Figure 3. .

Recombinant PP2A B and C subunits interact with CaBP4. GST or GST-CaBP4 immobilized on glutathione magnetic beads was incubated with lysates of HEK293 cells cotransfected with epitope-tagged PP2A subunits: HA-tagged Aα (A), c-myc–tagged Cβ (B), FLAG-tagged Bα (C), or c-myc–tagged Cα (D). Bound PP2A subunits were detected by Western blot analysis with antibodies against epitope tags (upper panels) or PP2A subunits (bottom panels). Bands corresponding to the epitope-tagged and endogenous untagged PP2A subunits are indicated in the lysates with black and grey arrowheads, respectively. Ponceau staining indicated the amounts of GST or GST-CaBP4 used in the pull-down assay (E).