DNA-Protein Cross-link Formation Mediated by Oxanine

Nakano, Toshiaki; Terato, Hiroaki; Asagoshi, Kenjiro; Masaoka, Aya; Mukuta, Miho; Ohyama, Yoshihiko; Suzuki, Toshinori; Makino, Keisuke; Ide, Hiroshi

doi:10.1074/jbc.m212847200

Cited by 80 publications

(40 citation statements)

References 63 publications

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“…E. coli endo VIII, FaPy-DNA glycosolase (MutM), hOGG1, hNEIL1, and hNEIL2 but not mouse methylpurine DNA glycosylase are known to form cross-linking products with oxanine (26,27). Under our assay conditions, human AAG was the only enzyme that showed oxanine DNA glycosylase activity (Fig.…”

Section: Resultsmentioning

confidence: 93%

Oxanine DNA Glycosylase Activity from Mammalian Alkyladenine Glycosylase

Hitchcock

Dong

Connor

et al. 2004

Journal of Biological Chemistry

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Oxanine (Oxa) is a deaminated base lesion derived from guanine in which the N 1 -nitrogen is substituted by oxygen. This work reports the mutagenicity of oxanine as well as oxanine DNA glycosylase (ODG) activities in mammalian systems. Using human DNA polymerase ␤, deoxyoxanosine triphosphate is only incorporated opposite cytosine (Cyt). When an oxanine base is in a DNA template, Cyt is efficiently incorporated opposite the template oxanine; however, adenine and thymine are also incorporated opposite Oxa with an efficiency ϳ80% of a Cyt/Oxa (C/O) base pair. Guanine is incorporated opposite Oxa with the least efficiency, 16% compared with cytosine. ODG activity was detected in several mammalian cell extracts. Among the known human DNA glycosylases tested, human alkyladenine glycosylase (AAG) shows ODG activity, whereas hOGG1, hNEIL1, or hNEIL2 did not. ODG activity was detected in spleen cell extracts of wild type age-matched mice, but little activity was observed in that of Aag knock-out mice, confirming that the ODG activity is intrinsic to AAG. Human AAG can excise Oxa from all four Oxa-containing double-stranded base pairs, Cyt/Oxa, Thy/Oxa, Ade/Oxa, and Gua/Oxa, with no preference to base pairing. Surprisingly, AAG can remove Oxa from single-stranded Oxacontaining DNA as well. Indeed, AAG can also remove 1,N 6 -ethenoadenine from single-stranded DNA. This study extends the deaminated base glycosylase activities of AAG to oxanine; thus, AAG is a mammalian enzyme that can act on all three purine deamination bases, hypoxanthine, xanthine, and oxanine.

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Section: Resultsmentioning

confidence: 93%

Oxanine DNA Glycosylase Activity from Mammalian Alkyladenine Glycosylase

Hitchcock

Dong

Connor

et al. 2004

Journal of Biological Chemistry

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“…Although hNEIL1 and hNEIL2 did not excise Oxa from DNA at appreciable rates (data not shown), both enzymes were crosslinked to Oxa, resulting in slow-migrating bands in the SDS-PAGE analysis. Endo VIII but not Endo III and hNTH1 was similarly cross-linked with Oxa under these conditions (45) (and data not shown), implying a common architecture of the active site pocket in human and E. coli Endo VIII homologues (hNEIL1, hNEIL2, and Endo VIII). a The activity ratio of purified enzymes for 5S-and 5R-Tg isomers (calculated from the data in Table II).…”

Section: Fig 6 Differential Excision Capacities Of Hela and E Colimentioning

confidence: 95%

“…The reaction with histone and HMG proteins is very slow, occurring on a time scale of days, but that with DNA glycosylases is very rapid, occurring in less than an hour, and possibly involves the direct interaction of Oxa in DNA with the active site residue of DNA glycosylases (tentatively assigned to Lys or Arg). Interestingly, despite sharing activities for oxidative pyrimidine lesions, Endo VIII but not Endo III and hNTH1 are crosslinked to Oxa (45). Accordingly, Oxa is a simple but useful lesion to probe the architecture of the active site of DNA glycosylases.…”

Section: Discussionmentioning

confidence: 99%

“…We have previously shown that Oxa, a major guanine lesion produced by the reaction with nitric oxide or nitrous acid (49,50), forms cross-links with DNA-binding proteins such as histone, HMG protein, and DNA glycosylases (45). The reaction with histone and HMG proteins is very slow, occurring on a time scale of days, but that with DNA glycosylases is very rapid, occurring in less than an hour, and possibly involves the direct interaction of Oxa in DNA with the active site residue of DNA glycosylases (tentatively assigned to Lys or Arg).…”

Section: Discussionmentioning

confidence: 99%

“…25FU, 25HMU, and 25OG containing 5-formyluracil (fU), 5-hydroxymethyluracil (hmU), and 7,8-dihydro-8-oxoguanine (8-oxoG), respectively, were chemically synthesized (42)(43)(44). 25HOU, 25HOC, 34FP, and 25OXA containing 5-hydroxyuracil (hoU), 5-hydroxycytosine (hoC), 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (mFapyG), and oxanine (Oxa), respectively, were prepared by DNA polymerase reactions with modified 2Ј-deoxynucleoside 5Ј-triphosphates as reported previously (19,(43)(44)(45). The oligonucleotides containing the base lesions were 5Ј-end labeled with [␥- DNA Glycosylases-The purification of Endo III, Endo VIII, and hNTH1 were reported previously (19,43 …”

Section: Methodsmentioning

confidence: 99%

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Differential Specificity of Human and Escherichia coli Endonuclease III and VIII Homologues for Oxidative Base Lesions

Katafuchi

Nakano

Masaoka

et al. 2004

Journal of Biological Chemistry

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118

117

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In human cells, oxidative pyrimidine lesions are restored by the base excision repair pathway initiated by homologues of Endo III (hNTH1) and Endo VIII (hNEIL1 and hNEIL2). In this study we have quantitatively analyzed and compared their activity toward nine oxidative base lesions and an apurinic/apyrimidinic (AP) site using defined oligonucleotide substrates. hNTH1 and hNEIL1 but not hNEIL2 excised the two stereoisomers of thymine glycol (5R-Tg and 5S-Tg), but their isomer specificity was markedly different: the relative activity for 5R-Tg:5S-Tg was 13:1 for hNTH1 and 1.5:1 for hNEIL1. This was also the case for their Escherichia coli homologues: the relative activity for 5R-Tg:5S-Tg was 1:2.5 for Endo III and 3.2:1 for Endo VIII. Among other tested lesions for hNTH1, an AP site was a significantly better substrate than urea, 5-hydroxyuracil (hoU), and guanine-derived formamidopyrimidine (mFapyG), whereas for hNEIL1 these base lesions and an AP site were comparable substrates. In contrast, hNEIL2 recognized an AP site exclusively, and the activity for hoU and mFapyG was marginal. hNEIL1, hNEIL2, and Endo VIII but not hNTH1 and Endo III formed cross-links to oxanine, suggesting conservation of the -fold of the active site of the Endo VIII homologues. The profiles of the excision of the Tg isomers with HeLa and E. coli cell extracts closely resembled those of hNTH1 and Endo III, confirming their major contribution to the repair of Tg isomers in cells. However, detailed analysis of the cellular activity suggests that hNEIL1 has a significant role in the repair of 5S-Tg in human cells.DNA carrying vital genetic information of cells constantly suffers from spontaneous deamination and depurination, alkylation, and oxidation (1-3). These reactions lead to modifications of the DNA backbone and bases, with the latter predominating. The resulting aberrant bases are potentially genotoxic because of the loss or alteration of base pairing information (4), and hence need to be restored by the cellular repair system (2, 3, 5). The major repair mechanism for such damage is the base excision repair (BER) 1 pathway (6), which is conserved from bacteria to humans. In the first step of BER, DNA glycosylases with distinct damage specificities detect the aberrant base in the vast sea of normal bases and remove it from the DNA backbone, leaving an apurinic/apyrimidinic (AP) site. The resulting AP site is further processed and repaired by the subsequent action of AP endonuclease (Endo), DNA polymerase, and DNA ligase through the short patch or long patch BER pathway.The initial search for DNA glycosylases involved in the repair of oxidatively damaged bases in Escherichia coli identified Endo III, Endo VIII, and formamidopyrimidine-DNA glycosylase (7,8). The principal substrates of Endo III and Endo VIII are oxidative pyrimidine lesions. They exhibit redundant damage specificity and catalyze the hydrolysis of the N-glycosidic bond (N-glycosylase activity) and the subsequent incision of an AP site by AP lyase activity via ␤-elimination ...

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Synthesis of 2′‐Deoxyoxanosine from 2′‐Deoxyguanosine, Conversion to Its Phosphoramidite, and Incorporation into Oxanine‐Containing Oligodeoxynucleotides

Pack

Makino

2010

CP Nucleic Acid Chemistry

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Oxanine (Oxa, O) is one of the damaged bases produced from guanine (G) through nitrosative deamination induced by nitric oxide (NO) or nitrous acid (HNO(2)). Large-scale preparation of Oxa-containing oligodeoxynucleotide (Oxa-ODN) with the desired base sequence is a prerequisite for exploring detailed properties of Oxa in DNA. This can be accomplished by incubation of G nucleosides with NaNO(2) in acetic acid buffer (pH 3.5) to produce Oxa nucleosides (e.g., 2'-deoxyoxanosine or dOxo), conversion of dOxo to DMT-dOxo-amidite by tritylation and conventional phosphoramidation, and subsequent synthesis of Oxa-ODN. The presence of Oxa in the synthetic ODN is confirmed by enzymatic digestion. Oxa-ODN is useful for analyzing the biochemical and biophysical properties of Oxa in DNA, which is believed to be involved in NO-induced genotoxicity and cytotoxicity. In addition, since Oxa possesses the carbodiimide-activated carboxylate function (O-acylisourea structure), Oxa-ODN can be used as a functional DNA oligomer that makes covalent cross-linkages with amine or amine-containing biomolecules and amine-modified solid surfaces.

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DNA-Protein Cross-link Formation Mediated by Oxanine

Cited by 80 publications

References 63 publications

Oxanine DNA Glycosylase Activity from Mammalian Alkyladenine Glycosylase

Oxanine DNA Glycosylase Activity from Mammalian Alkyladenine Glycosylase

Differential Specificity of Human and Escherichia coli Endonuclease III and VIII Homologues for Oxidative Base Lesions

Synthesis of 2′‐Deoxyoxanosine from 2′‐Deoxyguanosine, Conversion to Its Phosphoramidite, and Incorporation into Oxanine‐Containing Oligodeoxynucleotides

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