KR2 Rhodopsin (IMAGE) Moscow Institute of Physics and Technology Caption KR2 rhodopsin monomer (left) and pentamer (right) in the cell membrane, shown as blue disks. In the monomer state, sodium transport is blocked, the orange pore does not permit ion uptake into the protein. Credit Kirill Kovalev et al./<i>Science Advances</i> Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.