Question

What does GAP- GTPase Activating Protein do?

a.Promotes GTP Hydrolysis:

b.Terminates Signal Transduction:

c.Prevents Continuous GTPase Activation:

d.Inhibits Oncogenic Signaling:

Answer 1

GTPase Activating Protein (GAP) promotes GTP hydrolysis to terminate active G-protein signaling. In certain cancers, inhibition of RAS G-protein's GTPase activity prevents it from hydrolyzing GTP, leading to continuous signaling and potential uncontrolled cell proliferation.

Step-by-step explanation:

GAP, or GTPase Activating Protein, promotes GTP hydrolysis, which is a critical process in the regulation of G-protein signaling pathways. This hydrolysis effectively converts the molecule GTP into GDP, thereby terminating the active state of G-proteins such as RAS. When GAP function is normal, it ensures the signal transduction is transient and does not promote continuous signaling. However, in certain cancers, the GTPase activity of RAS G-protein is inhibited, leading to the RAS protein's inability to hydrolyze GTP into GDP, which would cause RAS to remain active continuously. This continuous activation can lead to uncontrolled cell growth, potentially resulting in cancer. RAS plays a crucial role in cell division, and its overactivity due to GTPase inhibition can lead to hyperproliferation of cells—a hallmark of cancerous growth.