Abstract
We used alkA'-lacZ' and umuC'-lacZ' fused genes and determined the ability of various alkylating agents to induce adaptive and SOS responses. The degree of induction of expression of these genes was quantitatively measured by a simple colorimetric assay of beta-galactosidase activity. SN1 type methylating agents, such as N-methyl-N'-nitro-N-nitrosoguanidine and N-methyl-N-nitrosourea, were more effective inducers for the alkA than for the umuC system, while SN1 type ethylating agents, such as N-ethyl-N'-nitro-N-nitrosoguanidine and N-ethyl-N-nitrosourea, were more potent inducers for the umuC than for the alkA system. Similar but less striking effects on the two systems were obtained with SN2 type alkylating agents.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alkylating Agents / pharmacology*
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Bacterial Proteins / genetics
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DNA Glycosylases*
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DNA Ligases / biosynthesis*
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DNA Ligases / genetics
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DNA Repair*
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Dose-Response Relationship, Drug
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Enzyme Induction / drug effects
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Escherichia coli / genetics
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Escherichia coli / metabolism
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Ethylnitrosourea / pharmacology
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Genes, Bacterial
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Genes, Synthetic / drug effects
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Guanine / metabolism
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Lac Operon*
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Methylation
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Methylnitronitrosoguanidine / pharmacology
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Methylnitrosourea / pharmacology
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N-Glycosyl Hydrolases / genetics
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Polynucleotide Ligases / biosynthesis*
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beta-Galactosidase / biosynthesis
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beta-Galactosidase / genetics
Substances
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Alkylating Agents
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Bacterial Proteins
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Methylnitronitrosoguanidine
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Guanine
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Methylnitrosourea
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beta-Galactosidase
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3-methyladenine-DNA glycosylase
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DNA Glycosylases
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N-Glycosyl Hydrolases
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DNA Ligases
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Polynucleotide Ligases
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Ethylnitrosourea