Epidermal growth factor (EGF) activates the EGF receptor (EGFR) and stimulates its internalization and trafficking to lysosomes for degradation. However, a percentage of EGFR undergoes ligand-independent endocytosis and is rapidly recycled back to the plasma membrane. Importantly, alterations in EGFR recycling are a common hallmark of cancer, and yet, our understanding of the machineries controlling the fate of endocytosed EGFR is incomplete. Intersectin-s is a multi-domain adaptor protein that is required for internalization of EGFR Here, we discover that intersectin-s binds DENND2B, a guanine nucleotide exchange factor for the exocytic GTPase Rab13, and this interaction promotes recycling of ligand-free EGFR to the cell surface. Intriguingly, upon EGF treatment, DENND2B is phosphorylated by protein kinase D and dissociates from intersectin-s, allowing for receptor targeting to degradation. Our study thus reveals a novel mechanism controlling the fate of internalized EGFR with important implications for cancer.
Keywords: DENN domain; endocytosis; exocytosis; growth signalling; intersectin‐s.
© 2017 The Authors.