Decoding the Structure of Ion Channels Solves Decades-Old Eye Mystery.

Researchers have used cryo-electron microscopy and mass spectrometry to decipher the structure of an ion channel in the eye as it interacts with the protein calmodulin, a puzzle that has stumped scientists for 30 years. This interaction could explain how our eyes can achieve such remarkable sensitivity to dim light. The researchers believe that this is nature’s way of holding the channels closed to reduce spontaneous channel openings that would cause background noise so that our eyes can be sensitive to dim light. Calmodulin regulates ion channels not only in the eye but throughout the body, controlling electrical signals that are essential to the correct functioning of diverse muscles and organs.