Question

A mutation that inhibits Ras from hydrolyzing GTP will

a. block association with the SOS1/GRB2/SHC1 complex.
b. inactivate p53.
c. block ELK1 location in the mitochondria.
d. bind ERK to the IGF1 receptor.
e. result in permanent activation of Ras.

Answer 1

The correct answer is option e. "result in permanent activation of Ras".

Step-by-step explanation:

Ras function is regulated by the GTP/GDP cycling rate, in a way that Ras is inhibited by the substrate GDP. Once Ras hydrolyzes GTP, GDP is produced and Ras is inhibited by GDP. A mutation that inhibits Ras from hydrolyzing GTP, would lock Ras in a permanently activated state because no GDP would be produced and there will be no substrate to inhibit Ras.