Department of General Surgery, Fuyang Hospital of Anhui Medical University, Fuyang 236000, Anhui, China
| | - Zhechen Zhu
- Department of Burn and Plastic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China
| | - Dong Zhang
- The State Key Lab of Reproductive, Department of Urology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China
| | - Qikai Tang
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China
| | - Li Li
- Department of General Surgery, Fuyang Hospital of Anhui Medical University, Fuyang 236000, Anhui, China
| | - Jiaheng Xie
- Department of Burn and Plastic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu, China
| | - Hongzhu Yu
- Department of General Surgery, Fuyang Hospital of Anhui Medical University, Fuyang 236000, Anhui, China
| |
Collapse
|
7
|
Xue C, Salunkhe SJ, Tomimatsu N, Kawale AS, Kwon Y, Burma S, Sung P, Greene EC. Bloom helicase mediates formation of large single-stranded DNA loops during DNA end processing. Nat Commun 2022; 13:2248. [PMID: 35473934 PMCID: PMC9042962 DOI: 10.1038/s41467-022-29937-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 03/14/2022] [Indexed: 01/27/2023] Open
Abstract
Bloom syndrome (BS) is associated with a profoundly increased cancer risk and is caused by mutations in the Bloom helicase (BLM). BLM is involved in the nucleolytic processing of the ends of DNA double-strand breaks (DSBs), to yield long 3' ssDNA tails that serve as the substrate for break repair by homologous recombination (HR). Here, we use single-molecule imaging to demonstrate that BLM mediates formation of large ssDNA loops during DNA end processing. A BLM mutant lacking the N-terminal domain (NTD) retains vigorous in vitro end processing activity but fails to generate ssDNA loops. This same mutant supports DSB end processing in cells, however, these cells do not form RAD51 DNA repair foci and the processed DSBs are channeled into synthesis-dependent strand annealing (SSA) instead of HR-mediated repair, consistent with a defect in RAD51 filament formation. Together, our results provide insights into BLM functions during homologous recombination.
Collapse
Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Sameer J Salunkhe
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- The Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Nozomi Tomimatsu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Ajinkya S Kawale
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- The Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Sandeep Burma
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Neurosurgery, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
- The Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA.
| |
Collapse
|
8
|
Ali A, Xiao W, Babar ME, Bi Y. Double-Stranded Break Repair in Mammalian Cells and Precise Genome Editing. Genes (Basel) 2022; 13:genes13050737. [PMID: 35627122 PMCID: PMC9142082 DOI: 10.3390/genes13050737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/16/2022] Open
Abstract
In mammalian cells, double-strand breaks (DSBs) are repaired predominantly by error-prone non-homologous end joining (NHEJ), but less prevalently by error-free template-dependent homologous recombination (HR). DSB repair pathway selection is the bedrock for genome editing. NHEJ results in random mutations when repairing DSB, while HR induces high-fidelity sequence-specific variations, but with an undesirable low efficiency. In this review, we first discuss the latest insights into the action mode of NHEJ and HR in a panoramic view. We then propose the future direction of genome editing by virtue of these advancements. We suggest that by switching NHEJ to HR, full fidelity genome editing and robust gene knock-in could be enabled. We also envision that RNA molecules could be repurposed by RNA-templated DSB repair to mediate precise genetic editing.
Collapse
Affiliation(s)
- Akhtar Ali
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Department of Biotechnology, Virtual University of Pakistan, Lahore 54000, Pakistan
| | - Wei Xiao
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
| | - Masroor Ellahi Babar
- The University of Agriculture Dera Ismail Khan, Dera Ismail Khan 29220, Pakistan;
| | - Yanzhen Bi
- Key Laboratory of Animal Embryo and Molecular Breeding of Hubei Province, Institute of Animal Science and Veterinary Medicine, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; (A.A.); (W.X.)
- Correspondence: ; Tel.: +86-151-0714-8708
| |
Collapse
|
9
|
Maity J, Horibata S, Zurcher G, Lee JM. Targeting of RecQ Helicases as a Novel Therapeutic Strategy for Ovarian Cancer. Cancers (Basel) 2022; 14:cancers14051219. [PMID: 35267530 PMCID: PMC8909030 DOI: 10.3390/cancers14051219] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022] Open
Abstract
RecQ helicases are essential for DNA replication, recombination, DNA damage repair, and other nucleic acid metabolic pathways required for normal cell growth, survival, and genome stability. More recently, RecQ helicases have been shown to be important for replication fork stabilization, one of the major mechanisms of PARP inhibitor resistance. Cancer cells often have upregulated helicases and depend on these enzymes to repair rapid growth-promoted DNA lesions. Several studies are now evaluating the use of RecQ helicases as potential biomarkers of breast and gynecologic cancers. Furthermore, RecQ helicases have attracted interest as possible targets for cancer treatment. In this review, we discuss the characteristics of RecQ helicases and their interacting partners that may be utilized for effective treatment strategies (as cancers depend on helicases for survival). We also discuss how targeting helicase in combination with DNA repair inhibitors (i.e., PARP and ATR inhibitors) can be used as novel approaches for cancer treatment to increase sensitivity to current treatment to prevent rise of treatment resistance.
Collapse
Affiliation(s)
- Jyotirindra Maity
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (J.M.); (G.Z.)
| | - Sachi Horibata
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Precision Health Program, Michigan State University, East Lansing, MI 48824, USA
- Department of Pharmacology and Toxicology, College of Human Medicine, Michigan State University, East Lansing, MI 48824, USA
- Correspondence: (S.H.); (J.M.L.)
| | - Grant Zurcher
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (J.M.); (G.Z.)
| | - Jung-Min Lee
- Women’s Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (J.M.); (G.Z.)
- Correspondence: (S.H.); (J.M.L.)
| |
Collapse
|
10
|
Harami GM, Pálinkás J, Seol Y, Kovács ZJ, Gyimesi M, Harami-Papp H, Neuman KC, Kovács M. The toposiomerase IIIalpha-RMI1-RMI2 complex orients human Bloom's syndrome helicase for efficient disruption of D-loops. Nat Commun 2022; 13:654. [PMID: 35115525 PMCID: PMC8813930 DOI: 10.1038/s41467-022-28208-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 01/12/2022] [Indexed: 01/05/2023] Open
Abstract
Homologous recombination (HR) is a ubiquitous and efficient process that serves the repair of severe forms of DNA damage and the generation of genetic diversity during meiosis. HR can proceed via multiple pathways with different outcomes that may aid or impair genome stability and faithful inheritance, underscoring the importance of HR quality control. Human Bloom's syndrome (BLM, RecQ family) helicase plays central roles in HR pathway selection and quality control via unexplored molecular mechanisms. Here we show that BLM's multi-domain structural architecture supports a balance between stabilization and disruption of displacement loops (D-loops), early HR intermediates that are key targets for HR regulation. We find that this balance is markedly shifted toward efficient D-loop disruption by the presence of BLM's interaction partners Topoisomerase IIIα-RMI1-RMI2, which have been shown to be involved in multiple steps of HR-based DNA repair. Our results point to a mechanism whereby BLM can differentially process D-loops and support HR control depending on cellular regulatory mechanisms.
Collapse
Affiliation(s)
- Gábor M Harami
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary. .,Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA.
| | - János Pálinkás
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary
| | - Yeonee Seol
- Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Zoltán J Kovács
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary
| | - Máté Gyimesi
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary.,MTA-ELTE Motor Pharmacology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary
| | - Hajnalka Harami-Papp
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary.,Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Keir C Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Mihály Kovács
- ELTE-MTA "Momentum" Motor Enzymology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary. .,MTA-ELTE Motor Pharmacology Research Group, Department of Biochemistry, Eötvös Loránd University, Pázmány P. s. 1/c, H-1117, Budapest, Hungary.
| |
Collapse
|
11
|
Gönenc II, Wolff A, Schmidt J, Zibat A, Müller C, Cyganek L, Argyriou L, Räschle M, Yigit G, Wollnik B. OUP accepted manuscript. Hum Mol Genet 2022; 31:2185-2193. [PMID: 35099000 PMCID: PMC9262399 DOI: 10.1093/hmg/ddab373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/02/2021] [Accepted: 12/27/2021] [Indexed: 11/12/2022] Open
Abstract
Bloom syndrome (BS) is an autosomal recessive disease clinically characterized by primary microcephaly, growth deficiency, immunodeficiency and predisposition to cancer. It is mainly caused by biallelic loss-of-function mutations in the BLM gene, which encodes the BLM helicase, acting in DNA replication and repair processes. Here, we describe the gene expression profiles of three BS fibroblast cell lines harboring causative, biallelic truncating mutations obtained by single-cell (sc) transcriptome analysis. We compared the scRNA transcription profiles from three BS patient cell lines to two age-matched wild-type controls and observed specific deregulation of gene sets related to the molecular processes characteristically affected in BS, such as mitosis, chromosome segregation, cell cycle regulation and genomic instability. We also found specific upregulation of genes of the Fanconi anemia pathway, in particular FANCM, FANCD2 and FANCI, which encode known interaction partners of BLM. The significant deregulation of genes associated with inherited forms of primary microcephaly observed in our study might explain in part the molecular pathogenesis of microcephaly in BS, one of the main clinical characteristics in patients. Finally, our data provide first evidence of a novel link between BLM dysfunction and transcriptional changes in condensin complex I and II genes. Overall, our study provides novel insights into gene expression profiles in BS on an sc level, linking specific genes and pathways to BLM dysfunction.
Collapse
Affiliation(s)
| | | | - Julia Schmidt
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Arne Zibat
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Christian Müller
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Lukas Cyganek
- Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, 37075 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, 37075 Göttingen, Germany
| | - Loukas Argyriou
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Markus Räschle
- Department of Molecular Genetics, Technical University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Gökhan Yigit
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, 37075 Göttingen, Germany
| | - Bernd Wollnik
- To whom correspondence should be addressed at: Institute of Human Genetics, University Medical Center Göttingen, Heinrich-Düker-Weg 12, 37073 Göttingen, Germany. Tel: +49 5513960606; Fax: +49 5513969303;
| |
Collapse
|
12
|
Shastri VM, Subramanian V, Schmidt KH. A novel cell-cycle-regulated interaction of the Bloom syndrome helicase BLM with Mcm6 controls replication-linked processes. Nucleic Acids Res 2021; 49:8699-8713. [PMID: 34370039 PMCID: PMC8421143 DOI: 10.1093/nar/gkab663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/16/2021] [Accepted: 07/22/2021] [Indexed: 11/13/2022] Open
Abstract
The Bloom syndrome DNA helicase BLM contributes to chromosome stability through its roles in double-strand break repair by homologous recombination and DNA replication fork restart during the replication stress response. Loss of BLM activity leads to Bloom syndrome, which is characterized by extraordinary cancer risk and small stature. Here, we have analyzed the composition of the BLM complex during unperturbed S-phase and identified a direct physical interaction with the Mcm6 subunit of the minichromosome maintenance (MCM) complex. Using distinct binding sites, BLM interacts with the N-terminal domain of Mcm6 in G1 phase and switches to the C-terminal Cdt1-binding domain of Mcm6 in S-phase, with a third site playing a role for Mcm6 binding after DNA damage. Disruption of Mcm6-binding to BLM in S-phase leads to supra-normal DNA replication speed in unperturbed cells, and the helicase activity of BLM is required for this increased replication speed. Upon disruption of BLM/Mcm6 interaction, repair of replication-dependent DNA double-strand breaks is delayed and cells become hypersensitive to DNA damage and replication stress. Our findings reveal that BLM not only plays a role in the response to DNA damage and replication stress, but that its physical interaction with Mcm6 is required in unperturbed cells, most notably in S-phase as a negative regulator of replication speed.
Collapse
Affiliation(s)
- Vivek M Shastri
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Veena Subramanian
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Kristina H 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
|
13
|
Transcription/Replication Conflicts in Tumorigenesis and Their Potential Role as Novel Therapeutic Targets in Multiple Myeloma. Cancers (Basel) 2021; 13:cancers13153755. [PMID: 34359660 PMCID: PMC8345052 DOI: 10.3390/cancers13153755] [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: 05/12/2021] [Revised: 07/13/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Multiple myeloma is a hematologic cancer characterized by the accumulation of malignant plasma cells in the bone marrow. It remains a mostly incurable disease due to the inability to overcome refractory disease and drug-resistant relapse. Oncogenic transformation of PC in multiple myeloma is thought to occur within the secondary lymphoid organs. However, the precise molecular events leading to myelomagenesis remain obscure. Here, we identified genes involved in the prevention and the resolution of conflicts between the replication and transcription significantly overexpressed during the plasma cell differentiation process and in multiple myeloma cells. We discussed the potential role of these factors in myelomagenesis and myeloma biology. The specific targeting of these factors might constitute a new therapeutic strategy in multiple myeloma. Abstract Plasma cells (PCs) have an essential role in humoral immune response by secretion of antibodies, and represent the final stage of B lymphocytes differentiation. During this differentiation, the pre-plasmablastic stage is characterized by highly proliferative cells that start to secrete immunoglobulins (Igs). Thus, replication and transcription must be tightly regulated in these cells to avoid transcription/replication conflicts (TRCs), which could increase replication stress and lead to genomic instability. In this review, we analyzed expression of genes involved in TRCs resolution during B to PC differentiation and identified 41 genes significantly overexpressed in the pre-plasmablastic stage. This illustrates the importance of mechanisms required for adequate processing of TRCs during PCs differentiation. Furthermore, we identified that several of these factors were also found overexpressed in purified PCs from patients with multiple myeloma (MM) compared to normal PCs. Malignant PCs produce high levels of Igs concomitantly with cell cycle deregulation. Therefore, increasing the TRCs occurring in MM cells could represent a potent therapeutic strategy for MM patients. Here, we describe the potential roles of TRCs resolution factors in myelomagenesis and discuss the therapeutic interest of targeting the TRCs resolution machinery in MM.
Collapse
|
14
|
Sanchez A, Reginato G, Cejka P. Crossover or non-crossover outcomes: tailored processing of homologous recombination intermediates. Curr Opin Genet Dev 2021; 71:39-47. [PMID: 34293660 DOI: 10.1016/j.gde.2021.06.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/15/2021] [Accepted: 06/23/2021] [Indexed: 12/14/2022]
Abstract
DNA breaks may arise accidentally in vegetative cells or in a programmed manner in meiosis. The usage of a DNA template makes homologous recombination potentially error-free, however, recombination is not always accurate. Cells possess a remarkable capacity to tailor processing of recombination intermediates to fulfill a particular need. Vegetatively growing cells aim to maintain genome stability and therefore repair accidental breaks largely accurately, using sister chromatids as templates, into mostly non-crossovers products. Recombination in meiotic cells is instead more likely to employ homologous chromosomes as templates and result in crossovers to allow proper chromosome segregation and promote genetic diversity. Here we review models explaining the processing of recombination intermediates in vegetative and meiotic cells and its regulation, with a focus on MLH1-MLH3-dependent crossing-over during meiotic recombination.
Collapse
Affiliation(s)
- Aurore Sanchez
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland
| | - Giordano Reginato
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona, Switzerland; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland.
| |
Collapse
|
15
|
Li Y, He X, Zhang X, Xu Y, Chen W, Liu X, Xu X. RMI2 is a prognostic biomarker and promotes tumor growth in hepatocellular carcinoma. Clin Exp Med 2021; 22:229-243. [PMID: 34275027 DOI: 10.1007/s10238-021-00742-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 07/02/2021] [Indexed: 02/08/2023]
Abstract
Genomic instability is a hallmark of all cancers. RMI2 is a crucial component of the BLM-TopoIIIa-RMI1-RMI2 complex that maintains genome stability. It has been shown to accelerate tumor progression in lung cancer, cervical cancer, and prostate cancer. However, its expression and function in hepatocellular carcinoma (HCC) remain poorly defined. In this study, gene expression data and corresponding clinical information of HCC were downloaded from the TCGA, ICGC, and GEO databases. The expression level and clinical significance of RMI2 in HCC were then analyzed. In addition, cellular and molecular biology experiments were conducted to explore the effects of silencing and overexpression of RMI2 on human liver cancer cells and the associated mechanisms. The results showed that RMI2 expression was elevated in HCC tissues. High expression of RMI2 was correlated with shorter survival and poor prognosis of patients. The results of CCK-8, Edu, and clonogenic assays confirmed that RMI2 overexpression promoted the proliferation of HCC cells. Flow cytometric analysis demonstrated that RMI2 overexpression enhanced G1-S phase transition and decreased apoptosis. Moreover, the protein expression of key effector molecules in the p53 signaling pathway was reduced following RMI2 overexpression. In summary, these results indicate that RMI2 promotes the growth of HCC cells and suppresses their apoptosis by inhibiting the p53 signaling pathway. This study provides new insights into the mechanisms driving HCC tumorigenesis and new therapeutic targets.
Collapse
Affiliation(s)
- Yue Li
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Xiaoqin He
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Xiaoyu Zhang
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Yangtao Xu
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Wenliang Chen
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Xin Liu
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China
| | - Ximing Xu
- Cancer Center, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, China.
| |
Collapse
|
16
|
Xue C, Greene EC. DNA Repair Pathway Choices in CRISPR-Cas9-Mediated Genome Editing. Trends Genet 2021; 37:639-656. [PMID: 33896583 PMCID: PMC8187289 DOI: 10.1016/j.tig.2021.02.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 12/14/2022]
Abstract
Many clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9)-based genome editing technologies take advantage of Cas nucleases to induce DNA double-strand breaks (DSBs) at desired locations within a genome. Further processing of the DSBs by the cellular DSB repair machinery is then necessary to introduce desired mutations, sequence insertions, or gene deletions. Thus, the accuracy and efficiency of genome editing are influenced by the cellular DSB repair pathways. DSBs are themselves highly genotoxic lesions and as such cells have evolved multiple mechanisms for their repair. These repair pathways include homologous recombination (HR), classical nonhomologous end joining (cNHEJ), microhomology-mediated end joining (MMEJ) and single-strand annealing (SSA). In this review, we briefly highlight CRISPR-Cas9 and then describe the mechanisms of DSB repair. Finally, we summarize recent findings of factors that can influence the choice of DNA repair pathway in response to Cas9-induced DSBs.
Collapse
Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
17
|
Chen S, Liu W, Huang Y. Identification and external validation of a prognostic signature associated with DNA repair genes in gastric cancer. Sci Rep 2021; 11:7141. [PMID: 33785812 PMCID: PMC8010105 DOI: 10.1038/s41598-021-86504-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/15/2021] [Indexed: 12/24/2022] Open
Abstract
The aim of this study was to construct and validate a DNA repair-related gene signature for evaluating the overall survival (OS) of patients with gastric cancer (GC). Differentially expressed DNA repair genes between GC and normal gastric tissue samples obtained from the TCGA database were identified. Univariate Cox analysis was used to screen survival-related genes and multivariate Cox analysis was applied to construct a DNA repair-related gene signature. An integrated bioinformatics approach was performed to evaluate its diagnostic and prognostic value. The prognostic model and the expression levels of signature genes were validated using an independent external validation cohort. Two genes (CHAF1A, RMI1) were identified to establish the prognostic signature and patients ware stratified into high- and low-risk groups. Patients in high-risk group presented significant shorter survival time than patients in the low-risk group in both cohorts, which were verified by the ROC curves. Multivariate analysis showed that the prognostic signature was an independent predictor for patients with GC after adjustment for other known clinical parameters. A nomogram incorporating the signature and known clinical factors yielded better performance and net benefits in calibration plot and decision curve analyses. Further, the logistic regression classifier based on the two genes presented an excellent diagnostic power in differentiating early HCC and normal tissues with AUCs higher than 0.9. Moreover, Gene Set Enrichment Analysis revealed that diverse cancer-related pathways significantly clustered in the high-risk and low-risk groups. Immune cell infiltration analysis revealed that CHAF1A and RMI1 were correlated with several types of immune cell subtypes. A prognostic signature using CHAF1A and RMI1 was developed that effectively predicted different OS rates among patients with GC. This risk model provides new clinical evidence for the diagnostic accuracy and survival prediction of GC.
Collapse
Affiliation(s)
- Shimin Chen
- Department of Gastroenterology, Traditional Chinese Medical Hospital of Taihe Country, No 59, Tuanjie West Road, Taihe County, Fuyang, 236600, Anhui Province, China
| | - Wenbo Liu
- Department of Gastroenterology, Traditional Chinese Medical Hospital of Taihe Country, No 59, Tuanjie West Road, Taihe County, Fuyang, 236600, Anhui Province, China
| | - Yu Huang
- Department of Gastroenterology, Traditional Chinese Medical Hospital of Taihe Country, No 59, Tuanjie West Road, Taihe County, Fuyang, 236600, Anhui Province, China.
| |
Collapse
|
18
|
Kaur E, Agrawal R, Sengupta S. Functions of BLM Helicase in Cells: Is It Acting Like a Double-Edged Sword? Front Genet 2021; 12:634789. [PMID: 33777104 PMCID: PMC7994599 DOI: 10.3389/fgene.2021.634789] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/11/2021] [Indexed: 12/14/2022] Open
Abstract
DNA damage repair response is an important biological process involved in maintaining the fidelity of the genome in eukaryotes and prokaryotes. Several proteins that play a key role in this process have been identified. Alterations in these key proteins have been linked to different diseases including cancer. BLM is a 3′−5′ ATP-dependent RecQ DNA helicase that is one of the most essential genome stabilizers involved in the regulation of DNA replication, recombination, and both homologous and non-homologous pathways of double-strand break repair. BLM structure and functions are known to be conserved across many species like yeast, Drosophila, mouse, and human. Genetic mutations in the BLM gene cause a rare, autosomal recessive disorder, Bloom syndrome (BS). BS is a monogenic disease characterized by genomic instability, premature aging, predisposition to cancer, immunodeficiency, and pulmonary diseases. Hence, these characteristics point toward BLM being a tumor suppressor. However, in addition to mutations, BLM gene undergoes various types of alterations including increase in the copy number, transcript, and protein levels in multiple types of cancers. These results, along with the fact that the lack of wild-type BLM in these cancers has been associated with increased sensitivity to chemotherapeutic drugs, indicate that BLM also has a pro-oncogenic function. While a plethora of studies have reported the effect of BLM gene mutations in various model organisms, there is a dearth in the studies undertaken to investigate the effect of its oncogenic alterations. We propose to rationalize and integrate the dual functions of BLM both as a tumor suppressor and maybe as a proto-oncogene, and enlist the plausible mechanisms of its deregulation in cancers.
Collapse
Affiliation(s)
- Ekjot Kaur
- Signal Transduction Laboratory-2, National Institute of Immunology, New Delhi, India
| | - Ritu Agrawal
- Signal Transduction Laboratory-2, National Institute of Immunology, New Delhi, India
| | - Sagar Sengupta
- Signal Transduction Laboratory-2, National Institute of Immunology, New Delhi, India
| |
Collapse
|
19
|
Xue C, Molnarova L, Steinfeld JB, Zhao W, Ma C, Spirek M, Kaniecki K, Kwon Y, Beláň O, Krejci K, Boulton S, Sung P, Greene EC, Krejci L. Single-molecule visualization of human RECQ5 interactions with single-stranded DNA recombination intermediates. Nucleic Acids Res 2021; 49:285-305. [PMID: 33332547 PMCID: PMC7797033 DOI: 10.1093/nar/gkaa1184] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 11/03/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
RECQ5 is one of five RecQ helicases found in humans and is thought to participate in homologous DNA recombination by acting as a negative regulator of the recombinase protein RAD51. Here, we use kinetic and single molecule imaging methods to monitor RECQ5 behavior on various nucleoprotein complexes. Our data demonstrate that RECQ5 can act as an ATP-dependent single-stranded DNA (ssDNA) motor protein and can translocate on ssDNA that is bound by replication protein A (RPA). RECQ5 can also translocate on RAD51-coated ssDNA and readily dismantles RAD51-ssDNA filaments. RECQ5 interacts with RAD51 through protein-protein contacts, and disruption of this interface through a RECQ5-F666A mutation reduces translocation velocity by ∼50%. However, RECQ5 readily removes the ATP hydrolysis-deficient mutant RAD51-K133R from ssDNA, suggesting that filament disruption is not coupled to the RAD51 ATP hydrolysis cycle. RECQ5 also readily removes RAD51-I287T, a RAD51 mutant with enhanced ssDNA-binding activity, from ssDNA. Surprisingly, RECQ5 can bind to double-stranded DNA (dsDNA), but it is unable to translocate. Similarly, RECQ5 cannot dismantle RAD51-bound heteroduplex joint molecules. Our results suggest that the roles of RECQ5 in genome maintenance may be regulated in part at the level of substrate specificity.
Collapse
Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Lucia Molnarova
- Department of Biology, Masaryk University, Brno 62500, Czech Republic
| | - Justin B Steinfeld
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Weixing Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Chujian Ma
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Mario Spirek
- Department of Biology, Masaryk University, Brno 62500, Czech Republic
| | - Kyle Kaniecki
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Ondrej Beláň
- DSB Repair Metabolism Lab, The Francis Crick Institute, Midland Road, London NW1 1AT, UK
| | - Katerina Krejci
- Department of Biology, Masaryk University, Brno 62500, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno 65691, Czech Republic
| | - Simon J Boulton
- DSB Repair Metabolism Lab, The Francis Crick Institute, Midland Road, London NW1 1AT, UK
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Lumir Krejci
- Department of Biology, Masaryk University, Brno 62500, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital Brno, Brno 65691, Czech Republic
- National Centre for Biomolecular Research, Masaryk, Brno 62500, Czech Republic
| |
Collapse
|
20
|
Bythell-Douglas R, Deans AJ. A Structural Guide to the Bloom Syndrome Complex. Structure 2020; 29:99-113. [PMID: 33357470 DOI: 10.1016/j.str.2020.11.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/03/2020] [Accepted: 11/25/2020] [Indexed: 01/19/2023]
Abstract
The Bloom syndrome complex is a DNA damage repair machine. It consists of several protein components which are functional in isolation, but interdependent in cells for the maintenance of accurate homologous recombination. Mutations to any of the genes encoding these proteins cause numerous physical and developmental markers as well as phenotypes of genome instability, infertility, and cancer predisposition. Here we review the published structural and biochemical data on each of the components of the complex: the helicase BLM, the type IA topoisomerase TOP3A, and the OB-fold-containing RMI and RPA subunits. We describe how each component contributes to function, interacts with each other, and the DNA that it manipulates/repairs.
Collapse
Affiliation(s)
- Rohan Bythell-Douglas
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia.
| | - Andrew J Deans
- Genome Stability Unit, St. Vincent's Institute of Medical Research, Fitzroy, VIC, 3056, Australia; Department of Medicine (St Vincent's), University of Melbourne, Fitzroy, VIC, 3056, Australia.
| |
Collapse
|
21
|
Amir M, Alam A, Ishrat R, Alajmi MF, Hussain A, Rehman MT, Islam A, Ahmad F, Hassan MI, Dohare R. A Systems View of the Genome Guardians: Mapping the Signaling Circuitry Underlying Oligonucleotide/Oligosaccharide-Binding Fold Proteins. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 24:518-530. [PMID: 32780668 DOI: 10.1089/omi.2020.0072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The oligonucleotide/oligosaccharide-binding (OB)-fold domain proteins are considered as genome guardians, whose functions are extending beyond genomic stability. The broad functional diversity of the OB-fold proteins is attributed to their protein-DNA, protein-RNA, and protein-protein interactions (PPI). To understand the connectivity of the human OB-fold proteins, we report here a systems-level approach. Specifically, we mapped all human OB-fold PPI networks and evaluated topological features such as network robustness and network hub, among others. We found that the OB-fold network comprised of 227 nodes forming 5523 interactions, and has a scale-free topology having UBA52, ATR, and TP53 as leading hub proteins that control efficient communication within the network. Furthermore, four different clusters and subclusters have been identified, which are implicated in diverse cellular processes, including DNA replication, repair, maintenance of genomic stability, RNA processing, spermatogenesis, complement system, and telomere maintenance. The importance of these clusters is further strengthened by knockout studies, which showed a significant decrease in topological properties. In summary, this study provides new insights on the role of OB-fold protein as genome guardians in regard to the underlying mechanism of signaling pathways, the roles of key regulators, and thus, offers new prospects as potential targets for diagnostics and therapeutics purposes.
Collapse
Affiliation(s)
- Mohd Amir
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Aftab Alam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Romana Ishrat
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Mohamed F Alajmi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Afzal Hussain
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Md Tabish Rehman
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Faizan Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Ravins Dohare
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| |
Collapse
|
22
|
Daley JM, Tomimatsu N, Hooks G, Wang W, Miller AS, Xue X, Nguyen KA, Kaur H, Williamson E, Mukherjee B, Hromas R, Burma S, Sung P. Specificity of end resection pathways for double-strand break regions containing ribonucleotides and base lesions. Nat Commun 2020; 11:3088. [PMID: 32555206 PMCID: PMC7303207 DOI: 10.1038/s41467-020-16903-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 05/29/2020] [Indexed: 12/19/2022] Open
Abstract
DNA double-strand break repair by homologous recombination begins with nucleolytic resection of the 5’ DNA strand at the break ends. Long-range resection is catalyzed by EXO1 and BLM-DNA2, which likely have to navigate through ribonucleotides and damaged bases. Here, we show that a short stretch of ribonucleotides at the 5’ terminus stimulates resection by EXO1. Ribonucleotides within a 5’ flap are resistant to cleavage by DNA2, and extended RNA:DNA hybrids inhibit both strand separation by BLM and resection by EXO1. Moreover, 8-oxo-guanine impedes EXO1 but enhances resection by BLM-DNA2, and an apurinic/apyrimidinic site stimulates resection by BLM-DNA2 and DNA strand unwinding by BLM. Accordingly, depletion of OGG1 or APE1 leads to greater dependence of DNA resection on DNA2. Importantly, RNase H2A deficiency impairs resection overall, which we attribute to the accumulation of long RNA:DNA hybrids at DNA ends. Our results help explain why eukaryotic cells possess multiple resection nucleases. DNA double-strand break repair by homologous recombination initiates with nucleolytic resection of the 5’ DNA strand at the break ends. Here, the authors reveal that the lesion context influences the action and efficiency of the long range resection factors EXO1 and BLM-DNA2.
Collapse
Affiliation(s)
- James M Daley
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA. .,Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
| | - Nozomi Tomimatsu
- Department of Neurosurgery, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Grace Hooks
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA.,Department of Biochemistry, Duke University, Durham, NC, 27710, USA
| | - Weibin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA.,Department of Radiation Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Adam S Miller
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA.,Regeneron, Rensselaer, NY, 12144, USA
| | - Xiaoyu Xue
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA.,Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA
| | - Kevin A Nguyen
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA.,David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Hardeep Kaur
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Elizabeth Williamson
- Department of Medicine, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Bipasha Mukherjee
- Department of Neurosurgery, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Robert Hromas
- Department of Medicine, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Sandeep Burma
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA. .,Department of Neurosurgery, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, 06510, USA. .,Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA.
| |
Collapse
|
23
|
Ran M, Luo H, Gao H, Tang X, Chen Y, Zeng X, Weng B, Chen B. miR-362 knock-down promotes proliferation and inhibits apoptosis in porcine immature Sertoli cells by targeting the RMI1 gene. Reprod Domest Anim 2020; 55:547-558. [PMID: 31916301 DOI: 10.1111/rda.13626] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/12/2019] [Accepted: 12/29/2019] [Indexed: 01/16/2023]
Abstract
Immature Sertoli cell proliferation determines the total number of mature Sertoli cells and further regulates normal spermatogenesis. Accumulating evidence demonstrates that microRNAs (miRNAs) play regulatory roles in immature Sertoli cell proliferation, while the functions and mechanisms of the Sertoli cells of domestic animals are poorly understood. In the present study, we aimed to investigate the roles of miR-362 in cell proliferation and apoptosis of porcine immature Sertoli cells. The results showed that miR-362 inhibition promoted the entrance of cells into the S phase and increased the expressions of cell cycle-related genes c-MYC, CNNE1, CCND1 and CDK4. Knock-down of miR-362 also promoted cell proliferation and inhibited apoptosis, which was demonstrated by the results from cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) and Annexin V-FITC/PI staining assays. The recQ-mediated genome instability protein 1 (RMI1) gene was identified as a potential target gene of miR-362 via luciferase reporter assay, and miR-362 repressed the protein expression of RMI1 in porcine immature Sertoli cells. siRNA-induced RMI1 knock-down further abolished the effects of miR-362 inhibition on porcine immature Sertoli cells. Collectively, we concluded that miR-362 knock-down promotes proliferation and inhibits apoptosis in porcine immature Sertoli cells by targeting the RMI1 gene, which indicates that miR-362 determines the fate of immature Sertoli cells.
Collapse
Affiliation(s)
- Maoliang Ran
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Hui Luo
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Hu Gao
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Xiangwei Tang
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Yao Chen
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Xinyu Zeng
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Bo Weng
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| | - Bin Chen
- College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animals, Hunan Agricultural University, Changsha, China
| |
Collapse
|
24
|
Xue C, Daley JM, Xue X, Steinfeld J, Kwon Y, Sung P, Greene EC. Single-molecule visualization of human BLM helicase as it acts upon double- and single-stranded DNA substrates. Nucleic Acids Res 2019; 47:11225-11237. [PMID: 31544923 PMCID: PMC6868385 DOI: 10.1093/nar/gkz810] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/06/2019] [Accepted: 09/17/2019] [Indexed: 11/12/2022] Open
Abstract
Bloom helicase (BLM) and its orthologs are essential for the maintenance of genome integrity. BLM defects represent the underlying cause of Bloom Syndrome, a rare genetic disorder that is marked by strong cancer predisposition. BLM deficient cells accumulate extensive chromosomal aberrations stemming from dysfunctions in homologous recombination (HR). BLM participates in several HR stages and helps dismantle potentially harmful HR intermediates. However, much remains to be learned about the molecular mechanisms of these BLM-mediated regulatory effects. Here, we use DNA curtains to directly visualize the activity of BLM helicase on single molecules of DNA. Our data show that BLM is a robust helicase capable of rapidly (∼70-80 base pairs per second) unwinding extensive tracts (∼8-10 kilobases) of double-stranded DNA (dsDNA). Importantly, we find no evidence for BLM activity on single-stranded DNA (ssDNA) that is bound by replication protein A (RPA). Likewise, our results show that BLM can neither associate with nor translocate on ssDNA that is bound by the recombinase protein RAD51. Moreover, our data reveal that the presence of RAD51 also blocks BLM translocation on dsDNA substrates. We discuss our findings within the context of potential regulator roles for BLM helicase during DNA replication and repair.
Collapse
Affiliation(s)
- Chaoyou Xue
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - James M Daley
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Xiaoyu Xue
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Justin Steinfeld
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY 10032, USA
| |
Collapse
|
25
|
Kasaciunaite K, Fettes F, Levikova M, Daldrop P, Anand R, Cejka P, Seidel R. Competing interaction partners modulate the activity of Sgs1 helicase during DNA end resection. EMBO J 2019; 38:e101516. [PMID: 31268598 PMCID: PMC6601037 DOI: 10.15252/embj.2019101516] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/24/2019] [Accepted: 05/08/2019] [Indexed: 11/09/2022] Open
Abstract
DNA double-strand break repair by homologous recombination employs long-range resection of the 5' DNA ends at the break points. In Saccharomyces cerevisiae, this process can be performed by the RecQ helicase Sgs1 and the helicase-nuclease Dna2. Though functional interplay between them has been shown, it remains unclear whether and how these proteins cooperate on the molecular level. Here, we resolved the dynamics of DNA unwinding by Sgs1 at the single-molecule level and investigated Sgs1 regulation by Dna2, the single-stranded DNA-binding protein RPA, and the Top3-Rmi1 complex. We found that Dna2 modulates the velocity of Sgs1, indicating that during end resection both proteins form a functional complex and couple their activities. Sgs1 drives DNA unwinding and feeds single-stranded DNA to Dna2 for degradation. RPA was found to regulate the processivity and the affinity of Sgs1 to the DNA fork, while Top3-Rmi1 modulated the velocity of Sgs1. We hypothesize that the differential regulation of Sgs1 activity by its protein partners is important to support diverse cellular functions of Sgs1 during the maintenance of genome stability.
Collapse
Affiliation(s)
- Kristina Kasaciunaite
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Fergus Fettes
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Maryna Levikova
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Peter Daldrop
- Institute for Molecular Cell Biology, University of Münster, Münster, Germany
| | - Roopesh Anand
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana, Bellinzona, Switzerland
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zurich, Switzerland
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
- Institute for Molecular Cell Biology, University of Münster, Münster, Germany
| |
Collapse
|
26
|
Regulatory control of Sgs1 and Dna2 during eukaryotic DNA end resection. Proc Natl Acad Sci U S A 2019; 116:6091-6100. [PMID: 30850524 DOI: 10.1073/pnas.1819276116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In the repair of DNA double-strand breaks by homologous recombination, the DNA break ends must first be processed into 3' single-strand DNA overhangs. In budding yeast, end processing requires the helicase Sgs1 (BLM in humans), the nuclease/helicase Dna2, Top3-Rmi1, and replication protein A (RPA). Here, we use single-molecule imaging to visualize Sgs1-dependent end processing in real-time. We show that Sgs1 is recruited to DNA ends through Top3-Rmi1-dependent or -independent means, and in both cases Sgs1 is maintained in an immoble state at the DNA ends. Importantly, the addition of Dna2 triggers processive Sgs1 translocation, but DNA resection only occurs when RPA is also present. We also demonstrate that the Sgs1-Dna2-Top3-Rmi1-RPA ensemble can efficiently disrupt nucleosomes, and that Sgs1 itself possesses nucleosome remodeling activity. Together, these results shed light on the regulatory interplay among conserved protein factors that mediate the nucleolytic processing of DNA ends in preparation for homologous recombination-mediated chromosome damage repair.
Collapse
|
27
|
Griffin WC, Trakselis MA. The MCM8/9 complex: A recent recruit to the roster of helicases involved in genome maintenance. DNA Repair (Amst) 2019; 76:1-10. [PMID: 30743181 DOI: 10.1016/j.dnarep.2019.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/03/2019] [Indexed: 12/11/2022]
Abstract
There are several DNA helicases involved in seemingly overlapping aspects of homologous and homoeologous recombination. Mutations of many of these helicases are directly implicated in genetic diseases including cancer, rapid aging, and infertility. MCM8/9 are recent additions to the catalog of helicases involved in recombination, and so far, the evidence is sparse, making assignment of function difficult. Mutations in MCM8/9 correlate principally with primary ovarian failure/insufficiency (POF/POI) and infertility indicating a meiotic defect. However, they also act when replication forks collapse/break shuttling products into mitotic recombination and several mutations are found in various somatic cancers. This review puts MCM8/9 in context with other replication and recombination helicases to narrow down its genomic maintenance role. We discuss the known structure/function relationship, the mutational spectrum, and dissect the available cellular and organismal data to better define its role in recombination.
Collapse
Affiliation(s)
- Wezley C Griffin
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798, USA
| | - Michael A Trakselis
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, 76798, USA.
| |
Collapse
|
28
|
Giant tortoise genomes provide insights into longevity and age-related disease. Nat Ecol Evol 2018; 3:87-95. [PMID: 30510174 PMCID: PMC6314442 DOI: 10.1038/s41559-018-0733-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 10/25/2018] [Indexed: 12/21/2022]
Abstract
Giant tortoises are among the longest-lived vertebrate animals and, as such, provide an excellent model to study traits like longevity and age-related diseases. However, genomic and molecular evolutionary information on giant tortoises is scarce. Here, we describe a global analysis of the genomes of Lonesome George-the iconic last member of Chelonoidis abingdonii-and the Aldabra giant tortoise (Aldabrachelys gigantea). Comparison of these genomes with those of related species, using both unsupervised and supervised analyses, led us to detect lineage-specific variants affecting DNA repair genes, inflammatory mediators and genes related to cancer development. Our study also hints at specific evolutionary strategies linked to increased lifespan, and expands our understanding of the genomic determinants of ageing. These new genome sequences also provide important resources to help the efforts for restoration of giant tortoise populations.
Collapse
|
29
|
Wang H, Li S, Zhang H, Wang Y, Hao S, Wu X. BLM prevents instability of structure-forming DNA sequences at common fragile sites. PLoS Genet 2018; 14:e1007816. [PMID: 30496191 PMCID: PMC6289451 DOI: 10.1371/journal.pgen.1007816] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 12/11/2018] [Accepted: 11/07/2018] [Indexed: 01/04/2023] Open
Abstract
Genome instability often arises at common fragile sites (CFSs) leading to cancer-associated chromosomal rearrangements. However, the underlying mechanisms of how CFS protection is achieved is not well understood. We demonstrate that BLM plays an important role in the maintenance of genome stability of structure-forming AT-rich sequences derived from CFSs (CFS-AT). BLM deficiency leads to increased DSB formation and hyper mitotic recombination at CFS-AT and induces instability of the plasmids containing CFS-AT. We further showed that BLM is required for suppression of CFS breakage upon oncogene expression. Both helicase activity and ATR-mediated phosphorylation of BLM are important for preventing genetic instability at CFS-AT sequences. Furthermore, the role of BLM in protecting CFS-AT is not epistatic to that of FANCM, a translocase that is involved in preserving CFS stability. Loss of BLM helicase activity leads to drastic decrease of cell viability in FANCM deficient cells. We propose that BLM and FANCM utilize different mechanisms to remove DNA secondary structures forming at CFS-AT on replication forks, thereby preventing DSB formation and maintaining CFS stability. Common fragile sites (CFSs) are large chromosomal regions which are more prone to breakage than other places in the genome. They are a part of normal chromosome structure and are present in all human beings, but are also hotspots for chromosomal rearrangement during oncogenesis. Understanding how CFSs are protected to prevent genome instability is thus extremely important for revealing the mechanism underlying cancer development. We found that Bloom syndrome protein BLM is involved in resolving DNA secondary structures that arise at AT-rich sequences in CFSs, suggesting a critical function of BLM in protecting CFSs. We also found that this BLM function is distinct from the role of Fanconi anemia protein FANCM in protecting CFSs, and loss of both BLM and FANCM activities leads to cell death. These studies reveal important mechanisms of the maintenance of CFS stability in mammalian cells.
Collapse
Affiliation(s)
- Hailong Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Science, Capital Normal University, Beijing, China
| | - Shibo Li
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Huimin Zhang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Ya Wang
- Beijing Key Laboratory of DNA Damage Response and College of Life Science, Capital Normal University, Beijing, China
| | - Shuailin Hao
- Beijing Key Laboratory of DNA Damage Response and College of Life Science, Capital Normal University, Beijing, China
| | - Xiaohua Wu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
30
|
Reconstitution of anaphase DNA bridge recognition and disjunction. Nat Struct Mol Biol 2018; 25:868-876. [PMID: 30177760 DOI: 10.1038/s41594-018-0123-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/01/2018] [Indexed: 11/08/2022]
Abstract
Faithful chromosome segregation requires that the sister chromatids be disjoined completely. Defective disjunction can lead to the persistence of histone-free threads of DNA known as ultra-fine bridges (UFBs) that connect the separating sister DNA molecules during anaphase. UFBs arise at specific genomic loci and can only be visualized by detection of associated proteins such as PICH, BLM, topoisomerase IIIα, and RPA. However, it remains unknown how these proteins work together to promote UFB processing. We used a combination of ensemble biochemistry and new single-molecule assays to reconstitute key steps of UFB recognition and processing by these human proteins in vitro. We discovered characteristic patterns of hierarchical recruitment and coordinated biochemical activities that were specific for DNA structures modeling UFBs arising at either centromeres or common fragile sites. Our results describe a mechanistic model for how unresolved DNA replication structures are processed by DNA-structure-specific binding factors in mitosis to prevent pathological chromosome nondisjunction.
Collapse
|
31
|
Daley JM, Jimenez-Sainz J, Wang W, Miller AS, Xue X, Nguyen KA, Jensen RB, Sung P. Enhancement of BLM-DNA2-Mediated Long-Range DNA End Resection by CtIP. Cell Rep 2018; 21:324-332. [PMID: 29020620 DOI: 10.1016/j.celrep.2017.09.048] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 07/18/2017] [Accepted: 09/14/2017] [Indexed: 01/24/2023] Open
Abstract
DNA double-strand break repair by homologous recombination entails the resection of DNA ends to reveal ssDNA tails, which are used to invade a homologous DNA template. CtIP and its yeast ortholog Sae2 regulate the nuclease activity of MRE11 in the initial stage of resection. Deletion of CtIP in the mouse or SAE2 in yeast engenders a more severe phenotype than MRE11 nuclease inactivation, indicative of a broader role of CtIP/Sae2. Here, we provide biochemical evidence that CtIP promotes long-range resection via the BLM-DNA2 pathway. Specifically, CtIP interacts with BLM and enhances its helicase activity, and it enhances DNA cleavage by DNA2. Thus, CtIP influences multiple aspects of end resection beyond MRE11 regulation.
Collapse
Affiliation(s)
- James M Daley
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Judit Jimenez-Sainz
- Department of Therapeutic Radiobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Weibin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Adam S Miller
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Xiaoyu Xue
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kevin A Nguyen
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ryan B Jensen
- Department of Therapeutic Radiobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA.
| |
Collapse
|
32
|
Fontana GA, Reinert JK, Thomä NH, Rass U. Shepherding DNA ends: Rif1 protects telomeres and chromosome breaks. MICROBIAL CELL 2018; 5:327-343. [PMID: 29992129 PMCID: PMC6035837 DOI: 10.15698/mic2018.07.639] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cells have evolved conserved mechanisms to protect DNA ends, such as those at the termini of linear chromosomes, or those at DNA double-strand breaks (DSBs). In eukaryotes, DNA ends at chromosomal termini are packaged into proteinaceous structures called telomeres. Telomeres protect chromosome ends from erosion, inadvertent activation of the cellular DNA damage response (DDR), and telomere fusion. In contrast, cells must respond to damage-induced DNA ends at DSBs by harnessing the DDR to restore chromosome integrity, avoiding genome instability and disease. Intriguingly, Rif1 (Rap1-interacting factor 1) has been implicated in telomere homeostasis as well as DSB repair. The protein was first identified in Saccharomyces cerevisiae as being part of the proteinaceous telosome. In mammals, RIF1 is not associated with intact telomeres, but was found at chromosome breaks, where RIF1 has emerged as a key mediator of pathway choice between the two evolutionary conserved DSB repair pathways of non-homologous end-joining (NHEJ) and homologous recombination (HR). While this functional dichotomy has long been a puzzle, recent findings link yeast Rif1 not only to telomeres, but also to DSB repair, and mechanistic parallels likely exist. In this review, we will provide an overview of the actions of Rif1 at DNA ends and explore how exclusion of end-processing factors might be the underlying principle allowing Rif1 to fulfill diverse biological roles at telomeres and chromosome breaks.
Collapse
Affiliation(s)
- Gabriele A Fontana
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Julia K Reinert
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.,University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| | - Ulrich Rass
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
| |
Collapse
|
33
|
Abstract
DNA end resection initiates the largely accurate repair of DNA double-strand breaks (DSBs) by homologous recombination. Specifically, recombination requires the formation of 3' overhangs at DSB sites, which is carried out by nucleases that specifically degrade 5'-terminated DNA. In most cases, DNA end resection is a two-step process, comprising of initial short-range followed by more processive long-range resection. In this chapter, we describe selected assays that reconstitute both the short- and long-range pathways. First, we define methods to study the exonuclease and endonuclease activities of the MRE11-RAD50-NBS1 (MRN) complex in conjunction with phosphorylated cofactor CtIP. This reaction is particularly important to initiate processing of DNA breaks and to recruit components belonging to the subsequent long-range pathway. Next, we describe assays that reconstitute the concerted reactions of Bloom (BLM) or Werner (WRN) helicases that function together with the DNA2 nuclease-helicase, and which are as a complex capable to resect DNA of kilobases in length. The reconstituted reactions allow us to understand how the resection pathways function at the molecular level. The assays will be invaluable to define regulatory mechanisms and to identify inhibitory compounds, which may be valuable in cancer therapy.
Collapse
Affiliation(s)
- Cosimo Pinto
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Roopesh Anand
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland; Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
| |
Collapse
|
34
|
Paudyal SC, Li S, Yan H, Hunter T, You Z. Dna2 initiates resection at clean DNA double-strand breaks. Nucleic Acids Res 2017; 45:11766-11781. [PMID: 28981724 PMCID: PMC5714177 DOI: 10.1093/nar/gkx830] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/30/2017] [Accepted: 09/06/2017] [Indexed: 02/07/2023] Open
Abstract
Nucleolytic resection of DNA double-strand breaks (DSBs) is essential for both checkpoint activation and homology-mediated repair; however, the precise mechanism of resection, especially the initiation step, remains incompletely understood. Resection of blocked ends with protein or chemical adducts is believed to be initiated by the MRN complex in conjunction with CtIP through internal cleavage of the 5' strand DNA. However, it is not clear whether resection of clean DSBs with free ends is also initiated by the same mechanism. Using the Xenopus nuclear extract system, here we show that the Dna2 nuclease directly initiates the resection of clean DSBs by cleaving the 5' strand DNA ∼10-20 nucleotides away from the ends. In the absence of Dna2, MRN together with CtIP mediate an alternative resection initiation pathway where the nuclease activity of MRN apparently directly cleaves the 5' strand DNA at more distal sites. MRN also facilitates resection initiation by promoting the recruitment of Dna2 and CtIP to the DNA substrate. The ssDNA-binding protein RPA promotes both Dna2- and CtIP-MRN-dependent resection initiation, but a RPA mutant can distinguish between these pathways. Our results strongly suggest that resection of blocked and clean DSBs is initiated via distinct mechanisms.
Collapse
Affiliation(s)
- Sharad C. Paudyal
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Shan Li
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Hong Yan
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA
| | - Tony Hunter
- Salk Institute, 10010 N Torrey Pines Road, La Jolla, CA 92037, USA
| | - Zhongsheng You
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| |
Collapse
|
35
|
Wiest NE, Houghtaling S, Sanchez JC, Tomkinson AE, Osley MA. The SWI/SNF ATP-dependent nucleosome remodeler promotes resection initiation at a DNA double-strand break in yeast. Nucleic Acids Res 2017; 45:5887-5900. [PMID: 28398510 PMCID: PMC5449591 DOI: 10.1093/nar/gkx221] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/06/2017] [Indexed: 12/27/2022] Open
Abstract
DNA double-strand breaks (DSBs) are repaired by either the non-homologous end joining (NHEJ) or homologous recombination (HR) pathway. Pathway choice is determined by the generation of 3΄ single-strand DNA overhangs at the break that are initiated by the action of the Mre11-Rad50-Xrs2 (MRX) complex to direct repair toward HR. DSB repair occurs in the context of chromatin, and multiple chromatin regulators have been shown to play important roles in the repair process. We have investigated the role of the SWI/SNF ATP-dependent nucleosome-remodeling complex in the repair of a defined DNA DSB. SWI/SNF was previously shown to regulate presynaptic events in HR, but its function in these events is unknown. We find that in the absence of functional SWI/SNF, the initiation of DNA end resection is significantly delayed. The delay in resection initiation is accompanied by impaired recruitment of MRX to the DSB, and other functions of MRX in HR including the recruitment of long-range resection factors and activation of the DNA damage response are also diminished. These phenotypes are correlated with a delay in the eviction of nucleosomes surrounding the DSB. We propose that SWI/SNF orchestrates the recruitment of a pool of MRX that is specifically dedicated to HR.
Collapse
Affiliation(s)
- Nathaniel E Wiest
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Scott Houghtaling
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Joseph C Sanchez
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Alan E Tomkinson
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Mary Ann Osley
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| |
Collapse
|
36
|
Jia PP, Junaid M, Ma YB, Ahmad F, Jia YF, Li WG, Pei DS. Role of human DNA2 (hDNA2) as a potential target for cancer and other diseases: A systematic review. DNA Repair (Amst) 2017; 59:9-19. [PMID: 28903076 DOI: 10.1016/j.dnarep.2017.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/29/2017] [Accepted: 09/01/2017] [Indexed: 11/28/2022]
Abstract
DNA nuclease/helicase 2 (DNA2), a multi-functional protein protecting the high fidelity of genomic transmission, plays critical roles in DNA replication and repair processes. In the maturation of Okazaki fragments, DNA2 acts synergistically with other enzymes to cleave the DNA-RNA primer flaps via different pathways. DNA2 is also involved in the stability of mitochondrial DNA and the maintenance of telomeres. Moreover, DNA2 potentially participates in controlling the cell cycle by repairing the DNA replication faults at main checkpoints. In addition, previous evidences demonstrated that DNA2 also functions in the repair process of DNA damages, such as base excision repair (BER). Currently, large studies revealed the structures and functions of DNA2 in prokaryotes and unicellular eukaryotes, such as bacteria and yeast. However, the studies that highlighted the functions of human DNA2 (hDNA2) and the relationships with other multifunctional proteins are still elusive, and more precise investigations are immensely needed. Therefore, this review mainly encompasses the key functions of DNA2 in human cells with various aspects, especially focusing on the genome integrity, and also generalizes the recent insights to the mechanisms related to the occurrence of cancer and other diseases potentially linked to the mutations in DNA2.
Collapse
Affiliation(s)
- Pan-Pan Jia
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China; College of Life Science, Henan Normal University, Xinxiang 453007, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Muhammad Junaid
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan-Bo Ma
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China
| | - Farooq Ahmad
- Sustainable Development Study Centre, GC University Lahore, Pakistan
| | - Yong-Fang Jia
- College of Life Science, Henan Normal University, Xinxiang 453007, China
| | - Wei-Guo Li
- College of Life Science, Henan Normal University, Xinxiang 453007, China.
| | - De-Sheng Pei
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China.
| |
Collapse
|
37
|
Pawłowska E, Szczepanska J, Blasiak J. DNA2-An Important Player in DNA Damage Response or Just Another DNA Maintenance Protein? Int J Mol Sci 2017; 18:ijms18071562. [PMID: 28718810 PMCID: PMC5536050 DOI: 10.3390/ijms18071562] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/13/2017] [Accepted: 07/17/2017] [Indexed: 02/01/2023] Open
Abstract
The human DNA2 (DNA replication helicase/nuclease 2) protein is expressed in both the nucleus and mitochondria, where it displays ATPase-dependent nuclease and helicase activities. DNA2 plays an important role in the removing of long flaps in DNA replication and long-patch base excision repair (LP-BER), interacting with the replication protein A (RPA) and the flap endonuclease 1 (FEN1). DNA2 can promote the restart of arrested replication fork along with Werner syndrome ATP-dependent helicase (WRN) and Bloom syndrome protein (BLM). In mitochondria, DNA2 can facilitate primer removal during strand-displacement replication. DNA2 is involved in DNA double strand (DSB) repair, in which it is complexed with BLM, RPA and MRN for DNA strand resection required for homologous recombination repair. DNA2 can be a major protein involved in the repair of complex DNA damage containing a DSB and a 5' adduct resulting from a chemical group bound to DNA 5' ends, created by ionizing radiation and several anticancer drugs, including etoposide, mitoxantrone and some anthracyclines. The role of DNA2 in telomere end maintenance and cell cycle regulation suggests its more general role in keeping genomic stability, which is impaired in cancer. Therefore DNA2 can be an attractive target in cancer therapy. This is supported by enhanced expression of DNA2 in many cancer cell lines with oncogene activation and premalignant cells. Therefore, DNA2 can be considered as a potential marker, useful in cancer therapy. DNA2, along with PARP1 inhibition, may be considered as a potential target for inducing synthetic lethality, a concept of killing tumor cells by targeting two essential genes.
Collapse
Affiliation(s)
- Elzbieta Pawłowska
- Department of Orthodontics, Medical University of Lodz, 92-216 Lodz, Poland.
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland.
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
| |
Collapse
|
38
|
Nickoloff JA, Boss MK, Allen CP, LaRue SM. Translational research in radiation-induced DNA damage signaling and repair. Transl Cancer Res 2017; 6:S875-S891. [PMID: 30574452 PMCID: PMC6298755 DOI: 10.21037/tcr.2017.06.02] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiotherapy is an effective tool in the fight against cancer. It is non-invasive and painless, and with advanced tumor imaging and beam control systems, radiation can be delivered to patients safely, generally with minor or no adverse side effects, accounting for its increasing use against a broad range of tumors. Tumors and normal cells respond to radiation-induced DNA damage by activating a complex network of DNA damage signaling and repair pathways that determine cell fate including survival, death, and genome stability. DNA damage response (DDR) proteins represent excellent targets to augment radiotherapy, and many agents that inhibit key response proteins are being combined with radiation and genotoxic chemotherapy in clinical trials. This review focuses on how insights into molecular mechanisms of DDR pathways are translated to small animal preclinical studies, to clinical studies of naturally occurring tumors in companion animals, and finally to human clinical trials. Companion animal studies, under the umbrella of comparative oncology, have played key roles in the development of clinical radiotherapy throughout its >100-year history. There is growing appreciation that rapid translation of basic knowledge of DNA damage and repair systems to improved radiotherapy practice requires a comprehensive approach that embraces the full spectrum of cancer research, with companion animal clinical trials representing a critical bridge between small animal preclinical studies, and human clinical trials.
Collapse
Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Mary-Keara Boss
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Christopher P Allen
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Susan M LaRue
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
39
|
Kumar S, Peng X, Daley J, Yang L, Shen J, Nguyen N, Bae G, Niu H, Peng Y, Hsieh HJ, Wang L, Rao C, Stephan CC, Sung P, Ira G, Peng G. Inhibition of DNA2 nuclease as a therapeutic strategy targeting replication stress in cancer cells. Oncogenesis 2017; 6:e319. [PMID: 28414320 PMCID: PMC5520492 DOI: 10.1038/oncsis.2017.15] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 02/10/2017] [Indexed: 02/06/2023] Open
Abstract
Replication stress is a characteristic feature of cancer cells, which is resulted from sustained proliferative signaling induced by activation of oncogenes or loss of tumor suppressors. In cancer cells, oncogene-induced replication stress manifests as replication-associated lesions, predominantly double-strand DNA breaks (DSBs). An essential mechanism utilized by cells to repair replication-associated DSBs is homologous recombination (HR). In order to overcome replication stress and survive, cancer cells often require enhanced HR repair capacity. Therefore, the key link between HR repair and cellular tolerance to replication-associated DSBs provides us with a mechanistic rationale for exploiting synthetic lethality between HR repair inhibition and replication stress. DNA2 nuclease is an evolutionarily conserved essential enzyme in replication and HR repair. Here we demonstrate that DNA2 is overexpressed in pancreatic cancers, one of the deadliest and more aggressive forms of human cancers, where mutations in the KRAS are present in 90–95% of cases. In addition, depletion of DNA2 significantly reduces pancreatic cancer cell survival and xenograft tumor growth, suggesting the therapeutic potential of DNA2 inhibition. Finally, we develop a robust high-throughput biochemistry assay to screen for inhibitors of the DNA2 nuclease activity. The top inhibitors were shown to be efficacious against both yeast Dna2 and human DNA2. Treatment of cancer cells with DNA2 inhibitors recapitulates phenotypes observed upon DNA2 depletion, including decreased DNA double strand break end resection and attenuation of HR repair. Similar to genetic ablation of DNA2, chemical inhibition of DNA2 selectively attenuates the growth of various cancer cells with oncogene-induced replication stress. Taken together, our findings open a new avenue to develop a new class of anticancer drugs by targeting druggable nuclease DNA2. We propose DNA2 inhibition as new strategy in cancer therapy by targeting replication stress, a molecular property of cancer cells that is acquired as a result of oncogene activation instead of targeting currently undruggable oncoprotein itself such as KRAS.
Collapse
Affiliation(s)
- S Kumar
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - X Peng
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA.,Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - J Daley
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - L Yang
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - J Shen
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - N Nguyen
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - G Bae
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - H Niu
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA.,Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - Y Peng
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - H-J Hsieh
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - L Wang
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - C Rao
- Department of Internal Medicine, University of Oklahoma, Oklahoma City, OK, USA
| | - C C Stephan
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
| | - P Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT, USA
| | - G Ira
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - G Peng
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| |
Collapse
|
40
|
Miller AS, Daley JM, Pham NT, Niu H, Xue X, Ira G, Sung P. A novel role of the Dna2 translocase function in DNA break resection. Genes Dev 2017; 31:503-510. [PMID: 28336516 PMCID: PMC5393064 DOI: 10.1101/gad.295659.116] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 02/17/2017] [Indexed: 11/24/2022]
Abstract
Here, Miller et al. investigated the role of Dna2, a flap endonuclease with 5′–3′ helicase activity, which is involved in the resection process. The Dna2 helicase activity has been implicated in Okazaki fragment processing during DNA replication but is thought to be dispensable for DNA end resection. In this study, the authors find a previously unrecognized role of the Dna2 translocase activity in DNA break end resection and in the imposition of the 5′ strand specificity of end resection. DNA double-strand break repair by homologous recombination entails nucleolytic resection of the 5′ strand at break ends. Dna2, a flap endonuclease with 5′–3′ helicase activity, is involved in the resection process. The Dna2 helicase activity has been implicated in Okazaki fragment processing during DNA replication but is thought to be dispensable for DNA end resection. Unexpectedly, we found a requirement for the helicase function of Dna2 in end resection in budding yeast cells lacking exonuclease 1. Biochemical analysis reveals that ATP hydrolysis-fueled translocation of Dna2 on ssDNA facilitates 5′ flap cleavage near a single-strand–double strand junction while attenuating 3′ flap incision. Accordingly, the ATP hydrolysis-defective dna2-K1080E mutant is less able to generate long products in a reconstituted resection system. Our study thus reveals a previously unrecognized role of the Dna2 translocase activity in DNA break end resection and in the imposition of the 5′ strand specificity of end resection.
Collapse
Affiliation(s)
- Adam S Miller
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - James M Daley
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Nhung Tuyet Pham
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Hengyao Niu
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, Indiana 47405, USA
| | - Xiaoyu Xue
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Grzegorz Ira
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| |
Collapse
|
41
|
Pinto C, Kasaciunaite K, Seidel R, Cejka P. Human DNA2 possesses a cryptic DNA unwinding activity that functionally integrates with BLM or WRN helicases. eLife 2016; 5. [PMID: 27612385 PMCID: PMC5030094 DOI: 10.7554/elife.18574] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/08/2016] [Indexed: 12/13/2022] Open
Abstract
Human DNA2 (hDNA2) contains both a helicase and a nuclease domain within the same polypeptide. The nuclease of hDNA2 is involved in a variety of DNA metabolic processes. Little is known about the role of the hDNA2 helicase. Using bulk and single-molecule approaches, we show that hDNA2 is a processive helicase capable of unwinding kilobases of dsDNA in length. The nuclease activity prevents the engagement of the helicase by competing for the same substrate, hence prominent DNA unwinding by hDNA2 alone can only be observed using the nuclease-deficient variant. We show that the helicase of hDNA2 functionally integrates with BLM or WRN helicases to promote dsDNA degradation by forming a heterodimeric molecular machine. This collectively suggests that the hDNA2 motor promotes the enzyme's capacity to degrade dsDNA in conjunction with BLM or WRN and thus promote the repair of broken DNA. DOI:http://dx.doi.org/10.7554/eLife.18574.001
Collapse
Affiliation(s)
- Cosimo Pinto
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | | | - Ralf Seidel
- Institute of Experimental Physics I, University of Leipzig, Leipzig, Germany
| | - Petr Cejka
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| |
Collapse
|
42
|
Sajesh BV, McManus KJ. Targeting SOD1 induces synthetic lethal killing in BLM- and CHEK2-deficient colorectal cancer cells. Oncotarget 2016; 6:27907-22. [PMID: 26318585 PMCID: PMC4695034 DOI: 10.18632/oncotarget.4875] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 07/21/2015] [Indexed: 12/22/2022] Open
Abstract
Cancer is a major cause of death throughout the world, and there is a large need for better and more personalized approaches to combat the disease. Over the past decade, synthetic lethal approaches have been developed that are designed to exploit the aberrant molecular origins (i.e. defective genes) that underlie tumorigenesis. BLM and CHEK2 are two evolutionarily conserved genes that are somatically altered in a number of tumor types. Both proteins normally function in preserving genome stability through facilitating the accurate repair of DNA double strand breaks. Thus, uncovering synthetic lethal interactors of BLM and CHEK2 will identify novel candidate drug targets and lead chemical compounds. Here we identify an evolutionarily conserved synthetic lethal interaction between SOD1 and both BLM and CHEK2 in two distinct cell models. Using quantitative imaging microscopy, real-time cellular analyses, colony formation and tumor spheroid models we show that SOD1 silencing and inhibition (ATTM and LCS-1 treatments), or the induction of reactive oxygen species (2ME2 treatment) induces selective killing within BLM- and CHEK2-deficient cells relative to controls. We further show that increases in reactive oxygen species follow SOD1 silencing and inhibition that are associated with the persistence of DNA double strand breaks, and increases in apoptosis. Collectively, these data identify SOD1 as a novel candidate drug target in BLM and CHEK2 cancer contexts, and further suggest that 2ME2, ATTM and LCS-1 are lead therapeutic compounds warranting further pre-clinical study.
Collapse
Affiliation(s)
- Babu V Sajesh
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada.,Research Institute of Oncology and Hematology, Winnipeg, Manitoba, Canada
| | - Kirk J McManus
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada.,Research Institute of Oncology and Hematology, Winnipeg, Manitoba, Canada
| |
Collapse
|
43
|
Myler LR, Finkelstein IJ. Eukaryotic resectosomes: A single-molecule perspective. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 127:119-129. [PMID: 27498169 DOI: 10.1016/j.pbiomolbio.2016.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/02/2016] [Indexed: 12/13/2022]
Abstract
DNA double-strand breaks (DSBs) disrupt the physical and genetic continuity of the genome. If unrepaired, DSBs can lead to cellular dysfunction and malignant transformation. Homologous recombination (HR) is a universally conserved DSB repair mechanism that employs the information in a sister chromatid to catalyze error-free DSB repair. To initiate HR, cells assemble the resectosome: a multi-protein complex composed of helicases, nucleases, and regulatory proteins. The resectosome nucleolytically degrades (resects) the free DNA ends for downstream homologous recombination. Several decades of intense research have identified the core resectosome components in eukaryotes, archaea, and bacteria. More recently, these proteins have been characterized via single-molecule approaches. Here, we focus on recent single-molecule studies that have begun to unravel how nucleases, helicases, processivity factors, and other regulatory proteins dictate the extent and efficiency of DNA resection in eukaryotic cells. We conclude with a discussion of outstanding questions that can be addressed via single-molecule approaches.
Collapse
Affiliation(s)
- Logan R Myler
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
44
|
Paudyal SC, You Z. Sharpening the ends for repair: mechanisms and regulation of DNA resection. Acta Biochim Biophys Sin (Shanghai) 2016; 48:647-57. [PMID: 27174871 DOI: 10.1093/abbs/gmw043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/12/2016] [Indexed: 12/23/2022] Open
Abstract
DNA end resection is a key process in the cellular response to DNA double-strand break damage that is essential for genome maintenance and cell survival. Resection involves selective processing of 5' ends of broken DNA to generate ssDNA overhangs, which in turn control both DNA repair and checkpoint signaling. DNA resection is the first step in homologous recombination-mediated repair and a prerequisite for the activation of the ataxia telangiectasia mutated and Rad3-related (ATR)-dependent checkpoint that coordinates repair with cell cycle progression and other cellular processes. Resection occurs in a cell cycle-dependent manner and is regulated by multiple factors to ensure an optimal amount of ssDNA required for proper repair and genome stability. Here, we review the latest findings on the molecular mechanisms and regulation of the DNA end resection process and their implications for cancer formation and treatment.
Collapse
Affiliation(s)
- Sharad C Paudyal
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Zhongsheng You
- Department of Cell Biology and Physiology, Washington University School of Medicine, St Louis, MO 63110, USA
| |
Collapse
|
45
|
Jasin M, Haber JE. The democratization of gene editing: Insights from site-specific cleavage and double-strand break repair. DNA Repair (Amst) 2016; 44:6-16. [PMID: 27261202 DOI: 10.1016/j.dnarep.2016.05.001] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
DNA double-strand breaks (DSBs) are dangerous lesions that if not properly repaired can lead to genomic change or cell death. Organisms have developed several pathways and have many factors devoted to repairing DSBs, which broadly occurs by homologous recombination, which relies on an identical or homologous sequence to template repair, or nonhomologous end-joining. Much of our understanding of these repair mechanisms has come from the study of induced DNA cleavage by site-specific endonucleases. In addition to their biological role, these cellular pathways can be co-opted for gene editing to study gene function or for gene therapy or other applications. While the first gene editing experiments were done more than 20 years ago, the recent discovery of RNA-guided endonucleases has simplified approaches developed over the years to make gene editing an approach that is available to the entire biomedical research community. Here, we review DSB repair mechanisms and site-specific cleavage systems that have provided insight into these mechanisms and led to the current gene editing revolution.
Collapse
Affiliation(s)
- Maria Jasin
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, 02454-9110, USA.
| |
Collapse
|
46
|
Shastri VM, Schmidt KH. Cellular defects caused by hypomorphic variants of the Bloom syndrome helicase gene BLM. Mol Genet Genomic Med 2016; 4:106-19. [PMID: 26788541 PMCID: PMC4707026 DOI: 10.1002/mgg3.188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/28/2015] [Accepted: 10/29/2015] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Bloom syndrome is an autosomal recessive disorder characterized by extraordinary cancer incidence early in life and an average life expectancy of ~27 years. Premature stop codons in BLM, which encodes a DNA helicase that functions in DNA double-strand-break repair, make up the vast majority of Bloom syndrome mutations, with only 13 single amino acid changes identified in the syndrome. Sequencing projects have identified nearly one hundred single nucleotide variants in BLM that cause amino acid changes of uncertain significance. METHODS AND RESULTS Here, in addition to identifying five BLM variants incapable of complementing certain defects of Bloom syndrome cells, making them candidates for new Bloom syndrome causing mutations, we characterize a new class of BLM variants that cause some, but not all, cellular defects of Bloom syndrome. We find elevated sister-chromatid exchanges, a delayed DNA damage response and inefficient DNA repair. Conversely, hydroxyurea sensitivity and quadriradial chromosome accumulation, both characteristic of Bloom syndrome cells, are absent. These intermediate variants affect sites in BLM that function in ATP hydrolysis and in contacting double-stranded DNA. CONCLUSION Allele frequency and cellular defects suggest candidates for new Bloom syndrome causing mutations, and intermediate BLM variants that are hypomorphic which, instead of causing Bloom syndrome, may increase a person's risk for cancer or possibly other Bloom-syndrome-associated disorders, such as type-2 diabetes.
Collapse
Affiliation(s)
- Vivek M Shastri
- Department of Cell Biology, Microbiology and Molecular BiologyUniversity of South FloridaTampaFlorida33620; Graduate Program in Cell and Molecular BiologyUniversity of South FloridaTampaFlorida33620
| | - Kristina H Schmidt
- Department of Cell Biology, Microbiology and Molecular BiologyUniversity of South FloridaTampaFlorida33620; Cancer Biology and Evolution ProgramH. Lee Moffitt Cancer Center and Research InstituteTampaFlorida33612
| |
Collapse
|
47
|
Kennedy JA, Syed S, Schmidt KH. Structural Motifs Critical for In Vivo Function and Stability of the RecQ-Mediated Genome Instability Protein Rmi1. PLoS One 2015; 10:e0145466. [PMID: 26717309 PMCID: PMC4696737 DOI: 10.1371/journal.pone.0145466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/03/2015] [Indexed: 11/18/2022] Open
Abstract
Rmi1 is a member of the Sgs1/Top3/Rmi1 (STR) complex of Saccharomyces cerevisiae and has been implicated in binding and catalytic enhancement of Top3 in the dissolution of double Holliday junctions. Deletion of RMI1 results in a severe growth defect resembling that of top3Δ. Despite the importance of Rmi1 for cell viability, little is known about its functional domains, particularly in Rmi1 of S. cerevisiae, which does not have a resolved crystal structure and the primary sequence is poorly conserved. Here, we rationally designed point mutations based on bioinformatics analysis of order/disorder and helical propensity to define three functionally important motifs in yeast Rmi1 outside of the proposed OB-fold core. Replacing residues F63, Y218 and E220 with proline, designed to break predicted N-terminal and C-terminal α-helices, or with lysine, designed to eliminate hydrophobic residues at positions 63 and 218, while maintaining α-helical structure, caused hypersensitivity to hydroxyurea. Further, Y218P and E220P mutations, but not F63P and F63K mutations, led to reduced Rmi1 levels compared to wild type Rmi1, suggesting a role of the C-terminal α-helix in Rmi1 stabilization, most likely by protecting the integrity of the OB-fold core. Our bioinformatics analysis also suggests the presence of a disordered linker between the N-terminal α-helix and the OB fold core; a P88A mutation, designed to increase helicity in this linker, also impaired Rmi1 function in vivo. In conclusion, we propose a model that maps all functionally important structural features for yeast Rmi1 based on biological findings in yeast and structure-prediction-based alignment with the recently established crystal structure of the N-terminus of human Rmi1.
Collapse
Affiliation(s)
- Jessica A Kennedy
- Department of Cell Biology, Molecular Biology, and Microbiology, University of South Florida, Tampa, Florida, 33620, United States of America.,Graduate Program in Cell and Molecular Biology, H. Lee Moffitt Cancer Center, Tampa, Florida, 33612, United States of America
| | - Salahuddin Syed
- Department of Cell Biology, Molecular Biology, and Microbiology, University of South Florida, Tampa, Florida, 33620, United States of America.,Graduate Program in Cell and Molecular Biology, H. Lee Moffitt Cancer Center, Tampa, Florida, 33612, United States of America
| | - Kristina H Schmidt
- Department of Cell Biology, Molecular Biology, and Microbiology, University of South Florida, Tampa, Florida, 33620, United States of America.,Cancer Biology and Evolution Program, H. Lee Moffitt Cancer Center, Tampa, Florida, 33612, United States of America
| |
Collapse
|
48
|
Xu C, Wang Y, Wang L, Wang Q, Du LQ, Fan S, Liu Q, Li L. Accumulation and Phosphorylation of RecQ-Mediated Genome Instability Protein 1 (RMI1) at Serine 284 and Serine 292 during Mitosis. Int J Mol Sci 2015; 16:26395-405. [PMID: 26556339 PMCID: PMC4661824 DOI: 10.3390/ijms161125965] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 02/07/2023] Open
Abstract
Chromosome instability usually leads to tumorigenesis. Bloom syndrome (BS) is a genetic disease associated with chromosome instability. The BS gene product, BLM, has been reported to function in the spindle assembly checkpoint (SAC) to prevent chromosome instability. BTR complex, composed of BLM, topoisomerase IIIα (Topo IIIα), RMI1 (RecQ-mediated genome instability protein 1, BLAP75) and RMI2 (RecQ-mediated genome instability protein 2, BLAP18), is crucial for maintaining genome stability. Recent work has demonstrated that RMI2 also plays critical role in SAC. However, little is know about RMI1 regulation during the cell cycle. Here we present that RMI1 protein level does not change through G1, S and G2 phases, but significantly increases in M phase. Moreover, phosphorylation of RMI1 occurs in mitosis. Upon microtubule-disturbing agent, RMI1 is phosphorylated primarily at the sites of Serine 284 and Serine 292, which does not interfere with the formation of BTR complex. Additionally, this phosphorylation is partially reversed by roscovitine treatment, implying cycling-dependent kinase 1 (CDK1) might be one of the upstream kinases.
Collapse
Affiliation(s)
- Chang Xu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Yan Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Lu Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Qin Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Li-Qing Du
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Saijun Fan
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Qiang Liu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Lei Li
- Department of Experimental Radiation Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| |
Collapse
|
49
|
Kowalczykowski SC. An Overview of the Molecular Mechanisms of Recombinational DNA Repair. Cold Spring Harb Perspect Biol 2015; 7:a016410. [PMID: 26525148 PMCID: PMC4632670 DOI: 10.1101/cshperspect.a016410] [Citation(s) in RCA: 313] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Recombinational DNA repair is a universal aspect of DNA metabolism and is essential for genomic integrity. It is a template-directed process that uses a second chromosomal copy (sister, daughter, or homolog) to ensure proper repair of broken chromosomes. The key steps of recombination are conserved from phage through human, and an overview of those steps is provided in this review. The first step is resection by helicases and nucleases to produce single-stranded DNA (ssDNA) that defines the homologous locus. The ssDNA is a scaffold for assembly of the RecA/RAD51 filament, which promotes the homology search. On finding homology, the nucleoprotein filament catalyzes exchange of DNA strands to form a joint molecule. Recombination is controlled by regulating the fate of both RecA/RAD51 filaments and DNA pairing intermediates. Finally, intermediates that mature into Holliday structures are disjoined by either nucleolytic resolution or topological dissolution.
Collapse
Affiliation(s)
- Stephen C Kowalczykowski
- Department of Microbiology & Molecular Genetics and Department of Molecular and Cellular Biology, University of California, Davis, Davis, California 95616
| |
Collapse
|
50
|
Cejka P. DNA End Resection: Nucleases Team Up with the Right Partners to Initiate Homologous Recombination. J Biol Chem 2015; 290:22931-8. [PMID: 26231213 DOI: 10.1074/jbc.r115.675942] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The repair of DNA double-strand breaks by homologous recombination commences by nucleolytic degradation of the 5'-terminated strand of the DNA break. This leads to the formation of 3'-tailed DNA, which serves as a substrate for the strand exchange protein Rad51. The nucleoprotein filament then invades homologous DNA to drive template-directed repair. In this review, I discuss mainly the mechanisms of DNA end resection in Saccharomyces cerevisiae, which includes short-range resection by Mre11-Rad50-Xrs2 and Sae2, as well as processive long-range resection by Sgs1-Dna2 or Exo1 pathways. Resection mechanisms are highly conserved between yeast and humans, and analogous machineries are found in prokaryotes as well.
Collapse
Affiliation(s)
- Petr Cejka
- From the Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| |
Collapse
|