Reactive oxygen species (ROS) promote cell death via oxidative damage of proteins, DNA and lipids. Cells limit the damage from ROS by activating signaling pathways that increase the production of anti-oxidant proteins (such as phase II detoxification enzymes) to remove high levels of ROS. One of the proteins that these signaling pathways converge on in C. elegans is SKN-1, an important regulator of expression of genes involved in the oxidative stress response. Our lab is interested in identifying other transcription factors that function with SKN-1 to promote phase II detoxification gene expression. We previously demonstrated that the E3 ligase BRAP-2 influences phase II detoxifying gene expression in C. elegans by indirectly inhibiting nuclear localization of SKN-1. We also carried out an RNA interference (RNAi) screen with
brap-2 mutant worms, and identified VAB-3 as a candidate regulator of phase II detoxifying gene expression. Here we investigate VAB-3 and its involvement in phase II detoxification mediated oxidative stress response in C. elegans. With the use of the phase II transcriptional reporter strain
gst-4p::gfp, we quantified GFP levels in the
brap-2;
gst-4p::gfp worms, and found a reduction in the GFP levels in
brap-2 mutant worms when
vab-3 is knocked down by RNAi. We also exposed
gst-4p::gfp worms to sodium arsenite - to induce ROS formation - and found that there was less GFP expression in presence of a
vab-3 mutation or when treated with
vab-3 RNAi compared to control. Furthermore, we generated
brap-2;
vab-3 double mutants and, using qPCR, found that
gst-4 mRNA levels were reduced in the double mutant compared to the
brap-2 single mutant, consistent with the idea that VAB-3 is required for
gst-4 expression. Our future work will determine if VAB-3 is required for expression of other phase II and non-phase II detoxification genes, and characterize the mechanism of VAB-3 function.