Question

With regards to G-proteins, when are GTP or ATP used?

A) GTP is used during activation, ATP is used during deactivation
B) ATP is used during activation, GTP is used during deactivation
C) GTP is used during both activation and deactivation
D) ATP is used during both activation and deactivation

Answer 1

G-proteins utilize GTP during activation and GDP during deactivation.

Step-by-step explanation:

G-proteins utilize GTP (guanosine 3-phosphate) during activation and GDP (guanosine diphosphate) during deactivation. When a ligand binds to a G-protein-linked receptor, the resulting shape change activates the G-protein, causing it to release GDP and pick up GTP. This activated G-protein can then activate other proteins to mediate changes in cellular processes. Eventually, GTP is hydrolyzed to GDP, leading to the deactivation of the G-protein.