Final answer:
Signal molecules bind to tyrosine kinase receptors, causing them to dimerize and initiate a phosphorylation cascade, resulting in a cellular response. Epidermal growth factor receptors are an example of this system, with defects leading to diseases like multiple sclerosis and Alzheimer's disease.
Step-by-step explanation:
During enzyme-linked reception, signal molecules bind to two tyrosine kinase receptors. The receptor proteins move closer together in the plasma membrane and pair, forming a dimer. This process is called dimerization. Once dimerized, the intracellular tyrosine kinase domains of the receptors phosphorylate each other's tyrosine residues. This phosphorylation triggers a cascade of events inside the cell that lead to a cellular response.
Epidermal growth factor receptors are an example of receptor tyrosine kinases that undergo this mode of signaling. Defects in this signaling pathway can lead to diseases such as multiple sclerosis and Alzheimer's disease. The signal initiated by the kinase activity is typically terminated by a phosphatase that removes the phosphates from the phosphotyrosine residues.