Figure 7
The Tax1(185-207) region negatively regulates the transforming activity of Tax1. (A) The amino acid sequences of the 185-207 region of Tax1. The exchanged amino acids in the respective mutants and leucine and isoleucine residues putatively constituting the cryptic NES are indicated. (B) CTLL-2 cells were infected with lentiviruses encoding the indicated Tax genes in the presence of IL-2. At 48 hours after infection, the cells (1 × 103, 3 × 103, and 1 × 104 cells/well) were cultured in 96-well plates without IL-2. After 4 weeks of culture, the wells containing the outgrowing cells were counted using light microscopy. The number of positive wells is shown, and the maximum number was 96. The data are representative of three independent experiments. *The P values and **the P value were < 0.001 and < 0.05, respectively. (C) The cell lysates prepared at 48 hours after infection were characterized by Western blot analysis probed with the anti-Tax1 antibody.