Figure 5

In vivo interaction of endogenous HBZ with intracellular molecules. In vivo interaction between endogenous HBZ and CBP or JunD was assessed by co-immunoprecipitation assay. Cell lysates from 50 million C5MJ, ATL-2s, PH961 ATL patient and Jurkat cells, prepared as described in the legend to Figure 2, were immunoprecipitated by using HBZ covalently linked to CNBr-activated Sepharose 4B beads (IP αHBZ). After elution from HBZ-Sepharose 4B beads, the eluted material was migrated on SDS-PAGE gels, blotted on nitrocellulose membranes and probed with antibodies specific for either anti-HBZ (4D4-F3 mAb, αHBZ WB), anti-CBP (αCBP WB) or anti-JunD (αJunD WB) (lower western blots in each series of upper, middle and lower panels, respectively). One twentieth of cell lysate from each sample was used to assess the presence of the specific protein (input) by western blot (upper western blot in each series of upper, middle and lower panels).