AAK1 activation-mediated iron trafficking drives ferroptotic cell death.

Ferrous iron is necessary for the occurrence of ferroptosis. The molecular mechanisms that maintain iron homeostasis within cells play a crucial role in the regulation of ferroptosis. However, how cells regulate iron uptake during ferroptosis remains unclear. Here, PKCβII is identified as a key kinase mediating transferrin receptor 1 (TFR1) endocytosis through phosphorylation and activation of AP2-associated protein kinase 1 (AAK1) during the ferroptotic process. Mechanistically, activated AAK1 phosphorylates AP2M1, which facilitates the recruitment of clathrin to mediate the endocytosis of TFR1, increasing the levels of both cellular total iron and ferrous iron and thereby promoting ferroptosis. The non-phosphorylatable mutation of AAK1 inhibits ferroptosis and consequently promotes breast tumor growth in vivo. In conclusion, we identify that the PKCβII-AAK1-AP2M1 pathway is a crucial mechanism for the regulation of cellular iron uptake during ferroptosis, which is correlated with the prognosis of breast cancer patients and presents a potential target for cancer therapy.