Involvement of 3BP2 in BCR-mediated activation of NFATs. (A) Daudi cells were transiently transfected with various 3BP2 mutant constructs, NFAT reporter plasmid, and Renilla luciferase plasmid (pRL-TK) used as internal control reporter. At 24 hours after transfection, cells were either left unstimulated, or stimulated with anti-IgM (2 μg/mL) for 6 hours, and harvested for the dual-luciferase assay. The luciferase activity was normalized by the Renilla luciferase activity and expressed as fold increase relative to the basal activity seen in unstimulated mock-transfected cells. Values represent the mean plus or minus the standard deviation from triplicate samples. The lower panel shows the relative expression of each of the 3BP2 constructs. (B) Daudi cells were transfected with an expression plasmid encoding HA-tagged 3BP2 SH2 (aa 454-aa 559), NFAT reporter plasmid, and Renilla luciferase plasmid used as internal control reporter. Cell stimulation and luciferase assay were performed as in panel A.