A mutation that knocks out the GTPase activity of a G protein would have what effect on a cell?
A) The concentration of available GTP would decrease.
B) The number of G proteins in the cell would increase.
C) The G protein would be inactivated by a G protein-coupled receptor/signal molecule complex.
D) The G protein would always be active.

Question

Quizplus · Accepted Answer

A G protein with a knocked out GTPase activity cannot hydrolyze GTP to GDP, therefore it would always be active. This means the downstream signaling pathway would be constantly activated, regardless of the presence or absence of a signal molecule.

A Mutation That Knocks Out the GTPase Activity of a G