FIG. 1.

Differential intracellular partitioning of colocalized Tax and SUMO or Tax and ubiquitin molecules. 293T cells were transfected with vectors expressing (A) Tax alone or (B) Tax in combination with HA-Ub or HA-SUMO-1 and stained by immunofluorescence with (A) an anti-Tax MAb or (B) the anti-Tax MAb (IgG2a), an anti-HA rabbit polyclonal antibody, and a MAb (IgG1) recognizing either the Golgi matrix marker GM130 (upper panels) or the promyelocytic leukemia protein (lower panels). The cells were analyzed by laser scanning confocal microscopy, with one confocal section being depicted in panel A and the projection of Z-series confocal images depicted in panel B. Diagrams depict the intensity of the fluorescence for each staining along lines drawn on the overlay images with the boundaries of the nuclei (NE, nuclear envelope), the Tax NB, the Golgi apparatus (G), and the PML bodies (PML) indicated. The percentages of cells having Tax in nuclear bodies only (NB), in the cytoplasm and in the nuclear bodies (Cy + NB), or in the cytoplasm only (Cy) with or without overexpression of HA-ubiquitin or HA-SUMO-1 are depicted in panels A and C. DIC, differential inference contrast.