FIG. 3.

Effect of CST on the folding of NSP4. Cells were infected with RRV (MOI, 10), and at 7 hpi, monolayers were either not treated or treated with CST (1 mM) for 1 h before the pulse, during the pulse, and during the chase. Cells were starved for 1 h in methionine- and cysteine-free medium and then metabolically labeled (250 μCi) for 5 min. Labeled proteins were chased in the presence or absence of 1 mM CST in Eagle’s MEM supplemented with 1 mM cycloheximide and 10 mM methionine for the lengths of time indicated over the lanes. At the end of the chase, the monolayers were incubated with ice-cold PBS containing 40 mM NEM for 2 min. Cells were then harvested in lysis buffer. The cell lysates were immunoprecipitated with antibodies to calnexin and NSP4 and analyzed by reducing SDS-PAGE. Numbers at left are kilodaltons.