Final answer:
Yes, tyrosine kinase requires a conformational change to initiate downstream signaling pathways.
Step-by-step explanation:
Yes
, tyrosine kinase does require a conformational change to initiate downstream signaling pathways. In receptor tyrosine kinases, such as the one illustrated in Figure 9.8, when a signaling molecule binds to the extracellular domain, the receptor undergoes dimerization. This dimerization triggers the autophosphorylation of tyrosine residues on the intracellular domain, which then activates downstream cellular responses. Therefore, the conformational change of the tyrosine kinase receptor is essential for initiating the signaling cascade.
Some important examples of receptor tyrosine kinases are epidermal growth factor receptors, which play a role in cellular proliferation. Mutations in these signaling pathways have been associated with diseases like cancer. Understanding the mechanism of tyrosine kinase activation and downstream signaling is crucial for studying various cellular processes and developing targeted therapies.