Explicit spatiotemporal simulation of receptor-G protein coupling in rod cell disk membranes.

ABSTRACT: Dim-light vision is mediated by retinal rod cells. Rhodopsin (R), a G-protein-coupled receptor, switches to its active form (R(∗)) in response to absorbing a single photon and activates multiple copies of the G-protein transducin (G) that trigger further downstream reactions of the phototransduction cascade. The classical assumption is that R and G are uniformly distributed and freely diffusing on disk membranes. Recent experimental findings have challenged this view by showing specific R architectures, including RG precomplexes, nonuniform R density, specific R arrangements, and immobile fractions of R. Here, we derive a physical model that describes the first steps of the photoactivation cascade in spatiotemporal detail and single-molecule resolution. The model was implemented in the Rea

SUBMITTER: Schoneberg J 

PROVIDER: S-EPMC4156778 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature