Regulation of cyclic AMP synthesis in Escherichia coli K-12: effects of the rpoD800 sigma mutation, glucose, and chloramphenicol.
An immediate 12-fold inhibition in the rate of beta-galactosidase synthesis occurs in Escherichia coli cells containing the mutant sigma allele rpoD800 after a shift to 42 degrees C. In the present study we characterize the nature of the inhibition. The severe inhibition of beta-galactosidase synthesis was partly relieved by cyclic AMP (cAMP). We inferred that the inhibition might be mediated by a decreased intracellular concentration of cAMP. Consistent with this inference, the rate of cAMP accumulation in mutant cells after a temperature upshift was depressed relative to that in wild-type cells. Glucose and chloramphenicol, two agents known to inhibit differentially beta-galactosidase mRNA synthesis, caused a similar inhibition in the rate of cAMP accumulation. Thus, three diverse stimuli, glucose, chloramphenicol, and a temperature-sensitive sigma mutation, appear to affect beta-galactosidase synthesis by regulating the synthesis of cAMP.
D002701:Chloramphenicol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000096:biosynthesis*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D005947:Glucose / Q000494:pharmacology*; D007700:Kinetics; D009154:Mutation; D012808:Sigma Factor / Q000235:genetics / Q000502:physiology*; D013696:Temperature; D014157:Transcription Factors / Q000502:physiology*; D001616:beta-Galactosidase / Q000096:biosynthesis
D012808:Sigma Factor; D014157:Transcription Factors; D002701:Chloramphenicol; D000242:Cyclic AMP; D001616:beta-Galactosidase; D005947:Glucose