Figure 4

Tax1 mutants in the Tax1(225-232) region interact with p100. (A) Amino acid sequence of Tax1(225-243) and Tax2B(225-243). The exchanged amino acids in the respective mutants and leucine residues putatively constituting the leucine zipper (LZ) structure are indicated. (B) 293T cells were transfected with the indicated Tax expression plasmids together with a p100 expression plasmid. At 48 hours following transfection, the cell lysates were prepared and immunoprecipitated with the anti-p100 antibody. The precipitated proteins were characterized by Western blot analysis with anti-Tax1, or anti-p100 antibodies. An aliquot of the lysates, removed before immunoprecipitation, was also characterized as an input (Input).