Mechanosensitive Channels in Archaea: Roles, Lipid-Protein Interactions and Future Questions pp. 143-161
Authors: (Daniel Balleza, Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU), Universidad del País Vasco, Bilbao, Spain)
Abstract: Archaea, the third domain of life, include micro-organisms adapted to a variety of environmental conditions, including some of the most hostile locations on Earth. Osmotic regulation is an important issue for a microbe, and mechanosensitive (MS) ion channels are important proteins capable to respond as transducers of mechanical stress by forming non-selective pores in order to deal with drastic osmotic changes in the milieu. As molecular sensors, MS channels respond to increases in membrane tension. When the membrane tension is small, these proteins are in the closed configuration; as the tension grows, the open state becomes ever more frequent, until it dominates at mild or high tensions. It has been proposed that these changes correspond to different channel conformations in a defined protein–lipid interface. This commentary discusses some of the most important aspects in order to understand the function of MS channels in archaebacteria. Special attention is focused on how archaebacterial lipids are attractive targets to study the function of these proteins.