ISSN:
0066-4278
Source:
Annual Reviews Electronic Back Volume Collection 1932-2001ff
Topics:
Medicine
,
Biology
Notes:
Abstract Phototransduction is the process by which a photon of light captured by a molecule of visual pigment generates an electrical response in a photoreceptor cell. Vertebrate rod phototransduction is one of the best-studied G protein signaling pathways. In this pathway the photoreceptor-specific G protein, transducin, mediates between the visual pigment, rhodopsin, and the effector enzyme, cGMP phosphodiesterase. This review focuses on two quantitative features of G protein signaling in phototransduction: signal amplification and response timing. We examine how the interplay between the mechanisms that contribute to amplification and those that govern termination of G protein activity determine the speed and the sensitivity of the cellular response to light.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1146/annurev.physiol.64.082701.102229
