The 6C RNA family is a class of small RNAs highly conserved in Actinobacteria, including the genera Mycobacterium, Streptomyces and Corynebacterium whose physiological function has not yet been elucidated. We found that strong transcription of the cgb_03605 gene, which encodes 6C RNA in C. glutamicum, was driven by the SigA- and SigB-dependent promoter Pcgb_03605. 6C RNA was detected at high level during exponential growth phase (180 to 240 molcules per cell) which even increased at the entry of the stationary phase. 6C RNA level did not decrease within 240 min after transcription had been stopped with rifampicin, which suggests high 6C RNA stability. The expression of cgb_03605 further increased approximately twofold in the presence of DNA-damaging mitomycin C (MMC) and nearly threefold in the absence of LexA. Deletion of the 6C RNA gene cgb_03605 resulted in a higher sensitivity of C. glutamicum toward MMC and UV radiation. These results indicate that 6C RNA is involved in the DNA damage response. Both 6C RNA level-dependent pausing of cell growth and branched cell morphology in response to MMC suggest that 6C RNA may also be involved in a control of cell division.
- Klíčová slova
- 6C RNA, Actinobacteria, Corynebacterium glutamicum, RNA stability, SOS response, branched morphology, cell division, sigma factor,
- MeSH
- bakteriální RNA genetika MeSH
- Corynebacterium glutamicum genetika růst a vývoj metabolismus MeSH
- genetická transkripce MeSH
- malá nekódující RNA chemie genetika MeSH
- promotorové oblasti (genetika) MeSH
- regulace genové exprese u bakterií MeSH
- sekvence nukleotidů MeSH
- sigma faktor metabolismus MeSH
- SOS odpověď (genetika) genetika MeSH
- stabilita RNA MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- bakteriální RNA MeSH
- malá nekódující RNA MeSH
- sigma faktor MeSH
Plant-derived smoke and certain smoke compounds improve seed germination and enhance seedling growth of many species. Thus, smoke-infused water and the active smoke-derived compounds have the potential to be used in different agricultural and horticultural applications. However, despite these interesting and potentially practical properties, it should also be ascertained whether such compounds may pose a health risk, particularly if they are to be used in the production of food or fodder crops. Amongst some of the aspects that would be important to understand are any possible genotoxic properties that the compounds may possess due to potential carry-over effects. Here, we report on a genotoxicity study of 3,4,5-trimethylfuran-2(5H)-one, a compound from plant-derived smoke previously shown to have germination inhibitory activity. Using two in vitro tests, namely the bacterial VITOTOX® test (with/without S9 metabolic activation) and the cytome assay on human C3A cells, no genotoxicity or toxicity was found. Furthermore, these results support a previous study where a related smoke-derived compound with germination promoting properties was investigated.
- Klíčová slova
- Butenolide, Cytome, VITOTOX,
- MeSH
- 4-nitrochinolin-1-oxid toxicita MeSH
- benzopyreny toxicita MeSH
- chinolony toxicita MeSH
- furany farmakologie MeSH
- hepatocyty cytologie účinky léků metabolismus MeSH
- klíčení účinky léků MeSH
- lidé MeSH
- luciferasy genetika metabolismus MeSH
- mutageny farmakologie MeSH
- nádorové buněčné linie MeSH
- reportérové geny MeSH
- rostliny účinky léků MeSH
- Salmonella typhimurium účinky léků genetika růst a vývoj MeSH
- semena rostlinná účinky léků růst a vývoj MeSH
- SOS odpověď (genetika) účinky léků MeSH
- testy genotoxicity MeSH
- transkripční faktory genetika metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 3,4,5-trimethylfuran-2(5H)-one MeSH Prohlížeč
- 4-nitrochinolin-1-oxid MeSH
- 4-nitroquinolone-1-oxide MeSH Prohlížeč
- benzopyreny MeSH
- chinolony MeSH
- furany MeSH
- luciferasy MeSH
- mutageny MeSH
- transkripční faktory MeSH
The paper deals with a possible use of the bacterial detection system of SOS chromotest to test mutagenicity of waste dump water checking the mutagenicity degree on real samples from Praksice waste dump, which is a controlled waste dump with mixed industrial, municipal and inert wastes. The waste dump surface water samples were taken from a no-name influent stream springing below the waste dump body between 2005 and 2009. After metabolic activation by microsomal fraction in vitro, medium to high mutagenicity was registered in all the samples. The SOS chromotest is assessed as an effective and economically acceptable method to check and determine the mutagenicity degree of contaminated water.
- MeSH
- Escherichia coli K12 účinky léků genetika MeSH
- látky znečišťující vodu toxicita MeSH
- monitorování životního prostředí metody MeSH
- mutageny toxicita MeSH
- nebezpečný odpad škodlivé účinky MeSH
- SOS odpověď (genetika) * MeSH
- testy genotoxicity metody MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- látky znečišťující vodu MeSH
- mutageny MeSH
- nebezpečný odpad MeSH
Toxaphene (CAS No. 800-35-2) is a complex mixture of several hundred components that was used worldwide primarily as an agricultural pesticide with insecticide effects in the second half of the 20th century. In vitro investigations of the genotoxicity and mutagenicity of toxaphene were generally described in the literature, but they provided somewhat equivocal results. We re-evaluated the genotoxicity of technical toxaphene in two prokaryotic systems. The SOS Chromotest showed high sensitivity to toxaphene: three concentrations (40, 20 and 10 mg/l) were clearly positive and the dose-response effect was evident. In the umuC assay, a dose-dependent increase in genotoxic activity was observed at toxaphene concentrations from 2.5 to 40.0 mg/l, but these results were found to be not significant. The genotoxicity of toxaphene and its photodegradation products after UV-irradiation (3-6-9 h) at concentrations ranging from 7.5 to 60.0 mg/l was also examined in this study. An irradiated solution of technical toxaphene after 3 h showed no significant evidence of bacterial growth inhibition. However, exposure of Salmonella to 6 h UV-irradiated toxaphene showed a toxic effect compared with the negative control. After 9 h irradiation, a decrease of bacterial growth was observed. Activity of beta-galactosidase in the presence of a toxaphene solution was significantly increased after 6 and 9 h irradiation, reaching values that were 2.4- and 3.1-fold higher, respectively, than the control, which exceeded the criteria of significant genotoxicity. These results show that while technical toxaphene is a weak, direct-acting mutagen in some bacterial tests, a dose-dependent toxicity and genotoxicity of its photoproducts could be conclusively demonstrated by the umuC test.
- MeSH
- DNA-dependentní DNA-polymerasy MeSH
- insekticidy chemie metabolismus toxicita MeSH
- proteiny z Escherichia coli genetika metabolismus MeSH
- Salmonella typhimurium účinky léků genetika metabolismus MeSH
- SOS odpověď (genetika) * MeSH
- světlo * MeSH
- testy genotoxicity * metody MeSH
- toxafen chemie metabolismus toxicita MeSH
- ultrafialové záření MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA-dependentní DNA-polymerasy MeSH
- insekticidy MeSH
- proteiny z Escherichia coli MeSH
- toxafen MeSH
- UmuC protein, E coli MeSH Prohlížeč
Tetracycline-producing strains of Streptomyces aureofaciens expressed SauLPI restriction-modification (R-M) system, which recognized specific DNA sequence 5'-GCCGGC-3' (isoschizomer Nael). The activation of the second R-M system SauLPII (5'-GAGCTC-3', isoschizomer of XhoI), which was silent during the growth cycle, after a foreign DNA transfer into this strain was observed. This phenomenon was tentatively explained as a response of the cells against the exogenous DNA entering the cells. The involvement of a SOS-like response in induction of R-M system genes in S. aureofaciens strains has been considered.
- MeSH
- bakteriofág mu genetika MeSH
- replikace DNA MeSH
- restrikční endonukleasy typu II metabolismus MeSH
- SOS odpověď (genetika) MeSH
- Streptomyces aureofaciens enzymologie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- CTCGAG-specific type II deoxyribonucleases MeSH Prohlížeč
- restrikční endonukleasy typu II MeSH
The study summarizes the results of an evaluation of mutagenicity of heterogeneous complex mixtures of substances, the main mutagenic component of which consists of polycyclic aromatic hydrocarbons. The testing was performed using bacterial assays of mutagenicity--the SOS chromotest and the S. typhimurium His-test (in modifications without and with metabolic activation in vitro). It was found that samples of tested tar mixtures (crude tar, pitch, anthracene oils III and II, granulated pitch and some of its extraction portions) induced SOS repair functions and frameshift mutations in tests with metabolic activation. Some of samples as tar, pitch and anthracene oils III, granulated pitch and two its extraction portions--LRAC and LRBe--induced also frameshift mutations, and SOS repairs in tests without the metabolic activation. In one sample--LRBe--the ability to induce mutations in all variants of both tests, was also proved. The evaluation of mutagenicity of fly ashes showed that differences in the mutagenic activity of samples can be directly dependent on the extraction method chosen and on the type of extraction agent used. The study results demonstrate that the bacterial tests Salmonella typhimurium His- and the SOS chromotest are uninterchangeable and quite independent. Both tests can be used for orientative screening for genotoxicity in a wide range of various complex mixtures arising from industrial production and contaminating the environment.
- MeSH
- dehty toxicita MeSH
- Escherichia coli účinky léků genetika MeSH
- hygiena práce MeSH
- pevné částice MeSH
- polycyklické aromatické uhlovodíky toxicita MeSH
- popel uhelný MeSH
- posunová mutace MeSH
- průmyslový odpad škodlivé účinky MeSH
- Salmonella typhimurium účinky léků genetika MeSH
- SOS odpověď (genetika) účinky léků MeSH
- testy genotoxicity MeSH
- uhlík toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- dehty MeSH
- pevné částice MeSH
- polycyklické aromatické uhlovodíky MeSH
- popel uhelný MeSH
- průmyslový odpad MeSH
- uhlík MeSH
The genotoxicity of quinolone antibiotics (ciprofloxacin, enoxacin, nalidixic acid, norfloxacin, ofloxacin, pefloxacin) was studied on the selected mutant E. coli strain PQ 37 (SOS chromotest). The genotoxicity was expressed by SOS-inducing potential (SOSIP) values. The highest SOSIP values were found with ciprofloxacin (SOSIP = 1967 delta IF/nmol), the lowest value was observed with nalidixic acid (SOSIP = 0.3 delta IF/nmol). Similar results were also found with the biosynthesis of nucleic acids, as indicated by incorporation of 14C-adenine into TCA-insoluble fractions of S. typhimurium cells (ciprofloxacin IC50 = 0.39, nalidixic acid IC50 = 400). DNA-damaging effects were tested in the absence of an exogenous metabolizing system.
- MeSH
- 4-chinolony MeSH
- antiinfekční látky farmakologie MeSH
- bakteriální proteiny biosyntéza genetika MeSH
- bakteriální RNA biosyntéza MeSH
- beta-galaktosidasa biosyntéza genetika MeSH
- DNA bakterií biosyntéza MeSH
- Escherichia coli účinky léků genetika MeSH
- operon MeSH
- poškození DNA MeSH
- proteiny z Escherichia coli * MeSH
- rekombinantní fúzní proteiny biosyntéza MeSH
- reportérové geny MeSH
- Salmonella typhimurium účinky léků metabolismus MeSH
- SOS odpověď (genetika) účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- 4-chinolony MeSH
- antiinfekční látky MeSH
- bakteriální proteiny MeSH
- bakteriální RNA MeSH
- beta-galaktosidasa MeSH
- DNA bakterií MeSH
- proteiny z Escherichia coli * MeSH
- rekombinantní fúzní proteiny MeSH
- sulA protein, E coli MeSH Prohlížeč
The mutagenicity of two non-aromatic organic azido compounds, 3-azido-1,2-propanediol (AG) and 9-(3-azido-2-hydroxypropyl)-adenine (AHPA), was studied in E. coli repair deficient strains uvrA6, uvrA6 + umuC36, uvrA6+ umuC122::Tn5, polA1, tagA1+ alkA1, ada and dam3. The mutagenicity of both agents was markedly enhanced by defects of UvrABC excinuclease (uvrA6) and was independent of umuC function of the SOS error-prone pathway. Neither azido compound promoted umuDC operon expression. The mutagenicity of AG in tag A1, alkA1 and ada mutants does not differ from that found in the wild-type strain. The expression of both ada and alkA genes was not elevated by AG. Experiments on polA1 and dam3 mutants suggest that DNA polymerase I as well as the mutHLS mismatch repair pathway does not contribute to the removal of putative DNA lesions induced by AG.
- MeSH
- adenin analogy a deriváty toxicita MeSH
- azidy toxicita MeSH
- Escherichia coli účinky léků genetika MeSH
- exprese genu účinky léků MeSH
- molekulární struktura MeSH
- mutageny toxicita MeSH
- oprava DNA * MeSH
- propylenglykoly toxicita MeSH
- SOS odpověď (genetika) MeSH
- testy genotoxicity MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 9-(3-azido-2-hydroxypropyl)adenine MeSH Prohlížeč
- adenin MeSH
- azidoglycerol MeSH Prohlížeč
- azidy MeSH
- mutageny MeSH
- propylenglykoly MeSH
beta-galactosidase and alkaline phosphatase activities of Escherichia coli strain PQ37 carrying the fusion gene of sulA and lacZ treated with different types of ionizing radiation were examined. The induction factor (ratio of beta-galactosidase to alkaline phosphatase activity), reflecting the SOS-induction potency, increases significantly with radiation dose. Maximum effectiveness to induce SOS-response has been found for deuterium and helium ions in comparison to gamma-rays, carbon or krypton ions. Increased energy of helium ions leads to greater SOS-induction potency of radiation.
A damage-inducible expression vector was constructed in which the original recA structural gene was replaced by the protein-coding region of the ada gene. The O6-alkylguanine-DNA alkyltransferase encoded by the ada gene can be measured by a rapid and highly sensitive assay. The introduction of this construct into an appropriate host cell provides an effective bacterial assay for genotoxins.
- MeSH
- Escherichia coli genetika MeSH
- genetické vektory * MeSH
- klonování DNA * MeSH
- methyltransferasy genetika MeSH
- O(6)-methylguanin-DNA-methyltransferasa MeSH
- plazmidy MeSH
- poškození DNA * MeSH
- RecA-rekombinasy genetika MeSH
- regulační oblasti nukleových kyselin MeSH
- SOS odpověď (genetika) genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- methyltransferasy MeSH
- O(6)-methylguanin-DNA-methyltransferasa MeSH
- RecA-rekombinasy MeSH
