The SARS Coronavirus E Protein Interacts with PALS1 and Alters Tight Junction Formation and Epithelial Morphogenesis

Teoh, Kim-Tat; Siu, Yu-Lam; Chan, Wing-Lim; Schlüter, Marc A.; Liu, Chia-Jen; Peiris, J. S. Malik; Bruzzone, Roberto; Margolis, Benjamin; Nal, Béatrice

We then decided to perform the same experiment but with a more detailed time course post-calcium switch to analyze the consequences of SARS-CoV E expression on PALS1 distribution and monitor any potential change of the structure of the MDCKII monolayer upon time. TER measurement and confocal microscopy analysis were conducted in parallel from 0 to 120 h post-calcium switch (Figure 8). Control, HA-E (ΔPBM) and HcRed (data not shown) MDCKII eGFP-PALS1 cells presented a peak of TER at 3 h post-calcium switch whereas a delay was observed for the HA-E (wt) expressing cells (Figure 8A). For all time points, MDCKII HA-E (ΔPBM) cells showed higher TER values than control cells, suggesting that they establish junctions more rapidly and that mature TJ are tighter in these cells. For MDCKII HA-E (wt) cells, the maximal recorded value of TER was at 8 h post-calcium switch (400 Ω/cm2), although it is possible that resistance had risen further between the 8–24 h interval, for which we do not have TER values.