Ras is a GTP-binding protein that is often defective in cancer cells. A signal f
ID: 74049 • Letter: R
Question
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?
Explanation / Answer
A. The mutation in RAS is point mutation which cause RAS to behave such as it is bind to GTO and proliferation continue. so it is advantegeous because any drug targetting RAS is of not use. and there is no other defect in pathway including RAS as intermaediate
B. now as he desgin drug to turn off tyrosin kinase which binds to growth factor therby stimulate RAS and thus binds to GTP, here there is mutation in RAS and it behave as it is bind to GTP so drug targetting a intermediate comes in pathway even before RAS action does not have any effect
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.