Expression of Oxidative Stress Genes soxS and katG and SOS Response Genes recA and colD in Escherichia coli, Induced by 8-Methoxypsoralen and Ultraviolet (365 nm)
TL;DR
It was established that when irradiated with UVA, 8-MOP induces the formation of superoxide anion and peroxide in the cells of pSoxS-lux and pKatG-lux biosensors, respectively and the dynamics of biosensor responses differed significantly, which indicates the activation sequence of the corresponding promoters.
Abstract
The effect of 8-methoxypsoralen (8-MOP) activated by UVA (365 nm) on the expression of the oxidative stress genes soxS and katG and SOS response genes recA and colD in Escherichia coli biosensors was studied. The luxCDABE operon of the luminescent bacterium Photorhabdus luminescens is a reporter for the expression of these genes in biosensors. A statistical method of segmented regressions was used to analyze the dynamics of dose–response relationships. It was established that when irradiated with UVA, 8-MOP induces the formation of superoxide anion and peroxide in the cells of pSoxS-lux and pKatG-lux biosensors, respectively. At the same time, the dynamics of biosensor responses differed significantly, which indicates the activation sequence of the corresponding promoters. pRecA-lux and pColD-lux biosensors are activated under conditions of DNA damage; however, the latter has significantly higher sensitivity. As compared to the recA, soxS, and katG promoters, the colD(cda) promoter shows a wider sensitivity and pronounced effect of signal amplification.