GNAT1

Alpha subunit of the heterotrimeric guanine nucleotide-binding protein (G protein) that transduces signals from the G protein-coupled photoreceptor rhodopsin (RHO). Essential for normal RHO-mediated light perception in retinal rod photoreceptors. Functions as a GTPase, cycling between an active GTP-bound state and an inactive GDP-bound state. Under dim light conditions, photoactivated RHO promotes GDP release and GTP binding. In its active state, GNAT1 stimulates downstream effectors, including rod cGMP-phosphodiesterase (PDE6) complex, to mediate the phototransduction cascade (By similarity). Activation of the PDE6 complex occurs through binding and repositioning of the inhibitory PDE6 gamma subunits (PDE6G), thereby promoting catalytic activity (By similarity)..

Function from UniProtKB (P11488), read 2026-09-23. CC BY 4.0.