Stringent Response Regulators Contribute to the Recovery from Glucose-Phosphate Stress in Escherichia coli.

Stringent Response Regulators Contribute to the Recovery from Glucose-Phosphate Stress in Escherichia coli. Appl Environ Microbiol. 2017 Oct 06;: Authors: Kessler JR, Cobe BL, Richards GR Abstract In enteric bacteria like Escherichia coli, the transcription factor SgrR and the small RNA SgrS regulate the response to glucose-phosphate stress, a metabolic dysfunction that results in growth inhibition and stems from the intracellular accumulation of sugar-phosphates. SgrR activates transcription of sgrS, and SgrS helps to rescue cells from stress in part by inhibiting uptake of stressor sugar-phosphates. While the regulatory targets of this stress response are well described, less is known about how the SgrR-SgrS response itself is regulated. To further characterize regulation of the glucose-phosphate stress response, we screened global regulator gene mutants for growth changes during glucose-phosphate stress. We found that deleting dksA, which encodes a regulator of the stringent response to nutrient starvation, decreases growth under glucose-phosphate stress conditions. The stringent response alarmone regulator ppGpp (synthesized by RelA and SpoT) also contributes to recovery from glucose-phosphate stress: as with dksA, mutating relA and spoT worsens the growth defect of an sgrS mutant during stress, although the sgrS relA spoT mutant defect was only detectable under lower stress levels. In addition, mutating dksA or relA and spoT low...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research