AP BIOLOGY

Detailed explanation-1: -Cross-linking activates the tyrosine kinase activity in these RTKs through phosphorylation-specifically, each RTK in the dimer phosphorylates multiple tyrosines on the other RTK. This process is called cross-phosphorylation.

Detailed explanation-2: -RTKs transduce biochemical signals via lateral dimerization in the membrane. While the monomers (left) are inactive, the dimers (right) are phosphorylated and active. RTK dimerization controls and ensures the close contact of the two kinase domains in the dimer.

Detailed explanation-3: -RTKs are generally activated by receptor-specific ligands. Growth factor ligands bind to extracellular regions of RTKs, and the receptor is activated by ligand-induced receptor dimerization and/or oligomerization [5] (Fig.

Detailed explanation-4: -Receptor tyrosine kinases (RTKs) are enzyme-linked receptors localized at the plasma membrane containing an extracellular ligand-binding domain, a transmembrane domain, and an intracellular protein–tyrosine kinase domain.

Detailed explanation-5: -Dimerization is a general mechanism to increase binding site affinity, specificity, and diversity. In this regard, RXRs play a central role in various signal transduction pathways since they can both homodimerize and act as promiscuous heterodimerization partner for almost 15 NRs.