Intracellular distribution of HTLV-1–Tax protein ubiquitin mutants in transiently transfected Jurkat cells. Jurkat cells are transfected with GFP-Tax or GFP-Tax-K263R, GFP-Tax-K280R, GFP-Tax-K284R, or GFP-Tax-K263R-K284R. The cells are fixed with cold methanol (6 hours after transfection) and permeabilized. The MTOC is stained with polyclonal antibody anti–γ-tubulin (red). Each panel shows projected images (x, z) corresponding to GFP-Tax or GFP-Tax mutant (green), MTOC (red), and the superposition of the 2 colors (merge). Scale bar represents 10 μm.