Question

If Ras contains a mutation that leads to a defect in GTP hydrolysis, this could fuel uncontrolled proliferation in cancer because Choose one:

A. Ras is unable to bind to the GEF for activation.
B. Ras is able to migrate to the nucleus and deactivate transcription of proliferation genes.
C. Ras is unable to send signals to downstream pathways.
D. Ras is able to signal to downstream pathways inappropriately.

Answer 1

D. Ras is able to signal to downstream pathways inappropriately. When the GTPase activity of the RAS G-protein is inhibited in certain cancers, the RAS protein is unable to hydrolyze GTP into GDP. This leads to a defect in GTP hydrolysis, which fuels uncontrolled proliferation in cancer because Ras is able to signal to downstream pathways inappropriately.

Step-by-step explanation:

When the GTPase activity of the RAS G-protein is inhibited in certain cancers, the RAS protein is unable to hydrolyze GTP into GDP. This leads to a defect in GTP hydrolysis, which has an effect on downstream cellular events. The correct answer is option D: Ras is able to signal to downstream pathways inappropriately. In this scenario, the Ras protein, when bound to GTP, remains active and continues to send signals to downstream pathways, leading to uncontrolled proliferation and cancer.