Dynamics of Arrestin-Rhodopsin Interactions: ACIDIC PHOSPHOLIPIDS ENABLE BINDING OF ARRESTIN TO PURIFIED RHODOPSIN IN DETERGENT

• Published in: The Journal of biological chemistry Vol. 281; no. 14; pp. 9407 - 9417
• Main Authors: Sommer, Martha E, Smith, W. Clay, Farrens, David L
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 07.04.2006
• Subjects: Animals; Arrestin - metabolism; Cattle; Ligands; Maltose - analogs & derivatives; Maltose - metabolism; Micelles; Phospholipids - physiology; Protein Binding; Retina - physiology; Retinaldehyde - metabolism; Rhodopsin - metabolism; Solubility
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M510037200

We report that acidic phospholipids can restore the binding of visual arrestin to purified rhodopsin solubilized in n-dodecyl-[beta]-D-maltopyranoside. We used this finding to investigate the interplay between arrestin binding and the status of the retinal chromophore ligand in the receptor binding pocket. Our results showed that arrestin can interact with the late photoproduct Meta III and convert it to a Meta II-like species. Interestingly in these mixed micelles, the release of retinal and arrestin was no longer directly coupled as it is in the native rod disk membrane. For example, up to [approximately]50% of the retinal could be released even though arrestin remains bound to the receptor in a long lived complex. We anticipate that this new ability to study these proteins in a defined, purified system will facilitate further structural and dynamic studies of arrestin-rhodopsin interactions.