Ras Is a GTP-Binding Protein That Is Often Defective in Cancer

Essay

Ras is a GTP-binding protein that is often defective in cancer cells.A signal from a growth factor through a receptor tyrosine kinase often stimulates normal cells to divide.When the receptor tyrosine kinase binds the growth factor, Ras is stimulated to bind GTP.Ras in turn activates proteins that promote cell proliferation.A common mutation in cancerous cells causes Ras to behave as though it were bound to GTP all the time.
A.Why is this mutation advantageous to cancerous cells?
B.Your friend decides that the signaling pathway involving the Ras protein is a good target for drug design, because the Ras protein is often defective in cancer cells.Your friend designs a drug that will turn off the receptor tyrosine kinase by preventing it from dimerizing.Do you think that this drug will affect cells that have a defective Ras protein that acts as if it were always bound to GTP? Why or why not?