Meeting Abstract

118-2  Thursday, Jan. 7 10:30  Regulation of mitochondrial F₁F_O-ATPase in the anoxia tolerant turtle, Trachemys scripta GOMEZ, C.G*; RICHARDS, J.G; University of British Columbia ; University of British Columbia gomezc@zoology.ubc.ca

The anoxia-tolerant turtle, Trachemys scripta is able to survive months buried in anoxic mud while overwintering in ice covered-ponds. In most vertebrates, anoxia leads to inner mitochondrial membrane depolarization causing the F₁F_O-ATPase to run in reverse, hydrolyzing ATP, in an effort to restore membrane potential. This depolarization triggers a signalling cascade ending in cellular apoptosis or necrosis. Previous studies have shown that when T. scripta is exposed to anoxia, they severely down-regulate F₁F_O-ATPase activity. The benefits of reducing F₁F_O-ATPase activity during anoxia are clear, but the mechanisms responsible for inhibition remain unknown. Inhibitory Factor-1, a well-characterized mitochondrial ATPase inhibitor, is not responsible for the inhibition of F₁F_O-ATPase in T. scripta. We predict that during long-term anoxia, the F₁F_O-ATPase is inhibited via post-transnational modification, which we investigated using proteomics approaches.