Figure 2.

Model representing possible molecular mechanisms by which E5 manipulates trafficking pathways and potentially predisposes the infected cell towards cancer development. E5 inhibits the transport of immune receptors (MHCI, MHCII, CD1d) to the cell surface, and prevents clearance of infected cells by the immune response (1). It also upregulates the cell surface expression of caveolin-1 and ganglioside GM1 (2). Moreover, E5 can inhibit endosome acidification (3) or the trafficking from early to late endosomes (4) which may promote recycling of EGFR to the cell surface and lead to aberrant proliferation (5). Note that E5 localizes primarily to the endoplasmatic reticulum (ER), but it can also be found in the Golgi apparatus, in perinuclear regions and on the plasma membrane.