Src-mediated tyrosine phosphorylation of dynamin is required for β2-adrenergic receptor internalization and mitogen-activated protein kinase signaling

Some forms of G protein-coupled receptor signaling, such as activation of mitogen-activated protein kinase cascade as well as resensitization of receptors after hormone-induced desensitization, require receptor internalization via dynamin-dependent clathrin-coated pit mechanisms. Here we demonstrate that activation of beta(2)-adrenergic receptors (beta(2)-ARs) leads to c-Src-mediated tyrosine phosphorylation of dynamin, which is required for receptor internalization. Two tyrosine residues, Tyr(231) and Tyr(597), are identified as the major phosphorylation sites. Mutation of these residues to phenylalanine dramatically decreases the c-Src-mediated phosphorylation of dynamin following beta(2)-AR stimulation. Moreover, expression of Y231F/Y597F dynamin inhibits beta(2)-AR internalization and the isoproterenol-stimulated mitogen-activated protein kinase activation. Thus, agonist-induced, c-Src-mediated tyrosine phosphorylation of dynamin is essential for its function in clathrin mediated G protein-coupled receptor endocytosis.