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Updated: Jul 5, 2026
12:11
A Rhodopsin Transport Assay by High-Content Imaging Analysis
Published on: January 16, 2019
Activity switches of rhodopsin
Eglof Ritter1, Matthias Elgeti, Franz J Bartl
1Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany.
Photochemistry and Photobiology
|April 22, 2008
Summary
Rhodopsin
Area of Science:
- Biochemistry
- Photochemistry
- Molecular Biology
Background:
- Rhodopsin, the visual pigment in rod cells, uses 11-cis retinal as a light-sensitive cofactor.
- Light triggers rhodopsin's activation via retinal isomerization to all-trans retinal, forming metarhodopsin II.
- Metarhodopsin II deactivates through Schiff base hydrolysis, initiating the retinoid cycle for regeneration.
Purpose of the Study:
- To compare the activating and deactivating pathways of rhodopsin.
- To investigate the role of retinal in rhodopsin's function.
- To explore the properties and potential roles of metarhodopsin III in vision.
Main Methods:
- UV/Vis spectroscopy
- FTIR spectroscopy
- Kinetic analysis of photoreactions
Main Results:
- A model for light-induced rhodopsin deactivation is proposed based on spectroscopic data.
- Metarhodopsin III is formed upon blue illumination of metarhodopsin II, leading to an inactive state.
- The regeneration cycle of rhodopsin cannot be accelerated by light.
Conclusions:
- Rhodopsin deactivation involves distinct pathways, with retinal playing a crucial role.
- Metarhodopsin III represents a significant, largely inactive intermediate in rhodopsin photochemistry.
- Understanding these pathways provides insights into visual processing and potential therapeutic targets.
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