GTPases serve in many signal transduction pathways and the presence of GTP or GDP dictates whether the pathway is on or off,respectively.Which of the following statements is true regarding guanine nucleotide exchange factors (GEF)and their role in these signaling pathways?
A)They hydrolyze GTP into GDP and Pᵢ.
B)They decrease the GTPase activity of the G-protein.
C)They catalyze the dissociation of GDP on the G-protein to therefore promote the replacement of GTP.
D)none of the above

Question

Quizplus · Accepted Answer

Guanine nucleotide exchange factors (GEFs) catalyze the dissociation of GDP on the G-protein to promote the replacement of GTP, leading to activation of downstream signaling pathways. They do not hydrolyze GTP into GDP and Pᵢ, and they do not decrease the GTPase activity of the G-protein.

GTPases Serve in Many Signal Transduction Pathways and the Presence