Rhodopsin activation

Sheikh, S. P, Zvyaga, T. A., Lichtarge, O., Sakmar, T. P., and Bourne, H. R. (1996) Rhodopsin activation blocked by metal-ion-binding sites linking transmembrane helices C and F. Nature 383, 347-350. 

Janz, J. M., and Farrens, D. L. (2004). Rhodopsin activation exposes a key hydrophobic binding site for the transducin a-subunit C terminus./. Biol. Chem. 279,29767-29773. 

V. Photoactivated Conformational Changes The Rhodopsin Activation Switch. 277... 

VI. Summary The Mechanism of Rhodopsin Activation and Future Directions. 285... 

Photoexcited rhodopsin activates transducin, a G-protein, which in turn stimulates cyclic GMP phosphodiesterase this leads to closing of an ion channel, hyperpolarization of the membrane, and a decreased rate of neurotransmitter release (Wald, 1968 Stryer, 1986 Chabre and Deterre, 1989). 

Atomistic insights into rhodopsin activation from a dynamic model. J. Am. Chem. Soc. 130, 10141-10149. 

DHA in the rod outer segments may impart unique membrane characteristics adapted to facilitating rhodopsin activation and association with G-proteins. 

Fig. 8.15 A model of the organization of the InaD signaling complex. InaD is composed of5 PDZ domains (PDZ1-5) which interact specifically with signaling proteins implicated in the vision process in Drosophila. TRP is a K+-channel. PLC is a 6-type phospolipase C, which is the target of rhodopsin-activated Gqa. ePKC is an eye-specific protein kinase C which inactivates the Trp channel by phosphorylation (after Huber, 2001).

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