The basis of molecular vision revealed
Now researchers have solved the three dimensional structure of a protein complex involved in vertebrate vision at atomic resolution, a finding that has broad implications for our understanding of biological signaling processes and the design of over a third of the drugs on the market today.
There are more than 800 GPCRs in humans that signal through around 20 diverse G proteins. GPCRs are responsible for sensing a wide scope of outside signals, for example, hormones, light, and sense of smell and taste and actuating corresponding responses inside the cell.
The findings illuminate how signals from photons (particles of light) get amplified in the eye. More importantly, the study provides insights into how the largest family of cell membrane proteins G-protein-coupled receptors (GPCRs) work in humans.
For the study, scientists used cryo-electron microscopy technique to get atomic resolution structures of the rhodopsin-transducin complex. The structures did not just give the molecular basis of vertebrate vision, yet additionally, uncover a previously unknown mechanism of how GPCRs, in general, activate G proteins.
Researchers said, What we’ve learned from these structures at an atomic level may be broadly applicable to other GPCR signaling systems.
By learning more about how different receptors, specifically couples with different G proteins, we hope to gain insights into designing drugs that specifically regulate GPCR signaling.
A lot of drug side effects occur when therapies are not specific enough and target both harmful and beneficial pathways.
The study is published in the journal Molecular Cell.