Figure 2.

Pttg1 and Pttg2 show different biochemical properties. (a) PTTG2 does not interact with Separase. Extracts of HEK293T cells expressing N-terminally Flag-tagged separase, C-terminally Myc-tagged PTTG2, or both were used for immunoprecipitation with anti-Myc antibodies. The immunoprecipitates were analyzed by immunoblotting with anti-FLAG and anti-Myc antibodies. The asterisks indicate the immunoglobulin light chains. As positive control, the interaction between PTTG1 and separase was tested using Flag-separase and Myc-tagged PTTG1. (b) PTTG2 lacks transactivation capacity. The ORF of Pttg2 was fused to the GAL4 DNA-binding domain (pGAL4-DBD-Pttg2) and tested for transcription activation in HEK293T cells cotransfected with a GAL4 site-dependent reporter plasmid driving expression of the luciferase gene (pGAL4-4RE-Luc). pGAL4-PTTG1 and pGAL4-VP16 were used as positive controls. Luciferase values from at least three independent transfections are plotted as fold activation over control