Tatsuo NUNOSHIBA - Academia.edu (original) (raw)
Papers by Tatsuo NUNOSHIBA
Biochemical and Biophysical Research Communications, May 1, 2021
5 x 108 plaque-forming units (pfu) per ,4g of purified X DNA were used. For cell DNA, up to 1 ,ug... more 5 x 108 plaque-forming units (pfu) per ,4g of purified X DNA were used. For cell DNA, up to 1 ,ug of DNA in up to 5 1l of water was added per 50-,41 packaging reaction. Packaged Abbreviations: SV40, simian virus 40; pfu, plaque-forming units; bp, base pair(s).
Effects of the 5'- and 3'-Flanking bases on the Formation of G→T Transversion by 8-oxoG
Journal of Radiation Research, Dec 1, 1999
Generation of 'OH and oxidative DNA lesions in aerobically grown E. coli lacking both SOD and Fur
Journal of Radiation Research, Dec 1, 1999
Two-Stage Gene Regulation of the Superoxide Stress Response soxRS System in Escherichia Coli
Critical Reviews in Eukaryotic Gene Expression, 1996
All organisms have adapted to environmental changes by acquiring various functions controlled by ... more All organisms have adapted to environmental changes by acquiring various functions controlled by gene regulation. In bacteria, a number of specific responses have been found to confer cell survival in various nutrient-limited conditions, and under physiological stresses such as high or low temperature, extreme pH, radiation, and oxidation (for review, see Neidhardt et al., 1987). In this article, I introduce an Escherichia coli (E. coli) global response induced by superoxide stress, the soxRS regulon. The functions controlled by this system consist of a wide variety of enzymes such as manganese-containing SOD (Mn-SOD); glucose 6-phosphate dehydrogenase (G6PD), the DNA repair enzyme endonuclease IV, fumarase C, NADPH:ferredoxin oxidoreductase, and aconitase. This response is positively regulated by a two-stage control system in which SoxR iron-sulfur protein senses exposure to superoxide and nitric oxide, and then activates transcription of the soxS gene, whose product stimulates the expression of the regulon genes. Our recent finding indicates that soxS transcription is initiated in a manner dependent on the rpoS gene encoding RNA polymerase sigma factor, theta s, in response to entering the stationary phase of growth. With this information, mechanisms for prokaryotic coordinating gene expression in response to superoxide stress and in stationary phase are discussed.
Thermoplasma volcanium GSS1の完全ゲノムDNA配列の決定
Mutation research, Oct 1, 1988
We have previously found the formation of 8-hydroxydeoxyguanosine (8-OH-dG) in DNA by treatment w... more We have previously found the formation of 8-hydroxydeoxyguanosine (8-OH-dG) in DNA by treatment with various oxygen radical-forming agents. As 8-OH-dG in DNA induces misreading during DNA synthesis in vitro, it might be one of the DNA damages related to mutagenesis or carcinogenesis by oxygen radical. In this presentation we show that auto-oxidized unsaturated fatty acids are effective for the formation of 8-OH-dG in DNA. Various auto-oxidized unsaturated fatty acids were shaken with a solution of deoxyguanosine or DNA in phosphate buffer (pH 7.4) and reacted in emulsion at 37°C. The formation of 8-OH-dG was monitored with highperformance liquid chromatography coupled with electrochemical detector. After the reaction with auto-oxidized linolenic acid and linoleic acid, a considerable amount of 8-OH-dG was detected. When EDTA or DETAPAC (iron chelator) was added to the reaction mixture the formation of 8-OH-dG was inhibited. It has been reported that unsaturated fatty acids stimulate rat mammary carcinogenesis and that their auto-oxidized products are mutagenic. DNA damages such as 8-OH-dG or strand break induced by lipid peroxide may be involved in the mutagenesis and carcinogenesis.
Role of Enzymes in Antimutagenesis of Human Saliva and Serum
Springer eBooks, 1986
In order to evaluate the risk of dietary environmental mutagens and/or carcinogens to man and to ... more In order to evaluate the risk of dietary environmental mutagens and/or carcinogens to man and to search for protection from them, it is important to study possible modifications in every part of the digestive tract.
P-076(O-16) Role of DNA Repair in Thermus thermophilus Genomic Integrity : Analyzing by a Homologous Recombinaton Detection System(Poster presentation)
Taikai Program Yoshisyu of the Environmental Mutagen Society of Japan, Oct 30, 2013
Infection and Immunity, Mar 1, 1995
Nitric oxide (NO •) is produced as a cytotoxic free radical through enzymatic oxidation of L-argi... more Nitric oxide (NO •) is produced as a cytotoxic free radical through enzymatic oxidation of L-arginine in activated macrophages. Pure NO • gas was previously found to induce the Escherichia coli soxRS oxidative stress regulon, which is readily monitored by using a soxS::lac fusion. The soxRS system includes antioxidant defenses, such as a superoxide dismutase and a DNA repair enzyme for oxidative damage, and protects E. coli from the cytotoxicity of NO •-generating macrophages. Previous experiments involved exposing E. coli to a bolus of NO • rather than the steadily generated gas expected of activated macrophages. We show here detectable induction of soxS transcription by NO • delivered at rates as low as 25 M/h. Maximal induction was observed at 25 M NO • per h under anaerobic conditions but at 125 M/h aerobically. After incubation with murine macrophages, soxS expression was induced in the phagocytosed bacteria up to ϳ30-fold after an 8-h exposure. This in vivo induction was almost completely eliminated by the NO • synthase inhibitor N G-monomethyl-Larginine. The inhibitor increased the survival of a ⌬soxRS strain but not that of wild-type E. coli after phagocytosis, which suggests that induction of the soxRS regulon by NO • can counteract most of the cytotoxic effects of NO • production by the macrophages. We show that the soxRS-regulated enzyme glucose-6-phosphate dehydrogenase is an important element of the defense against macrophages.
Mutation research, Dec 1, 1991
Biochemical and Biophysical Research Communications, Dec 1, 2000
Escherichia coli K-12 strain EY5, deficient in oxyR, was constructed to assess the role of oxyR a... more Escherichia coli K-12 strain EY5, deficient in oxyR, was constructed to assess the role of oxyR and oxyRregulated regulon in spontaneous mutagenesis. Mutagenesis was monitored by selecting two forward mutations of colicin B-sensitive to resistance and valinesensitive to resistance, one base substitution mutation of rifampicin-sensitive to resistance and one reversion of argE3 his-4 to Arg ؉ His ؉. Deficiency of oxyR did not lead to the enhancement of spontaneous mutation frequencies of the four markers tested. By DNA sequence analysis, we determined 49 colicin B-resistant mutants derived from EY5 and found that 37% were base substitutions, 29% IS element insertions, 20% deletions, and 14% single base frameshifts. Among the base substitutions, G:C3 T:A transversions predominated followed by G:C3 A:T transitions and A:T3 T:A transversions. These spectra were essentially the same as those from oxyR ؉ strains. The results indicate that oxyR and oxyR-regulated genes do not play a significant role in the defense against spontaneous mutagenesis.
Isolation and Identification of E. coli MutT Homologues in Saccharomyces cerevisiae
Journal of Radiation Research, Dec 1, 2002
Mutation research, Aug 1, 1986
Mutation research, Oct 1, 1988
Mutation research, Oct 1, 1985
A cluster ofconstitutive mutations affecting theC-terminus oftheRedox-sensitive SoxRtranscriptional activator
Activation ofEscherichia coil oxidative stress regulon genes(sodA, zwf,fumC, nfo, etc.) ismediate... more Activation ofEscherichia coil oxidative stress regulon genes(sodA, zwf,fumC, nfo, etc.) ismediated byatwostageregulatory system:theredox-sensitive SoxR protein transcriptionally activates thesoxSgene, whoseproduct thenstimulates transcription ofthe regulon genes.Previous experiments showedthat limited 3'truncation ofsoxRgenecausesconstitutive soxRSexpression. DNAsequence analysis ofthesoxR genesfromthesoxRS-constitutive strains isolated originally (Greenberg etal.(1990) Proc. Nat!. Acad.Sci. USA87,6181-6185) revealed that three alleles encode aminoacidsubstitutions or a chaintermination clustered neartheC-terminus ofSoxR.Twoother single-amino-acid substitutions inconstitutive alleles mappedtothehelix-turn-helix motif andtoaregion of unknownfunction inthecenter ofthepolypeptide, respectively. Noconstitutive mutation wasfound within theregion encoding thecysteines oftheSoxRFeS center, inthesoxRorsoxSpromoters, orinthesoxS structural gene.Since anin-frame deletion ofjust nine SoxRr...
Revi ' evv Spontaneous Mutagenesis in Saccharomyces cerevisiae Escherichia coll and
ln this article. we described the spontaneously occurring mutation specificities of defects that ... more ln this article. we described the spontaneously occurring mutation specificities of defects that are involved in translesion polymerase. mutS mismatch correction and potA mismatch correction in EScherichia coll. We argue that 1) there is no contribution of translesion polymerase to E. coli chromosomal mutation. 2) mutS system recognizes and corrects transition and frameshift mismatches and 3) potA system recognizes and corrects deletion. frameshift and transition mismatches. We also characterized the genetic alterations that inactivate either the CAN1 gene of Saccharomyces cerevisiae haploid cells or heterozygously situated in diploid ceils. The characteristics of mutation in haploid yeast are essentially consistent with those in E. coli. suggesting that similar mechanisms are
Construction of a supF-based system for detection of mutations in Thermus thermophilus II
The Molecular Biology Society of Japan, 2016
Role of oxidative stress defense system on genotoxicity and cytotoxicity of aldehydes. : Implication of glutathione
Journal of Radiation Research, 1997
Implication of iron in spontaneous mutagenesis in E. coli mutants lacking reactive oxygen species (ROS) scavenging enzymes
Biochemical and Biophysical Research Communications, May 1, 2021
5 x 108 plaque-forming units (pfu) per ,4g of purified X DNA were used. For cell DNA, up to 1 ,ug... more 5 x 108 plaque-forming units (pfu) per ,4g of purified X DNA were used. For cell DNA, up to 1 ,ug of DNA in up to 5 1l of water was added per 50-,41 packaging reaction. Packaged Abbreviations: SV40, simian virus 40; pfu, plaque-forming units; bp, base pair(s).
Effects of the 5'- and 3'-Flanking bases on the Formation of G→T Transversion by 8-oxoG
Journal of Radiation Research, Dec 1, 1999
Generation of 'OH and oxidative DNA lesions in aerobically grown E. coli lacking both SOD and Fur
Journal of Radiation Research, Dec 1, 1999
Two-Stage Gene Regulation of the Superoxide Stress Response soxRS System in Escherichia Coli
Critical Reviews in Eukaryotic Gene Expression, 1996
All organisms have adapted to environmental changes by acquiring various functions controlled by ... more All organisms have adapted to environmental changes by acquiring various functions controlled by gene regulation. In bacteria, a number of specific responses have been found to confer cell survival in various nutrient-limited conditions, and under physiological stresses such as high or low temperature, extreme pH, radiation, and oxidation (for review, see Neidhardt et al., 1987). In this article, I introduce an Escherichia coli (E. coli) global response induced by superoxide stress, the soxRS regulon. The functions controlled by this system consist of a wide variety of enzymes such as manganese-containing SOD (Mn-SOD); glucose 6-phosphate dehydrogenase (G6PD), the DNA repair enzyme endonuclease IV, fumarase C, NADPH:ferredoxin oxidoreductase, and aconitase. This response is positively regulated by a two-stage control system in which SoxR iron-sulfur protein senses exposure to superoxide and nitric oxide, and then activates transcription of the soxS gene, whose product stimulates the expression of the regulon genes. Our recent finding indicates that soxS transcription is initiated in a manner dependent on the rpoS gene encoding RNA polymerase sigma factor, theta s, in response to entering the stationary phase of growth. With this information, mechanisms for prokaryotic coordinating gene expression in response to superoxide stress and in stationary phase are discussed.
Thermoplasma volcanium GSS1の完全ゲノムDNA配列の決定
Mutation research, Oct 1, 1988
We have previously found the formation of 8-hydroxydeoxyguanosine (8-OH-dG) in DNA by treatment w... more We have previously found the formation of 8-hydroxydeoxyguanosine (8-OH-dG) in DNA by treatment with various oxygen radical-forming agents. As 8-OH-dG in DNA induces misreading during DNA synthesis in vitro, it might be one of the DNA damages related to mutagenesis or carcinogenesis by oxygen radical. In this presentation we show that auto-oxidized unsaturated fatty acids are effective for the formation of 8-OH-dG in DNA. Various auto-oxidized unsaturated fatty acids were shaken with a solution of deoxyguanosine or DNA in phosphate buffer (pH 7.4) and reacted in emulsion at 37°C. The formation of 8-OH-dG was monitored with highperformance liquid chromatography coupled with electrochemical detector. After the reaction with auto-oxidized linolenic acid and linoleic acid, a considerable amount of 8-OH-dG was detected. When EDTA or DETAPAC (iron chelator) was added to the reaction mixture the formation of 8-OH-dG was inhibited. It has been reported that unsaturated fatty acids stimulate rat mammary carcinogenesis and that their auto-oxidized products are mutagenic. DNA damages such as 8-OH-dG or strand break induced by lipid peroxide may be involved in the mutagenesis and carcinogenesis.
Role of Enzymes in Antimutagenesis of Human Saliva and Serum
Springer eBooks, 1986
In order to evaluate the risk of dietary environmental mutagens and/or carcinogens to man and to ... more In order to evaluate the risk of dietary environmental mutagens and/or carcinogens to man and to search for protection from them, it is important to study possible modifications in every part of the digestive tract.
P-076(O-16) Role of DNA Repair in Thermus thermophilus Genomic Integrity : Analyzing by a Homologous Recombinaton Detection System(Poster presentation)
Taikai Program Yoshisyu of the Environmental Mutagen Society of Japan, Oct 30, 2013
Infection and Immunity, Mar 1, 1995
Nitric oxide (NO •) is produced as a cytotoxic free radical through enzymatic oxidation of L-argi... more Nitric oxide (NO •) is produced as a cytotoxic free radical through enzymatic oxidation of L-arginine in activated macrophages. Pure NO • gas was previously found to induce the Escherichia coli soxRS oxidative stress regulon, which is readily monitored by using a soxS::lac fusion. The soxRS system includes antioxidant defenses, such as a superoxide dismutase and a DNA repair enzyme for oxidative damage, and protects E. coli from the cytotoxicity of NO •-generating macrophages. Previous experiments involved exposing E. coli to a bolus of NO • rather than the steadily generated gas expected of activated macrophages. We show here detectable induction of soxS transcription by NO • delivered at rates as low as 25 M/h. Maximal induction was observed at 25 M NO • per h under anaerobic conditions but at 125 M/h aerobically. After incubation with murine macrophages, soxS expression was induced in the phagocytosed bacteria up to ϳ30-fold after an 8-h exposure. This in vivo induction was almost completely eliminated by the NO • synthase inhibitor N G-monomethyl-Larginine. The inhibitor increased the survival of a ⌬soxRS strain but not that of wild-type E. coli after phagocytosis, which suggests that induction of the soxRS regulon by NO • can counteract most of the cytotoxic effects of NO • production by the macrophages. We show that the soxRS-regulated enzyme glucose-6-phosphate dehydrogenase is an important element of the defense against macrophages.
Mutation research, Dec 1, 1991
Biochemical and Biophysical Research Communications, Dec 1, 2000
Escherichia coli K-12 strain EY5, deficient in oxyR, was constructed to assess the role of oxyR a... more Escherichia coli K-12 strain EY5, deficient in oxyR, was constructed to assess the role of oxyR and oxyRregulated regulon in spontaneous mutagenesis. Mutagenesis was monitored by selecting two forward mutations of colicin B-sensitive to resistance and valinesensitive to resistance, one base substitution mutation of rifampicin-sensitive to resistance and one reversion of argE3 his-4 to Arg ؉ His ؉. Deficiency of oxyR did not lead to the enhancement of spontaneous mutation frequencies of the four markers tested. By DNA sequence analysis, we determined 49 colicin B-resistant mutants derived from EY5 and found that 37% were base substitutions, 29% IS element insertions, 20% deletions, and 14% single base frameshifts. Among the base substitutions, G:C3 T:A transversions predominated followed by G:C3 A:T transitions and A:T3 T:A transversions. These spectra were essentially the same as those from oxyR ؉ strains. The results indicate that oxyR and oxyR-regulated genes do not play a significant role in the defense against spontaneous mutagenesis.
Isolation and Identification of E. coli MutT Homologues in Saccharomyces cerevisiae
Journal of Radiation Research, Dec 1, 2002
Mutation research, Aug 1, 1986
Mutation research, Oct 1, 1988
Mutation research, Oct 1, 1985
A cluster ofconstitutive mutations affecting theC-terminus oftheRedox-sensitive SoxRtranscriptional activator
Activation ofEscherichia coil oxidative stress regulon genes(sodA, zwf,fumC, nfo, etc.) ismediate... more Activation ofEscherichia coil oxidative stress regulon genes(sodA, zwf,fumC, nfo, etc.) ismediated byatwostageregulatory system:theredox-sensitive SoxR protein transcriptionally activates thesoxSgene, whoseproduct thenstimulates transcription ofthe regulon genes.Previous experiments showedthat limited 3'truncation ofsoxRgenecausesconstitutive soxRSexpression. DNAsequence analysis ofthesoxR genesfromthesoxRS-constitutive strains isolated originally (Greenberg etal.(1990) Proc. Nat!. Acad.Sci. USA87,6181-6185) revealed that three alleles encode aminoacidsubstitutions or a chaintermination clustered neartheC-terminus ofSoxR.Twoother single-amino-acid substitutions inconstitutive alleles mappedtothehelix-turn-helix motif andtoaregion of unknownfunction inthecenter ofthepolypeptide, respectively. Noconstitutive mutation wasfound within theregion encoding thecysteines oftheSoxRFeS center, inthesoxRorsoxSpromoters, orinthesoxS structural gene.Since anin-frame deletion ofjust nine SoxRr...
Revi ' evv Spontaneous Mutagenesis in Saccharomyces cerevisiae Escherichia coll and
ln this article. we described the spontaneously occurring mutation specificities of defects that ... more ln this article. we described the spontaneously occurring mutation specificities of defects that are involved in translesion polymerase. mutS mismatch correction and potA mismatch correction in EScherichia coll. We argue that 1) there is no contribution of translesion polymerase to E. coli chromosomal mutation. 2) mutS system recognizes and corrects transition and frameshift mismatches and 3) potA system recognizes and corrects deletion. frameshift and transition mismatches. We also characterized the genetic alterations that inactivate either the CAN1 gene of Saccharomyces cerevisiae haploid cells or heterozygously situated in diploid ceils. The characteristics of mutation in haploid yeast are essentially consistent with those in E. coli. suggesting that similar mechanisms are
Construction of a supF-based system for detection of mutations in Thermus thermophilus II
The Molecular Biology Society of Japan, 2016
Role of oxidative stress defense system on genotoxicity and cytotoxicity of aldehydes. : Implication of glutathione
Journal of Radiation Research, 1997
Implication of iron in spontaneous mutagenesis in E. coli mutants lacking reactive oxygen species (ROS) scavenging enzymes