Fig. 3. HRSL3 suppresses the PP2A catalytic activity. (A) OVCAR-3 cells were transiently transfected with HREV1FL and HREV1-dNdC, transfection with pcDNA3 was used as a negative control, and treatment with 10 nM okadaic acid as a positive control. Forty-two hours after transfection cells were lysed and immunoprecipitated with an anti-PR65 antibody. Phosphatase activity of the immunoprecipitates was measured as the release of free phosphate (pmol/minute; y axis). Six independent experiments were performed, and included into a statistical analysis. Significance of the obtained results was assessed using an F-test. The difference between HREV1FL and dNdC, and HREV1FL and pcDNA3 values was considered as significant (P=0.02). (B) Immunoprecipitates used for the measurement of the phosphatase activity in the presence of HRSL3 and its interaction-deficient mutant were controlled by western blotting using HRSL3- and PR65-specific antibodies.