The magnitude of the light-induced conformational change in different rhodopsins correlates with their ability to activate G proteins.

ABSTRACT: Light converts rhodopsin, the prototypical G protein-coupled receptor, into a form capable of activating G proteins. Recent work has shown that the light-activated state of different rhodopsins can possess different molecular properties, especially different abilities to activate G protein. For example, bovine rhodopsin is approximately 20-fold more effective at activating G protein than parapinopsin, a non-visual rhodopsin, although these rhodopsins share relatively high sequence similarity. Here we have investigated possible structural aspects that might underlie this difference. Using a site-directed fluorescence labeling approach, we attached the fluorescent probe bimane to cysteine residues introduced in the cytoplasmic ends of transmembrane helices V and VI in both rhodopsins. The fl

SUBMITTER: Tsukamoto H 

PROVIDER: S-EPMC2742832 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature