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Zhao LL, Gu YX, Dong JH, Li XT, Pan HY, Xue CY, Liu Y, Zhou YL, Zhang XX. New G-Triplex DNA Dramatically Activates the Fluorescence of Thioflavin T and Acts as a Turn-On Fluorescent Sensor for Uracil-DNA Glycosylase Activity Detection. Anal Chem 2024; 96:8458-8466. [PMID: 38710075 DOI: 10.1021/acs.analchem.4c00164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
G-triplexes are G-rich oligonucleotides composed of three G-tracts and have absorbed much attention due to their potential biological functions and attractive performance in biosensing. Through the optimization of loop compositions, DNA lengths, and 5'-flanking bases of G-rich sequences, a new stable G-triplex sequence with 14 bases (G3-F15) was discovered to dramatically activate the fluorescence of Thioflavin T (ThT), a water-soluble fluorogenic dye. The fluorescence enhancement of ThT after binding with G3-F15 reached 3200 times, which was the strongest one by far among all of the G-rich sequences. The conformations of G3-F15 and G3-F15/ThT were studied by circular dichroism. The thermal stability measurements indicated that G3-F15 was a highly stable G-triplex structure. The conformations of G3-F15 and G3-F15/ThT in the presence of different metal cations were studied thoroughly by fluorescent spectroscopy, circular dichroism, and nuclear magnetic resonance. Furthermore, using the G3-F15/ThT complex as a fluorescent probe, a robust and simple turn-on fluorescent sensor for uracil-DNA glycosylase activity was developed. This study proposes a new systematic strategy to explore new functional G-rich sequences and their ligands, which will promote their applications in diagnosis, therapy, and biosensing.
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Affiliation(s)
- Ling-Li Zhao
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yi-Xuan Gu
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jia-Hui Dong
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiao-Tong Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Hui-Yu Pan
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Chen-Yu Xue
- Key Laboratory of Forensic Toxicology, Ministry of Public Security, Beijing 100191, China
| | - Ying Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Ying-Lin Zhou
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xin-Xiang Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), MOE Key Laboratory of Bioorganic Chemistry and Molecular Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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2
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Liang C, Yang Y, Ning P, Chang C, Cao W. Structural and functional coupling in cross-linking uracil-DNA glycosylase UDGX. Biosci Rep 2024; 44:BSR20231551. [PMID: 38059429 PMCID: PMC10776899 DOI: 10.1042/bsr20231551] [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: 09/11/2023] [Revised: 11/14/2023] [Accepted: 12/05/2023] [Indexed: 12/08/2023] Open
Abstract
Enzymes in uracil-DNA glycosylase (UDG) superfamily are involved in removal of deaminated nucleobases such as uracil, methylcytosine derivatives such as formylcytosine and carboxylcytosine, and other base damage in DNA repair. UDGX is the latest addition of a new class to the UDG superfamily with a sporadic distribution in bacteria. UDGX type enzymes have a distinct biochemical property of cross-linking itself to the resulting AP site after uracil removal. Built on previous biochemical and structural analyses, this work comprehensively investigated the kinetic and enzymatic properties of Mycobacterium smegmatis UDGX. Kinetics and mutational analyses, coupled with structural information, defined the roles of E52, D56, D59, F65 of motif 1, H178 of motif 2 and N91, K94, R107 and H109 of motif 3 play in uracil excision and cross-linking. More importantly, a series of quantitative analyses underscored the structural coupling through inter-motif and intra-motif interactions and subsequent functional coupling of the uracil excision and cross-linking reactions. A catalytic model is proposed, which underlies this catalytic feature unique to UDGX type enzymes. This study offers new insight on the catalytic mechanism of UDGX and provides a unique example of enzyme evolution.
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Affiliation(s)
- Chuan Liang
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, U.S.A
| | - Ye Yang
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, U.S.A
| | - Ping Ning
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, U.S.A
| | - Chenyan Chang
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, U.S.A
| | - Weiguo Cao
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, U.S.A
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3
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Paligaspe PR, Weerasinghe S, Dissanayake DP, Senthilnithy R, Abeysinghe T, Jayasinghe CD. Computational investigation of impact of Pb(II) and Ni(II) ions on hUNG enzyme: insights from molecular dynamics simulations. J Biomol Struct Dyn 2024:1-10. [PMID: 38279925 DOI: 10.1080/07391102.2024.2307442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 01/08/2024] [Indexed: 01/29/2024]
Abstract
Human uracil DNA glycosylase (hUNG), a crucial player in the initiation of the base excision repair pathway, is susceptible to alterations in function and conformation induced by the accumulation of toxic metals. Despite the recognized impact of toxic metals on DNA repair enzymes, there exists a notable deficiency in theoretical investigations addressing this phenomenon. This study investigates the impact of toxic heavy metal ions, Pb(II) and Ni(II), on the stability of hUNG through molecular dynamics (MD) simulations. The initial analysis involved the identification of key cavities in the hUNG enzyme. Notably, the active site cavity emerged as a promising site for ligand binding. Subsequently, AutoDockTools software was employed to dock Pb(II) and Ni(II) onto the identified cavities, followed by extensive MD simulations. The MD analysis, encompassing parameters such as root mean square deviation, radius of gyration, solvent accessible surface area, hydrogen bond variations, Ramachandran plot, principal component analysis, and root mean square fluctuations, collectively revealed distinct alterations in the behavior of the enzyme upon complexation with Pb(II) and Ni(II). Interestingly, the enzyme exhibited enhanced structural stability, reduced flexibility, and modified hydrogen bonding patterns in the presence of these toxic metal ions. The observed limitation in structural flexibility implies a more rigid and stable conformation when the enzyme complex with Pb(II) and Ni(II) compared to its free form. This structural alteration may lead to a potential reduction in enzymatic activity, suggesting that toxic metal ions influence the functional dynamics of hUNG. These computational findings offer valuable insights into the molecular interactions between metal ions and enzymes.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Priyani R Paligaspe
- Department of Chemistry, Faculty of Natural Sciences, The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka
| | - Samantha Weerasinghe
- Department of Chemistry, Faculty of Science, University of Colombo, Colombo, Sri Lanka
| | | | - Rajendram Senthilnithy
- Department of Chemistry, Faculty of Natural Sciences, The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka
| | - Thelma Abeysinghe
- Department of Chemistry, Faculty of Natural Sciences, The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka
| | - Chanika D Jayasinghe
- Department of Zoology, Faculty of Natural Sciences, The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka
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4
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Wang X, Ma L, Li N, Gao N. Structural insights into the assembly and mechanism of mpox virus DNA polymerase complex F8-A22-E4-H5. Mol Cell 2023; 83:4398-4412.e4. [PMID: 37995690 DOI: 10.1016/j.molcel.2023.10.038] [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: 02/14/2023] [Revised: 08/21/2023] [Accepted: 09/25/2023] [Indexed: 11/25/2023]
Abstract
The DNA replication of mpox virus is performed by the viral polymerase F8 and also requires other viral factors, including processivity factor A22, uracil DNA glycosylase E4, and phosphoprotein H5. However, the molecular roles of these viral factors remain unclear. Here, we characterize the structures of F8-A22-E4 and F8-A22-E4-H5 complexes in the presence of different primer-template DNA substrates. E4 is located upstream of F8 on the template single-stranded DNA (ssDNA) and is catalytically active, highlighting a functional coupling between DNA base-excision repair and DNA synthesis. Moreover, H5, in the form of tetramer, binds to the double-stranded DNA (dsDNA) region downstream of F8 in a similar position as PCNA (proliferating cell nuclear antigen) does in eukaryotic polymerase complexes. Omission of H5 or disruption of its DNA interaction showed a reduced synthesis of full-length DNA products. These structures provide snapshots for the working cycle of the polymerase and generate insights into the mechanisms of these essential factors in viral DNA replication.
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Affiliation(s)
- Xiaohan Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Liangwen Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China.
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China; Changping Laboratory, Beijing 102206, China; National Biomedical Imaging Center, Peking University, Beijing 100871, China.
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5
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Czernecki D, Nourisson A, Legrand P, Delarue M. Reclassification of family A DNA polymerases reveals novel functional subfamilies and distinctive structural features. Nucleic Acids Res 2023; 51:4488-4507. [PMID: 37070157 PMCID: PMC10201439 DOI: 10.1093/nar/gkad242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 03/07/2023] [Accepted: 03/24/2023] [Indexed: 04/19/2023] Open
Abstract
Family A DNA polymerases (PolAs) form an important and well-studied class of extant polymerases participating in DNA replication and repair. Nonetheless, despite the characterization of multiple subfamilies in independent, dedicated works, their comprehensive classification thus far is missing. We therefore re-examine all presently available PolA sequences, converting their pairwise similarities into positions in Euclidean space, separating them into 19 major clusters. While 11 of them correspond to known subfamilies, eight had not been characterized before. For every group, we compile their general characteristics, examine their phylogenetic relationships and perform conservation analysis in the essential sequence motifs. While most subfamilies are linked to a particular domain of life (including phages), one subfamily appears in Bacteria, Archaea and Eukaryota. We also show that two new bacterial subfamilies contain functional enzymes. We use AlphaFold2 to generate high-confidence prediction models for all clusters lacking an experimentally determined structure. We identify new, conserved features involving structural alterations, ordered insertions and an apparent structural incorporation of a uracil-DNA glycosylase (UDG) domain. Finally, genetic and structural analyses of a subset of T7-like phages indicate a splitting of the 3'-5' exo and pol domains into two separate genes, observed in PolAs for the first time.
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Affiliation(s)
- Dariusz Czernecki
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Sorbonne Université, Collège Doctoral, ED 515, 75005 Paris, France
| | - Antonin Nourisson
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Sorbonne Université, Collège Doctoral, ED 515, 75005 Paris, France
| | - Pierre Legrand
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
- Synchrotron SOLEIL, L’Orme des Merisiers, 91190 Saint-Aubin, France
| | - Marc Delarue
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unit of Architecture and Dynamics of Biological Macromolecules, 75015 Paris, France
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6
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Britan-Rosich Y, Ma J, Kotler E, Hassan F, Botvinnik A, Smith Y, Moshel O, Nasereddin A, Sharma G, Pikarsky E, Ross S, Kotler M. APOBEC3G protects the genome of human cultured cells and mice from radiation-induced damage. FEBS J 2023; 290:1822-1839. [PMID: 36325681 PMCID: PMC10079569 DOI: 10.1111/febs.16673] [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: 03/24/2022] [Revised: 09/14/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022]
Abstract
Cytosine deaminases AID/APOBEC proteins act as potent nucleic acid editors, playing important roles in innate and adaptive immunity. However, the mutagenic effects of some of these proteins compromise genomic integrity and may promote tumorigenesis. Here, we demonstrate that human APOBEC3G (A3G), in addition to its role in innate immunity, promotes repair of double-strand breaks (DSBs) in vitro and in vivo. Transgenic mice expressing A3G successfully survived lethal irradiation, whereas wild-type controls quickly succumbed to radiation syndrome. Mass spectrometric analyses identified the differential upregulation of a plethora of proteins involved in DSB repair pathways in A3G-expressing cells early following irradiation to facilitate repair. Importantly, we find that A3G not only accelerates DSB repair but also promotes deamination-dependent error-free rejoining. These findings have two implications: (a) strategies aimed at inhibiting A3G may improve the efficacy of genotoxic therapies used to cure malignant tumours; and (b) enhancing A3G activity may reduce acute radiation syndrome in individuals exposed to ionizing radiation.
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Affiliation(s)
- Yelena Britan-Rosich
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Jing Ma
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, USA
| | - Eran Kotler
- Department of Genetics, Stanford University School of Medicine, Ca, USA
| | - Faizan Hassan
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Alexander Botvinnik
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Yoav Smith
- Genomic Data Analysis, Hadassah Medical School, Hebrew University, Jerusalem, Israel
| | - Ofra Moshel
- Core Research Facility, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Abed Nasereddin
- Core Research Facility of the Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Gunjan Sharma
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Eli Pikarsky
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Susan Ross
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, USA
| | - Moshe Kotler
- Department of Pathology and Immunology, The Lautenberg Center for Immunology and Cancer Research, The Hebrew University Hadassah Medical School, Jerusalem, Israel
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7
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Wu M, Lin T, Dong K, Gong Y, Liu X, Zhang L. Biochemical characterization and mechanistic insight of the family IV uracil DNA glycosylase from Sulfolobus islandicus REY15A. Int J Biol Macromol 2023; 230:123222. [PMID: 36639072 DOI: 10.1016/j.ijbiomac.2023.123222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/23/2022] [Accepted: 01/07/2023] [Indexed: 01/12/2023]
Abstract
Uracil DNA glycosylase (UDG) can remove uracil from DNA, thus playing an essential role in maintaining genomic stability. Family IV UDG members are mostly widespread in hyperthermophilic Archaea and bacteria. In this work, we characterized the family IV UDG from the hyperthermophilic crenarchaeon Sulfolobus islandicus REY15A (Sis-UDGIV) biochemically, and dissected the roles of nine conserved residues in uracil excision by mutational analyses. Biochemical data demonstrate that Sis-UDGIV displays maximum efficiency for uracil excision at 50 °C ~ 70 °C and at pH 7.0-9.0. Additionally, the enzyme has displays a weak activity without a divalent metal ion, but maximum activity with Mg2+. Our mutational analyses show that residues E48 and F55 in Sis-UDGIV are essential for uracil removal, and residues E48, F55, R87, R92 and K146 are responsible for binding DNA. Importantly, we systemically revealed the roles of four conserved cysteine residues C14, C17, C86 and C102 in Sis-UDGIV that are required for being ligands of FeS cluster in maintaining the overall protein conformation and stability by circular dichroism analyses. Overall, our work has provided insights into biochemical function and DNA-binding specificity of archaeal family IV UDGs.
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Affiliation(s)
- Mai Wu
- College of Environmental Science and Engineering, Yangzhou University, China
| | - Tan Lin
- College of Environmental Science and Engineering, Yangzhou University, China
| | - Kunming Dong
- College of Environmental Science and Engineering, Yangzhou University, China
| | - Yong Gong
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Xipeng Liu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, China
| | - Likui Zhang
- College of Environmental Science and Engineering, Yangzhou University, China; Guangling College, Yangzhou University, China.
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8
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Mingarro G, Del Olmo ML. Improvements in the genetic editing technologies: CRISPR-Cas and beyond. Gene 2023; 852:147064. [PMID: 36435506 DOI: 10.1016/j.gene.2022.147064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/31/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022]
Abstract
Gene editing is a great hope not only for the scientific community, but also for society in general. This is due to its potential therapeutic applications that would allow curing diseases of genetic origin. The first realistic approach to achieve this goal was the development of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) tools. This review deals with some of the improvements that have been designed to obtain more efficient and safer genome editing. Initial CRISPR-Cas (CRISPR associated) editing systems yield low efficiency and undesired editing products. To solve these problems, new approaches emerged, such as the creation of base editors. Recent discoveries have led to the development of many interesting alternatives, such as the CRISPR-associated transposable systems, which open the range by generating guided insertions, or the discovery of other programmable nucleases like the IscB family, which greatly increase the range of proteins available for editing uses. Also, to address the limitations of base editors, prime editors were created; this novel system, despite having some disadvantages compared to base editor systems, has the potential to generate all the possible point mutations. On the other hand, dual prime editing systems (like twin and homologous 3' extension-mediated prime editors) have been developed to create targeted insertions and enhance the editing outcomes, respectively. Furthermore, advances in gene editing do not reside solely in CRISPR-dependent systems, as we will discuss when treating the Replication Interrupted Template-Driven DNA Modification technique.
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Affiliation(s)
- Gerard Mingarro
- Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València. Burjassot (València), Spain
| | - Marcel Lí Del Olmo
- Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València. Burjassot (València), Spain.
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9
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Lactobacillus for ribosome peptide editing cancer. Clin Transl Oncol 2023; 25:1522-1544. [PMID: 36694080 PMCID: PMC9873400 DOI: 10.1007/s12094-022-03066-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/24/2022] [Indexed: 01/25/2023]
Abstract
This study reviews newly discovered insect peptide point mutations as new possible cancer research targets. To interpret newly discovered peptide point mutations in insects as new possible cancer research targets, we focused on the numerous peptide changes found in the 'CSP' family on the sex pheromone gland of the female silkworm moth Bombyx mori. We predict that the Bombyx peptide modifications will have a significant effect on cancer CUP (cancers of unknown primary) therapy and that bacterial peptide editing techniques, specifically Lactobacillus combined to CRISPR, will be used to regulate ribosomes and treat cancer in humans.
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10
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Li J, Yang Y, Chang C, Cao W. DR0022 from Deinococcus radiodurans is an acid uracil-DNA glycosylase. FEBS J 2022; 289:6420-6434. [PMID: 35607831 PMCID: PMC9796141 DOI: 10.1111/febs.16533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/08/2022] [Accepted: 05/23/2022] [Indexed: 01/02/2023]
Abstract
Uracil-DNA glycosylase (UDG) initiates base excision repair (BER) by removing damaged or modified nucleobases during DNA repair or mammalian demethylation. The UDG superfamily consists of at least six families with a variety of catalytic specificities and functions. Deinococcus radiodurans, an extreme radiation resistant bacterium, contains multiple members of UDG enzymes within its genome. The present study reveals that the putative protein, DR0022, is a uracil-DNA glycosylase that requires acidic conditions for its glycosylase activity, which is the first case of such an enzyme within the UDG superfamily. The key residues in the catalytic motifs are investigated by biochemical, enzyme kinetics, and de novo structural prediction, as well as molecular modeling analyses. The structural and catalytic roles of several distinct residues are discussed in light of predicted and modeled DR0022 glycosylase structures. The spontaneous mutation rate analysis performed in a dr0022 deficient D. radiodurans strain indicated that the dr0022 gene plays a role in mutation prevention. Furthermore, survival rate analysis in a dr0022 deficient D. radiodurans strain demonstrated its role in stress resistance, including γ-irradiation. Additionally, the novel acid UDG activity in relationship to its in vivo roles is discussed. This work underscores the functional diversity in the UDG superfamily.
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Affiliation(s)
- Jing Li
- Department of Genetics and BiochemistryClemson UniversityClemsonSCUSA
| | - Ye Yang
- Department of Genetics and BiochemistryClemson UniversityClemsonSCUSA
| | - Chenyan Chang
- Department of Genetics and BiochemistryClemson UniversityClemsonSCUSA
| | - Weiguo Cao
- Department of Genetics and BiochemistryClemson UniversityClemsonSCUSA
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11
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A novel Family V uracil DNA glycosylase from Sulfolobus islandicus REY15A. DNA Repair (Amst) 2022; 120:103420. [DOI: 10.1016/j.dnarep.2022.103420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/09/2022] [Accepted: 10/16/2022] [Indexed: 11/18/2022]
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12
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Screening of glycosylase activity on oxidative derivatives of methylcytosine: Pedobacter heparinus SMUG2 as a formylcytosine- and carboxylcytosine-DNA glycosylase. DNA Repair (Amst) 2022; 119:103408. [PMID: 36179537 DOI: 10.1016/j.dnarep.2022.103408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/16/2022] [Accepted: 09/20/2022] [Indexed: 11/22/2022]
Abstract
5-Methylcytosine (mC) is an epigenetic mark that impacts transcription, development, diseases including cancer and aging. The demethylation process involves Tet-mediated stepwise oxidation of mC to hmC, fC, or caC, excision of fC or caC by thymine-DNA glycosylase (TDG), and subsequent base excision repair. Thymine-DNA glycosylase (TDG) belongs to uracil-DNA glycosylase (UDG) superfamily, which is a group of enzymes that are initially found to be responsible for excising the deaminated bases from DNA and generating apurinic/apyrimidinic (AP) sites. mC oxidative derivatives may also be generated from Fenton chemistry and γ-irradiation. In screening DNA glycosylase activity in UDG superfamily, we identified new activity on fC- and caC-containing DNA in family 2 MUG/TDG and family 6 HDG enzymes. Surprisingly, we found a glycosylase SMUG2 from bacterium Pedobacter heparinus (Phe), a subfamily of family 3 SMUG1 DNA glycosylase, displayed catalytic activity towards not only DNA containing uracil, but also fC and caC. Given the sequence and structural differences between the family 3 and other family enzymes, we investigated the catalytic mechanism using mutational, enzyme kinetics and molecular modeling approaches. Mutational analysis and kinetics measurements identified I62, N63 and F76 of motif 1, and H205 of motif 2 in Phe SMUG2 as important catalytic residues, of which H205 of motif 2 played a critical role in catalyzing the removal of fC and caC. A catalytic model underlying the roles of these residues was proposed. The structural and catalytic differences between Phe SMUG2 and human TDG were compared by molecular modeling and molecular dynamics simulations. This study expands our understanding of DNA glycosylase capacity in UDG superfamily and provides insights into the molecular mechanism of fC and caC excision in Phe SMUG2.
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13
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Baljinnyam T, Sowers ML, Hsu CW, Conrad JW, Herring JL, Hackfeld LC, Sowers LC. Chemical and enzymatic modifications of 5-methylcytosine at the intersection of DNA damage, repair, and epigenetic reprogramming. PLoS One 2022; 17:e0273509. [PMID: 36037209 PMCID: PMC9423628 DOI: 10.1371/journal.pone.0273509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 08/09/2022] [Indexed: 11/19/2022] Open
Abstract
The DNA of all living organisms is persistently damaged by endogenous reactions including deamination and oxidation. Such damage, if not repaired correctly, can result in mutations that drive tumor development. In addition to chemical damage, recent studies have established that DNA bases can be enzymatically modified, generating many of the same modified bases. Irrespective of the mechanism of formation, modified bases can alter DNA-protein interactions and therefore modulate epigenetic control of gene transcription. The simultaneous presence of both chemically and enzymatically modified bases in DNA suggests a potential intersection, or collision, between DNA repair and epigenetic reprogramming. In this paper, we have prepared defined sequence oligonucleotides containing the complete set of oxidized and deaminated bases that could arise from 5-methylcytosine. We have probed these substrates with human glycosylases implicated in DNA repair and epigenetic reprogramming. New observations reported here include: SMUG1 excises 5-carboxyuracil (5caU) when paired with A or G. Both TDG and MBD4 cleave 5-formyluracil and 5caU when mispaired with G. Further, TDG not only removes 5-formylcytosine and 5-carboxycytosine when paired with G, but also when mispaired with A. Surprisingly, 5caU is one of the best substrates for human TDG, SMUG1 and MBD4, and a much better substrate than T. The data presented here introduces some unexpected findings that pose new questions on the interactions between endogenous DNA damage, repair, and epigenetic reprogramming pathways.
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Affiliation(s)
- Tuvshintugs Baljinnyam
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Mark L. Sowers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
- MD-PhD Combined Degree Program, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Chia Wei Hsu
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
- MD-PhD Combined Degree Program, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - James W. Conrad
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jason L. Herring
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Linda C. Hackfeld
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Lawrence C. Sowers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
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14
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ÇAĞLAR HO. Identification of Genes Related to DNA Repair Mechanism in Glioblastoma by Bioinformatics Methods. KOCAELI ÜNIVERSITESI SAĞLIK BILIMLERI DERGISI 2022. [DOI: 10.30934/kusbed.1003777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Objective: Aberrant expression of genes involved in DNA repair mechanisms (DRM) have been associated with radiation sensitivity of glioblastoma (GBM) cells. Identification of genes in DRM through bioinformatics methods may help identify potential novel therapeutic targets that can be used in GBM treatment. This study aims to identify genes that play a role in DRM in GBM using bioinformatics methods.
Methods: Genes associated with DRM were identified using the “Reactome” and “KEGG” databases. The mRNA expression profiles of DRM related genes were analyzed in the GEO GDS1813 and GDS2853 datasets including GBM tumor samples using the "Orange Canvas" software. Genetic changes of genes were identified in GBM TCGA cases using the cBioPortal database. The GEPIA2 was used to show the effect of altered expression profiles of these genes on patient survival.
Results: The mRNA expression profiles of ERCC6, FAN1, MBD4, PARP1 and UNG genes were found to be altered in GBM tumors. Mutations and copy number alterations for the identified genes were observed in TCGA GBM cases. The overall survival and disease-free survival of TCGA GBM patients were not significantly different between high and low expression groups.
Conclusion: ERCC6, PARP1 and UNG genes identified in the current study may be potential therapeutic targets that can increase the efficacy of radiotherapy in GBM in case of their suppression.
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15
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Melanker O, Goloubinoff P, Schreiber G. In vitro evolution of uracil glycosylase towards DnaKJ and GroEL binding evolves different misfolded states. J Mol Biol 2022; 434:167627. [PMID: 35597550 DOI: 10.1016/j.jmb.2022.167627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Abstract
Natural evolution is driven by random mutations that improve fitness. In vitro evolution mimics this process, however, on a short time-scale and is driven by the given bait. Here, we used directed in vitro evolution of a random mutant library of Uracil glycosylase (eUNG) displayed on yeast surface to select for binding to chaperones GroEL, DnaK+DnaJ+ATP (DnaKJ) or E.coli cell extract (CE), using binding to the eUNG inhibitor Ugi as probe for native fold. The CE selected population was further divided to Ugi binders (+U) or non-binders (-U). The aim here was to evaluate the sequence space and physical state of the evolved protein binding the different baits. We found that GroEL, DnaKJ and CE-U select and enrich for mutations causing eUNG to misfold, with the three being enriched in mutations in buried and conserved positions, with a tendency to increase positive charge. Still, each selection had its own trajectory, with GroEL and CE-U selecting mutants highly sensitive to protease cleavage while DnaKJ selected partially structured misfolded species with a tendency to refold, making them less sensitive to proteases. More general, our results show that GroEL has a higher tendency to purge promiscuous misfolded protein mutants from the system, while DnaKJ binds misfolding-prone mutant species that are, upon chaperone release, more likely to natively refold. CE-U shares some of the properties of GroEL- and DnaKJ-selected populations, while harboring also unique properties that can be explained by the presence of additional chaperones in CE, such as Trigger factor, HtpG and ClpB.
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Affiliation(s)
- Oran Melanker
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Lausanne University, 1015 Lausanne, Switzerland
| | - Gideon Schreiber
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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16
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Barka A, Berríos KN, Bailer P, Schutsky EK, Wang T, Kohli RM. The Base-Editing Enzyme APOBEC3A Catalyzes Cytosine Deamination in RNA with Low Proficiency and High Selectivity. ACS Chem Biol 2022; 17:629-636. [PMID: 35262324 PMCID: PMC9949940 DOI: 10.1021/acschembio.1c00919] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human APOBEC3A (A3A) is a nucleic acid-modifying enzyme that belongs to the cytidine deaminase family. Canonically, A3A catalyzes the deamination of cytosine into uracil in single-stranded DNA, an activity that makes A3A both a critical antiviral defense factor and a useful tool for targeted genome editing. However, mutagenesis by A3A has also been readily detected in both cellular DNA and RNA, activities that have been implicated in cancer. Given the importance of substrate discrimination for the physiological, pathological, and biotechnological activities of A3A, here we explore the mechanistic basis for its preferential targeting of DNA over RNA. Using a chimeric substrate containing a target ribocytidine within an otherwise DNA backbone, we demonstrate that a single hydroxyl at the sugar of the target base acts as a major selectivity determinant for deamination. To assess the contribution of bases neighboring the target cytosine, we show that overall RNA deamination is greatly reduced relative to that of DNA but can be observed when ideal features are present, such as preferred sequence context and secondary structure. A strong dependence on idealized substrate features can also be observed with a mutant of A3A (eA3A, N57G), which has been employed for genome editing due to altered selectivity for DNA over RNA. Altogether, our work reveals a relationship between the overall decreased reactivity of A3A and increased substrate selectivity, and our results hold implications both for characterizing off-target mutagenesis and for engineering optimized DNA deaminases for base-editing technologies.
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Affiliation(s)
- Aleksia Barka
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kiara N Berríos
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Peter Bailer
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Emily K Schutsky
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Tong Wang
- Graduate Group in Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Rahul M Kohli
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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17
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Computational design of a thermolabile uracil-DNA glycosylase of Escherichia coli. Biophys J 2022; 121:1276-1288. [PMID: 35183522 PMCID: PMC9034189 DOI: 10.1016/j.bpj.2022.02.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/01/2021] [Accepted: 02/15/2022] [Indexed: 11/23/2022] Open
Abstract
Polymerase chain reaction (PCR) is a powerful tool to diagnose infectious diseases. Uracil DNA glycosylase (UDG) is broadly used to remove carryover contamination in PCR. However, UDG can contribute to false negative results when not inactivated completely, leading to DNA degradation during the amplification step. In this study, we designed novel thermolabile UDG derivatives by supercomputing molecular dynamic simulations and residual network analysis. Based on enzyme activity analysis, thermolability, thermal stability, and biochemical experiments of Escherichia coli-derived UDG and 22 derivatives, we uncovered that the UDG D43A mutant eliminated the false negative problem, demonstrated high efficiency, and offered great benefit for use in PCR diagnosis. We further obtained structural and thermodynamic insights into the role of the D43A mutation, including perturbed protein structure near D43; weakened pairwise interactions of D43 with K42, N46, and R80; and decreased melting temperature and native fraction of the UDG D43A mutant compared with wild-type UDG.
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18
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dCas9 binding inhibits the initiation of base excision repair in vitro. DNA Repair (Amst) 2022; 109:103257. [PMID: 34847381 PMCID: PMC8748382 DOI: 10.1016/j.dnarep.2021.103257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/08/2021] [Accepted: 11/16/2021] [Indexed: 01/03/2023]
Abstract
Cas9 targets DNA during genome editing by forming an RNA:DNA heteroduplex (R-loop) between the Cas9-bound guide RNA and the targeted DNA strand. We have recently demonstrated that R-loop formation by catalytically inactive Cas9 (dCas9) is inherently mutagenic, in part, by promoting spontaneous cytosine deamination within the non-targeted single-stranded DNA of the dCas9-induced R-loop. However, the extent to which dCas9 binding and R-loop formation affect the subsequent repair of uracil lesions or other damaged DNA bases is unclear. Here, we show that DNA binding by dCas9 inhibits initiation of base excision repair (BER) for uracil lesions in vitro. Our data indicate that cleavage of uracil lesions by Uracil-DNA glycosylase (UDG) is generally inhibited at dCas9-bound DNA, in both the dCas9:sgRNA-bound target strand (TS) or the single-stranded non-target strand (NT). However, cleavage of a uracil lesion within the base editor window of the NT strand was less inhibited than at other locations, indicating that this site is more permissive to UDG activity. Furthermore, our data suggest that dCas9 binding to PAM sites can inhibit UDG activity. However, this non-specific inhibition can be relieved with the addition of an sgRNA lacking sequence complementarity to the DNA substrate. Moreover, we show that dCas9 binding also inhibits human single-strand selective monofunctional uracil-DNA glycosylase (SMUG1). Structural analysis of a Cas9-bound target site subsequently suggests a molecular mechanism for BER inhibition. Taken together, our results imply that dCas9 (or Cas9) binding may promote background mutagenesis by inhibiting the removal of DNA base lesions by BER.
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19
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Alexeeva M, Moen MN, Xu XM, Rasmussen A, Leiros I, Kirpekar F, Klungland A, Alsøe L, Nilsen H, Bjelland S. Intrinsic Strand-Incision Activity of Human UNG: Implications for Nick Generation in Immunoglobulin Gene Diversification. Front Immunol 2021; 12:762032. [PMID: 35003074 PMCID: PMC8730318 DOI: 10.3389/fimmu.2021.762032] [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: 08/20/2021] [Accepted: 11/17/2021] [Indexed: 12/05/2022] Open
Abstract
Uracil arises in cellular DNA by cytosine (C) deamination and erroneous replicative incorporation of deoxyuridine monophosphate opposite adenine. The former generates C → thymine transition mutations if uracil is not removed by uracil-DNA glycosylase (UDG) and replaced by C by the base excision repair (BER) pathway. The primary human UDG is hUNG. During immunoglobulin gene diversification in activated B cells, targeted cytosine deamination by activation-induced cytidine deaminase followed by uracil excision by hUNG is important for class switch recombination (CSR) and somatic hypermutation by providing the substrate for DNA double-strand breaks and mutagenesis, respectively. However, considerable uncertainty remains regarding the mechanisms leading to DNA incision following uracil excision: based on the general BER scheme, apurinic/apyrimidinic (AP) endonuclease (APE1 and/or APE2) is believed to generate the strand break by incising the AP site generated by hUNG. We report here that hUNG may incise the DNA backbone subsequent to uracil excision resulting in a 3´-α,β-unsaturated aldehyde designated uracil-DNA incision product (UIP), and a 5´-phosphate. The formation of UIP accords with an elimination (E2) reaction where deprotonation of C2´ occurs via the formation of a C1´ enolate intermediate. UIP is removed from the 3´-end by hAPE1. This shows that the first two steps in uracil BER can be performed by hUNG, which might explain the significant residual CSR activity in cells deficient in APE1 and APE2.
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Affiliation(s)
- Marina Alexeeva
- Department of Chemistry, Bioscience and Environmental Technology, University of Stavanger, Stavanger, Norway
| | - Marivi Nabong Moen
- Department of Chemistry, Bioscience and Environmental Technology, University of Stavanger, Stavanger, Norway
- Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | - Xiang Ming Xu
- Department of Chemistry, Bioscience and Environmental Technology, University of Stavanger, Stavanger, Norway
| | - Anette Rasmussen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Ingar Leiros
- Department of Chemistry, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Finn Kirpekar
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Arne Klungland
- Department of Microbiology, Oslo University Hospital, Oslo, Norway
| | - Lene Alsøe
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
- Section of Clinical Molecular Biology, Akershus University Hospital, Lørenskog, Norway
| | - Hilde Nilsen
- Department of Clinical Molecular Biology, University of Oslo, Oslo, Norway
- Section of Clinical Molecular Biology, Akershus University Hospital, Lørenskog, Norway
- *Correspondence: Svein Bjelland, ; Hilde Nilsen,
| | - Svein Bjelland
- Department of Chemistry, Bioscience and Environmental Technology, University of Stavanger, Stavanger, Norway
- Section of Clinical Molecular Biology, Akershus University Hospital, Lørenskog, Norway
- *Correspondence: Svein Bjelland, ; Hilde Nilsen,
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20
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Abstract
Staphylococcus aureus is a common cause of both superficial and invasive infections of humans and animals. Despite a potent host response and apparently appropriate antibiotic therapy, staphylococcal infections frequently become chronic or recurrent, demonstrating a remarkable ability of S. aureus to withstand the hostile host environment. There is growing evidence that staphylococcal DNA repair makes important contributions to the survival of the pathogen in host tissues, as well as promoting the emergence of mutants that resist host defenses and antibiotics. While much of what we know about DNA repair in S. aureus is inferred from studies with model organisms, the roles of specific repair mechanisms in infection are becoming clear and differences with Bacillus subtilis and Escherichia coli have been identified. Furthermore, there is growing interest in staphylococcal DNA repair as a target for novel therapeutics that sensitize the pathogen to host defenses and antibiotics. In this review, we discuss what is known about staphylococcal DNA repair and its role in infection, examine how repair in S. aureus is similar to, or differs from, repair in well-characterized model organisms, and assess the potential of staphylococcal DNA repair as a novel therapeutic target.
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21
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Xie Y, Karki CB, Chen J, Liu D, Li L. Computational Study on DNA Repair: The Roles of Electrostatic Interactions Between Uracil-DNA Glycosylase (UDG) and DNA. Front Mol Biosci 2021; 8:718587. [PMID: 34422909 PMCID: PMC8377759 DOI: 10.3389/fmolb.2021.718587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/30/2021] [Indexed: 11/28/2022] Open
Abstract
Uracil-DNA glycosylase (UDG) is one of the most important base excision repair (BER) enzymes involved in the repair of uracil-induced DNA lesion by removing uracil from the damaged DNA. Uracil in DNA may occur due to cytosine deamination or deoxy uridine monophosphate (dUMP) residue misincorporation during DNA synthesis. Medical evidences show that an abnormal expression of UDG is related to different types of cancer, including colorectal cancer, lung cancer, and liver cancer. Therefore, the research of UDG is crucial in cancer treatment and prevention as well as other clinical activities. Here we applied multiple computational methods to study UDG in several perspectives: Understanding the stability of the UDG enzyme in different pH conditions; studying the differences in charge distribution between the pocket side and non-pocket side of UDG; analyzing the field line distribution at the interfacial area between UDG and DNA; and performing electrostatic binding force analyses of the special region of UDG (pocket area) and the target DNA base (uracil) as well as investigating the charged residues on the UDG binding pocket and binding interface. Our results show that the whole UDG binding interface, and not the UDG binding pocket area alone, provides the binding attractive force to the damaged DNA at the uracil base.
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Affiliation(s)
- Yixin Xie
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States
| | - Chitra B Karki
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States
| | - Jiawei Chen
- Computer Science Program, Santa Monica College, Santa Monica, CA, United States
| | - Dongfang Liu
- Department of Computer Engineering, Rochester Institute of Technology, Rochester, NY, United States
| | - Lin Li
- Computational Science Program, University of Texas at El Paso, El Paso, TX, United States.,Department of Physics, University of Texas at El Paso, El Paso, TX, United States
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22
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Smith AD, Kamiński MJ, Kanda K, Sweet AD, Betancourt JL, Holmgren CA, Hempel E, Alberti F, Hofreiter M. Recovery and analysis of ancient beetle DNA from subfossil packrat middens using high-throughput sequencing. Sci Rep 2021; 11:12635. [PMID: 34135378 PMCID: PMC8209150 DOI: 10.1038/s41598-021-91896-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/26/2021] [Indexed: 11/16/2022] Open
Abstract
The study of ancient DNA is revolutionizing our understanding of paleo-ecology and the evolutionary history of species. Insects are essential components in many ecosystems and constitute the most diverse group of animals. Yet they are largely neglected in ancient DNA studies. We report the results of the first targeted investigation of insect ancient DNA to positively identify subfossil insects to species, which includes the recovery of endogenous content from samples as old as ~ 34,355 ybp. Potential inhibitors currently limiting widespread research on insect ancient DNA are discussed, including the lack of closely related genomic reference sequences (decreased mapping efficiency) and the need for more extensive collaborations with insect taxonomists. The advantages of insect-based studies are also highlighted, especially in the context of understanding past climate change. In this regard, insect remains from ancient packrat middens are a rich and largely uninvestigated resource for exploring paleo-ecology and species dynamics over time.
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Affiliation(s)
- Aaron D Smith
- Department of Entomology, Purdue University, 901 W. State Street, West Lafayette, IN, 47907, USA.
| | - Marcin J Kamiński
- Department of Entomology, Purdue University, 901 W. State Street, West Lafayette, IN, 47907, USA
- Zoological Museum, Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679, Warszawa, Poland
| | - Kojun Kanda
- USDA Systematic Entomology Laboratory, C/O Smithsonian Institution, National Museum of Natural History, Washington, DC, USA
| | - Andrew D Sweet
- Department of Entomology, Purdue University, 901 W. State Street, West Lafayette, IN, 47907, USA
- Department of Biological Sciences, Arkansas State University, State University, AR, 72467, USA
| | | | - Camille A Holmgren
- Department of Geography and Planning, SUNY Buffalo State College, Buffalo, NY, USA
| | - Elisabeth Hempel
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Museum Für Naturkunde, Berlin, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Federica Alberti
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Reiss-Engelhorn-Museen, Mannheim, Germany
| | - Michael Hofreiter
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
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23
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Zhang Y, Yun K, Huang H, Tu R, Hua E, Wang M. Antisense RNA Interference-Enhanced CRISPR/Cas9 Base Editing Method for Improving Base Editing Efficiency in Streptomyces lividans 66. ACS Synth Biol 2021; 10:1053-1063. [PMID: 33720688 DOI: 10.1021/acssynbio.0c00563] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CRISPR/Cas9-mediated base editors, based on cytidine deaminase or adenosine deaminase, are emerging genetic technologies that facilitate genomic manipulation in many organisms. Since base editing is free from DNA double-strand breaks (DSBs), it has certain advantages, such as a lower toxicity, compared to the traditional DSB-based genome engineering technologies. In terms of Streptomyces, a base editing method has been successfully applied in several model and non-model species, such as Streptomyces coelicolor and Streptomyces griseofuscus. In this study, we first proved that BE2 (rAPOBEC1-dCas9-UGI) and BE3 (rAPOBEC1-nCas9-UGI) were functional base editing tools in Streptomyces lividans 66, albeit with a much lower editing efficiency compared to that of S. coelicolor. Uracil generated in deamination is a key intermediate in the base editing process, and it can be hydrolyzed by uracil DNA glycosidase (UDG) involved in the intracellular base excision repair, resulting in a low base editing efficiency. By knocking out two endogenous UDGs (UDG1 and UDG2), we managed to improve the base editing efficiency by 3.4-67.4-fold among different loci. However, the inactivation of UDG is detrimental to the genome stability and future application of engineered strains. Therefore, we finally developed antisense RNA interference-enhanced CRISPR/Cas9 Base Editing method (asRNA-BE) to transiently disrupt the expression of uracil DNA glycosidases during base editing, leading to a 2.8-65.8-fold enhanced editing efficiency and better genome stability. Our results demonstrate that asRNA-BE is a much better editing tool for base editing in S. lividans 66 and might be beneficial for improving the base editing efficiency and genome stability in other Streptomyces strains.
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Affiliation(s)
- Yue Zhang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Kaiyue Yun
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Huamei Huang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ran Tu
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Erbing Hua
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Meng Wang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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24
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Westwood MN, Ljunggren KD, Boyd B, Becker J, Dwyer TJ, Meints GA. Single-Base Lesions and Mismatches Alter the Backbone Conformational Dynamics in DNA. Biochemistry 2021; 60:873-885. [PMID: 33689312 DOI: 10.1021/acs.biochem.0c00784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
DNA damage has been implicated in numerous human diseases, particularly cancer, and the aging process. Single-base lesions and mismatches in DNA can be cytotoxic or mutagenic and are recognized by a DNA glycosylase during the process of base excision repair. Altered local dynamics and conformational properties in damaged DNAs have previously been suggested to assist in recognition and specificity. Herein, we use solution nuclear magnetic resonance to quantify changes in BI-BII backbone conformational dynamics due to the presence of single-base lesions in DNA, including uracil, dihydrouracil, 1,N6-ethenoadenine, and T:G mismatches. Stepwise changes to the %BII and ΔG of the BI-BII dynamic equilibrium compared to those of unmodified sequences were observed. Additionally, the equilibrium skews toward endothermicity for the phosphates nearest the lesion/mismatched base pair. Finally, the phosphates with the greatest alterations correlate with those most relevant to the repair of enzyme binding. All of these results suggest local conformational rearrangement of the DNA backbone may play a role in lesion recognition by repair enzymes.
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Affiliation(s)
- M N Westwood
- Department of Chemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States
| | - K D Ljunggren
- Department of Chemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States
| | - Benjamin Boyd
- Department of Chemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States
| | - Jaclyn Becker
- Department of Chemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States
| | - Tammy J Dwyer
- Department of Chemistry and Biochemistry, University of San Diego, San Diego, California 92110, United States
| | - Gary A Meints
- Department of Chemistry, Missouri State University, 901 South National Avenue, Springfield, Missouri 65897, United States
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25
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Ablation of SMUG1 Reduces Cell Viability and Increases UVC-Mediated Apoptosis in Hepatocarcinoma HepG2 Cells. Genes (Basel) 2021; 12:genes12020201. [PMID: 33573186 PMCID: PMC7911780 DOI: 10.3390/genes12020201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/16/2021] [Accepted: 01/28/2021] [Indexed: 01/21/2023] Open
Abstract
Uracil is an unavoidable aberrant base in DNA sequences, the repair of which takes place by a highly efficient base excision repair mechanism. The removal of uracil from the genome requires multiple biochemical steps with conformational changes of DNA that inhibit DNA replication and interfere with transcription. However, the relevance of uracil in DNA for cellular physiology and transcriptional regulation is not fully understood. We investigated the functional roles of SMUG1 using knock-down (KD) and knock-out (KO) models. The proliferation ratio of SMUG1 KD and KO cells was decreased compared to WT control cells, and the cell cycle was arrested in the G2/M phases before the transition to mitosis. The apoptotic cell death was increased in KD and KO cell lines through the increase of BAX and active caspase 3 expression. Phospho-gamma-H2AX expression, which reflected accumulated DNA damage, was also increased in KO cells. Moreover, the apoptotic cells by DNA damage accumulation were markedly increased in SMUG1 KD and KO cells after ultraviolet C irradiation. Transcriptomic analysis using RNA-seq revealed that SMUG1 was involved in gene sets expression including cell cycle transition and chromatin silencing. Together, the results implicate SMUG1 as a critical factor in cell cycle and transcriptional regulation.
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RNA Metabolism Guided by RNA Modifications: The Role of SMUG1 in rRNA Quality Control. Biomolecules 2021; 11:biom11010076. [PMID: 33430019 PMCID: PMC7826747 DOI: 10.3390/biom11010076] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/29/2020] [Accepted: 01/05/2021] [Indexed: 12/19/2022] Open
Abstract
RNA modifications are essential for proper RNA processing, quality control, and maturation steps. In the last decade, some eukaryotic DNA repair enzymes have been shown to have an ability to recognize and process modified RNA substrates and thereby contribute to RNA surveillance. Single-strand-selective monofunctional uracil-DNA glycosylase 1 (SMUG1) is a base excision repair enzyme that not only recognizes and removes uracil and oxidized pyrimidines from DNA but is also able to process modified RNA substrates. SMUG1 interacts with the pseudouridine synthase dyskerin (DKC1), an enzyme essential for the correct assembly of small nucleolar ribonucleoproteins (snRNPs) and ribosomal RNA (rRNA) processing. Here, we review rRNA modifications and RNA quality control mechanisms in general and discuss the specific function of SMUG1 in rRNA metabolism. Cells lacking SMUG1 have elevated levels of immature rRNA molecules and accumulation of 5-hydroxymethyluridine (5hmU) in mature rRNA. SMUG1 may be required for post-transcriptional regulation and quality control of rRNAs, partly by regulating rRNA and stability.
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Molecular characterization of EhAK6, an endonuclease V domain-containing aurora kinase protein from Entamoeba histolytica: Protein-protein interaction, docking and functional aspect. CURRENT RESEARCH IN BIOTECHNOLOGY 2021. [DOI: 10.1016/j.crbiot.2021.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Elsakrmy N, Zhang-Akiyama QM, Ramotar D. The Base Excision Repair Pathway in the Nematode Caenorhabditis elegans. Front Cell Dev Biol 2020; 8:598860. [PMID: 33344454 PMCID: PMC7744777 DOI: 10.3389/fcell.2020.598860] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022] Open
Abstract
Exogenous and endogenous damage to the DNA is inevitable. Several DNA repair pathways including base excision, nucleotide excision, mismatch, homologous and non-homologous recombinations are conserved across all organisms to faithfully maintain the integrity of the genome. The base excision repair (BER) pathway functions to repair single-base DNA lesions and during the process creates the premutagenic apurinic/apyrimidinic (AP) sites. In this review, we discuss the components of the BER pathway in the nematode Caenorhabditis elegans and delineate the different phenotypes caused by the deletion or the knockdown of the respective DNA repair gene, as well as the implications. To date, two DNA glycosylases have been identified in C. elegans, the monofunctional uracil DNA glycosylase-1 (UNG-1) and the bifunctional endonuclease III-1 (NTH-1) with associated AP lyase activity. In addition, the animal possesses two AP endonucleases belonging to the exonuclease-3 and endonuclease IV families and in C. elegans these enzymes are called EXO-3 and APN-1, respectively. In mammalian cells, the DNA polymerase, Pol beta, that is required to reinsert the correct bases for DNA repair synthesis is not found in the genome of C. elegans and the evidence indicates that this role could be substituted by DNA polymerase theta (POLQ), which is known to perform a function in the microhomology-mediated end-joining pathway in human cells. The phenotypes observed by the C. elegans mutant strains of the BER pathway raised many challenging questions including the possibility that the DNA glycosylases may have broader functional roles, as discuss in this review.
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Affiliation(s)
- Noha Elsakrmy
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar
| | - Qiu-Mei Zhang-Akiyama
- Laboratory of Stress Response Biology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Dindial Ramotar
- Division of Biological and Biomedical Sciences, College of Health and Life Sciences, Hamad Bin Khalifa University, Education City, Qatar
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Jia Q, Zeng H, Tu J, Sun L, Cao W, Xie W. Structural insights into an MsmUdgX mutant capable of both crosslinking and uracil excision capability. DNA Repair (Amst) 2020; 97:103008. [PMID: 33248387 DOI: 10.1016/j.dnarep.2020.103008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 11/30/2022]
Abstract
UdgX from Mycobacterium smegmatis (MsmUdgX) is a prototypical enzyme representing a new class of uracil-DNA glycosylases (UDG) closely related to the family 4 enzymes. It possesses a unique R-loop rich in positive residues and forms a covalent bond with single-stranded uracil-containing DNAs (ssDNA-Us) that is resistant to denaturants after the removal of the target uracil. We previously identified the H109E mutant of MsmUdgX that forms a weak covalent complex with ssDNA-U and yet possesses moderate uracil excision activity, but the mechanism of its action is not fully understood. To further study the catalytic process of MsmUdgX, we solved the high-resolution crystal structures of H109E in the free and DNA-bound forms, respectively. We found that the key residue Glu109 adopts a similar conformation to that of WT to form the covalent bond, suggesting that it still employs the same "excision-inhibition" mechanism to that of the WT enzyme. The enzyme remains nearly intact before and after the crosslinking reaction, but the first half of the R-loop exhibits large structural differences while the rest of the loop barely moves, owing to the salt-bridge interaction formed via Arg107. Additionally, Arg107, along with Gln53 was found to play important roles in the biochemical properties of MsmUdgX. Our studies provide new insights into the MsmUdgX catalysis and improve our understanding on this unique enzyme.
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Affiliation(s)
- Qian Jia
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, 510006, China
| | - Hui Zeng
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, 510006, China
| | - Jie Tu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, 510006, China
| | - Litao Sun
- School of Public Health (Shenzhen), The Sun Yat-sen University, Guangdong, 518107, China
| | - Weiguo Cao
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, 29634, USA
| | - Wei Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, 510006, China.
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Lian M, Chen F, Huang X, Zhao X, Gou S, Li N, Jin Q, Shi H, Liang Y, Xie J, Ge W, Zhuang Z, Wang J, Ye Y, Yang Y, Wang K, Lai L, Wu H. Improving the Cpf1-mediated base editing system by combining dCas9/dead sgRNA with human APOBEC3A variants. J Genet Genomics 2020; 48:92-95. [PMID: 33504469 DOI: 10.1016/j.jgg.2020.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 06/29/2020] [Accepted: 07/20/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Meng Lian
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Institute of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Fangbing Chen
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingyun Huang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaozhu Zhao
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shixue Gou
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nan Li
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qin Jin
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hui Shi
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanhui Liang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingke Xie
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weikai Ge
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenpeng Zhuang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiaowei Wang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yinghua Ye
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou 510530, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
| | - Yi Yang
- Key Laboratory for Major Obstetrics Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Hospital Affiliated of Guangzhou Medical University, Guangzhou 510150, China
| | - Kepin Wang
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou 510530, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China.
| | - Liangxue Lai
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou 510530, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China.
| | - Han Wu
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Research Unit of Generation of Large Animal Disease Models, Chinese Academy of Medical Sciences (2019RU015), Guangzhou 510530, China; Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China.
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Zhu W, Hu J, Chi J, Li Y, Yang B, Hu W, Chen F, Xu C, Chai L, Bao Y. Label-Free Proteomics Reveals the Molecular Mechanism of Subculture Induced Strain Degeneration and Discovery of Indicative Index for Degeneration in Pleurotus ostreatus. Molecules 2020; 25:molecules25214920. [PMID: 33114310 PMCID: PMC7660624 DOI: 10.3390/molecules25214920] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 11/16/2022] Open
Abstract
Pleurotus ostreatus is one of the widely cultivated edible fungi across the world. Mycelial subculture is an indispensable part in the process of cultivation and production for all kinds of edible fungi. However, successive subcultures usually lead to strain degeneration. The degenerated strains usually have a decrease in stress resistance, yield, and an alteration in fruiting time, which will subsequently result in tremendous economic loss. Through proteomic analysis, we identified the differentially expressed proteins (DEPs) in the mycelium of Pleurotus ostreatus from different subcultured generations. We found that the DNA damage repair system, especially the double-strand breaks (DSBs), repairs via homologous recombination, was impaired in the subcultured mycelium, and gradual accumulation of the DSBs would lead to the strain degeneration after successive subculture. The TUNEL assay further confirmed our finding about the DNA breaks in the subcultured mycelium. Interestingly, the enzyme activity of laccase, carboxylic ester hydrolase, α-galactosidase, and catalase directly related to passage number could be used as the characteristic index for strain degeneration determination. Our results not only reveal for the first time at the molecular level that genomic instability is the cause of degeneration, but also provide an applicable approach for monitoring strain degeneration in process of edible fungi cultivation and production.
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Affiliation(s)
- Weiwei Zhu
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China;
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Jinbo Hu
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; (J.H.); (B.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingliang Chi
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Yang Li
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Bing Yang
- Laboratory of Photosynthesis and Environment, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China; (J.H.); (B.Y.)
| | - Wenli Hu
- Core Facility Center, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China;
| | - Fei Chen
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Chong Xu
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Linshan Chai
- Microbial Research Institute of Liaoning Province, Chaoyang 122000, China; (J.C.); (Y.L.); (F.C.); (C.X.); (L.C.)
| | - Yongming Bao
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China;
- School of Ocean Science and Technology, Dalian University of Technology, Panjin 124021, China
- Correspondence: ; Tel.: +86-427-2631777; Fax: +86-411-84706365
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Tran A, Zheng S, White DS, Curry AM, Cen Y. Retracted Article: Divergent synthesis of 5-substituted pyrimidine 2'-deoxynucleosides and their incorporation into oligodeoxynucleotides for the survey of uracil DNA glycosylases. Chem Sci 2020; 11:11818-11826. [PMID: 34123208 PMCID: PMC8162711 DOI: 10.1039/d0sc04161k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/07/2020] [Indexed: 11/21/2022] Open
Abstract
Recent studies have indicated that 5-methylcytosine (5mC) residues in DNA can be oxidized and potentially deaminated to the corresponding thymine analogs. Some of these oxidative DNA damages have been implicated as new epigenetic markers that could have profound influences on chromatin function as well as disease pathology. In response to oxidative damage, the cells have a complex network of repair systems that recognize, remove and rebuild the lesions. However, how the modified nucleobases are detected and repaired remains elusive, largely due to the limited availability of synthetic oligodeoxynucleotides (ODNs) containing these novel DNA modifications. A concise and divergent synthetic strategy to 5mC derivatives has been developed. These derivatives were further elaborated to the corresponding phosphoramidites to enable the site-specific incorporation of modified nucleobases into ODNs using standard solid-phase DNA synthesis. The synthetic methodology, along with the panel of ODNs, is of great value to investigate the biological functions of epigenetically important nucleobases, and to elucidate the diversity in chemical lesion repair.
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Affiliation(s)
- Ai Tran
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences Colchester VT 05446 USA
| | - Song Zheng
- Department of Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences Colchester VT 05446 USA
| | - Dawanna S White
- Department of Medicinal Chemistry, Virginia Commonwealth University Richmond VA 23219 USA +1-804-828-7405
| | - Alyson M Curry
- Department of Medicinal Chemistry, Virginia Commonwealth University Richmond VA 23219 USA +1-804-828-7405
| | - Yana Cen
- Department of Medicinal Chemistry, Virginia Commonwealth University Richmond VA 23219 USA +1-804-828-7405
- Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University Richmond VA 23219 USA
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Kara H, Chazal N, Bouaziz S. Is Uracil-DNA Glycosylase UNG2 a New Cellular Weapon Against HIV-1? Curr HIV Res 2020; 17:148-160. [PMID: 31433761 DOI: 10.2174/1570162x17666190821154331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/01/2019] [Accepted: 08/09/2019] [Indexed: 01/12/2023]
Abstract
Uracil-DNA glycosylase-2 (UNG2) is a DNA repair protein that removes uracil from single and double-stranded DNA through a basic excision repair process. UNG2 is packaged into new virions by interaction with integrase (IN) and is needed during the early stages of the replication cycle. UNG2 appears to play both a positive and negative role during HIV-1 replication; UNG2 improves the fidelity of reverse transcription but the nuclear isoform of UNG2 participates in the degradation of cDNA and the persistence of the cellular genome by repairing its uracil mismatches. In addition, UNG2 is neutralized by Vpr, which redirects it to the proteasome for degradation, suggesting that UNG2 may be a new cellular restriction factor. So far, we have not understood why HIV-1 imports UNG2 via its IN and why it causes degradation of endogenous UNG2 by redirecting it to the proteasome via Vpr. In this review, we propose to discuss the ambiguous role of UNG2 during the HIV-1 replication cycle.
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Affiliation(s)
- Hesna Kara
- Cibles Therapeutiques et Conception de Medicaments (CiTCoM), CNRS UMR8038, Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, Paris, France
| | - Nathalie Chazal
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS UMR9004, Universite de Montpellier, Montpellier, France
| | - Serge Bouaziz
- Cibles Therapeutiques et Conception de Medicaments (CiTCoM), CNRS UMR8038, Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, Paris, France
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Zhang J, Wang S, Abee T, van der Veen S. Role of Base Excision Repair in Listeria monocytogenes DNA Stress Survival During Infections. J Infect Dis 2020; 223:721-732. [PMID: 32644146 DOI: 10.1093/infdis/jiaa412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/07/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Base excision repair (BER), consisting mostly of lesion-specific DNA glycosylases and apurinic/apyrimidinic (AP) endonucleases, is one of the most important DNA repair mechanisms for repair of single nucleobase lesions generated by reactive oxygen and nitrogen species as part of an immune response against bacterial infections. However, few studies have addressed the contribution of BER to bacterial virulence and Listeria monocytogenes BER has thus far remained completely uncharacterized. METHODS Analysis of the L. monocytogenes EGDe genome identified 7 DNA glycosylases (MutM, MutY, Nth, Tag, Mpg, Ung, and Ung2) and 2 apurinic/apyrimidinic endonucleases (Xth and Nfo) as part of BER. Markerless in-frame deletion mutants were generated for all 9 genes, and mutants were tested for DNA damage survival, mutagenesis, and the ability to colonize a mouse model of infection. RESULTS Distinct lesion-specific phenotypes were identified for all deletion mutants. Importantly, the Δnth, ΔmutY, and Δnfo mutants were significantly attenuated for virulence in the mouse model and showed much lower colonization of the liver and spleen or were unable to compete with the wild-type strain during in vivo competition assays. CONCLUSIONS Our results highlight the importance of BER for L. monocytogenes virulence and survival of DNA-damaging insults during host colonization.
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Affiliation(s)
- Juan Zhang
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuyi Wang
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Tjakko Abee
- Food Microbiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Stijn van der Veen
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Evseev P, Sykilinda N, Gorshkova A, Kurochkina L, Ziganshin R, Drucker V, Miroshnikov K. Pseudomonas Phage PaBG-A Jumbo Member of an Old Parasite Family. Viruses 2020; 12:E721. [PMID: 32635178 PMCID: PMC7412058 DOI: 10.3390/v12070721] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 11/17/2022] Open
Abstract
Bacteriophage PaBG is a jumbo Myoviridae phage isolated from water of Lake Baikal. This phage has limited diffusion ability and thermal stability and infects a narrow range of Pseudomonas aeruginosa strains. Therefore, it is hardly suitable for phage therapy applications. However, the analysis of the genome of PaBG presents a number of insights into the evolutionary history of this phage and jumbo phages in general. We suggest that PaBG represents an ancient group distantly related to all known classified families of phages.
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Affiliation(s)
- Peter Evseev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (P.E.); (N.S.); (R.Z.)
| | - Nina Sykilinda
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (P.E.); (N.S.); (R.Z.)
| | - Anna Gorshkova
- Limnological Institute, Siberian Branch of Russian Academy of Sciences, 664033 Irkutsk, Russia; (A.G.); (V.D.)
| | - Lidia Kurochkina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Rustam Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (P.E.); (N.S.); (R.Z.)
| | - Valentin Drucker
- Limnological Institute, Siberian Branch of Russian Academy of Sciences, 664033 Irkutsk, Russia; (A.G.); (V.D.)
| | - Konstantin Miroshnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (P.E.); (N.S.); (R.Z.)
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Ghosh Biswas R, Fortier-McGill B, Akhter M, Soong R, Ning P, Bastawrous M, Jenne A, Schmidig D, De Castro P, Graf S, Kuehn T, Busse F, Struppe J, Fey M, Heumann H, Boenisch H, Gundy M, Simpson MJ, Simpson AJ. Ex vivo Comprehensive Multiphase NMR of whole organisms: A complementary tool to in vivo NMR. Anal Chim Acta X 2020; 6:100051. [PMID: 33392494 PMCID: PMC7772632 DOI: 10.1016/j.acax.2020.100051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/29/2020] [Accepted: 06/23/2020] [Indexed: 12/15/2022] Open
Abstract
Nuclear Magnetic Resonance (NMR) spectroscopy is a non-invasive analytical technique which allows for the study of intact samples. Comprehensive Multiphase NMR (CMP-NMR) combines techniques and hardware from solution state and solid state NMR to allow for the holistic analysis of all phases (i.e. solutions, gels and solids) in unaltered samples. This study is the first to apply CMP-NMR to deceased, intact organisms and uses 13C enriched Daphnia magna (water fleas) as an example. D. magna are commonly used model organisms for environmental toxicology studies. As primary consumers, they are responsible for the transfer of nutrients across trophic levels, and a decline in their population can potentially impact the entire freshwater aquatic ecosystem. Though in vivo research is the ultimate tool to understand an organism’s most biologically relevant state, studies are limited by conditions (i.e. oxygen requirements, limited experiment time and reduced spinning speed) required to keep the organisms alive, which can negatively impact the quality of the data collected. In comparison, ex vivo CMP-NMR is beneficial in that; organisms do not need oxygen (eliminating air holes in rotor caps and subsequent evaporation); samples can be spun faster, leading to improved spectral resolution; more biomass per sample can be analyzed; and experiments can be run for longer. In turn, higher quality ex vivo NMR, can provide more comprehensive NMR assignments, which in many cases could be transferred to better understand less resolved in vivo signals. This manuscript is divided into three sections: 1) multiphase spectral editing techniques, 2) detailed metabolic assignments of 2D NMR of 13C enriched D. magna and 3) multiphase biological changes over different life stages, ages and generations of D. magna. In summary, ex vivo CMP-NMR proves to be a very powerful approach to study whole organisms in a comprehensive manner and should provide very complementary information to in vivo based research. Comprehensive Multiphase NMR detects all phases (solid/liquid/gel) in whole samples. Deceased organisms are not subjected to the limitations of in vivo NMR studies. 2D ex vivo NMR offer increased spectral resolution, improving metabolite assignment. Holistic analysis shows biological changes in D. magna over different life stages. Ex vivo NMR can be a complementary tool for in vivo NMR metabolomic studies.
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Affiliation(s)
- Rajshree Ghosh Biswas
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Blythe Fortier-McGill
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Mohammad Akhter
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Ronald Soong
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Paris Ning
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Monica Bastawrous
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Amy Jenne
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - Daniel Schmidig
- Bruker Switzerland AG, Industriestrasse 26, 8117, Fällanden, Switzerland
| | - Peter De Castro
- Bruker Switzerland AG, Industriestrasse 26, 8117, Fällanden, Switzerland
| | - Stephan Graf
- Bruker Switzerland AG, Industriestrasse 26, 8117, Fällanden, Switzerland
| | - Till Kuehn
- Bruker Switzerland AG, Industriestrasse 26, 8117, Fällanden, Switzerland
| | - Falko Busse
- Bruker Biospin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany
| | - Jochem Struppe
- Bruker Corporation, 15 Fortune Drive, Billerica, MA, 01821-3991, USA
| | - Michael Fey
- Bruker Corporation, 15 Fortune Drive, Billerica, MA, 01821-3991, USA
| | - Hermann Heumann
- Silantes GmbH, Gollierstrasse 70c, D-80339, München, Germany
| | - Holger Boenisch
- Silantes GmbH, Gollierstrasse 70c, D-80339, München, Germany
| | - Marcel Gundy
- Silantes GmbH, Gollierstrasse 70c, D-80339, München, Germany
| | - Myrna J Simpson
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
| | - André J Simpson
- University of Toronto Scarborough, Department of Physical & Environmental Sciences, 1265, Military Trail, M1C 1A4, ON, Canada
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Hölz K, Pavlic A, Lietard J, Somoza MM. Specificity and Efficiency of the Uracil DNA Glycosylase-Mediated Strand Cleavage Surveyed on Large Sequence Libraries. Sci Rep 2019; 9:17822. [PMID: 31780717 PMCID: PMC6883067 DOI: 10.1038/s41598-019-54044-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/07/2019] [Indexed: 02/07/2023] Open
Abstract
Uracil-DNA glycosylase (UDG) is a critical DNA repair enzyme that is well conserved and ubiquitous in nearly all life forms. UDG protects genomic information integrity by catalyzing the excision from DNA of uracil nucleobases resulting from misincorporation or spontaneous cytosine deamination. UDG-mediated strand cleavage is also an important tool in molecular biotechnology, allowing for controlled and location-specific cleavage of single- and double DNA chemically or enzymatically synthesized with single or multiple incorporations of deoxyuridine. Although the cleavage mechanism is well-understood, detailed knowledge of efficiency and sequence specificity, in both single and double-stranded DNA contexts, has so far remained incomplete. Here we use an experimental approach based on the large-scale photolithographic synthesis of uracil-containing DNA oligonucleotides to comprehensively probe the context-dependent uracil excision efficiency of UDG.
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Affiliation(s)
- Kathrin Hölz
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Angelina Pavlic
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Jory Lietard
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.
| | - Mark M Somoza
- Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.
- Chair of Food Chemistry and Molecular and Sensory Science, Technical University of Munich, Lise-Meitner-Straße 34, D-85354, Freising, Germany.
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Datta M, Aroli S, Karmakar K, Dutta S, Chakravortty D, Varshney U. Development of mCherry tagged UdgX as a highly sensitive molecular probe for specific detection of uracils in DNA. Biochem Biophys Res Commun 2019; 518:38-43. [PMID: 31402116 DOI: 10.1016/j.bbrc.2019.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 08/01/2019] [Indexed: 02/07/2023]
Abstract
Uracil is not always a mistakenly occurring base in DNA. Uracils in DNA genomes are known to be important in the life cycles of Bacillus subtilis phages (PBS1/2) and the malarial parasite, Plasmodium falciparum; and have been implicated in the development of fruit fly and antibody maturation in B-lymphocytes. Availability of a sensitive, specific and robust technique for the detection uracils in genes/genomes is essential to understand its varied biological roles. Mycobacterium smegmatis UdgX (MsmUdgX), identified and characterised in our laboratory, forms covalent complexes with the uracil sites in DNA in a specific manner. MsmUdgX cleaves the glycosidic bond between uracil and the deoxyribose sugar in DNA to produce uracilate and oxocarbenium ions. The oxocarbenium ion is then captured into a covalent complex by the nucleophilic attack of a histidine side chain of MsmUdgX. Here, we describe the use of a fusion protein, mCherry tagged MsmUdgX (mChUdgX), which combines the property of MsmUdgX to covalently and specifically bind the uracil sites in the genome, with the sensitivity of fluorescent detection of mCherry as a reporter. We show that both the purified mChUdgX and the Escherichia coli cell-extracts overexpressing mChUdgX provide high sensitivity and specificity of detecting uracils in DNA.
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Affiliation(s)
- Madhurima Datta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Shashanka Aroli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Kapudeep Karmakar
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Somnath Dutta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, 560012, India; Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064, India.
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Evdokimov A, Kutuzov M, Petruseva I, Lukjanchikova N, Kashina E, Kolova E, Zemerova T, Romanenko S, Perelman P, Prokopov D, Seluanov A, Gorbunova V, Graphodatsky A, Trifonov V, Khodyreva S, Lavrik O. Naked mole rat cells display more efficient excision repair than mouse cells. Aging (Albany NY) 2019; 10:1454-1473. [PMID: 29930219 PMCID: PMC6046242 DOI: 10.18632/aging.101482] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 06/13/2018] [Indexed: 12/29/2022]
Abstract
Naked mole rat (NMR) is the long-lived and tumor-resistant rodent. NMRs possess multiple adaptations that may contribute to longevity and cancer-resistance. However, whether NMRs have more efficient DNA repair have not been directly tested. Here we compared base excision repair (BER) and nucleotide excision repair (NER) systems in extracts from NMR and mouse fibroblasts after UVC irradiation. Transcript levels of the key repair enzymes demonstrated in most cases higher inducibility in the mouse vs the NMR cells. Ratios of repair enzymes activities in the extracts somewhat varied depending on post-irradiation time. NMR cell extracts were 2–3-fold more efficient at removing the bulky lesions, 1.5–3-fold more efficient at removing uracil, and about 1.4-fold more efficient at cleaving the AP-site than the mouse cells, while DNA polymerase activities being as a whole higher in the mouse demonstrate different patterns of product distribution. The level of poly(ADP-ribose) synthesis was 1.4–1.8-fold higher in the NMR cells. Furthermore, NMR cell extracts displayed higher binding of PARP1 to DNA probes containing apurinic/apyrimidinic site or photo-reactive DNA lesions. Cumulatively, our results suggest that the NMR has more efficient excision repair systems than the mouse, which may contribute to longevity and cancer resistance of this species.
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Affiliation(s)
- Alexei Evdokimov
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Mikhail Kutuzov
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Irina Petruseva
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | | | - Elena Kashina
- Institute of Cytology and Genetics, Novosibirsk 630090, Russia
| | - Ekaterina Kolova
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Tatyana Zemerova
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | | | - Polina Perelman
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Dmitry Prokopov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Andrei Seluanov
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | - Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY 14627, USA
| | | | - Vladimir Trifonov
- Institute of Molecular and Cellular Biology, Novosibirsk 630090, Russia
| | - Svetlana Khodyreva
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
| | - Olga Lavrik
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk 630090, Russia
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Alexeeva M, Moen MN, Grøsvik K, Tesfahun AN, Xu XM, Muruzábal-Lecumberri I, Olsen KM, Rasmussen A, Ruoff P, Kirpekar F, Klungland A, Bjelland S. Excision of uracil from DNA by hSMUG1 includes strand incision and processing. Nucleic Acids Res 2019; 47:779-793. [PMID: 30496516 PMCID: PMC6344882 DOI: 10.1093/nar/gky1184] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 11/08/2018] [Indexed: 12/22/2022] Open
Abstract
Uracil arises in DNA by hydrolytic deamination of cytosine (C) and by erroneous incorporation of deoxyuridine monophosphate opposite adenine, where the former event is devastating by generation of C → thymine transitions. The base excision repair (BER) pathway replaces uracil by the correct base. In human cells two uracil-DNA glycosylases (UDGs) initiate BER by excising uracil from DNA; one is hSMUG1 (human single-strand-selective mono-functional UDG). We report that repair initiation by hSMUG1 involves strand incision at the uracil site resulting in a 3′-α,β-unsaturated aldehyde designated uracil-DNA incision product (UIP), and a 5′-phosphate. UIP is removed from the 3′-end by human apurinic/apyrimidinic (AP) endonuclease 1 preparing for single-nucleotide insertion. hSMUG1 also incises DNA or processes UIP to a 3′-phosphate designated uracil-DNA processing product (UPP). UIP and UPP were indirectly identified and quantified by polyacrylamide gel electrophoresis and chemically characterised by matrix-assisted laser desorption/ionisation time-of-flight mass-spectrometric analysis of DNA from enzyme reactions using 18O- or 16O-water. The formation of UIP accords with an elimination (E2) reaction where deprotonation of C2′ occurs via the formation of a C1′ enolate intermediate. A three-phase kinetic model explains rapid uracil excision in phase 1, slow unspecific enzyme adsorption/desorption to DNA in phase 2 and enzyme-dependent AP site incision in phase 3.
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Affiliation(s)
- Marina Alexeeva
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Marivi N Moen
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway.,Department of Microbiology, Oslo University Hospital, Rikshospitalet, NO-0372 Oslo, Norway
| | - Kristin Grøsvik
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Almaz N Tesfahun
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Xiang Ming Xu
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Izaskun Muruzábal-Lecumberri
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Kristine M Olsen
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Anette Rasmussen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Peter Ruoff
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
| | - Finn Kirpekar
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Arne Klungland
- Department of Microbiology, Oslo University Hospital, Rikshospitalet, NO-0372 Oslo, Norway.,Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, NO-0317 Oslo, Norway
| | - Svein Bjelland
- Department of Chemistry, Bioscience and Environmental Technology-Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, P.O. Box 8600 Forus, N-4021 Stavanger, Norway
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Germinal Immunogenetics predict treatment outcome for PD-1/PD-L1 checkpoint inhibitors. Invest New Drugs 2019; 38:160-171. [PMID: 31402427 DOI: 10.1007/s10637-019-00845-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/01/2019] [Indexed: 02/07/2023]
Abstract
Background Checkpoint inhibitors bring marked benefits but only in a minority of patients and may also be associated with severe adverse events. Treatment outcome still cannot be faithfully predicted. The following study hypothesized that host genetics could be applied as predictive biomarkers for checkpoint inhibitor response and immune-related adverse events. We conducted a study based on germinal polymorphisms from genes coding for proteins involved in immune regulation. Methods Germinal DNA was obtained from advanced cancer patients treated with anti-PD-1/PD-L1 checkpoint inhibitors. DNA was genotyped using a custom panel of 166 single nucleotide polymorphisms covering 86 preselected immunogenetic-related genes. Computational analysis using a GTEX portal was made to determine potential expression Quantitative Trait Loci in tissues. Results Ninety-four consecutive patients were included. Objective response rate (complete or partial response) was significantly correlated to tumor microenvironment-related SNPs concerning CCL2, NOS3, IL1RN, IL12B, CXCR3 and IL6R genes. Toxicity were linked to target-related gene SNPs including UNG, IFNW1, CTLA4, PD-L1 and IFNL4 genes. The Area Under the ROC curve (AUC) was 0.81 (95% CI: 0.72-0.9) for response and 0.89 (95% CI: 0.76-1.00) for toxicity. In silico functionality exploring pointed rs4845618 (IL6R), rs10964859 (IFNW1) and rs3087243 (CTLA4) as potentially impacting gene expression. Conclusion These results strongly support a role for distinct immunogenetic-related gene SNPs able to predict efficacy and safety of anti-PD1/PD-L1 therapies. The results highlight the existence of patient-specific, germinal biomarkers able predict response to checkpoint inhibitor efficacy and, possibly, to predict treatment-related adverse events.
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42
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Ahn WC, Aroli S, Kim JH, Moon JH, Lee GS, Lee MH, Sang PB, Oh BH, Varshney U, Woo EJ. Covalent binding of uracil DNA glycosylase UdgX to abasic DNA upon uracil excision. Nat Chem Biol 2019; 15:607-614. [PMID: 31101917 DOI: 10.1038/s41589-019-0289-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 04/10/2019] [Indexed: 11/09/2022]
Abstract
Uracil DNA glycosylases (UDGs) are important DNA repair enzymes that excise uracil from DNA, yielding an abasic site. Recently, UdgX, an unconventional UDG with extremely tight binding to DNA containing uracil, was discovered. The structure of UdgX from Mycobacterium smegmatis in complex with DNA shows an overall similarity to that of family 4 UDGs except for a protruding loop at the entrance of the uracil-binding pocket. Surprisingly, H109 in the loop was found to make a covalent bond to the abasic site to form a stable intermediate, while the excised uracil remained in the pocket of the active site. H109 functions as a nucleophile to attack the oxocarbenium ion, substituting for the catalytic water molecule found in other UDGs. To our knowledge, this change from a catalytic water attack to a direct nucleophilic attack by the histidine residue is unprecedented. UdgX utilizes a unique mechanism of protecting cytotoxic abasic sites from exposure to the cellular environment.
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Affiliation(s)
- Woo-Chan Ahn
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea.,Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Shashanka Aroli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Jin-Hahn Kim
- Creative Research Initiative Center for Chemical Dynamics in Living Cells, Department of Chemistry, Chung-Ang University, Seoul, Korea
| | - Jeong Hee Moon
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Ga Seal Lee
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Min-Ho Lee
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Pau Biak Sang
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Byung-Ha Oh
- Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Umesh Varshney
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.
| | - Eui-Jeon Woo
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea. .,University of Science and Technology, Daejeon, Republic of Korea.
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43
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Tu J, Chen R, Yang Y, Cao W, Xie W. Suicide inactivation of the uracil DNA glycosylase UdgX by covalent complex formation. Nat Chem Biol 2019; 15:615-622. [PMID: 31101915 DOI: 10.1038/s41589-019-0290-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/10/2019] [Indexed: 01/08/2023]
Abstract
A uracil DNA glycosylase (UDG) from Mycobacterium smegmatis (MsmUdgX) shares sequence similarity with family 4 UDGs and forms exceedingly stable complexes with single-stranded uracil-containing DNAs (ssDNA-Us) that are resistant to denaturants. However, MsmUdgX has been reported to be inactive in excising uracil from ssDNA-Us and the underlying structural basis is unclear. Here, we report high-resolution crystal structures of MsmUdgX in the free, uracil- and DNA-bound forms, respectively. The structural information, supported by mutational and biochemical analyses, indicates that the conserved residue His109 located on a characteristic loop forms an irreversible covalent linkage with the deoxyribose at the apyrimidinic site of ssDNA-U, thus rendering the enzyme unable to regenerate. By proposing the catalytic pathway and molecular mechanism for MsmUdgX, our studies provide an insight into family 4 UDGs and UDGs in general.
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Affiliation(s)
- Jie Tu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Ran Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Ye Yang
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, USA
| | - Weiguo Cao
- Department of Genetics and Biochemistry, Clemson University, Clemson, SC, USA
| | - Wei Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong, China.
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Cui J, Gizzi A, Stivers JT. Deoxyuridine in DNA has an inhibitory and promutagenic effect on RNA transcription by diverse RNA polymerases. Nucleic Acids Res 2019; 47:4153-4168. [PMID: 30892639 PMCID: PMC6486633 DOI: 10.1093/nar/gkz183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/04/2019] [Accepted: 03/09/2019] [Indexed: 12/16/2022] Open
Abstract
dUTP is a close structural congener of dTTP and can be readily incorporated into DNA opposite to adenine during DNA replication leading to non-mutagenic dU/A base pairs ('uracilation'). We find that dU/A pairs located within DNA transcriptional templates optimized for either T7 RNA polymerase (T7 RNAP) or human RNA polymerase II (pol II) have inhibitory and mutagenic effects on transcription. The data for T7 RNAP establishes that even a single dU/A pair can inhibit promoter binding and transcription initiation up to 30-fold, and that inhibitory effects on transcription elongation are also possible. Sequencing of the mRNA transcribed from uniformly uracilated DNA templates by T7 RNAP indicated an increased frequency of transversion and insertion mutations compared to all T/A templates. Strong effects of dU/A pairs on cellular transcription activity and fidelity were also observed with RNA pol II using uracil base excision repair (UBER)-deficient human cells. At the highest levels of template uracilation, transcription by RNA pol II was completely blocked. We propose that these effects arise from the decreased thermodynamic stability and increased dynamics of dU/A pairs in DNA. The potential implications of these findings on gene regulation and disease are discussed.
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Affiliation(s)
- Junru Cui
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - Anthony Gizzi
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
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45
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Trasviña-Arenas CH, David SS, Delaye L, Azuara-Liceaga E, Brieba LG. Evolution of Base Excision Repair in Entamoeba histolytica is shaped by gene loss, gene duplication, and lateral gene transfer. DNA Repair (Amst) 2019; 76:76-88. [DOI: 10.1016/j.dnarep.2019.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 01/14/2019] [Accepted: 02/19/2019] [Indexed: 12/22/2022]
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46
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Sańko-Sawczenko I, Łotocka B, Mielecki J, Rekosz-Burlaga H, Czarnocka W. Transcriptomic Changes in Medicago truncatula and Lotus japonicus Root Nodules during Drought Stress. Int J Mol Sci 2019; 20:E1204. [PMID: 30857310 PMCID: PMC6429210 DOI: 10.3390/ijms20051204] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 12/16/2022] Open
Abstract
Drought is one of the major environmental factors limiting biomass and seed yield production in agriculture. In this research, we focused on plants from the Fabaceae family, which has a unique ability for the establishment of symbiosis with nitrogen-fixing bacteria, and are relatively susceptible to water limitation. We have presented the changes in nitrogenase activity and global gene expression occurring in Medicago truncatula and Lotus japonicus root nodules during water deficit. Our results proved a decrease in the efficiency of nitrogen fixation, as well as extensive changes in plant and bacterial transcriptomes, shortly after watering cessation. We showed for the first time that not only symbiotic plant components but also Sinorhizobium meliloti and Mesorhizobium loti bacteria residing in the root nodules of M. truncatula and L. japonicus, respectively, adjust their gene expression in response to water shortage. Although our results demonstrated that both M. truncatula and L. japonicus root nodules were susceptible to water deprivation, they indicated significant differences in plant and bacterial response to drought between the tested species, which might be related to the various types of root nodules formed by these species.
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Affiliation(s)
- Izabela Sańko-Sawczenko
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Barbara Łotocka
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Jakub Mielecki
- Department of Plant Genetics, Breeding and Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Hanna Rekosz-Burlaga
- Department of Microbial Biology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland.
| | - Weronika Czarnocka
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland.
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47
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YwqL (EndoV), ExoA and PolA act in a novel alternative excision pathway to repair deaminated DNA bases in Bacillus subtilis. PLoS One 2019; 14:e0211653. [PMID: 30726292 PMCID: PMC6364969 DOI: 10.1371/journal.pone.0211653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 01/17/2019] [Indexed: 11/19/2022] Open
Abstract
DNA deamination generates base transitions and apurinic/apyrimidinic (AP)-sites which are potentially genotoxic and cytotoxic. In Bacillus subtilis uracil can be removed from DNA by the uracil DNA-glycosylase through the base excision repair pathway. Genetic evidence suggests that B. subtilis YwqL, a homolog of Endonuclease-V (EndoV), acts on a wider spectrum of deaminated bases but the factors that complete this pathway have remained elusive. Here, we report that a purified His6-YwqL (hereafter BsEndoV) protein had in vitro endonuclease activity against double-stranded DNAs containing a single uracil (U), hypoxanthine (Hx), xanthine (X) or an AP site. Interestingly, while BsEndoV catalyzed a single strand break at the second phosphodiester bond towards the 3'-end of the U and AP lesions, there was an additional cleavage of the phosphodiester bond preceding the Hx and X lesions. Remarkably, the repair event initiated by BsEndoV on Hx and X, was completed by a recombinant B. subtilis His6-DNA polymerase A (BsPolA), but not on BsEndoV-processed U and AP lesions. For the latter lesions a second excision event performed by a recombinant B. subtilis His6-ExoA (BsExoA) was necessary before completion of their repair by BsPolA. These results suggest the existence of a novel alternative excision repair pathway in B. subtilis that counteracts the genotoxic effects of base deamination. The presence of this novel pathway in vivo in B. subtilis was also supported by analysis of effects of single or multiple deletions of exoA, endoV and polA on spontaneous mutations in growing cells, and the sensitivity of growing wild-type and mutant cells to a DNA deaminating agent.
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48
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Yang Y, Park SH, Alford-Zappala M, Lee HW, Li J, Cunningham RP, Cao W. Role of endonuclease III enzymes in uracil repair. Mutat Res 2019; 813:20-30. [PMID: 30590231 PMCID: PMC6378108 DOI: 10.1016/j.mrfmmm.2018.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
Endonuclease III is a DNA glycosylase previously known for its repair activity on oxidative pyrimidine damage. Uracil is a deamination product derived from cytosine. Uracil DNA N-glycosylase (UNG) and mismatch-specific uracil DNA glycosylase (MUG) are two known repair enzymes with enzymatic activity on uracil in E. coli. Here we report a G/U specific uracil DNA glycosylase activity in E. coli endonuclease III (endo III, Nth), which is comparable to MUG but significantly lower than its thymine glycol DNA glycosylase activity. The possibility that the novel activity is due to contamination is ruled out by expressing the wild type nth gene and an active site mutant in a uracil-repair-deficient genetic background. Consistent with the biochemical analysis, analyses of lac+ reversion and mutation frequencies in the presence of human AID induced cytosine deamination indicate the endo III can play a role in repair of cytosine deamination. In addition to E. coli, UDG activity is found in endo III homologs from other organisms. E. coli nucleoside diphosphate kinase (Ndk) was also tested for UDG activity because it was previously reported as an uracil repair enzyme. Under the assay conditions, very limited UDG activity was detected in single-stranded uracil-containing DNA from E. coli Ndk and no UDG activity was detected in human Ndk homologs. This study provides definitive clarification on uracil repair by endo III and reveals that endonuclease III is a G/U-specific UDG that can be viewed as a prototype for the human MBD4 uracil DNA glycosylase.
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Affiliation(s)
- Ye Yang
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, USA
| | - Sung-Hyun Park
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, USA
| | - Maria Alford-Zappala
- Department of Biological Sciences, The University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Hyun-Wook Lee
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, USA
| | - Jing Li
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, USA
| | - Richard P Cunningham
- Department of Biological Sciences, The University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Weiguo Cao
- Department of Genetics and Biochemistry, Clemson University, Room 049 Life Sciences Facility, 190 Collings Street, Clemson, SC 29634, USA.
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49
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Abstract
RNA-guided programmable nucleases from CRISPR systems generate precise breaks in DNA or RNA at specified positions. In cells, this activity can lead to changes in DNA sequence or RNA transcript abundance. Base editing is a newer genome-editing approach that uses components from CRISPR systems together with other enzymes to directly install point mutations into cellular DNA or RNA without making double-stranded DNA breaks. DNA base editors comprise a catalytically disabled nuclease fused to a nucleobase deaminase enzyme and, in some cases, a DNA glycosylase inhibitor. RNA base editors achieve analogous changes using components that target RNA. Base editors directly convert one base or base pair into another, enabling the efficient installation of point mutations in non-dividing cells without generating excess undesired editing by-products. In this Review, we summarize base-editing strategies to generate specific and precise point mutations in genomic DNA and RNA, highlight recent developments that expand the scope, specificity, precision and in vivo delivery of base editors and discuss limitations and future directions of base editing for research and therapeutic applications.
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Affiliation(s)
- Holly A Rees
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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50
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DeNizio JE, Liu MY, Leddin EM, Cisneros GA, Kohli RM. Selectivity and Promiscuity in TET-Mediated Oxidation of 5-Methylcytosine in DNA and RNA. Biochemistry 2018; 58:411-421. [PMID: 30387995 DOI: 10.1021/acs.biochem.8b00912] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Enzymes of the ten-eleven translocation (TET) family add diversity to the repertoire of nucleobase modifications by catalyzing the oxidation of 5-methylcytosine (5mC). TET enzymes were initially found to oxidize 5-methyl-2'-deoxycytidine in genomic DNA, yielding products that contribute to epigenetic regulation in mammalian cells, but have since been found to also oxidize 5-methylcytidine in RNA. Considering the different configurations of single-stranded (ss) and double-stranded (ds) DNA and RNA that coexist in a cell, defining the scope of TET's preferred activity and the mechanisms of substrate selectivity is critical to better understand the enzymes' biological functions. To this end, we have systematically examined the activity of human TET2 on DNA, RNA, and hybrid substrates in vitro. We found that, while ssDNA and ssRNA are well tolerated, TET2 is most proficient at dsDNA oxidation and discriminates strongly against dsRNA. Chimeric and hybrid substrates containing mixed DNA and RNA character helped reveal two main features by which the enzyme discriminates between substrates. First, the identity of the target nucleotide alone is the strongest reactivity determinant, with a preference for 5-methyldeoxycytidine, while both DNA or RNA are relatively tolerated on the rest of the target strand. Second, while a complementary strand is not required for activity, DNA is the preferred partner, and complementary RNA diminishes reactivity. Our biochemical analysis, complemented by molecular dynamics simulations, provides support for an active site optimally configured for dsDNA reactivity but permissive for various nucleic acid configurations, suggesting a broad range of plausible roles for TET-mediated 5mC oxidation in cells.
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Affiliation(s)
| | | | - Emmett M Leddin
- Department of Chemistry , University of North Texas , Denton , Texas 76201 , United States
| | - G Andrés Cisneros
- Department of Chemistry , University of North Texas , Denton , Texas 76201 , United States
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