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Raper AT, Maxwell BA, Suo Z. Dynamic Processing of a Common Oxidative DNA Lesion by the First Two Enzymes of the Base Excision Repair Pathway. J Mol Biol 2021; 433:166811. [PMID: 33450252 DOI: 10.1016/j.jmb.2021.166811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/23/2020] [Accepted: 01/02/2021] [Indexed: 01/25/2023]
Abstract
Base excision repair (BER) is the primary pathway by which eukaryotic cells resolve single base damage. One common example of single base damage is 8-oxo-7,8-dihydro-2'-deoxoguanine (8-oxoG). High incidence and mutagenic potential of 8-oxoG necessitate rapid and efficient DNA repair. How BER enzymes coordinate their activities to resolve 8-oxoG damage while limiting cytotoxic BER intermediates from propagating genomic instability remains unclear. Here we use single-molecule Förster resonance energy transfer (smFRET) and ensemble-level techniques to characterize the activities and interactions of consecutive BER enzymes important for repair of 8-oxoG. In addition to characterizing the damage searching and processing mechanisms of human 8-oxoguanine glycosylase 1 (hOGG1), our data support the existence of a ternary complex between hOGG1, the damaged DNA substrate, and human AP endonuclease 1 (APE1). Our results indicate that hOGG1 is actively displaced from its abasic site containing product by protein-protein interactions with APE1 to ensure timely repair of damaged DNA.
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Affiliation(s)
- Austin T Raper
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Brian A Maxwell
- The Ohio State Biophysics Ph.D. Program, The Ohio State University, Columbus, OH 43210, USA
| | - Zucai Suo
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA; The Ohio State Biophysics Ph.D. Program, The Ohio State University, Columbus, OH 43210, USA; Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL 32306, USA.
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Kuznetsov NA, Fedorova OS. Thermodynamic analysis of fast stages of specific lesion recognition by DNA repair enzymes. BIOCHEMISTRY (MOSCOW) 2016; 81:1136-1152. [DOI: 10.1134/s0006297916100114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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3
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Depletion of tyrosyl DNA phosphodiesterase 2 activity enhances etoposide-mediated double-strand break formation and cell killing. DNA Repair (Amst) 2016; 43:38-47. [DOI: 10.1016/j.dnarep.2016.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 11/20/2022]
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Varghese JJ, Trinh QT, Mushrif SH. Insights into the synergistic role of metal–lattice oxygen site pairs in four-centered C–H bond activation of methane: the case of CuO. Catal Sci Technol 2016. [DOI: 10.1039/c5cy01784j] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Of the three mechanisms for activation of methane on copper and copper oxide surfaces, the under-coordinated Cu–O site pair mediated mechanism on CuO surfaces has the lowest activation energy barriers.
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Affiliation(s)
- Jithin John Varghese
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 637459 Singapore
| | - Quang Thang Trinh
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 637459 Singapore
| | - Samir H. Mushrif
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- 637459 Singapore
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Woodrick J, Gupta S, Khatkar P, Dave K, Levashova D, Choudhury S, Elias H, Saha T, Mueller S, Roy R. A novel method for monitoring functional lesion-specific recruitment of repair proteins in live cells. Mutat Res 2015; 775:48-58. [PMID: 25879709 DOI: 10.1016/j.mrfmmm.2015.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/17/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023]
Abstract
DNA-protein relationships have been studied by numerous methods, but a particular gap in methodology lies in the study of DNA adduct-specific interactions with proteins in vivo, which particularly affects the field of DNA repair. Using the repair of a well-characterized and ubiquitous adduct, the abasic (AP) site, as a model, we have developed a comprehensive method of monitoring DNA lesion-specific recruitment of proteins in vivo over time. We utilized a surrogate system in which a Cy3-labeled plasmid containing a single AP-site was transfected into cells, and the interaction of the labeled DNA with BER enzymes, including APE1, Polβ, LIG1, and FEN1, was monitored by immunofluorescent staining of the enzymes by Alexafluor-488-conjugated secondary antibody. The recruitment of enzymes was characterized by quantification of Cy3-Alexafluor-488 co-localization. To validate the microscopy-based method, repair of the transfected AP-site DNA was also quantified at various time points post-transfection using a real time PCR-based method. Notably, the recruitment time kinetics for each enzyme were consistent with AP-site repair time kinetics. This microscopy-based methodology is reliable in detecting the recruitment of proteins to specific DNA substrates and can be extended to study other in vivo DNA-protein relationships in any DNA sequence and in the context of any DNA structure in transfectable proliferating or quiescent cells. The method may be applied to a variety of disciplines of nucleic acid transaction pathways, including repair, replication, transcription, and recombination.
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Affiliation(s)
- Jordan Woodrick
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Suhani Gupta
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Pooja Khatkar
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Kalpana Dave
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Darya Levashova
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Sujata Choudhury
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Hadi Elias
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Tapas Saha
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Susette Mueller
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States
| | - Rabindra Roy
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical School, Washington, DC 20057, United States.
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A comparative study of recombinant mouse and human apurinic/apyrimidinic endonuclease. Mol Cell Biochem 2011; 362:195-201. [PMID: 22042551 DOI: 10.1007/s11010-011-1142-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 10/22/2011] [Indexed: 10/16/2022]
Abstract
Mammalian apurinic/apyrimidinic endonuclease (APE1) initiates the repair of abasic sites (AP-sites), which are highly toxic, mutagenic, and implicated in carcinogenesis. Also, reducing the activity of APE1 protein in cancer cells and tumors sensitizes mammalian tumor cells to a variety of laboratory and clinical chemotherapeutic agents. In general, mouse models are used in studies of basic mechanisms of carcinogenesis, as well as pre-clinical studies before transitioning into humans. Human APE1 (hAPE1) has previously been cloned, expressed, and extensively characterized. However, the knowledge regarding the characterization of mouse APE1 (mAPE1) is very limited. Here we have expressed and purified full-length hAPE1 and mAPE1 in and from E. coli to near homogeneity. mAPE1 showed comparable fast reaction kinetics to its human counterpart. Steady-state enzyme kinetics showed an apparent K(m) of 91 nM and k(cat) of 4.2 s(-1) of mAPE1 for the THF cleavage reaction. For hAPE1 apparent K(m) and k(cat) were 82 nM and 3.2 s(-1), respectively, under similar reaction conditions. However, k(cat)/K(m) were in similar range for both APE1s. The optimum pH was in the range of 7.5-8 for both APE1s and had an optimal activity at 50-100 mM KCl, and they showed Mg(2+) dependence and abrogation of activity at high salt. Circular dichroism spectroscopy revealed that increasing the Mg(2+) concentration altered the ratio of "turns" to "β-strands" for both proteins, and this change may be associated with the conformational changes required to achieve an active state. Overall, compared to hAPE1, mAPE1 has higher K(m) and k(cat) values. However, overall results from this study suggest that human and mouse APE1s have mostly similar biochemical and biophysical properties. Thus, the conclusions of mouse studies to elucidate APE1 biology and its role in carcinogenesis may be extrapolated to apply to human biology. This includes the development and validation of effective APE1 inhibitors as chemosensitizers in clinical studies.
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Kim WC, Berquist BR, Chohan M, Uy C, Wilson DM, Lee CH. Characterization of the endoribonuclease active site of human apurinic/apyrimidinic endonuclease 1. J Mol Biol 2011; 411:960-71. [PMID: 21762700 DOI: 10.1016/j.jmb.2011.06.050] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 06/27/2011] [Accepted: 06/30/2011] [Indexed: 11/17/2022]
Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1) is the major mammalian enzyme in DNA base excision repair that cleaves the DNA phosphodiester backbone immediately 5' to abasic sites. Recently, we identified APE1 as an endoribonuclease that cleaves a specific coding region of c-myc mRNA in vitro, regulating c-myc mRNA level and half-life in cells. Here, we further characterized the endoribonuclease activity of APE1, focusing on the active-site center of the enzyme previously defined for DNA nuclease activities. We found that most site-directed APE1 mutant proteins (N68A, D70A, Y171F, D210N, F266A, D308A, and H309S), which target amino acid residues constituting the abasic DNA endonuclease active-site pocket, showed significant decreases in endoribonuclease activity. Intriguingly, the D283N APE1 mutant protein retained endoribonuclease and abasic single-stranded RNA cleavage activities, with concurrent loss of apurinic/apyrimidinic (AP) site cleavage activities on double-stranded DNA and single-stranded DNA (ssDNA). The mutant proteins bound c-myc RNA equally well as wild-type (WT) APE1, with the exception of H309N, suggesting that most of these residues contributed primarily to RNA catalysis and not to RNA binding. Interestingly, both the endoribonuclease and the ssRNA AP site cleavage activities of WT APE1 were present in the absence of Mg(2+), while ssDNA AP site cleavage required Mg(2+) (optimally at 0.5-2.0 mM). We also found that a 2'-OH on the sugar moiety was absolutely required for RNA cleavage by WT APE1, consistent with APE1 leaving a 3'-PO(4)(2-) group following cleavage of RNA. Altogether, our data support the notion that a common active site is shared for the endoribonuclease and other nuclease activities of APE1; however, we provide evidence that the mechanisms for cleaving RNA, abasic single-stranded RNA, and abasic DNA by APE1 are not identical, an observation that has implications for unraveling the endoribonuclease function of APE1 in vivo.
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Affiliation(s)
- Wan-Cheol Kim
- Chemistry Program, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia, Canada V2N 4Z9
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Lakomek K, Dickmanns A, Ciirdaeva E, Schomacher L, Ficner R. Crystal structure analysis of DNA uridine endonuclease Mth212 bound to DNA. J Mol Biol 2010; 399:604-17. [PMID: 20434457 DOI: 10.1016/j.jmb.2010.04.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 04/21/2010] [Indexed: 11/30/2022]
Abstract
The reliable repair of pre-mutagenic U/G mismatches that originated from hydrolytic cytosine deamination is crucial for the maintenance of the correct genomic information. In most organisms, any uracil base in DNA is attacked by uracil DNA glycosylases (UDGs), but at least in Methanothermobacter thermautotrophicus DeltaH, an alternative strategy has evolved. The exonuclease III homologue Mth212 from the thermophilic archaeon M. thermautotrophicus DeltaH exhibits a DNA uridine endonuclease activity in addition to the apyrimidinic/apurinic site endonuclease and 3'-->5'exonuclease functions. Mth212 alone compensates for the lack of a UDG in a single-step reaction thus substituting the two-step pathway that requires the consecutive action of UDG and apyrimidinic/apurinic site endonuclease. In order to gain deeper insight into the structural basis required for the specific uridine recognition by Mth212, we have characterized the enzyme by means of X-ray crystallography. Structures of Mth212 wild-type or mutant proteins either alone or in complex with DNA substrates and products have been determined to a resolution of up to 1.2 A, suggesting key residues for the uridine endonuclease activity. The insertion of the side chain of Arg209 into the DNA helical base stack resembles interactions observed in human UDG and seems to be crucial for the uridine recognition. In addition, Ser171, Asn153, and Lys125 in the substrate binding pocket appear to have important functions in the discrimination of aberrant uridine against naturally occurring thymidine and cytosine residues in double-stranded DNA.
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Affiliation(s)
- Kristina Lakomek
- Department of Molecular Structural Biology, Institute of Microbiology and Genetics, Georg-August University Göttingen, Justus-von-Liebig Weg 11, D-37077 Göttingen, Germany
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Rich RL, Myszka DG. Grading the commercial optical biosensor literature-Class of 2008: 'The Mighty Binders'. J Mol Recognit 2010; 23:1-64. [PMID: 20017116 DOI: 10.1002/jmr.1004] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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