Which alteration of oncogen Ras activity is most likely to contribute to the uncontrolled growth of cancer cells?

Answer 1

Ras is a GTPase that functions in many growth-factor signaling pathways. In its active form,with GTP bound, it transmits a downstream signal that leads to cell proliferation; in its inactive form, with GDP bound, the signal is not transmitted. Uncontrolled growth of cancer cells will occur when there is an alteration that decreases the rate of hydrolysis of GTP by Ras. If thius rate is decreased, GTP will not be hydrolysed as quickly to GDP, causing there to be more cell proliferation than needed.

Answer 2

The mutation in oncogenic Ras that locks it in the active GTP-bound state is most likely to contribute to uncontrolled growth of cancer cells. This mutation prevents Ras from switching off its signaling, leading to sustained activation of pathways that promote cell proliferation and survival.