The domains of Tax and USP10 are required for the interaction. (A) A schematic representation of Tax and its mutants used in this study. (B) Cell lysates were prepared from 293T cells transfected with the HA-USP10 plasmid together with Tax mutant plasmids, and then were immunoprecipitated with anti-Tax. The total lysates (input) and immunoprecipitates (IP) were characterized using a western blot analysis with anti-Tax and anti-HA antibodies. (C) A schematic representation of USP10 and its mutants used in this study. PAM2 (PABP-interacting motif 2) mediates the interaction with PABP.²¹  (D) 293T cells were transfected with plasmids encoding HA-tagged USP10 (HA-WT) or its mutants (HA-1-116, HA-96-798, HA-1-726, or HA-1-439), as described in (C), together with Tax plasmids. Cell lysates prepared from 293T cells were then immunoprecipitated with anti-Tax antibodies. The input and immunoprecipitates were characterized using a western blot analysis with anti-Tax and anti-HA antibodies. The asterisks indicate nonspecific bands.