(Montana State University - Bozeman, College of Letters & Science, 2007) Angel, Thomas Emil; Chairperson, Graduate Committee: Algirdas J. Jesaitis
Rhodopsin is the integral membrane protein responsible for black and white vision in low light conditions and is found at high concentration in the mammalian retina. Rhodopsin is a prototypical member of the G protein coupled receptor super family that control much of physiology. Improved understanding of rhodopsin signal transduction and amplification via coupling to the heterotrimeric G protein transducin may reveal conserved activation mechanisms that are relevant to other members of the GPCR super family. Described here are several studies that examine the molecular determinants responsible for heterotrimeric G protein coupling to metarhodopsin II, the active photointermediate of bovine rhodopsin. Employing uv-visible spectroscopy we have investigated the nature of the interaction between the C-terminal tail of transducin and metarhodopsin II. We have provided evidence that suggests the orientation of transducin when it interacts with metarhodopsin II.
