Decoding Hydrogen Peroxide's Impact on Cellular Signaling and Stress Response Pathways

About This Grant

Project Summary/Abstract Since the 70s, reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) have become increasingly appreciated as paradoxical signaling molecules. While initially thought to be only a damaging by-product of aerobic respiration, it is now clear that H2O2 plays a vital role in several cellular functions such as signal propagation, immune response, and differentiation. However, if these physiological roles for H2O2 become dysregulated, H2O2 can reach harmful levels and cause oxidative stress and therefore must be carefully monitored by cellular antioxidant systems. How cells respond to variable levels of H2O2 is the overarching goal of the F99 portion of this proposal. Importantly, this work will shed light on a long-standing question in the field of redox biology: How is specificity achieved in redox signaling? Discoveries in this realm will additionally support understanding of how conditions marked by aberrant redox environments (e.g. – cancer, neurodegeneration, and chronic inflammation) could be improved or exacerbated. Three aims are set forth in the F99 phase. In Aim 1a, completed work is described on how high levels of H2O2 stress prevent p53 accumulation by inhibiting cap-dependent translation initiation and elongation. In Aim 1b, an unbiased proteome-wide approach is proposed to uncover dose-dependent cysteine oxidation events. In Aim 1c, live cell microscopy experiments are proposed to unravel DNA repair dynamics in response to different H2O2 doses. In summary, this work will generate a deeper understanding of how cells coordinate the stress response caused by variable levels of H2O2. As well, this work will provide evidence for cysteine oxidation as a vital post-translational modification (PTM) in coordinating the oxidative stress response. In Aim 2 (K00 phase), the use of organoids to understand complex tissue development, organization, and maintenance using live cell microscopy is proposed. This work will improve the field’s understanding of differences in signaling dynamics between healthy and diseased tissues. Under the supervision of experts in signaling dynamics, mass-spectrometry, organoids, and computational analysis at both the University of Arizona (F99 phase) and the K00 institution, this award will provide ample technical training for a successful independent academic research career. Additionally, through mentorship and leadership activities available at both institutions, the ability to be an impactful and effective mentor will be achieved.