The Glutathione S-transferases (GSTs) are a family of phase II enzymes that utilize glutathione in reactions contributing to the transformation of a wide range of exogenous and endogenous compounds, including carcinogens, therapeutic drugs, and products of oxidative stress. The omega-class GST
p29 - C29E4.7 - is a candidate for the protection against oxidative stress in C. elegans. Following affinity-chromatography, the enzymatic activity of the recombinantly expressed enzyme was determined using several model substrates. The "halo assay" provided a test of resistance to long-term exposure to oxidative stress conditions. Here it was demonstrated that the survival of bacteria, overexpressing
p29, significantly increased under several stress conditions. Furthermore, ectopic overexpression of
p29 resulted in a significant reduced production of progeny and a reduced lifespan of the worms. The specific silencing of the
p29 by RNAi created worms with an increased sensitivity to the stressor Juglone. In addition, under "knock down" conditions, a reduced lifespan was observed. Promoter-GFP (green fluorescent protein)-constructs localised
p29 expression exclusively in the intestine of all post-embryonic stages. To determine the factors regulating the expression of this stress responsive GST, promotor mutation analysis are near completion.