FIG 6.

IPTG-mediated induction of F17 expression is cell-type specific. (A) Schematic of the Lac repressor system in the iF17 virus. The LacI gene repressor under the control of an early/late p7.5 promoter is inserted into the TK gene. The LacO binding site represses F17 expression in the absence of IPTG. ORF, open reading frame. (B) BSC40 cells were infected at an MOI of 5 for 24 h with WT or iF17 viruses in the presence or absence of 5 mM IPTG. Note that restoration of F17 expression in iF17 viruses with IPTG treatment restores processing of A10. (C) Growth-arrested NHDFs were infected at an MOI of 3 for 30 h with the indicated viruses in the presence or absence of 5 mM IPTG. S.E., short exposure; int, intermediate; U>, unprocessed A10; P>, processed A10. Fast-migrating nonphosphorylated (0) and slower-migrating species of differently phosphorylated (P) forms of 4E-BP1 or p70S6K are shown. All data are derived from and representative of at least 3 biological replicates.