Stability and Adaptation of Proteins, Membranes and Cells to Extreme Temperature and Pressure

All biological systems, from low complexity (single molecules) to high complexity (whole cells), must find a way to maintain stability and function under a wide array of environmental conditions. Archaea have been found to be particularly effective at inhabiting the most extreme environments found on Earth. Proto-cells at the origin of life are hypothesised to have originated under even harsher conditions. Therefore, in this review, we summarise our recent works which have provided insights into the molecular bases for adaptation in various archaeal and proto-cell systems, to temperature and high hydrostatic pressure. First, we discuss adaptation in archaeal membranes, which differ significantly from membranes of Bacteria and eukaryotes, having been adapted by evolution to extreme environments. Next, we consider how functionality could have arisen and been maintained in simple proto-membranes. Finally, we discuss proteome and cell-wide adaptation strategies seen in adapted vs non-adapted species.