Which of the following is NOT part of a negative feedback mechanism in adaptation to light in retinal rod cells?
A) Phosphorylation of G-protein-coupled receptor
B) Binding of arrestin to G protein
C) Stimulation of guanylyl cyclase by decreased Ca²⁺ levels
D) Binding of regulator of G protein signaling to transducin

Question

Quizplus · Accepted Answer

Following the phosphorylation of the receptor by rhodopsin kinase, arrestin binds to it to prevent transducin activation. Other mechanisms, such as binding of RGS (regulator of G protein signaling) to the G protein α subunit or activation of guanylyl cyclase, are also involved in visual adaptation in rod cells.

Which of the Following Is NOT Part of a Negative