Differential induction of heat shock, SOS, and oxidation stress regulons and accumulation of nucleotides in Escherichia coli.

AUTOR(ES)

VanBogelen, R A

RESUMO

Heat and various inhibitory chemicals were tested in Escherichia coli for the ability to cause accumulation of adenylylated nucleotides and to induce proteins of the heat shock (htpR-controlled), the oxidation stress (oxyR-controlled), and the SOS (lexA-controlled) regulons. Under the conditions used, heat and ethanol initiated solely a heat shock response, hydrogen peroxide and 6-amino-7-chloro-5,8-dioxoquinoline (ACDQ) induced primarily an oxidation stress response and secondarily an SOS response, nalidixic acid and puromycin induced primarily an SOS and secondarily a heat shock response, isoleucine restriction induced a poor heat shock response, and CdCl2 strongly induced all three stress responses. ACDQ, CdCl2, and H2O2 each stimulated the synthesis of approximately 35 proteins by factors of 5- to 50-fold, and the heat shock, oxidation stress, and SOS regulons constituted a minor fraction of the overall cellular response. The pattern of accumulation of adenylylated nucleotides during these treatments was inconsistent with a simple role for these nucleotides as alarmones sufficient for triggering the heat shock response, but was consistent with a role in the oxyR-mediated response.

Documentos Relacionados

• ATP hydrolysis during SOS induction in Escherichia coli.
• Induction of DnaK and GroEL heat shock proteins by fluoroquinolones in Escherichia coli.
• Ribosomes as sensors of heat and cold shock in Escherichia coli.
• Induction of SOS functions by alkaline intracellular pH in Escherichia coli.
• Induction of superoxide dismutase in Escherichia coli by heat shock.