Techniques are available to allow one to introduce mutations in proteins at a selected amino acid residue (site-directed mutagenesis). Which step of the signal transduction pathway would be blocked if you created a tyrosine kinase receptor in which all of the tyrosine residues normally phosphorylated on the receptor were converted to phenylalanine residues?
A.
Grb2 binding to the receptor to propagate the response
B.
Binding of the growth factor to the receptor
C.
Induction of a conformational change in the receptor upon growth factor binding
D.
Activation of the receptor ’ s intrinsic tyrosine kinase activity
E.
Dimerization of the receptors