Disease relevance of NSC33670

• Photosynthesis-defective mutants of the transformable cyanobacterium Synechocystis 6803 have been isolated following nitrosoguanidine mutagenesis [1].
• Mutants of Escherichia coli with much decreased activity of D-alanine carboxypeptidase (peptidyl-D alanine hydrolase, EC 3.4.12.11) were found among E. coli K12 extensively mutagenized with nitrosoguanidine treatment by assaying individual colonies for the enzyme activity [2].
• Agrobacterium A136 harboring plasmid pGP159, which contains virA, virG, and a reporter virB:lacZ gene fusion, was mutagenized with UV light or nitrosoguanidine [3].
• Nitrosoguanidine mutagenesis of Pseudomonas aeruginosa strain PAO-1 yielded a mutant strain, PAO-PR1, which produced a protein that was immunologically indistinguishable from native toxin A and was nontoxic for cultured Chinese hamster ovary cells [4].
• Eight temperature-sensitive mutants of human cytomegalovirus have been isolated after mutagenesis with nitrosoguanidine [5].

High impact information on NSC33670

• Yeast cells growing exponentially were more sensitive to mutagenesis by NG than cells in which DNA synthesis had been inhibited [6].
• NG was used to test for temporal order in the replication of the genome of the unicellular eucaryote, Saccaromyces cerevisiae [6].
• Several mutants of the human cell line ME-180 resistant to the cytotoxic effect of interferon gamma (IFN-gamma) were isolated after mutagenesis with nitrosoguanidine [7].
• Ouabain resistance was induced by nitrosoguanidine, but not by ICR 191 [8].
• The results indicate that nitrosoguanidine acts primarily during DNA replication and that different markers appear to be affected at different intervals during the DNA biosynthetic period [9].

Chemical compound and disease context of NSC33670

• A group of 43 phosphonoacetic acid (PAA)-resistant mutants of herpes simplex virus type 1 was isolated after the mutagenesis of infected cells with nitrosoguanidine [10].
• The specificities of NTG and 5AZ in D. radiodurans are the same as those found for E. coli and other organisms [11].
• Mutants of Escherichia coli showing a rifampin-dependent phenotype were isolated from cells of strain CP78 mutagenized with ethyl methane sulfonate or nitrosoguanidine when an antibiotic underlay technique was used [12].
• Enchancement of nitrosoguanidine mutagenesis by chloramphenicol in Escherichia coli K-12 [13].
• The ultrastructure of extracellular polysaccharides produced in colonies by two clinical isolates and that of a nitrosoguanidine-induced mutant of serotype c Streptococcus mutans with different polysaccharide-synthesizing abilities were compared electron-microscopically [14].

Biological context of NSC33670

• Exponentially growing cells were treated with nitrosoguanidine and then separated by zonal rotor centrifugation into fractions equivalent to stages in the cell cycle [9].
• Loss of heterozygosity occurred at a frequency ranging from 10(-4) to 10(-6) and was elevated 24-fold by treatment with gamma-irradiation, while the frequency of other events was less than 10(-6) and was increased more than 1,000-fold by nitrosoguanidine treatment [15].
• Restoration of the responsiveness of purified guanylate cyclase to nitrosoguanidine, nitric oxide, and related activators by heme and hemeproteins. Evidence for involvement of the paramagnetic nitrosyl-heme complex in enzyme activation [16].
• Second-site suppressor mutations were identified following hydroxylamine and nitrosoguanidine mutagenesis [17].
• Recent evidence indicates that the monofunctional DNA alkylating agent N-methyl-N'-nitro-N- nitrosoguanidine (MNNG) also triggers up-regulation and phosphorylation of p53; however, the mechanism(s) responsible for this are unknown [18].

Anatomical context of NSC33670

• Shiga toxin-resistant Vero cells were isolated by treatment of the cells with nitrosoguanidine [19].
• Nitrosoguanidine mutagenesis produced a stable blue epsilon form that was more virulent than the parent in a mouse model of urinary tract infection [20].
• The rationale was to grow a nitrosoguanidine-mutated population for many generations under nonselective conditions followed by two cycles of protoplast formation and regeneration [21].
• Two major metabolites are detected on incubation of IMI with rabbit liver cytosol: the nitrosoguanidine (IMI-NO) and the aminoguanidine (IMI-NH2) [22].
• We monitored the response of human keratinocytes to a very low concentration of a methylating agent, namely 2.5 nM N-methyl-N'-nitro- N-nitrosoguanidine (MNNG) [23].

Associations of NSC33670 with other chemical compounds

• Previous work with bacteria has shown that a gene is maximally sensitive to mutagenesis by N-methyl-N'-nitro-N-nitrosoguanidine (NG) at the time it is being replicated [6].
• A mutant Xy1R regulator called Xy1R7 was isolated after nitrosoguanidine mutagenesis of the wild-type gene and phenotypic selection for mutants that had acquired the ability to recognize m-nitrotoluene, a nitroarene that is not an effector for the wild-type regulator [24].
• Reversion from the suppressed to nonsuppressed phenotype in strains of geno;type SUQ5 [psi+] ade2-1 his5-2 lys1-1 can1-100 ura3-1 has been induced by treatment with ethyl methanesulphonate, nitrosoguanidine or UV (254 nm) light [25].
• After nitrosoguanidine mutagenesis we isolated from mouse leukemia L5178Y cells a mutant cell (Bla-R) resistant to blasticidin S, an inhibitor of protein synthesis [26].
• Three nitrosoguanidine-induced mutants of the archaeon Methanobacterium thermoautotrophicum Marburg resistant to 5-methyltryptophan were isolated and characterized [27].

Gene context of NSC33670

• We conclude that errors in the recA-dependent repair of induced DNA damage (after 4NQO, MTC, UV and X-rays) or errors in replication enhanced by damage to the replication system or to the template strands (after NTG, EMS, and HA) give rise to deletions as well as to base changes [28].
• A novel mutant isolate of Saccharomyces cerevisiae, sensitive to photoactivated mono- and bi-functional psoralens, to UV at 254 nm (UVC), and to nitrosoguanidine, was found to complement the photoactivated psoralen-sensitivity phenotype conferred by the pso1- pso7 mutations and was therefore named pso8-1 [29].
• While there was none for HYR to nitrosoguanidine, and other low glutathione-related phenotypes, some other phenotypic characteristics of pso3-1, e.g. UVC sensitivity and UVC-induced mutability were restored to a wild-type level [30].
• Overexpression of the SNQ3/YAP1 gene confers hyper-resistance to nitrosoguanidine in Saccharomyces cerevisiae via a glutathione-independent mechanism [31].
• Escherichia coli WC196, which was obtained from the strain W3110 by nitrosoguanidine mutagenesis as an overproducer of lysine, produced approximately twenty times more cadaverine than did W3110, and had a twenty fold higher level of rpoS gene product, sigma38, than in W3110 [32].

Analytical, diagnostic and therapeutic context of NSC33670

• Site-directed mutagenesis and analysis of nitrosoguanidine-induced mutT mutants suggest that a small region of high homology between the two proteins (61% identity over 23 residues) is part of the catalytic site of the nucleoside triphosphatase [33].
• The Comet assay was used to study basal DNA damage, DNA susceptibility to a mutagen (N-methyl N-nitro N-nitrosoguanidine) and DNA repair efficiency [34].
• A mutant of Aspergillus flavus having a high and relatively stable aflatoxin B2/B1 ratio was recovered after treatment with nitrosoguanidine [35].
• The severity of gastric mucosal lesions was evaluated in 60 rats after 5 days and 30 days of continuous oral administration of NG (120 mg/l) or NG plus misoprostol (200 micrograms/kg-1/day-1) or tap water, and a histological study was carried out [36].
• The ribosomal proteins of temperature-sensitive mutants of Escherichia coli isolated independently after mutagenesis with nitrosoguanidine were analyzed by two-dimensional gel electrophoresis [37].

References