Question

Activation of most RTKs requires:

A. Ligand binding
B. Dimerization
C. Transautophosphorylation
D. All of the above

Answer 1

Activation of most RTKs requires ligand binding, dimerization, and trans autophosphorylation, thus the correct answer is 'All of the above'. These steps are essential for the activation and subsequent cellular response that RTKs control.

Step-by-step explanation:

Activation of most receptor tyrosine kinases (RTKs) requires multiple steps. These include ligand binding, which initiates the process, followed by dimerization, where two RTKs bind together, and finally, transautophosphorylation, which is when the dimerized tyrosine kinase enzymes add phosphates to themselves. Therefore, the correct answer to the question 'Activation of most RTKs requires:

A. Ligand binding B. Dimerization C. Transautophosphorylation D. All of the above' is D. All of the above. This multistep process is crucial for the downstream cellular response, which can include cell division, growth, and other important cellular functions.

Drugs like Lapatinib work by inhibiting these steps, thereby blocking the downstream effects that can lead to conditions such as unregulated cell division in cancers.