Use of the rpoB gene to determine the specificity of base substitution mutations on the Escherichia coli chromosome

Garibyan, Lilit; Huang, Tiffany; Kim, Mandy; Wolff, Erika M.; Nguyen, Anh Thi Hong; Nguyen, Theresa; Diep, Amy; Hu, Kaibin; Iverson, Ayuko; Yang, Hanjing; Miller, Jeffrey H

doi:10.1016/s1568-7864(03)00024-7

Cited by 270 publications

(358 citation statements)

References 63 publications

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“…Almost all of the mutations observed in the mutT, mutT/nth, and mutT/nei strains were A:TC:G transversions (Table 6 and Supplemental Table 2). Hotspots were observed at positions 1538 and 1714 as reported previously [30].…”

Section: Effects Of Endonuclease Iii-and Viii-deficiencies In the Mutsupporting

confidence: 78%

Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP

et al. 2008

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To examine whether base excision repair suppresses mutations induced by oxidized deoxyribonucleotide 5'-triphosphates in the nucleotide pool, 8-hydroxy-dGTP (8-OH-dGTP) and 2-hydroxy-dATP were introduced into Escherichia coli strains deficient in endonucleases III (Nth) and VIII (Nei), and MutY, and mutations in the chromosomal rpoB gene were analyzed. The spontaneous rpoB mutant frequency was also examined in mutT/nth and mutT/nei strains, to assess the influence on the mutations induced by the endogenous 8-OH-dGTP accumulated in the mutT mutant. The mutations induced by exogenous 2-hydroxy-dATP were similar in all of the strains tested. Exogenous 8-OH-dGTP increased the rpoB mutant frequency more efficiently in the nth strain than that in the wild-type strain. The spontaneous mutant frequency in the mutT/nth strain was 2-fold higher than that in the mutT strain. These results suggest that E. coli endonuclease III also acts as a defense against the mutations caused by 8-OH-dGTP in the nucleotide pool.

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Section: Effects Of Endonuclease Iii-and Viii-deficiencies In the Mutsupporting

confidence: 78%

Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP

et al. 2008

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“…Mutations responsible for Rif R map exclusively to rpoB and produce amino-acid substitutions in three primary regions of the b subunit of RNA polymerase (Garibyan et al, 2003;Jatsenko et al, 2010). The 38 diverse mutational possibilities in rpoB available to achieve resistance include all transition and transversion substitutions, providing a suitable system for analyzing mutability.…”

Section: Drug-resistance Proteins and Other Outer Membrane Proteins Amentioning

confidence: 99%

Interspecies competition triggers virulence and mutability in Candida albicans–Pseudomonas aeruginosa mixed biofilms

et al. 2014

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Inter-kingdom and interspecies interactions are ubiquitous in nature and are important for the survival of species and ecological balance. The investigation of microbe-microbe interactions is essential for understanding the in vivo activities of commensal and pathogenic microorganisms. Candida albicans, a polymorphic fungus, and Pseudomonas aeruginosa, a Gram-negative bacterium, are two opportunistic pathogens that interact in various polymicrobial infections in humans. To determine how P. aeruginosa affects the physiology of C. albicans and vice versa, we compared the proteomes of each species in mixed biofilms versus single-species biofilms. In addition, extracellular proteins were analyzed. We observed that, in mixed biofilms, both species showed differential expression of virulence proteins, multidrug resistance-associated proteins, proteases and cell defense, stress and iron-regulated proteins. Furthermore, in mixed biofilms, both species displayed an increase in mutability compared with monospecific biofilms. This characteristic was correlated with the downregulation of enzymes conferring protection against DNA oxidation. In mixed biofilms, P. aeruginosa regulates its production of various molecules involved in quorum sensing and induces the production of virulence factors (pyoverdine, rhamnolipids and pyocyanin), which are major contributors to the ability of this bacterium to cause disease. Overall, our results indicate that interspecies competition between these opportunistic pathogens enhances the production of virulence factors and increases mutability and thus can alter the course of hostpathogen interactions in polymicrobial infections.

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“…Significantly, increased expression of wild-type mutS in cells subjected to MAC is reported to diminish the MAC phenotype (5). However, mutS is associated with both GC 3 AT and AT 3 GC mutations (12). The paucity of AT 3 GC mutations suggests that a loss of MutS activity is not a significant contributor to the MAC phenotype in this case.…”

Section: Resultsmentioning

confidence: 71%

“…In particular, Rif R mutations typically fall in one of three clusters of rpoB. These regions have been extensively sequenced and characterized in earlier work (10)(11)(12). To examine the mutations in detail, 48 clonal DNA isolates were sequenced for each genotype (wild-type and ileS Ala ) after each time period (1 and 7 days).…”

Section: Resultsmentioning

confidence: 99%

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An editing-defective aminoacyl-tRNA synthetase is mutagenic in aging bacteria via the SOS response

Bacher

Schimmel

2007

Proc. Natl. Acad. Sci. U.S.A.

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Mistranslation in bacterial and mammalian cells leads to production of statistical proteins that are, in turn, associated with specific cell or animal pathologies, including death of bacterial cells, apoptosis of mammalian cells in culture, and neurodegeneration in the mouse. A major source of mistranslation comes from heritable defects in the editing activities of aminoacyl-tRNA synthetases. These activities clear errors of aminoacylation by deacylation of mischarged tRNAs. We hypothesized that, in addition to previously reported phenotypes in bacterial and mammalian systems, errors of aminoacylation could be mutagenic and lead to disease. As a first step in testing this hypothesis, the effect of an editing defect in a single tRNA synthetase on the accumulation of mutations in aging bacteria was investigated. A striking, statistically significant, enhancement of the mutation rate in aging bacteria was found. This enhancement comes from an increase in error-prone DNA repair through induction of the bacterial SOS response. Thus, mistranslation, as caused by an editing-defective tRNA synthetase, can lead to heritable genetic changes that could, in principle, be linked to disease.aminoacylation errors ͉ error-prone DNA polymerases ͉ amino acid misincorporation ͉ genetic code ambiguity A s organisms age, mutations accumulate over time owing to direct environmental insults that are incompletely or inaccurately repaired. Recent work directed our attention to the possibility that mistranslation could play a role in producing mutations in aging populations. In particular, mistranslation can arise from editing defects in aminoacyl-tRNA synthetases. These enzymes catalyze the first step of protein synthesis, where each amino acid is linked to its cognate tRNA bearing the anticodon triplet associated with the amino acid. Because of inherent physiochemical limitations of some enzymes to discriminate between structurally similar amino acids, mischarged tRNAs, such as Val-tRNA Ile or Ser-tRNA Ala , are produced. Normally, these mischarged tRNAs are cleared by hydrolytic editing, which occurs at a distinct active site within the synthetase. But even a small defect, caused by a mutation in the editing center, can lead to extreme cell pathologies and disease.For example, mice that carry a mild mutation in the editing domain of alanyl-tRNA synthetase suffer from ataxia (1). The mutant alanyl-tRNA synthetase mischarges tRNA Ala with serine and, as a consequence, mistranslation occurs that leads to induction of the unfolded protein response. That, in turn, leads to the degeneration of Purkinje cells in the cerebellum, beginning within 3 weeks of age. Similarly, in human cell culture, an inducible, editing-defective valyl-tRNA synthetase caused cellular degradation and apoptosis (2).With these recent results in mind, we were motivated to investigate the possibility that mistranslation could also lead to heritable genetic changes. Previously, we generated a knock-in mutant allele of ileS that encodes no functional editing domain (3)....

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Use of the rpoB gene to determine the specificity of base substitution mutations on the Escherichia coli chromosome

Cited by 270 publications

References 63 publications

Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP

Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP

Interspecies competition triggers virulence and mutability in Candida albicans–Pseudomonas aeruginosa mixed biofilms

An editing-defective aminoacyl-tRNA synthetase is mutagenic in aging bacteria via the SOS response

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