Fig. 1.

Internalized SV40 colocalizes with endosomal markers (see also Movies S1 to S3 in the supplemental material). (A) CV-1 cells were incubated with SV40-AF488 for 120 min at 37°C. Cells were mixed and immunostained with antibodies against the EE marker EEA1. A confocal section was imaged using the Zeiss LSM 510 confocal microscope system. (B to D) Fluorescently labeled SV40 was added to CV-1 cells transfected with different XFP-tagged endosomal markers and imaged live with a spinning-disc confocal microscope (except C, which was imaged with the Zeiss LSM 510 system) at the indicated time points. (E) Percentage of viruses colocalizing with the markers Rab7-EGFP and Rab5-mRFP at different times postwarming. It was calculated from images such as those shown in D. Error bars are standard errors of the means (SEM) of data from each time point for 5 to 15 cells from three different experiments, with an average of 50 to 100 particles per cell. (F) Same as A, but cells were incubated with SV40-AF594 and stained against the LE marker LAMP1.