1. Ultrafast structural changes direct the first molecular events of vision
- Author
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Thomas Gruhl, Tobias Weinert, Matthew Rodrigues, Christopher J Milne, Giorgia Ortolani, Karol Nass, Eriko Nango, Saumik Sen, Philip J M Johnson, Claudio Cirelli, Antonia Furrer, Sandra Mous, Petr Skopintsev, Daniel James, Florian Dworkowski, Petra Båth, Demet Kekilli, Dmitry Ozerov, Rie Tanaka, Hannah Glover, Camila Bacellar, Steffen Brünle, Cecilia M Casadei, Azeglio D Diethelm, Dardan Gashi, Guillaume Gotthard, Ramon Guixà-González, Yasumasa Joti, Victoria Kabanova, Gregor Knopp, Elena Lesca, Pikyee Ma, Isabelle Martiel, Jonas Mühle, Shigeki Owada, Filip Pamula, Daniel Sarabi, Oliver Tejero, Ching-Ju Tsai, Niranjan Varma, Anna Wach, Sébastien Boutet, Kensuke Tono, Przemyslaw Nogly, Xavier Deupi, So Iwata, Richard Neutze, Jörg Standfuss, Gebhard FX Schertler, and Valerie Panneels
- Subjects
basis-sets ,Multidisciplinary ,software ,energy-storage ,dynamics ,Photobiology ,isomerization ,rhodopsin ,excited-state ,retinal chromophore ,counterion displacement ,Visual system ,crystallography ,X-ray crystallography - Abstract
Vision is initiated by the rhodopsin family of light-sensitive G protein-coupled receptors (GPCRs). A photon is absorbed by the 11-cis retinal chromophore of rhodopsin, which isomerizes within 200 femtoseconds to the all-trans conformation, thereby initiating the cellular signal transduction processes that ultimately lead to vision. However, the intramolecular mechanism by which the photoactivated retinal induces the activation events inside rhodopsin remains experimentally unclear. Here we use ultrafast time-resolved crystallography at room temperature to determine how an isomerized twisted all-trans retinal stores the photon energy that is required to initiate the protein conformational changes associated with the formation of the G protein-binding signalling state. The distorted retinal at a 1-ps time delay after photoactivation has pulled away from half of its numerous interactions with its binding pocket, and the excess of the photon energy is released through an anisotropic protein breathing motion in the direction of the extracellular space. Notably, the very early structural motions in the protein side chains of rhodopsin appear in regions that are involved in later stages of the conserved class A GPCR activation mechanism. Our study sheds light on the earliest stages of vision in vertebrates and points to fundamental aspects of the molecular mechanisms of agonist-mediated GPCR activation., 視覚に関わるタンパク質の超高速分子動画 --薄暗いところで光を感じる仕組み--. 京都大学プレスリリース. 2023-03-23.
- Published
- 2023