9407205 Siebenaller The low temperatures and high hydrostatic pressures of the deep sea influence the structure and function of proteins and membranes in marine animals. These environmental factors represent an important selective force shaping the molecular evolution of organisms colonizing and inhabiting the deep sea. This project addresses the influence of these environmental parameters on the transduction of extracellular signals into intracellular effects. How extensive are the effects of hydrostatic pressure on transmembrane signaling in cold-adapted fishes? At the molecular level, what are the loci at which pressure acts? How are species which live in deep water adapted to cope with the high pressure? These studies will be conducted in marine teleost species which are abundant at different depths. The effects of pressure will be examined for membrane receptors which are coupled to adenylyl cyclase via guanine nucleotide binding proteins (G proteins). Both receptors which negatively modulate adenylyl cyclase and those which stimulate adenylyl cyclase will be examined.
