Regulation of Ion Channel Function by Gas Molecules.

Our understanding of the gaseous signaling molecules that play important roles in diverse physiological processes keeps expanding. These gas molecules, also called gasotransmitters, include NO, H2S, 1O2, CO, and CO2 and are generated within the cell through enzymatic pathways and photochemical reactions. These molecules are chemically unstable and directly react with amino acids such as cysteine, histidine, and so on. Compared to well-characterized reactive oxygen species (ROS), including H2O2, ONOO-, O2-, and OH·, the gasotransmitters are in general less polar and show higher solubility in hydrophobic environments like the lipid membrane. Correspondingly, accumulating evidence has begun to unveil the broad impacts of these gaseous molecules on the function of membrane proteins, including ion channels. This review summarizes the major physicochemical characteristics of representative gasotransmitters and their regulation of ion channel functions.