The activation of receptor tyrosine kinases is characterized by

dimerization and phosphorylation

Explanation:

Protein kinase receptors are simply saying receptors with associated kinases (usually tyrosine kinases).

Protein kinases are enzymes that have the ability to modulate other enzymes (or some other proteins) by adding the phosphate group. This is known as phosphorilation process. As a result of structural change, protein can change its activity (phosphorilation usually increase the activity).

Such receptors are involved in a many processes within an organism that are important for the cellular growth, differentiation, metabolism .

format change of dna.  

straight or amphibians are homeothermic to thermal