Cellular spreading of pleckstrin-2, but not membrane localization, is dependent on the actin cytoskeleton. Jurkat cells expressing GFP fused to the amino-terminus of wild-type pleckstrin-2 were plated on OKT3. When indicated, 1 μM final concentration latrunculin A was added to the chamber slide. Shown is a cell expressing pleckstrin-2 before and after inhibition of the actin cytoskeleton with latrunculin A for 60 seconds. This figure shows that wild-type pleckstrin-2 associates with membrane projections in cells spread on fibronectin, and this membrane localization remains despite the disruption in cellular spreading by the addition of latrunculin A. Similar results were seen when the actin cytoskeleton was disrupted with cytochalasin D. Images were captured using an UtraVIEW-LCI confocal scanner at × 100 magnification.