FIG 2.

SUMO does not alter VSV entry but inhibits viral mRNA transcription. (A) HeLa-wt, HeLa-SUMO1, and HeLa-SUMO3 cells were infected with MLV-G-GFP for 48 h. The transduction efficiency, expressed as the percentage of GFP-positive (GFP⁺) cells, was measured at 48 h postinfection using flow cytometry. Mean values and standard deviations from three independent experiments are shown. (B) HeLa-wt, HeLa-SUMO1 (S1), and HeLa-SUMO3 (S3) cells were infected by VSV at an MOI of 4 in the absence of cycloheximide (−CHX) or the presence of cycloheximide (+CHX). After 6 h of infection, samples were analyzed for the presence of VSV N mRNA, antigenome mRNA, and GAPDH (glyceraldehyde-3-phosphate dehydrogenase) mRNA, as described in Materials and Methods. A lower level of exposure of the membrane shows the presence of N mRNA exclusively in the wt cells (in the absence of cycloheximide [−CHX]) (top); a higher level of exposure allowed the detection of a small amount of antigenome and N mRNA (bottom).