Meeting Abstract
P1.159 Friday, Jan. 4 The Proteomic Response of Mytilus galloprovincialis and Mytilus trossulus to Acute Oxidative Stress in the Presence of Sirtuin Inhibitors CHILTON, H*; TOMANEK, L; ZUZOW, M; California Polytechnic State University, San Luis Obispo; California Polytechnic State University, San Luis Obispo; California Polytechnic State University, San Luis Obispo hchilton@calpoly.edu
Global climate change imposes physiological constraints on marine ecosystems that can alter the distribution of intertidal organisms. In one such instance, the native cold-adapted Mytilus trossulus has been replaced along its southern range by the invasive warm-adapted Mytilus galloprovincialis. These blue mussels occur throughout rocky intertidal zones where they are subjected to greatly varying environmental conditions in terms of temperature and hypoxia, stressors that are known to induce oxidative stress. It has been hypothesized that while under acute heat stress, related Mytilus congeners undergo a shift in redox potential through the reduction of NADH fueled respiration pathways to the production of the reducing agent NADPH as a potential defensive mechanism against the production of reactive oxygen species. In addition, it has been hypothesized that sirtuins (a family of NAD-dependent deacetylases) might be involved in the regulation of this metabolic transition. To test the latter hypothesis, a discovery approach was used to analyze the proteomic response of these species to varying concentrations of the pro-oxidant menadione, and the sirtuin-inhibitors nicotinamide and suramin. Menadione can induce apoptosis through the elevated production of peroxide and superoxide radicals, while suramin and nicotinamde both inhibit sirtuin activity. Organisms were exposed to these compounds in filtered seawater for 8 h, followed by a 24 h recovery period under constant aeration. Tissues were then prepared for 2D-gel electrophoresis and proteins were identified with tandem mass spectrometry. Observed results characterize the role of deacetylation of the two Mytilus congeners to responding to stressful conditions.
