Electronic Thesis and Dissertation Repository

Degree

Master of Science

Program

Biology

Supervisor

Dr. Robert Cumming

Abstract

The longevity associated protein p66Shc has been suggested to regulate organismal lifespan through initiation of apoptotic pathways. Following stress-induced translocation into the mitochondria, p66Shc promotes increased reactive oxygen species (ROS) production and triggers poorly defined downstream signaling events that lead to decreased cell viability. Protein disulfide bonding has recently emerged as aROSdependent post-translational modification that regulates protein function and signaling processes. Using the mouse hippocampal HT-22 cell line, I sought to determine the changes in the disulfide proteome associated with p66Shc mediatedROSproduction. Through Redox 2D-SDSPAGEanalysis of mitochondrial and cytosolic extracts, redox sensitive proteins altered by p66Shc mediatedROSformation were identified. Of specific interest to this study, lamin B1 (LMNB1) and peroxidedoxin1 (PRXI) were identified as proteins that underwent an alteration in redox status and localization to the mitochondria in a p66Shc dependent manner. Furthermore, cytoskeletal proteins moesin, radixin tropomyosin-3 (TPM-3) and adenylate cyclase associated protein 1 (CAP1) were identified as undergoing changes in disulfide bonding in response to p66Shc mediatedROSproduction. The disulfide altered proteins identified in this study are generally associated with maintainingROSbalance and regulating cytoskeletal actin dynamics. Recent studies suggest these proteins may also acquire secondary roles involved in stress response and apoptotic pathways. My findings reveal that p66Shc elicits redox signaling events viaROS-dependent disulfide bonding of key antioxidant and cytoskeletal regulatory proteins which may affect apoptotic processes associated with organismal and cellular aging.


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