title: A gene regulating the heat shock response in Escherichia coli also affects proteolysis.
abstract: The htpR locus in Escherichia coli encodes a regulator of the heat shock response. Cells containing the htpR165 mutation are defective in the induction of synthesis of heat-shock proteins at high temperature. We show that these cells are also defective in degrading two proteins that are normally unstable in htpR+ cells. The proteolytic defect is manifest at both 30 degrees C and 42 degrees C. We used a marker rescue technique to map this defect to the htpR locus. Although both proteolytic substrates are partially stabilized in lon- strains, we argue that the defect in proteolysis exhibited by the htpR165 strain does not mimic the lon- state. The htpR165 strain synthesizes Lon at the normal rate at 30 degrees C and does not show the phenotypes of mucoidy and radiation sensitivity associated with lon- strains.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005798:Genes, Bacterial; D005809:Genes, Regulator; D006360:Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics*; D006358:Hot Temperature; D009154:Mutation; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D013489:Suppression, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004274:DNA, Recombinant; D006360:Heat-Shock Proteins; D010447:Peptide Hydrolases