AP2-associated protein kinase 1 (AAK1)

Regulates clathrin-mediated endocytosis by phosphorylating the AP2M1/mu2 subunit of the adaptor protein complex 2 (AP-2) which ensures high affinity binding of AP-2 to freight membrane proteins during the beginning stages of endocytosis. Isoform 1 and isoform 2 display similar levels of kinase activity towards AP2M1.

Regulates phosphorylation of other AP-2 subunits in addition to AP-2 localization and AP-2-mediated internalization of ligand complexes. Phosphorylates NUMB and regulates its cellular localization, boosting NUMB localization into endosomes.