The growth factor Superchick stimulates the proliferation of cultured chicken cells. The receptor that binds Superchick is a receptor tyrosine kinase (RTK), and many chicken tumor cell lines have mutations in the gene that encodes this receptor. For the following types of mutation, what would be the affect if any on 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 protein tyrosine phosphatase that normally removes the phosphates from tyrosines on the activated receptor
(d) a mutation that prevents the binding of the normal extracellular signal to the receptor

Option C, a mutation that inactivates the protein tyrosine phosphatase that normally removes the phosphates from tyrosines on the activated receptor

Explanation:

Protein tyrosine phosphatases (PTP) causes dephosphorylation of protein due to which the pathways for signal transmission get terminated, growth of cell also get inhibited along with cell proliferation, and differentiation. Cell proliferation is a mechanism by which the number of cells increases in an organism. Also this mechanism keeps a balance between the cell divisions and cell loss.  

Since this growth factor Superchick is stimulating the proliferation of cultured chicken cells by inhibiting the functioning of Protein tyrosine phosphatases due to which cell growth is not terminated and more cultured mutated cells are originating  

Hence, option C is correct