Oxidative stress

Much has been learnt about oxidative stress from studies of Escherichia col i. Key regulators of the adaptive responses in this organism are the SoxRS and OxyR transcription factors, which induce the expression of antioxidant activities in response to O-2.(-) and H2O2 stress, respectively Recently, a variety of biochemical assays together, with the characterization of strai ns carrying mutations affecting the antioxidant activities and the regulato rs have given general Insights into the sources of oxidative stress, the da mage caused by oxidative stress, defenses against the oxidative stress, and the mechanisms by which the stress is perceived. These studies have also s hown that the oxidative stress responses are intimately coupled to other re gulatory networks in the cell.