Phosphoinositide 3-kinases (PI(3)Ks) are mainly known for their lipid kinase activity in various cellular functions; however, PI(3)Ks also have protein kinase activity. Non-muscle tropomyosin has been identified as a novel protein target for PI(3)Kγ. Phosphorylation of tropomyosin is required for β-adrenergic receptor internalization, providing new insight into PI(3)K function during clathrin-mediated endocytosis.