You are studying a newly discovered growth factor. You find that this growth factor stimulates the proliferation of chicken cells grown in the laboratory. You have also found that the receptor that binds the growth factor is a receptor kinase. Which of the following mutations would you expect to promote uncontrolled cell proliferation?
A)a mutation that prevents dimerization of the receptor
B)a mutation that destroys the kinase activity of the receptor
C)a mutation that inactivates the phosphatase that dephosphorylates the activated receptor
D)a mutation that prevents the binding of the normal extracellular signal to the receptor

Question

Quizplus · Accepted Answer

A mutation that inactivates the phosphatase responsible for dephosphorylating the activated receptor would lead to prolonged receptor activation, promoting uncontrolled cell proliferation. Phosphatases typically act to turn off signaling pathways by removing phosphate groups, and their inactivation would prevent the shutdown of proliferative signals.

You Are Studying a Newly Discovered Growth Factor