Fig. 1.

PEDV activates the ERK1/2 signaling pathway in cultured cells. Vero cells were mock infected or infected with PEDV at an MOI of 1 or an equal amount of UV-inactivated PEDV. (A and B) Whole cell lysates were prepared for the indicated times following PEDV infection (hpi) and subjected to Western blot analysis with the antibody specific for phosphorylated ERK1/2 (pERK1/2), ERK1/2, or the PEDV N protein. The blot was also reacted with mouse MAb against β-actin to verify equal protein loading. Fold changes in the pERK1/2:total ERK1/2 ratio are plotted. (C and D) ERK1/2 activation induced by PEDV infection was quantitatively determined using a FACE assay. Vero cells were fixed at the indicated time points with 4% formaldehyde and incubated with an anti-ERK1/2 or anti-pERK1/2 antibody followed by HRP-conjugated IgG antibodies. The absorbance of the solution was determined at 450 nm using a spectrophotometer. These results are representative of the results of three independent experiments and error bars represent standard deviations. ^⁎, P=0.001 to 0.05; †, P<0.001.