What happens when the GTPase activity of a G protein is blocked?
A)the $\alpha$ subunit associates only with the $\beta$ subunit, not the $\gamma$subunit
B)GTP cyclizes to cGMP
C)binding to GAP occurs with very high affinity
D)adenylate cyclase remains active
E)none of the above

Question

Quizplus · Accepted Answer

Blocking the GTPase activity of a G protein would prevent it from hydrolyzing GTP into GDP, meaning that the G protein would remain in its active state for a longer period of time. In the case of adenylate cyclase, which is activated by G alpha stimulatory subunits (Gs), the prolonged activation of the G protein would lead to continued stimulation of adenylate cyclase and increased production of cAMP. Therefore, choice D is the best answer. Choices A, B, and C are not accurate with regard to the effects of blocking GTPase activity.

What Happens When the GTPase Activity of a G Protein α\alphaα

What Happens When the GTPase Activity of a G Protein $\alpha$