Receptor tyrosine kinases have been called ____ as a result of their ____ and ____.
A) membrane-associated allosteric enzymes; induced conformation changes; oligomeric interactions
B) adrenergic receptors; binding insulin; binding epinephrine
C) GTP-binding proteins; GTPase activity; guanylyl cyclase activity
D) multi-TMS receptors; complex structure; G-protein binding
E) none of the above

Question

Quizplus · Accepted Answer

Receptor tyrosine kinases (RTKs) are membrane-associated enzymes that are activated by binding of extracellular ligands. Upon ligand binding, RTKs undergo conformational changes that promote homo- or hetero-dimerization, leading to trans-autophosphorylation of tyrosine residues in the intracellular domain of the receptor. This activates the kinase activity of RTKs, which phosphorylate downstream signaling proteins and initiate intracellular signaling cascades. The term "allosteric enzyme" describes enzymes that undergo conformational changes upon binding of a ligand at a site other than the active site; this term is appropriate for the activation of RTKs by ligand binding. The term "oligomeric interactions" describes how RTKs can form complexes or oligomers upon ligand binding, which is also characteristic of this class of receptors.

Receptor Tyrosine Kinases Have Been Called ____ as a Result