Co-evolution of proteins and solutions: protein adaptation versus cytoprotective micromolecules and their roles in marine organisms.

Organisms experience a wide range of environmental factors such as temperature, salinity and hydrostatic pressure, which pose challenges to biochemical processes. Studies on adaptations to such factors have largely focused on macromolecules, especially intrinsic adaptations in protein structure and function. However, micromolecular cosolutes can act as cytoprotectants in the cellular milieu to affect biochemical function and they are now recognized as important extrinsic adaptations.

Scientific teaching targeting faculty from diverse institutions.

We offered four annual professional development workshops called STAR (for Scientific Teaching, Assessment, and Resources) modeled after the National Academies Summer Institute (SI) on Undergraduate Education in Biology. In contrast to the SI focus on training faculty from research universities, STAR's target was faculty from community colleges, 2-yr campuses, and public and private research universities. Because of the importance of community colleges and 2-yr institutions as entries to higher education, we wanted to determine whether the SI model can be successfully extended to this broader range of institutions.

Non-additive counteraction of KCl-perturbation of lactate dehydrogenase by trimethylamine N-oxide.

Added KCl increases the apparent Michaelis constant (Km) of pyruvate for porcine muscle-type lactate dehydrogenase (100 mM KCl, 83%; 200 mM KCl, 188%). The effects of 100 mM KCl were fully reversed by 375 mM trimethylamine N-oxide (TMAO). TMAO (375-750 mM) partially reversed the effects of 200 mM KCl.

Pressure effects on the GTPase activity of brain membrane G proteins of deep-living marine fishes.

In marine fishes, heterotrimeric guanyl nucleotide binding proteins (G proteins), which couple cell surface membrane receptors to their effector elements, are sensitive to hydrostatic pressure. The intrinsic high affinity GTPase activity of the alpha subunits of G proteins in three signaling systems coupled to adenylyl cyclase, the A(1) adenosine receptor, the muscarinic cholinergic receptor and the beta-adrenergic receptor, was tested at pressures up to 340 atm. Brain membrane preparations from four members of the deep-sea teleost fish family Macrouridae were studied.

The effects of the deep-sea environment on transmembrane signaling.

Membrane-associated processes may be particularly susceptible to perturbation by the high hydrostatic pressures and low temperatures of the deep ocean. Transmembrane signaling by guanyl nucleotide binding protein (G protein) coupled receptors (GPCRs) is affected at a number of steps: (1) agonist activation of the GPCR; (2) the interaction of the receptor with the heterotrimeric G protein; (3) the G protein GTPase cycle; and (4) the activation and function of the effector element, adenylyl cyclase. The effects of low temperature and high hydrostatic pressures on the A(1) adenosine receptor-inhibitory G protein (G(i))-adenylyl cyclase signaling complex were examined in teleost fishes from three families, Scorpaenidae, Macrouridae and Moridae.