Figure 1.

EGF receptor (EGFR) trafficking pathways and associated outcomes. Activated cell-surface EGFRs are internalized and sorted at the early endosome. The fate of the receptor has important consequences for biological cell outputs, with the recycling pathway favoring cell proliferation (depicted green), although the degradative pathway via ESCRT (endosomal sorting complex required for transport)-mediated sorting within multivesicular bodies (MVBs)/lysosomes correlates with normal cellular homeostasis (depicted in blue). Atypical trafficking pathways to the nucleus and mitochondria have also been described and are proposed to favor survival, but the transport mechanisms are not well established. Exposure to stress leads to the removal of the receptor from the cell surface, and this has been proposed to potentiate cell death (depicted in red). Conversely, stress-activated receptor might also be recycled, thereby promoting cell survival and/or proliferation.