1
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Stolyarenko AD, Novikova AA, Shilkin ES, Poltorachenko VA, Makarova AV. The Catalytic Activity of Human REV1 on Undamaged and Damaged DNA. Int J Mol Sci 2024; 25:4107. [PMID: 38612916 PMCID: PMC11012841 DOI: 10.3390/ijms25074107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
Eukaryotic REV1 serves as a scaffold protein for the coordination of DNA polymerases during DNA translesion synthesis. Besides this structural role, REV1 is a Y-family DNA polymerase with its own distributive deoxycytidyl transferase activity. However, data about the accuracy and efficiency of DNA synthesis by REV1 in the literature are contrasting. Here, we expressed and purified the full-length human REV1 from Saccharomyces cerevisiae and characterized its activity on undamaged DNA and a wide range of damaged DNA templates. We demonstrated that REV1 carried out accurate synthesis opposite 8-oxoG and O6-meG with moderate efficiency. It also replicated thymine glycol surprisingly well in an error-prone manner, but was blocked by the intrastrand 1,2-GG cisplatin crosslink. By using the 1,N6-ethenoadenine and 7-deaza-adenine lesions, we have provided biochemical evidence of the importance for REV1 functioning of the Hoogsteen face of template A, the second preferable template after G.
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Affiliation(s)
- Anastasia D. Stolyarenko
- National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.A.N.); (E.S.S.); (V.A.P.)
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia
| | - Anna A. Novikova
- National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.A.N.); (E.S.S.); (V.A.P.)
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia
| | - Evgeniy S. Shilkin
- National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.A.N.); (E.S.S.); (V.A.P.)
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia
| | | | - Alena V. Makarova
- National Research Center “Kurchatov Institute”, 123182 Moscow, Russia; (A.A.N.); (E.S.S.); (V.A.P.)
- Institute of Gene Biology of the Russian Academy of Sciences, 119334 Moscow, Russia
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2
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Weaver TM, Click TH, Khoang TH, Todd Washington M, Agarwal PK, Freudenthal BD. Mechanism of nucleotide discrimination by the translesion synthesis polymerase Rev1. Nat Commun 2022; 13:2876. [PMID: 35610266 PMCID: PMC9130138 DOI: 10.1038/s41467-022-30577-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/06/2022] [Indexed: 11/09/2022] Open
Abstract
Rev1 is a translesion DNA synthesis (TLS) polymerase involved in the bypass of adducted-guanine bases and abasic sites during DNA replication. During damage bypass, Rev1 utilizes a protein-template mechanism of DNA synthesis, where the templating DNA base is evicted from the Rev1 active site and replaced by an arginine side chain that preferentially binds incoming dCTP. Here, we utilize X-ray crystallography and molecular dynamics simulations to obtain structural insight into the dCTP specificity of Rev1. We show the Rev1 R324 protein-template forms sub-optimal hydrogen bonds with incoming dTTP, dGTP, and dATP that prevents Rev1 from adopting a catalytically competent conformation. Additionally, we show the Rev1 R324 protein-template forms optimal hydrogen bonds with incoming rCTP. However, the incoming rCTP adopts an altered sugar pucker, which prevents the formation of a catalytically competent Rev1 active site. This work provides novel insight into the mechanisms for nucleotide discrimination by the TLS polymerase Rev1.
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Affiliation(s)
- Tyler M Weaver
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA
| | - Timothy H Click
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma, 74048, USA
| | - Thu H Khoang
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA
| | - M Todd Washington
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Pratul K Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma, 74048, USA.
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA. .,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, 66160, USA.
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3
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Tan Y, Guo S, Wu J, Du H, Li L, You C, Wang Y. DNA Polymerase η Promotes the Transcriptional Bypass of N2-Alkyl-2'-deoxyguanosine Adducts in Human Cells. J Am Chem Soc 2021; 143:16197-16205. [PMID: 34555898 DOI: 10.1021/jacs.1c07374] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
To cope with unrepaired DNA lesions, cells are equipped with DNA damage tolerance mechanisms, including translesion synthesis (TLS). While TLS polymerases are well documented in facilitating replication across damaged DNA templates, it remains unknown whether TLS polymerases participate in transcriptional bypass of DNA lesions in cells. Herein, we employed the competitive transcription and adduct bypass assay to examine the efficiencies and fidelities of transcription across N2-alkyl-2'-deoxyguanosine (N2-alkyl-dG, alkyl = methyl, ethyl, n-propyl, or n-butyl) lesions in HEK293T cells. We found that N2-alkyl-dG lesions strongly blocked transcription and elicited CC → AA tandem mutations in nascent transcripts, where adenosines were misincorporated opposite the lesions and their adjacent 5' nucleoside. Additionally, genetic ablation of Pol η, but not Pol κ, Pol ι, or Pol ζ, conferred marked diminutions in the transcriptional bypass efficiencies of the N2-alkyl-dG lesions, which is exacerbated by codepletion of Rev1 in Pol η-deficient background. We also observed that the repair of N2-nBu-dG was not pronouncedly affected by genetic depletion of Pol η or Rev1. Hence, our results provided insights into transcriptional perturbations induced by N2-alkyl-dG lesions and expanded the biological functions of TLS DNA polymerases.
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Affiliation(s)
- Ying Tan
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Su Guo
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States
| | - Jun Wu
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Hua Du
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Lin Li
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Changjun You
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521-0403, United States.,Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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4
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Pande P, Rebello KR, Chatterjee A, Naldiga S, Basu AK. Site-Specific Incorporation of N-(2'-Deoxyguanosine-8-yl)-6-aminochrysene Adduct in DNA and Its Replication in Human Cells. Chem Res Toxicol 2020; 33:1997-2005. [PMID: 32551527 DOI: 10.1021/acs.chemrestox.0c00197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The environmental pollutant 6-nitrochrysene (6-NC) is a potent mutagen and a mammary carcinogen in rats. 6-NC is the most potent carcinogen ever tested in the newborn mouse assay. In mammalian cells, it is metabolically activated by nitroreduction and a combination of ring oxidation and nitroreduction pathways. The nitroreduction pathway yields two major adducts with 2'-deoxyguanosine (dG), one at the C8-position, N-(dG-8-yl)-6-AC, and the other at the exocyclic N2-position, 5-(dG-N2-yl)-6-AC. Here, we report the total synthesis of a site-specific oligonucleotide containing the 6-NC-derived C8 dG adduct, N-(dG-8-yl)-6-AC. Pd-catalyzed Buchwald-Hartwig cross coupling of 6-aminochrysene with protected C8-bromo-dG derivative served as the key reaction to furnish protected N-(dG-8-yl)-6-AC in 56% yield. The monomer for solid-phase DNA synthesis was prepared by its deprotection followed by conversion to the corresponding 5'-O-dimethoxytrityl 3'-phosphoramidite, which was used to synthesize a site-specifically adducted oligonucleotide. After purification and characterization, the adduct-containing oligonucleotide was incorporated into a plasmid and replicated in human embryonic kidney (HEK) 293T cells, which showed that N-(dG-8-yl)-6-AC stalls DNA replication as evidenced by 77% translesion synthesis (TLS) efficiency relative to the control and that the adduct is mutagenic (mutation frequency (MF) 17.8%) inducing largely G→T transversions. We also investigated the roles of several translesion synthesis DNA polymerases in the bypass of N-(dG-8-yl)-6-AC using siRNA knockdown approach. TLS efficiency was reduced in hPol η-, hPol κ-, hPol ζ-, and hREV1-deficient HEK 293T cells to 66%, 45%, 37%, and 32%, respectively. Notably, TLS efficiency was reduced to 18% in cells with concurrent knockdown of hPol κ, hPol ζ, and REV1, suggesting that these three polymerases play critical roles in bypassing N-(dG-8-yl)-6-AC. MF increased to 23.1% and 32.2% in hPol κ- and hREV1-deficient cells, whereas it decreased to 11.8% in hPol ζ-deficient cells. This suggests that hPol κ and hREV1 are involved in error-free TLS of this lesion, whereas hPol ζ performs error-prone bypass.
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Affiliation(s)
- Paritosh Pande
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Kimberly R Rebello
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Arindom Chatterjee
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Spandana Naldiga
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Ashis K Basu
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
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5
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Nava GM, Grasso L, Sertic S, Pellicioli A, Muzi Falconi M, Lazzaro F. One, No One, and One Hundred Thousand: The Many Forms of Ribonucleotides in DNA. Int J Mol Sci 2020; 21:E1706. [PMID: 32131532 PMCID: PMC7084774 DOI: 10.3390/ijms21051706] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/26/2020] [Accepted: 02/28/2020] [Indexed: 12/14/2022] Open
Abstract
In the last decade, it has become evident that RNA is frequently found in DNA. It is now well established that single embedded ribonucleoside monophosphates (rNMPs) are primarily introduced by DNA polymerases and that longer stretches of RNA can anneal to DNA, generating RNA:DNA hybrids. Among them, the most studied are R-loops, peculiar three-stranded nucleic acid structures formed upon the re-hybridization of a transcript to its template DNA. In addition, polyribonucleotide chains are synthesized to allow DNA replication priming, double-strand breaks repair, and may as well result from the direct incorporation of consecutive rNMPs by DNA polymerases. The bright side of RNA into DNA is that it contributes to regulating different physiological functions. The dark side, however, is that persistent RNA compromises genome integrity and genome stability. For these reasons, the characterization of all these structures has been under growing investigation. In this review, we discussed the origin of single and multiple ribonucleotides in the genome and in the DNA of organelles, focusing on situations where the aberrant processing of RNA:DNA hybrids may result in multiple rNMPs embedded in DNA. We concluded by providing an overview of the currently available strategies to study the presence of single and multiple ribonucleotides in DNA in vivo.
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Affiliation(s)
| | | | | | | | - Marco Muzi Falconi
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy; (G.M.N.); (L.G.); (S.S.); (A.P.)
| | - Federico Lazzaro
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy; (G.M.N.); (L.G.); (S.S.); (A.P.)
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6
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Sassa A, Yasui M, Honma M. Current perspectives on mechanisms of ribonucleotide incorporation and processing in mammalian DNA. Genes Environ 2019; 41:3. [PMID: 30700998 PMCID: PMC6346524 DOI: 10.1186/s41021-019-0118-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/08/2019] [Indexed: 01/09/2023] Open
Abstract
Ribonucleotides, which are RNA precursors, are often incorporated into DNA during replication. Although embedded ribonucleotides in the genome are efficiently removed by canonical ribonucleotide excision repair (RER), inactivation of RER causes genomic ribonucleotide accumulation, leading to various abnormalities in cells. Mutation of genes encoding factors involved in RER is associated with the neuroinflammatory autoimmune disorder Aicardi–Goutières syndrome. Over the last decade, the biological impact of ribonucleotides in the genome has attracted much attention. In the present review, we particularly focus on recent studies that have elucidated possible mechanisms of ribonucleotide incorporation and repair and their significance in mammals.
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Affiliation(s)
- Akira Sassa
- 1Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522 Japan
| | - Manabu Yasui
- 2Division of Genetics and Mutagenesis, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki 210-9501 Japan
| | - Masamitsu Honma
- 2Division of Genetics and Mutagenesis, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki 210-9501 Japan
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7
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Vaisman A, Woodgate R. Ribonucleotide discrimination by translesion synthesis DNA polymerases. Crit Rev Biochem Mol Biol 2018; 53:382-402. [PMID: 29972306 DOI: 10.1080/10409238.2018.1483889] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The well-being of all living organisms relies on the accurate duplication of their genomes. This is usually achieved by highly elaborate replicase complexes which ensure that this task is accomplished timely and efficiently. However, cells often must resort to the help of various additional "specialized" DNA polymerases that gain access to genomic DNA when replication fork progression is hindered. One such specialized polymerase family consists of the so-called "translesion synthesis" (TLS) polymerases; enzymes that have evolved to replicate damaged DNA. To fulfill their main cellular mission, TLS polymerases often must sacrifice precision when selecting nucleotide substrates. Low base-substitution fidelity is a well-documented inherent property of these enzymes. However, incorrect nucleotide substrates are not only those which do not comply with Watson-Crick base complementarity, but also those whose sugar moiety is incorrect. Does relaxed base-selectivity automatically mean that the TLS polymerases are unable to efficiently discriminate between ribonucleoside triphosphates and deoxyribonucleoside triphosphates that differ by only a single atom? Which strategies do TLS polymerases employ to select suitable nucleotide substrates? In this review, we will collate and summarize data accumulated over the past decade from biochemical and structural studies, which aim to answer these questions.
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Affiliation(s)
- Alexandra Vaisman
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Roger Woodgate
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
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8
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Raper AT, Reed AJ, Suo Z. Kinetic Mechanism of DNA Polymerases: Contributions of Conformational Dynamics and a Third Divalent Metal Ion. Chem Rev 2018; 118:6000-6025. [DOI: 10.1021/acs.chemrev.7b00685] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Austin T. Raper
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andrew J. Reed
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
| | - Zucai Suo
- Department of Chemistry and Biochemistry, Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, United States
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9
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Abstract
Life as we know it, simply would not exist without DNA replication. All living organisms utilize a complex machinery to duplicate their genomes and the central role in this machinery belongs to replicative DNA polymerases, enzymes that are specifically designed to copy DNA. "Hassle-free" DNA duplication exists only in an ideal world, while in real life, it is constantly threatened by a myriad of diverse challenges. Among the most pressing obstacles that replicative polymerases often cannot overcome by themselves are lesions that distort the structure of DNA. Despite elaborate systems that cells utilize to cleanse their genomes of damaged DNA, repair is often incomplete. The persistence of DNA lesions obstructing the cellular replicases can have deleterious consequences. One of the mechanisms allowing cells to complete replication is "Translesion DNA Synthesis (TLS)". TLS is intrinsically error-prone, but apparently, the potential downside of increased mutagenesis is a healthier outcome for the cell than incomplete replication. Although most of the currently identified eukaryotic DNA polymerases have been implicated in TLS, the best characterized are those belonging to the "Y-family" of DNA polymerases (pols η, ι, κ and Rev1), which are thought to play major roles in the TLS of persisting DNA lesions in coordination with the B-family polymerase, pol ζ. In this review, we summarize the unique features of these DNA polymerases by mainly focusing on their biochemical and structural characteristics, as well as potential protein-protein interactions with other critical factors affecting TLS regulation.
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Affiliation(s)
- Alexandra Vaisman
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
| | - Roger Woodgate
- a Laboratory of Genomic Integrity , National Institute of Child Health and Human Development, National Institutes of Health , Bethesda , MD , USA
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10
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Tokarsky EJ, Wallenmeyer PC, Phi KK, Suo Z. Significant impact of divalent metal ions on the fidelity, sugar selectivity, and drug incorporation efficiency of human PrimPol. DNA Repair (Amst) 2016; 49:51-59. [PMID: 27989484 DOI: 10.1016/j.dnarep.2016.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 01/17/2023]
Abstract
Human PrimPol is a recently discovered bifunctional enzyme that displays DNA template-directed primase and polymerase activities. PrimPol has been implicated in nuclear and mitochondrial DNA replication fork progression and restart as well as DNA lesion bypass. Published evidence suggests that PrimPol is a Mn2+-dependent enzyme as it shows significantly improved primase and polymerase activities when binding Mn2+, rather than Mg2+, as a divalent metal ion cofactor. Consistently, our fluorescence anisotropy assays determined that PrimPol binds to a primer/template DNA substrate with affinities of 29 and 979nM in the presence of Mn2+ and Mg2+, respectively. Our pre-steady-state kinetic analysis revealed that PrimPol incorporates correct dNTPs with 100-fold higher efficiency with Mn2+ than with Mg2+. Notably, the substitution fidelity of PrimPol in the presence of Mn2+ was determined to be in the range of 3.4×10-2 to 3.8×10-1, indicating that PrimPol is an error-prone polymerase. Furthermore, we kinetically determined the sugar selectivity of PrimPol to be 57-1800 with Mn2+ and 150-4500 with Mg2+, and found that PrimPol was able to incorporate the triphosphates of two anticancer drugs (cytarabine and gemcitabine), but not two antiviral drugs (emtricitabine and lamivudine).
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Affiliation(s)
- E John Tokarsky
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210, USA
| | - Petra C Wallenmeyer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Kenneth K Phi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Zucai Suo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210, USA.
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11
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Tokarsky EJ, Gadkari VV, Zahurancik WJ, Malik CK, Basu AK, Suo Z. Pre-steady-state kinetic investigation of bypass of a bulky guanine lesion by human Y-family DNA polymerases. DNA Repair (Amst) 2016; 46:20-28. [PMID: 27612622 DOI: 10.1016/j.dnarep.2016.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 12/12/2022]
Abstract
3-Nitrobenzanthrone (3-NBA), a byproduct of diesel exhaust, is highly present in the environment and poses a significant health risk. Exposure to 3-NBA results in formation of N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (dGC8-N-ABA), a bulky DNA lesion that is of particular importance due to its mutagenic and carcinogenic potential. If not repaired or bypassed during genomic replication, dGC8-N-ABA can stall replication forks, leading to senescence and cell death. Here we used pre-steady-state kinetic methods to determine which of the four human Y-family DNA polymerases (hPolη, hPolκ, hPolι, or hRev1) are able to catalyze translesion synthesis of dGC8-N-ABAin vitro. Our studies demonstrated that hPolη and hPolκ most efficiently bypassed a site-specifically placed dGC8-N-ABA lesion, making them good candidates for catalyzing translesion synthesis (TLS) of this bulky lesion in vivo. Consistently, our publication (Biochemistry 53, 5323-31) in 2014 has shown that small interfering RNA-mediated knockdown of hPolη and hPolκ in HEK293T cells significantly reduces the efficiency of TLS of dGC8-N-ABA. In contrast, hPolι and hRev1 were severely stalled by dGC8-N-ABA and their potential role in vivo was discussed. Subsequently, we determined the kinetic parameters for correct and incorrect nucleotide incorporation catalyzed by hPolη at various positions upstream, opposite, and downstream from dGC8-N-ABA. Notably, nucleotide incorporation efficiency and fidelity both decreased significantly during dGC8-N-ABA bypass and the subsequent extension step, leading to polymerase pausing and error-prone DNA synthesis by hPolη. Furthermore, hPolη displayed nucleotide concentration-dependent biphasic kinetics at the two polymerase pause sites, suggesting that multiple enzyme•DNA complexes likely exist during nucleotide incorporation.
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Affiliation(s)
- E John Tokarsky
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210, USA.
| | - Varun V Gadkari
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
| | - Walter J Zahurancik
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
| | - Chanchal K Malik
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA.
| | - Ashis K Basu
- Department of Chemistry, University of Connecticut, Storrs, CT 06269, USA.
| | - Zucai Suo
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Program, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
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12
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Structural basis for the binding and incorporation of nucleotide analogs with L-stereochemistry by human DNA polymerase λ. Proc Natl Acad Sci U S A 2014; 111:E3033-42. [PMID: 25015085 DOI: 10.1073/pnas.1401286111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although lamivudine and emtricitabine, two L-deoxycytidine analogs, have been widely used as antiviral drugs for years, a structural basis for D-stereoselectivity against L-dNTPs, enantiomers of natural nucleotides (D-dNTPs), by any DNA polymerase or reverse transcriptase has not been established due to lack of a ternary structure of a polymerase, DNA, and an incoming L-dNTP. Here, we report 2.10-2.25 Å ternary crystal structures of human DNA polymerase λ, DNA, and L-deoxycytidine 5'-triphosphate (L-dCTP), or the triphosphates of lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) with four ternary complexes per asymmetric unit. The structures of these 12 ternary complexes reveal that relative to D-deoxycytidine 5'-triphosphate (D-dCTP) in the canonical ternary structure of Polλ-DNA-D-dCTP, L-dCTP, (-)3TC-TP, and (-)FTC-TP all have their ribose rotated by 180°. Among the four ternary complexes with a specific L-nucleotide, two are similar and show that the L-nucleotide forms three Watson-Crick hydrogen bonds with the templating nucleotide dG and adopts a chair-like triphosphate conformation. In the remaining two similar ternary complexes, the L-nucleotide surprisingly interacts with the side chain of a conserved active site residue R517 through one or two hydrogen bonds, whereas the templating dG is anchored by a hydrogen bond with the side chain of a semiconserved residue Y505. Furthermore, the triphosphate of the L-nucleotide adopts an unprecedented N-shaped conformation. Our mutagenic and kinetic studies further demonstrate that the side chain of R517 is critical for the formation of the abovementioned four complexes along proposed catalytic pathways for L-nucleotide incorporation and provide the structural basis for the D-stereoselectivity of a DNA polymerase.
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13
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Taggart DJ, Fredrickson SW, Gadkari VV, Suo Z. Mutagenic potential of 8-oxo-7,8-dihydro-2'-deoxyguanosine bypass catalyzed by human Y-family DNA polymerases. Chem Res Toxicol 2014; 27:931-40. [PMID: 24779885 PMCID: PMC4033635 DOI: 10.1021/tx500088e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
One
of the most common lesions induced by oxidative DNA damage
is 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG). Replicative
DNA polymerases poorly traverse this highly mutagenic lesion, suggesting
that the replication fork may switch to a polymerase specialized for
translesion DNA synthesis (TLS) to catalyze 8-oxodG bypass in vivo. Here, we systematically compared the 8-oxodG bypass
efficiencies and fidelities of the TLS-specialized, human Y-family
DNA polymerases eta (hPolη), iota (hPolι), kappa (hPolκ),
and Rev1 (hRev1) either alone or in combination. Primer extension
assays revealed that the times required for hPolη, hRev1, hPolκ,
and hPolι to bypass 50% of the 8-oxodG lesions encountered (t50bypass) were 0.58, 0.86, 108, and
670 s, respectively. Although hRev1 bypassed 8-oxodG efficiently,
hRev1 failed to catalyze the extension step of TLS, and a second polymerase
was required to extend the lesion bypass products. A high-throughput
short oligonucleotide sequencing assay (HT-SOSA) was used to quantify
the types and frequencies of incorporation errors produced by the
human Y-family DNA polymerases at and near the 8-oxodG site. Although
hPolη bypassed 8-oxodG most efficiently, hPolη correctly
incorporated dCTP opposite 8-oxodG within only 54.5% of the sequences
analyzed. In contrast, hPolι bypassed the lesion least efficiently
but correctly incorporated dCTP at a frequency of 65.8% opposite the
lesion. The combination of hRev1 and hPolκ was most accurate
opposite 8-oxodG (92.3%), whereas hPolκ alone was the least
accurate (18.5%). The t50bypass value and correct dCTP incorporation frequency in the presence of
an equal molar concentration of all four Y-family enzymes were 0.60
s and 43.5%, respectively. These values are most similar to those
of hPolη alone, suggesting that hPolη outcompetes the
other three Y-family polymerases to catalyze 8-oxodG bypass in vitro and possibly in vivo.
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Affiliation(s)
- David J Taggart
- Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States
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14
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Maxwell BA, Suo Z. Recent insight into the kinetic mechanisms and conformational dynamics of Y-Family DNA polymerases. Biochemistry 2014; 53:2804-14. [PMID: 24716482 PMCID: PMC4018064 DOI: 10.1021/bi5000405] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
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The
kinetic mechanisms by which DNA polymerases catalyze DNA replication
and repair have long been areas of active research. Recently discovered
Y-family DNA polymerases catalyze the bypass of damaged DNA bases
that would otherwise block replicative DNA polymerases and stall replication
forks. Unlike DNA polymerases from the five other families, the Y-family
DNA polymerases have flexible, solvent-accessible active sites that
are able to tolerate various types of damaged template bases and allow
for efficient lesion bypass. Their promiscuous active sites, however,
also lead to fidelities that are much lower than those observed for
other DNA polymerases and give rise to interesting mechanistic properties.
Additionally, the Y-family DNA polymerases have several other unique
structural features and undergo a set of conformational changes during
substrate binding and catalysis different from those observed for
replicative DNA polymerases. In recent years, pre-steady-state kinetic
methods have been extensively employed to reveal a wealth of information
about the catalytic properties of these fascinating noncanonical DNA
polymerases. Here, we review many of the recent findings on the kinetic
mechanisms of DNA polymerization with undamaged and damaged DNA substrates
by the Y-family DNA polymerases, and the conformational dynamics employed
by these error-prone enzymes during catalysis.
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Affiliation(s)
- Brian A Maxwell
- Ohio State Biophysics Program and ‡Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States
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15
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Makarova AV, Nick McElhinny SA, Watts BE, Kunkel TA, Burgers PM. Ribonucleotide incorporation by yeast DNA polymerase ζ. DNA Repair (Amst) 2014; 18:63-7. [PMID: 24674899 DOI: 10.1016/j.dnarep.2014.02.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 02/26/2014] [Indexed: 12/01/2022]
Abstract
During replication in yeast, the three B family DNA replicases frequently incorporate ribonucleotides (rNMPs) into DNA, and their presence in the nuclear genome can affect genome stability. This prompted us to examine ribonucleotide incorporation by the fourth B family member, Pol ζ, the enzyme responsible for the majority of damage-induced mutagenesis in eukaryotes. We first show that Pol ζ inserts rNMPs into DNA and can extend primer termini containing 3'-ribonucleotides. We then measure rNMP incorporation by Pol ζ in the presence of its cofactors, RPA, RFC and PCNA and at normal cellular dNTP and rNTP concentrations that exist under unstressed conditions. Under these conditions, Pol ζ stably incorporates one rNMP for every 200-300 dNMPs incorporated, a frequency that is slightly higher than for the high fidelity replicative DNA polymerases. Under damage-induced conditions wherein cellular dNTP concentrations are elevated 5-fold, Pol ζ only incorporates one rNMP per 1300 dNMPs. Functional interaction of Pol ζ with the mutasome assembly factor Rev1 gives comparable rNMP incorporation frequencies. These results suggest that ribonucleotide incorporation into DNA during Pol ζ-mediated mutagenesis in vivo may be rare.
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Affiliation(s)
- Alena V Makarova
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Stephanie A Nick McElhinny
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Brian E Watts
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Thomas A Kunkel
- Laboratory of Molecular Genetics and Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA
| | - Peter M Burgers
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
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16
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Kasuya T, Hori S, Hiramatsu H, Yanagimoto T. Highly accurate synthesis of the fully 2'-fluoro-modified oligonucleotide by Therminator DNA polymerases. Bioorg Med Chem Lett 2014; 24:2134-6. [PMID: 24703229 DOI: 10.1016/j.bmcl.2014.03.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/07/2014] [Accepted: 03/13/2014] [Indexed: 02/03/2023]
Abstract
Oligonucleotides composed of natural nucleotides are inapplicable for biotechnical and therapeutic use due to its instability under biological conditions. Therminator DNA polymerases, mutant DNA polymerases of thermophilic marine archaea, show that they can efficiently synthesize fully 2'-fluoro-modified (2'F-) oligonucleotides. Furthermore, the sequence analysis reveals that the oligonucleotide sequence is highly accurate, especially the fidelity of a 2'F-oligonucleotide synthesized by Therminator II is more accurate than that of natural RNA synthesized by conventional RNA polymerase. These finding would be helpful for the synthesis of chemically modified oligonucleotides, for the use of biotechnical or medical applications.
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Affiliation(s)
- Takeshi Kasuya
- Innovative Drug Discovery Research Laboratories, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Shinichiro Hori
- Innovative Drug Discovery Research Laboratories, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Hisanao Hiramatsu
- Innovative Drug Discovery Research Laboratories, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Toru Yanagimoto
- Innovative Drug Discovery Research Laboratories, Shionogi & Co., Ltd., 3-1-1, Futaba-cho, Toyonaka, Osaka 561-0825, Japan.
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17
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Sherrer SM, Taggart DJ, Pack LR, Malik CK, Basu AK, Suo Z. Quantitative analysis of the mutagenic potential of 1-aminopyrene-DNA adduct bypass catalyzed by Y-family DNA polymerases. Mutat Res 2012; 737:25-33. [PMID: 22917544 DOI: 10.1016/j.mrfmmm.2012.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/12/2012] [Accepted: 08/07/2012] [Indexed: 01/29/2023]
Abstract
N-(Deoxyguanosin-8-yl)-1-aminopyrene (dG(AP)) is the predominant nitro polyaromatic hydrocarbon product generated from the air pollutant 1-nitropyrene reacting with DNA. Previous studies have shown that dG(AP) induces genetic mutations in bacterial and mammalian cells. One potential source of these mutations is the error-prone bypass of dG(AP) lesions catalyzed by the low-fidelity Y-family DNA polymerases. To provide a comparative analysis of the mutagenic potential of the translesion DNA synthesis (TLS) of dG(AP), we employed short oligonucleotide sequencing assays (SOSAs) with the model Y-family DNA polymerase from Sulfolobus solfataricus, DNA Polymerase IV (Dpo4), and the human Y-family DNA polymerases eta (hPolη), kappa (hPolκ), and iota (hPolι). Relative to undamaged DNA, all four enzymes generated far more mutations (base deletions, insertions, and substitutions) with a DNA template containing a site-specifically placed dG(AP). Opposite dG(AP) and at an immediate downstream template position, the most frequent mutations made by the three human enzymes were base deletions and the most frequent base substitutions were dAs for all enzymes. Based on the SOSA data, Dpo4 was the least error-prone Y-family DNA polymerase among the four enzymes during the TLS of dG(AP). Among the three human Y-family enzymes, hPolκ made the fewest mutations at all template positions except opposite the lesion site. hPolκ was significantly less error-prone than hPolι and hPolη during the extension of dG(AP) bypass products. Interestingly, the most frequent mutations created by hPolι at all template positions were base deletions. Although hRev1, the fourth human Y-family enzyme, could not extend dG(AP) bypass products in our standing start assays, it preferentially incorporated dCTP opposite the bulky lesion. Collectively, these mutagenic profiles suggest that hPolk and hRev1 are the most suitable human Y-family DNA polymerases to perform TLS of dG(AP) in humans.
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Affiliation(s)
- Shanen M Sherrer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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18
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Loakes D. Nucleotides and nucleic acids; oligo- and polynucleotides. ORGANOPHOSPHORUS CHEMISTRY 2012. [DOI: 10.1039/9781849734875-00169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- David Loakes
- Medical Research Council Laboratory of Molecular Biology, Hills Road Cambridge CB2 2QH UK
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19
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Sherrer SM, Sanman LE, Xia CX, Bolin ER, Malik CK, Efthimiopoulos G, Basu AK, Suo Z. Kinetic analysis of the bypass of a bulky DNA lesion catalyzed by human Y-family DNA polymerases. Chem Res Toxicol 2012; 25:730-40. [PMID: 22324639 DOI: 10.1021/tx200531y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
1-Nitropyrene (1-NP), a mutagen and potential carcinogen, is the most abundant nitro polyaromatic hydrocarbon in diesel exhaust, which reacts with DNA to form predominantly N-(deoxyguanosin-8-yl)-1-aminopyrene (dG(AP)). If not repaired, this DNA lesion is presumably bypassed in vivo by any of human Y-family DNA polymerases kappa (hPolκ), iota (hPolι), eta (hPolη), and Rev1 (hRev1). Our running start assays demonstrated that each of these enzymes was indeed capable of traversing a site-specifically placed dG(AP) on a synthetic DNA template but that hRev1 was stopped after lesion bypass. The time required to bypass 50% of the dG(AP) sites (t(50)(bypass)) encountered by hPolη, hPolκ, and hPolι was determined to be 2.5 s, 4.1 s, and 106.5 s, respectively. The efficiency order of catalyzing translesion synthesis of dG(AP) (hPolη > hPolκ > hPolι ≫ hRev1) is the same as the order for these human Y-family enzymes to elongate undamaged DNA. Although hPolη bypassed dG(AP) efficiently, replication by both hPolκ and hPolι was strongly stalled at the lesion site and at a site immediately downstream from dG(AP). By employing presteady state kinetic methods, a kinetic basis was established for polymerase pausing at these DNA template sites. Besides efficiency of bypass, the fidelity of those low-fidelity polymerases at these pause sites was also significantly decreased. Thus, if the translesion DNA synthesis of dG(AP)in vivo is catalyzed by a human Y-family DNA polymerase, e.g., hPolη, the process is certainly mutagenic.
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Affiliation(s)
- Shanen M Sherrer
- Departments of Biochemistry and Chemistry, The Ohio State University, Columbus, Ohio 43210, USA
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20
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Brown JA, Pack LR, Fowler JD, Suo Z. Presteady state kinetic investigation of the incorporation of anti-hepatitis B nucleotide analogues catalyzed by noncanonical human DNA polymerases. Chem Res Toxicol 2011; 25:225-33. [PMID: 22132702 DOI: 10.1021/tx200458s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Antiviral nucleoside analogues have been developed to inhibit the enzymatic activities of the hepatitis B virus (HBV) polymerase, thereby preventing the replication and production of HBV. However, the usage of these analogues can be limited by drug toxicity because the 5'-triphosphates of these nucleoside analogues (nucleotide analogues) are potential substrates for human DNA polymerases to incorporate into host DNA. Although they are poor substrates for human replicative DNA polymerases, it remains to be established whether these nucleotide analogues are substrates for the recently discovered human X- and Y-family DNA polymerases. Using presteady state kinetic techniques, we have measured the substrate specificity values for human DNA polymerases β, λ, η, ι, κ, and Rev1 incorporating the active forms of the following anti-HBV nucleoside analogues approved for clinical use: adefovir, tenofovir, lamivudine, telbivudine, and entecavir. Compared to the incorporation of a natural nucleotide, most of the nucleotide analogues were incorporated less efficiently (2 to >122,000) by the six human DNA polymerases. In addition, the potential for entecavir and telbivudine, two drugs which possess a 3'-hydroxyl, to become embedded into human DNA was examined by primer extension and DNA ligation assays. These results suggested that telbivudine functions as a chain terminator, while entecavir was efficiently extended by the six enzymes and was a substrate for human DNA ligase I. Our findings suggested that incorporation of anti-HBV nucleotide analogues catalyzed by human X- and Y-family polymerases may contribute to clinical toxicity.
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Affiliation(s)
- Jessica A Brown
- Department of Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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21
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Pryor JM, Washington MT. Pre-steady state kinetic studies show that an abasic site is a cognate lesion for the yeast Rev1 protein. DNA Repair (Amst) 2011; 10:1138-44. [PMID: 21975119 PMCID: PMC3197757 DOI: 10.1016/j.dnarep.2011.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 08/16/2011] [Accepted: 08/30/2011] [Indexed: 12/17/2022]
Abstract
Rev1 is a eukaryotic DNA polymerase that rescues replication forks stalled at sites of DNA damage by inserting nucleotides opposite the damaged template bases. Yeast genetic studies suggest that Rev1 plays an important role in rescuing replication forks stalled at one of the most common forms of DNA damage, an abasic site; however, steady state kinetic studies suggest that an abasic site acts as a significant block to nucleotide incorporation by Rev1. Here we examined the pre-steady state kinetics of nucleotide incorporation by yeast Rev1 with damaged and non-damaged DNA substrates. We found that yeast Rev1 is capable of rapid nucleotide incorporation, but only a small fraction of the protein molecules possessed this robust activity. We characterized the nucleotide incorporation by the catalytically robust fraction of yeast Rev1 and found that it efficiently incorporated dCTP opposite a template abasic site under pre-steady state conditions. We conclude from these studies that the abasic site is a cognate lesion for Rev1.
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Affiliation(s)
- John M. Pryor
- Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA 52242-1109
| | - M. Todd Washington
- Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA 52242-1109
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22
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Abstract
To maintain genomic stability, ribonucleotide incorporation during DNA synthesis is controlled predominantly at the DNA polymerase level. A steric clash between the 2'-hydroxyl of an incoming ribonucleotide and a bulky active site residue, known as the "steric gate", establishes an effective mechanism for most DNA polymerases to selectively insert deoxyribonucleotides. Recent kinetic, structural, and in vivo studies have illuminated novel features about ribonucleotide exclusion and the mechanistic consequences of ribonucleotide misincorporation on downstream events, such as the bypass of a ribonucleotide in a DNA template and the subsequent extension of the DNA lesion bypass product. These important findings are summarized in this review.
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Affiliation(s)
- Jessica A Brown
- Department of Biochemistry, Ohio State University, Columbus, Ohio 43210, United States
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23
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Pre-steady-state kinetic analysis of the incorporation of anti-HIV nucleotide analogs catalyzed by human X- and Y-family DNA polymerases. Antimicrob Agents Chemother 2010; 55:276-83. [PMID: 21078938 DOI: 10.1128/aac.01229-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) are an important class of antiviral drugs used to manage infections by human immunodeficiency virus, which causes AIDS. Unfortunately, these drugs cause unwanted side effects, and the molecular basis of NRTI toxicity is not fully understood. Putative routes of NRTI toxicity include the inhibition of human nuclear and mitochondrial DNA polymerases. A strong correlation between mitochondrial toxicity and NRTI incorporation catalyzed by human mitochondrial DNA polymerase has been established both in vitro and in vivo. However, it remains to be determined whether NRTIs are substrates for the recently discovered human X- and Y-family DNA polymerases, which participate in DNA repair and DNA lesion bypass in vivo. Using pre-steady-state kinetic techniques, we measured the substrate specificity constants for human DNA polymerases β, λ, η, ι, κ, and Rev1 incorporating the active, 5'-phosphorylated forms of tenofovir, lamivudine, emtricitabine, and zidovudine. For the six enzymes, all of the drug analogs were incorporated less efficiently (40- to >110,000-fold) than the corresponding natural nucleotides, usually due to a weaker binding affinity and a slower rate of incorporation for the incoming nucleotide analog. In general, the 5'-triphosphate forms of lamivudine and zidovudine were better substrates than emtricitabine and tenofovir for the six human enzymes, although the substrate specificity profile depended on the DNA polymerase. Our kinetic results suggest NRTI insertion catalyzed by human X- and Y-family DNA polymerases is a potential mechanism of NRTI drug toxicity, and we have established a structure-function relationship for designing improved NRTIs.
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24
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The DNA polymerase activity of Saccharomyces cerevisiae Rev1 is biologically significant. Genetics 2010; 187:21-35. [PMID: 20980236 DOI: 10.1534/genetics.110.124172] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A cell's ability to tolerate DNA damage is directly connected to the human development of diseases and cancer. To better understand the processes underlying mutagenesis, we studied the cell's reliance on the potentially error-prone translesion synthesis (TLS), and an error-free, template-switching pathway in Saccharomyces cerevisiae. The primary proteins mediating S. cerevisiae TLS are three DNA polymerases (Pols): Rev1, Pol ζ (Rev3/7), and Pol η (Rad30), all with human homologs. Rev1's noncatalytic role in recruiting other DNA polymerases is known to be important for TLS. However, the biological significance of Rev1's unusual conserved DNA polymerase activity, which inserts dC, is much less well understood. Here, we demonstrate that inactivating Rev1's DNA polymerase function sensitizes cells to both chronic and acute exposure to 4-nitroquinoline-1-oxide (4-NQO) but not to UV or cisplatin. Full Rev1-dependent resistance to 4-NQO, however, also requires the additional Rev1 functions. When error-free tolerance is disrupted through deletion of MMS2, Rev1's catalytic activity is more vital for 4-NQO resistance, possibly explaining why the biological significance of Rev1's catalytic activity has been elusive. In the presence or absence of Mms2-dependent error-free tolerance, the catalytic dead strain of Rev1 exhibits a lower 4-NQO-induced mutation frequency than wild type. Furthermore, Pol ζ, but not Pol η, also contributes to 4-NQO resistance. These results show that Rev1's catalytic activity is important in vivo when the cell has to cope with specific DNA lesions, such as N(2)-dG.
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25
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Brown JA, Pack LR, Sherrer SM, Kshetry AK, Newmister SA, Fowler JD, Taylor JS, Suo Z. Identification of critical residues for the tight binding of both correct and incorrect nucleotides to human DNA polymerase λ. J Mol Biol 2010; 403:505-15. [PMID: 20851705 DOI: 10.1016/j.jmb.2010.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 08/31/2010] [Accepted: 09/08/2010] [Indexed: 10/19/2022]
Abstract
DNA polymerase λ (Pol λ) is a novel X-family DNA polymerase that shares 34% sequence identity with DNA polymerase β. Pre-steady-state kinetic studies have shown that the Pol λ-DNA complex binds both correct and incorrect nucleotides 130-fold tighter, on average, than the DNA polymerase β-DNA complex, although the base substitution fidelity of both polymerases is 10(-)(4) to 10(-5). To better understand Pol λ's tight nucleotide binding affinity, we created single-substitution and double-substitution mutants of Pol λ to disrupt the interactions between active-site residues and an incoming nucleotide or a template base. Single-turnover kinetic assays showed that Pol λ binds to an incoming nucleotide via cooperative interactions with active-site residues (R386, R420, K422, Y505, F506, A510, and R514). Disrupting protein interactions with an incoming correct or incorrect nucleotide impacted binding to each of the common structural moieties in the following order: triphosphate≫base>ribose. In addition, the loss of Watson-Crick hydrogen bonding between the nucleotide and the template base led to a moderate increase in K(d). The fidelity of Pol λ was maintained predominantly by a single residue, R517, which has minor groove interactions with the DNA template.
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Affiliation(s)
- Jessica A Brown
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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26
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Sherrer SM, Fiala KA, Fowler JD, Newmister SA, Pryor JM, Suo Z. Quantitative analysis of the efficiency and mutagenic spectra of abasic lesion bypass catalyzed by human Y-family DNA polymerases. Nucleic Acids Res 2010; 39:609-22. [PMID: 20846959 PMCID: PMC3025555 DOI: 10.1093/nar/gkq719] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Higher eukaryotes encode various Y-family DNA polymerases to perform global DNA lesion bypass. To provide complete mutation spectra for abasic lesion bypass, we employed short oligonucleotide sequencing assays to determine the sequences of abasic lesion bypass products synthesized by human Y-family DNA polymerases eta (hPolη), iota (hPolι) and kappa (hPolκ). The fourth human Y-family DNA polymerase, Rev1, failed to generate full-length lesion bypass products after 3 h. The results indicate that hPolι generates mutations with a frequency from 10 to 80% during each nucleotide incorporation event. In contrast, hPolη is the least error prone, generating the fewest mutations in the vicinity of the abasic lesion and inserting dAMP with a frequency of 67% opposite the abasic site. While the error frequency of hPolκ is intermediate to those of hPolη and hPolι, hPolκ has the highest potential to create frameshift mutations opposite the abasic site. Moreover, the time (t50bypass) required to bypass 50% of the abasic lesions encountered by hPolη, hPolι and hPolκ was 4.6, 112 and 1 823 s, respectively. These t50bypass values indicate that, among the enzymes, hPolη has the highest abasic lesion bypass efficiency. Together, our data suggest that hPolη is best suited to perform abasic lesion bypass in vivo.
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Affiliation(s)
- Shanen M Sherrer
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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