Defining the landscape and mechanisms of protein redox regulation during aging

PROJECT SUMMARY: Mammalian tissues engage in specialized physiology that is regulated through reversible modification of protein cysteine residues by reactive oxygen species (ROS). ROS regulate a myriad of biological processes, and dysregulation of ROS and redox signaling is one of the longest postulated underlying causes of physiological decline of tissues with age. Despite the widespread importance of redox regulation of tissue-specific physiology and mammalian aging, there is a persistent lack of information regarding the specific protein modifications that explain the molecular basis for these processes in vivo. We recently developed a mass spectrometric (MS) technology for the first comprehensive and quantitative mapping of the mouse cysteine redox proteome in vivo. Our current objective is to define the landscape and mechanisms of cysteine oxidation networks that underlie age-dependent tissue pathology and lifespan. Our preliminary data demonstrate a fundamental remodeling of cysteine oxidation networks occurs in all aged tissues, and many of these networks map to established disease-relevant protein families. We will test the hypothesis that coordinated redox regulation governs spatial organization, assembly, and function of protein networks already known to be relevant to age-related disease. Building on additional preliminary data, we will test the hypothesis that interventions that robustly extend lifespan and healthspan exert systematic remodeling of protein cysteine oxidation networks. To test these hypotheses, we will pursue the following specific aims. In Aim 1 we will systematically determine the role that cysteine oxidation plays in coordinating these protein complex network assemblies. Moreover, for two priority protein networks already associated with diseases of aging, we will define the role of cysteine oxidation on corresponding biological function and lifespan. In Aim 2 we will redox regulated networks that are regulated by the longevity promoting intervention of dietary restriction will determine those pro-longevity cysteine oxidation networks that are conserved across sexes and throughout evolution by applying parallel redox proteomics analyses in models of C. elegans aging and DR. We will additionally determine the mechanisms and metabolic consequences of redox regulation of newfound redox regulated targets of α-ketoglutarate metabolism, which we hypothesize play a central role in DR-mediated metabolic regulation. Taken together, we propose to define, for the first time, the proteome-wide redox regulatory landscape that defines tissue aging and DR- dependent promotion of lifespan. Successful completion of these Aims will define mechanisms for a mode of biological regulation by ROS that has long been associated with aging, but for decades has remained elusive.