NSP4 transport kinetics to the exofacial PM of HT29.F8 and MDCK cells vary. The cloned intestinal and canine kidney cells simultaneously were infected with RV SA11.4F (MOI = 2). At 2, 3, 4, 7, and 8 hpi, the cells were surface biotinylated at 4°C, lysed, and precipitated with streptavidin agarose. The cell lysates and precipitated surface proteins were separated by SDS-PAGE and analyzed by Western blot using NSP4150-175.peptide-specific antibodies (panels A and B). A cytofacial membrane (anti-caveolin-1) and intracellular (anti-NSP5) control are shown in panels C and D, respectively. Lanes were loaded as follows: Lane 1 = cell lysates recovered from the streptavidin pull-downs. Lane 2 = streptavidin precipitate of the surface biotinylated proteins. Lane 3 = cell lysates from a mock-biotinylated control. Lane 4 = streptavidin precipitate of the mock-biotinylated control, Lane 5 = cell lysates from an uninfected cell control.