Fig. 8.

APN and EGFR synergistically promote TGEV invasion. EGFR is a co-factor for TGEV invasion. TGEV S1 protein interacts with EGFR extracellular receptor binding domain 1. TGEV infection induces EGFR internalization and causes APN and EGFR clustering. APN and EGFR synergistically promote TGEV invasion. APN and EGFR synergistically activate PI3K/AKT and MEK/ERK1/2 signaling pathways. Clathrin and caveolin mediate the endocytosis of TGEV and EGFR internalization through clathrin endocytosis pathway.