MII catalyses GDP/GTP exchange on Gt

Stable Identifier
Reaction [transition]
Bos taurus
SVG |   | PPTX  | SBGN
MII catalyses GDP/GTP exchange on Gt
In darkness, the heterotrimeric G protein transducin (Gt) is attached to the disk membrane surface with a GDP bound to it and is inactive. Photoexcited rhodopsin (MII) binds Gt enabling the latter to release GDP. GTP, which is present at a high concentration within the outer segment, then takes its place (Bennett et al. 1982, Emeis et al. 1982, Fung & Stryer 1980, Fung et al. 1981).
Literature References
PubMed ID Title Journal Year
6291939 Light-induced interaction between rhodopsin and the GTP-binding protein. Metarhodopsin II is the major photoproduct involved

Michel-Villaz, M, Bennett, N, Kühn, H

Eur. J. Biochem. 1982
6264430 Flow of information in the light-triggered cyclic nucleotide cascade of vision

Fung, BK, Hurley, JB, Stryer, L

Proc. Natl. Acad. Sci. U.S.A. 1981
6288450 Complex formation between metarhodopsin II and GTP-binding protein in bovine photoreceptor membranes leads to a shift of the photoproduct equilibrium

Reichert, J, Kühn, H, Emeis, D, Hofmann, KP

FEBS Lett. 1982
6930647 Photolyzed rhodopsin catalyzes the exchange of GTP for bound GDP in retinal rod outer segments

Kwok-Keung Fung, B, Stryer, L

Proc. Natl. Acad. Sci. U.S.A. 1980
Catalyst Activity

guanyl-nucleotide exchange factor activity of MII [photoreceptor disc membrane]

Orthologous Events
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