Mutagenesis, Vol. 14, No. 1, 95-102,
January 1999
© 1999 UK Environmental Mutagen Society/Oxford University Press
Hydrogen peroxide and coffee induce G:C
T:A transversions in the lacI gene of catalase-defective Escherichia coli
Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Avenida de Medina Azahara s/n, 14071-Córdoba, España
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and methodsResultsDiscussionReferences |
|---|
The mutagenicity of hydrogen peroxide (H2O2) was compared with that of coffee, a complex mixture which generates H2O2. An Escherichia coli strain defective in catalase activity (katG katE double mutant) and carrying a single copy mucAB (pRW144) plasmid was constructed to enhance the mutagenic response to oxidants. The ability of the mucAB genes to influence the type, frequency and distribution of H2O2-induced mutations was also investigated in isogenic bacteria lacking pRW144. Induced mutational spectra were characterized and compared with that of spontaneous mutagenesis. A total of 444 independent forward mutations affecting the first 210 bp of the lacI gene were identified by DNA sequence analysis. The spontaneous mutation spectrum showed no bias (P = 0.52) for substitutions at G:C base pairs. In contrast, in the H2O2-induced spectrum substitutions occurred preferentially at G:C base pairs (P < 0.0001) with a preponderance of G:C
T:A transversions (43.4% of H2O2-induced mutants versus 17.3% of spontaneous mutants). These data support the view that 7,8-dihydro-8-oxoguanine is the main premutagenic lesion induced by H2O2 and that catalase-defective bacteria have elevated levels of 8-oxoguanine in chromosome DNA after H2O2 exposure. Coffee produced a similar distribution of mutational events as H2O2 (P > 0.05), suggesting that this compound may be the main cause of the coffee-induced mutagenesis. The presence of plasmid pRW144 did not affect the frequency of H2O2-induced G:CT:A transversions, but caused an increase in A:TT:A transversions and a decrease in –1 base frameshifts. Although the frequencies of G:CT:A transversions were similar in all three induced spectra (H2O2 and coffee ± pRW144), differences were observed in location of mutations throughout the target gene. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
There is growing evidence that the cellular formation of reactive oxygen species (ROS) and the resulting oxidative DNA damage play an important role in processes like aging, mutagenesis and carcinogenesis and a number of degenerative diseases (see Sies, 1991
; Halliwell and Arouma, 1993). Hydrogen peroxide (H2O2) is generated in cells from many enzymatic and non-enzymatic reactions of dioxygen. Because of its unique properties of high diffusion and a long lifetime, H2O2 seems to be an important molecule contributing to oxidative damage (Hauptmann and Cadenas, 1997). A variety of exogenous agents may also contribute to the H2O2 load (Davies, 1995) and it is known that H2O2 is generated in beverages, such as coffee and tea (Ariza et al., 1988; Stadler et al., 1994), with high levels of consumption all over the world. Formation of H2O2 in these beverages is attributed to the oxidation of polyphenolic components (Aeschbacher, 1991).
Cellular DNA damage from H2O2 arises from the highly reactive hydroxyl radicals (OH·), generated in Fenton-like reactions between H2O2 and metal ions, such as Fe2+ (Epe, 1995). 7,8-Dihydro-8-oxoguanine (8-oxoG) is one of the multiple oxidative damages induced in DNA by OH· (Halliwell, 1993; Epe, 1995). This lesion represents 30–50% of the total base modification products induced by OH·-producing models and therefore is considered a `fingerprint' of OH· attack on DNA (Dizdaroglu et al., 1991). 8-oxoG contributes to the mutational load by inducing targeted G:CT:A transversions upon DNA replication (Wood et al., 1990).
Hydrogen peroxide is mainly detoxified in Escherichia coli by two distinct species of catalase. The katG gene encodes a bifunctional catalase hydroperoxidase I (HPI) (Loewen et al., 1985) which is transcriptionally induced by OxyR as part of the genetic response to H2O2 (Storz et al., 1990). The katE gene codes for the monofunctional HPII (Loewen, 1984) and is under the control of rpoS, an alternative 
factor which is activated in stationary phase cells (Sak et al., 1989). Recent studies have also shown an OxyR-independent regulation of HPI by rpoS as exponentially growing cells enter stationary phase (Ivanova et al., 1994). Bacteria lacking the H2O2 scavengers, HPI and HPII catalases, have been engineered by simultaneous mutation of the katG and katE genes (Abril and Pueyo, 1990). These bacteria show extreme sensitivity to the cytotoxic and mutagenic effects of both H2O2 and coffee (Abril and Pueyo, 1990; Prieto-Álamo et al., 1993) and display increased 8-oxoG content in chromosomal DNA when grown under hyperoxygenation and, particularly, following H2O2 exposure (Alhama et al., 1998).
Here we determined the spectrum of mutations induced by H2O2 and compared this with that arising from coffee-induced DNA damage in E.coli defective in catalase activity and carrying a single copy mucAB plasmid (katG katE double mutant/pRW144). Spontaneous mutations were also analyzed for comparison with those induced by H2O2 or coffee. In addition, mutations induced by H2O2 in bacteria lacking the mucAB plasmid were characterized to study the effect of SOS mutagenic processing on the spectrum of this oxidant.
|
Materials and methods |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
Mutagens
Coffee (instant, regular roast) was bought at a local store. Hydrogen peroxide (H2O2) as a 30% aqueous solution and 4-nitroquinoline 1-oxide (4NQO) were purchased from Sigma Chemical Co. (St Louis, MO). Coffee and H2O2 were dissolved in water and 4NQO in dimethylsulfoxide from Merck (Darmstadt, Germany).
Bacterial strains
Escherichia coli K-12 UC838 [F– araD81 arg56 nad113 
(uvrB-bio) (ogt-fnr)1 (pro-lac)/F' lac-pro] (Vidal et al., 1995) is a catalase-proficient strain considered as the parental wild-type in this study. UC1221 is a catalase-defective [katG katE::Tn10 double mutant] derivative isolated in this work. UC1217 is as UC838 and UC1218 as UC1221, but with the mutagenesis-enhancing plasmid pRW144. This plasmid (Ho et al., 1993) contains the mucAB genes cloned into pGB2 (SpcR, low copy pSC101 derivative). Genetic manipulations were carried out as described by Miller (1992).
Media
Luria-Bertani (LB) nutrient medium (Gerhardt et al., 1994) was used. The nutrient agar was LB medium solidified with Difco agar (17 g/l) supplemented (when necessary) with tetracycline (20 µg/ml) or spectinomycin (100 µg/ml). Selective plates for L-arabinose-resistant mutants (AraR) were made up of Vogel-Bonner (VB) minimal medium (Gerhardt et al., 1994) containing Difco agar (17 g/l), glycerol, L-arabinose, D-biotin, thiamine, nicotinic acid, adenine, arginine, methionine and casamino acids (0.25 g/l). These plates were supplemented with a trace amount (0.5 mg/plate) of D-glucose for expression of AraR mutants. Selective plates for mutants that synthesize ß-galactosidase constitutively (Lacc) were made up of VB medium containing Difco agar (17 g/l), phenyl-ß-D-galactoside (P-gal) (750 mg/l) as the sole carbon source and D-biotin, thiamine, nicotinic acid, adenine and arginine. Sugars were at 2 g/l, amino acids at 40 µg/ml, vitamins at 5 µg/ml and adenine at 100 µg/ml. The top agar was Difco agar (6 g/l) with NaCl (5 g/l).
Mutagenesis and survival assays
Ara test. The assays were carried out basically as previously described (Prieto-Álamo et al., 1993). Briefly, bacteria were grown at 37°C for 12 h with shaking (90 r.p.m.) in LB medium. Cells were then harvested by centrifugation and resuspended in VB salts. An aliquot of bacterial suspension (containing ~1x108 cells) and the mutagen to be tested were preincubated at 37°C for 40 min with shaking (90 r.p.m.) in 1 ml VB salts containing a trace amount of 0.5 mg D-glucose for full expression of AraR mutants. Aliquots of 0.1 ml were then combined in 2 ml molten top agar and the contents poured on selective plates. For survival determinations, ~5x103 bacteria and the mutagen were preincubated at 37°C for 20 min with shaking (90 r.p.m.) in 0.5 ml VB salts. The mixture was then plated on LB plates. Viable colonies were counted after 24 h and mutants after 72 h at 37°C. Bacterial colonies were counted automatically (model 40-10; Analytical Measuring System Ltd). All data represent averages from at least two duplicate plates. Each mutagenesis and survival assay was repeated on at least two separate occasions with a wide range of chemical concentrations. The slope of the linear regression line fitted to the ascending portion of the corresponding dose–response curve gave the number of AraR mutants induced per dose of mutagen.
Lac test. Stationary cultures in LB medium were diluted 50-fold into fresh LB broth and incubated at 37°C and 150 r.p.m. until the cell density reached an optical density at 600 nm of 0.6. Cells were then harvested by centrifugation and resuspended in VB salts. Bacterial suspension (~1x108 cells/ml) and the mutagen to be tested were incubated at 37°C for 40 min with shaking (90 r.p.m.). The mutagen was then eliminated by centrifugation and the bacteria were resuspended in fresh LB broth (3–6x107 cells/ml). Aliquots of 1 ml were incubated overnight for full expression of Lacc mutants. Overnight cultures (1–3x109 cells/ml) were diluted and bacteria were plated on LB and P-gal plates for determination of survivors and Lacc mutants, respectively. The mutation frequency was expressed as the number of induced Lacc mutants/10–6 viable bacteria.
Selection and sequencing of lacI–d mutations
Bacteria treated as indicated before and resuspended in fresh LB medium were split in 1 ml aliquots. The split cultures were then allowed to recover overnight. Dominant mutations (lacI–d, lacOc) were identified from total Lacc mutants by following a simple complementation test (Miller, 1972). Only one dominant mutant per split culture was subject to DNA sequence analysis, to guarantee that each lacI–d mutation represented an independent event. The lacI gene was amplified in a DNA thermal cycler (Perkin-Elmer Cetus) using a Gene Amp Kit (Perkin-Elmer Cetus) and two specific 25mer primers (Operon Technologies) with their 3'-ends at positions –16 and 1186 of the gene, respectively. The PCR mixture was then subjected to 30 cycles at 94, 55 and 72°C for 1, 1 and 3 min (2 s extension), respectively, and 72°C for 10 min. PCR products were sequenced using the Applied Biosystem Dye Terminator Cycle Sequencing Ready Reaction Kit followed by analysis on an ABI model 377 DNA sequencer. The synthetic oligonucleotide 3'-AGTTGACCCACGGTCGCACC-5' was used as sequencing primer for the first 300 bp of the lacI gene.
Statistical analysis
Statistical comparisons were performed with Fischer's exact test for differences in proportions and with the 
2 test for differences between observed and expected number of mutations. Mutational spectra were compared according to Cariello et al. (1994). The computer program uses a random number generator to produce a large number of simulated spectra based on the hypergeometric probability of the experimentally observed input spectra. The degree to which the simulated spectra differ from the input spectra is used to estimate the probability that the input spectra were derived from the same population (i.e. to measure belief in the null hypothesis that the input spectra are not different). A P value 
0.05 leads one to conclude that the input spectra are different.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
In this paper we describe the spectra of forward mutational changes observed in the N-terminal region of the lacI gene of Escherichia coli after treatment with hydrogen peroxide (H2O2) or coffee, a complex mixture which generates H2O2 (Ariza et al., 1988
). To this end, we first constructed a catalase-defective derivative from UC838, a uvrB mutant strain that we have extensively used in previous mutation spectra analysis (see for example Vidal et al., 1995). Null mutations in katG and katE genes were subsequently transduced into UC838, as described by Abril and Pueyo (1990). The resulting katG katE double mutant was named UC1221. As indicated in Table I, UC1221 retained <1% of the catalase activity of the parental wild-type and showed increased sensitivity to mutagenesis by coffee (15.3-fold), as measured by the induction of forward mutations to L-arabinose resistance (AraR). In contrast, as expected, impairment of catalase activity in UC1221 did not affect sensitivity to the mutagenic action of the monofunctional ethylating agent EMS (Table I).
|
Plasmid pKM101, which encodes the mucA and mucB genes, is typically used to make bacteria more susceptible to mutagenesis by chemical oxidants and a number of other SOS-dependent mutagenic agents, like 4NQO (Ruiz-Rubio et al., 1985
; Ruiz-Laguna et al., 1994). However, E.coli strains carrying pKM101 grow more slowly on defined medium compared with counterparts lacking pKM101 (Abril and Pueyo, 1990). To avoid the growth-retarding effect of pKM101, a low copy umuDC or mucAB plasmid was introduced into UC838 (wild-type) and UC1221 (katG katE double mutant). The resulting strains showed increased sensitivity to mutagenesis by 4NQO, however, the bacteria carrying the mucAB plasmid (denoted UC1217 and UC1218, respectively) were consistently more sensitive (by a factor of two) than those carrying the umuDC plasmid (data not shown). Figure 1 shows that strain UC1218 (katG katE/pRW144) was particularly sensitive to the lethal and mutagenic effects of coffee compared with UC1217 (wild-type/pRW144). UC1218 was 5-fold more sensitive than UC1221 (which lacks the pRW144 plasmid) to coffee mutagenesis (1686 AraR mutants/plate in Figure 1 versus 352 in Table I
, respectively). The increased sensitivity of UC1218 to coffee mutagenesis was also clearly visible by the selection of Lacc mutants (Figure 1), giving a maximal mutant frequency (80 induced Lacc mutants/106 bacteria) at 4 mg/ml coffee. In contrast, the mutant frequency in the catalase-proficient parent (UC1217) was much lower even with a higher dose coffee (11 induced Lacc mutants/106 bacteria at 20 mg/ml).
|
Based on the dose–reponse curve in Figure 1,
a dose of 4 mg/ml coffee was chosen for the characterization of lacI–d mutations induced in bacteria defective in catalase activity (UC1218, katG katE/pRW144). This mutagenic treatment increased 14.6-fold the spontaneous level of constitutive lac mutant frequency (Table II). Of the constitutive induced lac mutants, 26% carried dominant mutations in the lacI gene, whereas only 16% of the spontaneous mutants resulted from dominant mutations in this gene. Thus, 4 mg/ml coffee generated a 24.6-fold increase in lacI–d mutations compared with the level observed in the untreated bacteria. The mutation spectrum induced by H2O2 was obtained and compared with that generated by coffee. UC1218 bacteria treated with 1 mM H2O2 exhibited increments in mutation frequencies similar to those induced by 4 mg/ml coffee (Table II). The lacI mutations induced by H2O2 were also characterized in bacterial strain UC1221 (katG katE), which lacks the mucAB (pRW144) plasmid, to study the influence of SOS mutagenic processing on mutation spectrum induced by this oxidant.
|
A total of 444 independent lacI–d mutations were subjected to DNA sequence analysis: 145 coffee-induced (in UC1218), 247 H2O2-induced (129 in UC1218 and 118 in UC1221) and 52 spontaneous (in UC1218). The distribution of mutations by class is summarized in Table III
. Coffee and H2O2 induced the same types of mutation at similar percentages in UC1218 (P > 0.05), but differences were observed with the spontaneous background of untreated bacteria. Mutations at G:C base pairs were more common in the coffee- and H2O2-induced spectra (63.4 and 68.2%, respectively) compared with the spontaneous spectrum (44.2%) and, among base substitutions at G:C sites, there was a significant increase in G:CT:A transversions following coffee and H2O2 treatments (33.8 and 43.4 versus 17.3%). Other differences with the spontaneous spectrum were a significant decrease in substitutions at AT base pairs in the H2O2-induced spectrum (16.3 versus 28.8%) and of multibase mutations in the coffee-induced spectrum (2.1 versus 9.6%). The spectrum of H2O2-induced mutations characterized from UC1218 showed differences with that from strain UC1221, which did not contain the mucAB (pRW144) plasmid. Specifically, there was an increase in base pair substitutions, particularly A:TT:A transversions, and a concurrent decrease in –1 bp frameshifts.
|
Although G:C
T:A transversions were recovered at similar percentages in the three induced spectra (Table III), the site distribution of mutations within the lacI–d target was different (Table IV). Assuming a Poisson distribution, positions with at least 5 mutations/site were real hotspots (P < 0.01). The induced G:CT:A spectra did not share common hotspot positions and there was also variation in the percentage of mutations induced at certain sites. In fact, these data were statistically different (P < 0.05) when analyzed with a computer program designed to compare mutational spectra (Cariello et al., 1994). The overall distribution along the lacI gene of G:CT:A transversions and all other induced single base mutations (single base substitutions and frameshift mutations) are displayed in Figures 2 and 3.
|
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
We have characterized the mutational spectra produced by coffee and H2O2 at the lacI gene in a catalase-defective strain of E.coli transfected with plasmid pRW144. This plasmid contains the mucAB genes that are believed to facilitate progression of the replication fork past sites of DNA damage (reviewed in Woodgate and Sedgwick, 1992
). To determine whether the mucAB genes influence the type, frequency and distribution of H2O2-caused mutations, we also obtained the mutational spectrum induced by this oxidant in isogenic bacteria lacking pRW144. Mutations were characterized by DNA sequencing of the first 210 bp of the lacI gene (target for lacI–d mutations) and mutational spectra were compiled and compared using computer software specifically designed for this (Cariello et al. 1994).
The majority of the mutational events characterized in this study were point mutations with substantial numbers of base substitutions. It is known from previous studies that there are 94 sites sensitive to base pair substitutions in the N-terminal region of the lacI gene; 52 consist of G:C base pairs and 42 A:T base pairs. In the spontaneous mutational spectrum there was no bias (P = 0.52 by 2 test) in favor of base substitutions at G:C base pairs. In contrast, in the coffee- and H2O2-induced spectra, base substitutions occurred preferentially at G:C base pairs (P < 0.0001) and specifically involved an increment in G:CT:A transversions, i.e. 33.8 and 43.4% of the coffee-and H2O2-induced mutants, respectively, compared with only 17.3% of spontaneous mutants. There is evidence to suggest that G:CT:A transversions might arise from misreplication of 8-oxoG (Wood et al., 1990; Shibutani et al., 1991) and this is in agreement with previous data from our group which showed that formation of this oxidative lesion in the DNA of catalase-defective bacteria increases with the dose of H2O2 (0–20 mM dose range), but remains unchanged in the corresponding wild-type (Alhama et al.,1998).
The type of base substitutions induced by H2O2 in the present study differs from those previously reported for the supF gene on the shuttle vector pZ189 (Moraes et al., 1989, 1990; Akasaka and Yamamoto, 1994). Treatment of pZ189 with a combination of H2O2 and a ferric–EDTA complex prior to transfection and passage in simian cells produced in supF a base change spectrum dominated by G:CA:T transitions and marked by an increase in changes at A:T base pairs (Moraes et al., 1989). When the in vitro treated pZ189 were propagated in E.coli cells that had been induced for SOS functions by UV irradiation, the spectrum was characterized by an increase in G:CC:G transversions (34 versus 17% of all mutations) (Akasaka and Yamamoto, 1994). G:CT:A mutations were also observed by Akasaka and Yamamoto (1994), though at similar proportions in the H2O2-induced and spontaneous spectra (32 and 29%, respectively). An increase in G:CC:G changes (but not in G:CT:A mutations) was also observed after in vivo mutagenesis by H2O2 of simian cells previously transfected with pZ189 (Moraes et al., 1990). All these results, in contrast to our data, do not support the view that 8-oxoG is the main premutagenic lesion induced by H2O2, since 8-oxoG, by mispairing with A, should generate G:CT:A transversions, not G:CA:T transitions or G:CC:G transversions (Shibutani et al., 1991; Chen et al., 1992).
The mutagenesis-enhancing plasmid pRW144, which carries the mucAB analogs of the E.coli umuDC genes, resulted in an increase in H2O2-induced A:TT:A transversions. Abasic sites are one of the numerous classes of oxidative DNA lesions (Wallace, 1997). Translesion DNA synthesis at abasic sites is strongly dependent on SOS functions (Schaaper and Loeb, 1981) and the induction of A:TT:A transversions is consistent with a preference for adenine insertion during translesion bypass at sites of base loss derived from depurination (Kunkel, 1984). No other class of base substitution was enhanced by pRW144. This result is apparently in contrast to previous data showing that 
-radiation-induced damage at G:C sites is more strongly dependent on umuC function than damage at A:T sites, especially when producing transversions (Sargentini and Smith, 1994).
Any analysis of the influence of the neighboring base sequence on a particular mutation type requires knowledge of the base at which the mutation has arisen. Previous analyses have assumed that H2O2-induced transversions at G:C base pairs originate from modifications to guanines, not cytosines (Akasaka and Yamamoto, 1994). If this assumption is correct, then our data on H2O2 (or coffee) mutagenesis suggest that guanines at the center of the triplet 5'-PuGA-3' are more likely to mutate (on average 2.5 times) than those that were not (P < 0.01 by 2 test) in bacteria with pRW144 (UC1218) and that such a preference disappeared in UC1221 lacking pRW144 (P = 0.72). This suggests an influence of the local base sequence on the efficiency of the mutagenic processing of guanine lesions by either the MucAB proteins expressed from pRW144 (this work) or the UmuCD proteins induced by UV irradiation (Akasaka and Yamamoto, 1994).
Coffee is a complex mixture which covers a wide spectrum of genetic activity in bacteria, fungi and cultured mammalian cells and can either potentiate or inhibit the effects of a great number of mutagenic agents (Nehlig and Debry, 1994). Numerous studies deal with the genetic effects of the various constituents of coffee, such as caffeine, aliphatic dicarbonyls like glyoxal and methylglyoxal, phenolic compounds, aromatic amines and H2O2, which is generated by oxygenation of coffee during the preparation procedure (see for example Ariza et al., 1988; Nehlig and Debry, 1994; Stadler et al., 1994; Johansson et al., 1995). The contribution of these components to the mutagenic activity of coffee depends upon other parameters of the biological endpoints used for measurement. Therefore, while the strains TA100 and TA98 of the His reverse mutation test might mainly recognize the mutagenicity of aliphatic dicarbonyls or aromatic amines, respectively, the Ara forward mutation assay, sensitive to low coffee doses, mainly detects the mutagenic activity of H2O2 (Pueyo and Ariza, 1993; Nehlig and Debry, 1994; Johansson et al., 1995).
Glyoxal, a mutagenic component of coffee and major product of DNA oxidation, has recently been related to mutagenesis by oxygen free radicals (Murata-Kamiya et al., 1997a,b). Glyoxal increased the percentage of substitutions at G:C base pairs in the entire lacI gene, in particular G:CA:T transitions. In addition, G:CT:A transversions induced by glyoxal in the lacI gene were preferentially located at 5'-CG or 5'-GG sequences. Our coffee-induced spectrum differs notably from these results. The coffee spectrum was dominated by G:CT:A transversions and these were not preferentially located at 5'-C/GG sequences (P = 0.48 by 2 test). These differences suggest that glyoxal is not contributing significantly to the mutational spectrum induced by coffee in the catalase-defective background of E.coli UC1218. In contrast, our data further support the hypothesis that H2O2 plays a key role in mediating coffee mutagenicity in vitro and this probably accounts for the similarities between the frequency of GCTA transversions in the H2O2- and coffee-treated bacteria. Nevertheless, it should be noted that mutational spectra involving H2O2 as a pure chemical or as a constituent of coffee showed differences in the site distribution of G:CT:A transversions throughout the lacI gene, although no clear trend was obvious.
The data (like those reported in this work) obtained on coffee mutagenicity from in vitro bioassays are not easily extrapolated in vivo to assess the impact on human health. Nehlig and Debry (1994) have suggested that the formation of H2O2 by coffee (as well as by other beverages rich in polyphenolics) could be a confounding factor in the evaluation of its mutagenic potency in vivo, as H2O2 is not formed after coffee ingestion. Likewise, most in vivo evidence suggests that coffee drinking does not have a significant relationship with mutagenic or cancer risk. However, for heavier consumption, defined as at least 4–5 cups/day, a statistically significant increase in risk of bladder cancer has been seen in men (WCRF/AICR, 1997).
|
Acknowledgments |
|---|
This work was subsidized by grant PB95-0557-CO2-01 from the DGES, Ministerio de Educación y Cultura and by Junta de Andalucía (groups CVI 0187). JR-L was the recipient of a fellowship from Junta de Andalucía and Fundación Caja de Madrid.
|
Notes |
|---|
1 To whom correspondence should be addressed. Tel: +34 957 218695; Fax: +34 957 218688; Email: bb1pucuc{at}uco.es
|
References |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
-
Abril,N. and Pueyo,C. (1990) Mutagenesis in E.coli lacking catalase. Environ. Mol. Mutagen., 15, 184–189.[ISI][Medline]
Aeschbacher,H.U. (1991) Mutagenic and antimutagenic compounds in beverages. In Hayatsu,H. (ed.), Mutagens in Food: Detection and Prevention. CRC Press, Boca Raton, FL, pp. 181–191.
Akasaka,S. and Yamamoto,K. (1994) Hydrogen peroxide induces G:C to T:A and G:C to C:G transversions in the supF gene of Escherichia coli. Mol. Gen. Genet., 243, 500–505.[ISI][Medline]
Alhama,J., Ruiz-Laguna,J., Rodriguez-Ariza,A., Toribio,F., López-Barea,J. and Pueyo,C. (1998) Formation of 8-oxo-guanine in cellular DNA of Escherichia coli strains defective in different antioxidant defenses. Mutagenesis, 13, 589–594.
Ariza,R.R., Dorado,G., Barbancho,M. and Pueyo,C. (1988) Study on the causes of direct-acting mutagenicity in coffee and tea using the Ara test in Salmonella typhimurium. Mutat. Res., 201, 89–96.[ISI][Medline]
Beers,R.F.,Jr and Sizer,I.W. (1952) A spectrophotometric method for measuring the breakdown of hydrogen peroxide by catalase. J. Biol. Chem., 195, 133–139.
Bradford,M.M. (1976) A rapid and sensitive method for the quantification of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem., 72, 248–254.[ISI][Medline]
Cariello,N.F., Piegorsch,W.W., Adams,W.T. and Skopek,T.R. (1994) Computer program for the analysis of mutational spectra: application to p53 mutations. Carcinogenesis, 15, 2281–2285.
Chen,K.C., Cahill,D.S., Kasai,H., Nishimura,S. and Loeb,L.A. (1992) 8-Hydroxyguanine, an abundant form of oxidative DNA damage, causes GT and AC substitutions. J. Biol. Chem., 267, 166–172.
Davies,K.J.A. (1995) Oxidative stress: the paradox of aerobic life. In Rice-Evans,C., Halliwell,B. and Lunt,G.G. (eds), Free Radicals and Oxidative Stress: Environment, Drugs and Food Additives. Portland Press, London, UK, pp. 1–31.
Dizdaroglu,M., Rao,G., Halliwell,B. and Gajewski,E. (1991) Damage to the DNA bases in mammalian chromatin by hydrogen peroxide in the presence of ferric and cupric ions. Arch. Biochem. Biophys., 285, 317–324.[ISI][Medline]
Epe,B. (1995) DNA damage profiles induced by oxidizing agents. Rev. Physiol. Biochem. Pharmacol., 127, 223–249.
Farabaugh,P.J. (1978) Sequence of the lacI gene. Nature, 274, 765–769.[Medline]
Gerhardt,P., Murray,R.G.E., Wood,W.A. and Krieg,N.R. (1994) Methods for General and Molecular Bacteriology. American Society for Microbiology, Washington, DC.
Halliwell,B. (1993) Oxidative DNA damage: meaning and measurement. In Halliwell,B. and Aruoma,O.I. (eds), DNA and Free Radicals. Ellis Horwood Ltd, Chichester, UK, pp. 67–79.
Halliwell,B. and Arouma,O.I. (1993) DNA and Free Radicals. Ellis Horwood Ltd, Chichester, UK.
Hauptmann,N. and Cadenas,E. (1997) The oxygen paradox: biochemistry of active oxygen. In Scandalios,J.G. (ed.), Oxidative Stress and the Molecular Biology of Antioxidant Defenses. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, pp. 1–20.
Ho,C., Kulaeva,O.I., Levine,A.S. and Woodgate,R. (1993) A rapid method for cloning mutagenic DNA repair genes: isolation of umu-complementing genes from multidrug resistance plasmids R391, R446b, and R471a. J. Bacteriol., 175, 5411–5419.
Ivanova,A., Miller,C., Glinsky,G. and Eisenstark,A. (1994) Role of rpoS (katF) in oxyR-independent regulation of hydroperoxidase I in Escherichia coli. Mol. Microbiol., 12, 571–578.[ISI][Medline]
Johansson,M.A.E., Knize,M.G., Jägerstad,M. and Felton,J.S. (1995) Characterization of mutagenic activity in instant hot beverage powders. Environ. Mol. Mutagen., 25, 154–161.[ISI][Medline]
Kunkel,T.A. (1984) Mutational specificity of depurination. Proc. Natl Acad. Sci. USA, 81, 1494–1498.
Loewen,P.C. (1984) Isolation of catalase-deficient Escherichia coli mutants and genetic mapping of katE, a locus that affects catalase activity. J. Bacteriol., 157, 622–626.
Loewen,P.C., Triggs,B.L., George,C.S. and Hrabarchuk,B.E. (1985) Genetic mapping of katG, a locus that affects synthesis of the bifunctional catalase-peroxidase hydroperoxidase I in Escherichia coli. J. Bacteriol., 162, 661–667.
Miller,J.H. (1972) Experiments in Molecular Genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY.
Miller,J.H. (1992) A Short Course in Bacterial Genetics. A Laboratory Manual and a Handbook for Escherichia coli and Related Bacteria. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY.
Moraes,E.C., Keyse,S.M., Pidoux,M. and Tyrrell,R.M. (1989) The spectrum of mutations generated by passage of a hydrogen peroxide damaged shuttle vector plasmid through a mammalian host. Nucleic Acids Res., 17, 8301–8312.
Moraes,E.C., Keyse,S.M. and Tyrrell,R.M. (1990) Mutagenesis by hydrogen peroxide treatment of mammalian cells: a molecular analysis. Mutagenesis, 11, 283–293.
Murata-Kamiya,N., Kamiya,H., Kaji,H. and Kasai,H. (1997a) Mutational specificity of glyoxal, a product of DNA oxidation, in the lacI gene of wild-type Escherichia coli W3110. Mutat. Res., 377, 255–262.[ISI][Medline]
Murata-Kamiya,N., Kamiya,H., Kaji,H. and Kasai,H. (1997b) Glyoxal, a major product of DNA oxidation, induces mutations at G:C sites on a shuttle vector plasmid replicated in mammalian cells. Nucleic Acids Res., 25, 1897–1902.
Nehlig,A. and Debry,G. (1994) Potential genotoxic, mutagenic and antimutagenic effects of coffee: a review. Mutat Res., 317, 145–162.[ISI][Medline]
Prieto-Álamo,M.J., Abril,N. and Pueyo,C. (1993) Mutagenesis in Escherichia coli K-12 mutants defective in superoxide dismutase or catalase. Carcinogenesis, 14, 237–244.
Pueyo,C. and Ariza,R.R. (1993) Role of reactive oxygen species in the mutagenicity of complex mixtures of plant origin. In Haliwell,B. and Aruoma,O.I. (eds), DNA and Free Radicals. Ellis Horwood Ltd, Chichester, UK, pp. 275–291.
Ruiz-Laguna,J., Ariza,R.R., Prieto-Álamo,M.J., Boiteux,S. and Pueyo,C. (1994) Fpg protein protects Escherichia coli K-12 from mutation induction by the carcinogen 4-nitroquinoline 1-oxide. Carcinogenesis, 15, 425–429.
Ruiz-Rubio,M., Alejandre-Durán,E. and Pueyo,C. (1985) Oxidative mutagens specific for A·T base pairs induce forward mutations to L-arabinose resistance in Salmonella typhimurium. Mutat. Res., 147, 153–163.[ISI][Medline]
Sak,B.D., Eisenstark,A. and Touati,D. (1989) Exonuclease III and the catalase hydroperoxidase II in Escherichia coli are both regulated by the katF gene product. Proc. Natl Acad. Sci. USA, 86, 3271–3275.
Sargentini,N.J. and Smith,K.C. (1994) DNA sequence analysis of spontaneous and -radiation (anoxic)-induced lacId mutations in Escherichia coli umuC122::Tn5: differential requirement for umuC at G·C vs. A·T sites and for the production of transversions vs. transitions. Mutat. Res., 311, 175–189.[ISI][Medline]
Schaaper,R.M. and Loeb,L.A. (1981) Depurination causes mutations in SOS-induced cells. Proc. Natl Acad. Sci. USA, 79, 1773–1777.
Shibutani,S., Takeshita,M. and Grollman,A.P. (1991) Insertion of specific bases during DNA synthesis past the oxidation-damaged base 8-oxodG. Nature, 349, 431–434.[Medline]
Sies,H. (1991) Oxidative Stress. Academic Press, San Diego, CA.
Stadler,R.H., Turesky,R.J., Müller,O., Markovic,J. and Leong-Morgenthaler,P.-M. (1994) The inhibitory effects of coffee on radical-mediated oxidation and mutagenicity. Mutat Res., 308, 177–190.[ISI][Medline]
Storz,G., Tartaglia,L.A. and Ames,B.N. (1990) Transcriptional regulator of oxidative stress-inducible genes: direct activation by oxidation. Science, 248, 189–194.
Vidal,A., Abril,N. and Pueyo,C. (1995) DNA repair by Ogt alkyltransferase influences EMS mutational specificity. Carcinogenesis, 16, 817–821.
Wallace,S.S. (1997) Oxidative damage to DNA and its repair. In Scandalios,J.G. (ed.), Oxidative Stress and the Molecular Biology of Antioxidant Defenses. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, pp. 49–90.
WCRF/AICR (1997) Food, Nutrition and the Prevention of Cancer: A Global Perspective. World Cancer Research Fund and American Institute for Cancer Research, Washington, DC.
Wood,M.L., Dizdaroglu,M., Gajewki,E. and Essigmann,J.M. (1990) Mechanistic studies of ionizing radiation and oxidative mutagenesis: genetic effects of a single 8-hydroxyguanine (7-hydro-8-oxoguanine) residue inserted at a unique site in a viral genome. Biochemistry, 29, 7024–7032.[Medline]
Woodgate,R. and Sedgwick,S.G. (1992) Mutagenesis induced by bacterial UmuDC proteins and their plasmid homologues. Mol. Microbiol., 6, 2213–2218.[ISI][Medline]
Received on April 23, 1998; accepted on August 11, 1998.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. M. Skinner and M. S. Turker Oxidative Mutagenesis, Mismatch Repair, and Aging Sci. Aging Knowl. Environ., March 2, 2005; 2005(9): re3 - re3. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. H. Smith, J. A. Imlay, and R. I. Mackie Increasing the Oxidative Stress Response Allows Escherichia coli To Overcome Inhibitory Effects of Condensed Tannins Appl. Envir. Microbiol., June 1, 2003; 69(6): 3406 - 3411. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||