Figure 3.

BVr-S6K1 is resistant to phosphatase inactivation. S6Kα1-WT immuno-precipitated with anti-HA antibodies from infected Sf9, HEK 293, CHO or NIH-3T3 cells as above. The immunoprecipitate was split into aliquots and incubated with indicated concentrations of acid phosphatase (3a, 3b) or protein phosphatase 2A (b) for 30 min and washed with buffer containing phosphatase inhibitors or okadaic acid (5nM) respectively, followed by excessive washing with kinase buffer and processed for S6 phosphorylation assay as above.