Rhodopsin is a member of the G-protein coupled receptor (GPCR) family. Rhodopsin is the
common GPCR structure used to understand functionality of G-protein coupled receptors.
Rhodopsin is commonly found in the photoreceptors in the retina, specifically in the rod
photoreceptors and become activated by photons of light. Rhodopsin contains a chromophore
(compound that absorbs light), specifically 11-cis-retinal, which when active recruites G proteins
to transmit a signaling cascade in neural impulses to the gray matter of the occipital lobe. Once
the receptor has been activated, a new rhodopsin needs to be regenerated. Rhodopsin is
located in the rod outer segment (ROS) which consists of stacked disks enclosed by a
membrane. The entire family of GPCR’s have the common structure of seven alpha-helices
across membranes. Rhodopsin’s structure changes upon photoactivation. The sixth helix bends
away from the seventh creating a pocket that allows for binding of a G protein. A salt bridge
covers this pocket until the helices shift away from one another. Once the G protein has bound
then the signal can be transmitted to the occipital lobe. Over 120 point mutations to rhodopsin
have been identified which can lead to night blindness and more several visual problems.
Function
Disease
Relevance
Structural highlights
This is a sample scene created with SAT to by Group, and another to make of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.
