FIG. 4.

Disruption of the actin but not the microtubular network induced changes in the localization of the viral 110K polymerase in CPMV-infected protoplasts. Immediately after infection, protoplasts were treated with oryzalin (10 μM) (B) or latrunculin B (20 μM) (C and D) or left untreated (A) and harvested at the indicated time points, followed by immunostaining with anti-110K serum. In untreated (A) and oryzalin-treated (B) protoplasts, the polymerase was present in a central large amorphous structure at 16 hpi. In cells treated with latrunculin B, the polymerase was present in numerous small spots scattered throughout the cytoplasm at both 16 hpi (C) and 36 hpi (D). Protoplasts transiently expressing GFP-MBD to visualize the microtubules (E and F) or Talin-YFP to visualize the actin cytoskeleton (G and H) show that oryzalin (F) and latrunculin B (H) were active at the concentration used at 16 h posttransfection. Lat. B, latrunculin B. Bars, 10 μm.