FIG 2.

HSP90 activity is required at a postentry step and for viral propagation. (A) Inhibition of HSP90 activity with 17-DMAG blocks ongoing MeV propagation in ex vivo mouse brain explants. Brain slices in organotypic cultures were infected with a recombinant MeV IC323-GFP strain (10⁴ PFU) and treated at different time points with 1 μM 17-DMAG. Observations were made at 3 days postinfection, and viral infection was assessed by measuring GFP expression by fluorescence microscopy (A) (note the increased exposure times for earlier treatment with 17-DMAG so as to visualize various levels of fluorescence intensity). (B to D) Addition of 17-DMAG at different times postinfection blocks the ongoing viral replication cycle. As schematized in panel B, 2 μM 17-DMAG was added at various times after the infection of Vero/hSLAM cells with Mor-Flag/L at an MOI of 1 and the production of MeV N, P, and Flag/L and cellular GAPDH from 8 M urea-treated whole-cell extracts was monitored by Western blotting (C) with quantification after normalization for GAPDH content (D). Data obtained in the presence of the solvent are indicated as nontreated (n.t.).