Final answer:
Mutant proteins can disrupt intracellular signaling by altering protein function, such as stability or dimerization. Studying these mutant proteins provides insights into the precise mechanisms and locations of intracellular pathways.
Step-by-step explanation:
Mutant proteins can help determine where an intracellular signaling molecule binds by disrupting the normal function of the protein. For example, if a mutation affects the stability of a protein dimerization after ligand binding, it may alter the downstream signaling process.
In the case of a mutation in the transmembrane region of EGFR that eliminates its ability to be stabilized by binding interactions during dimerization after ligand binding, it could lead to the activation of EGF signaling cascades for a longer duration in the cell.
By studying these mutant proteins and their effects on cellular signaling, scientists can gain insights into the precise mechanisms and locations of intracellular pathways.