Fig. 1.

Inhibition of UL97 kinase activity by CPV. Transient expression of a pp65-GFP fusion in COS7 cells (green staining in the middle column) induces the formation of nuclear aggresomes, and coexpression of the CMV UL97 kinase (red staining in the first column) can inhibit their formation in a kinase-dependent manner (compare row A with the catalytically inactive UL97 mutant in row B). Pharmacologic inhibition of the UL97 kinase by 15 μM MBV also inhibits the ability of the kinase to prevent aggresome formation (row C) and leads to recruitment of the kinase to aggresomes (merged image in the last column with blue 4′,6-diamidino-2-phenylindole [DAPI] staining). Treatment with 15 μM CPV also inhibits the UL97 kinase and induces its recruitment into aggresomes (row D), whereas neither CDV nor GCV exhibits this activity at a concentration of 15 μM (rows E and F, respectively). UL97 with the V3656G mutation shows an inability to prevent aggresome formation (row G).