Figure 6.

${\text{SiI}}_2^{\text{PP2A}}$ decreases the expression of ${\text{I}}_2^{\text{PP2A}}$ and increases PP2A activity in cell lines. ${\text{pSUP - siI}}_2^{\text{PP2A}}$ (pSUP-siI₂) was transfected into HEK293/tau or N2a/tau cells to knockdown the expression of ${\text{I}}_2^{\text{PP2A}}$, pSUP, and pSUP-siC were transfected as the controls. After 24 h, the level of ${\text{I}}_2^{\text{PP2A}}$ in the cell extracts was estimated by Western blotting (A,D) and immunostaining (B). The activity of PP2A was measured by a PP2A activity assay kit as described in the Section “Materials and Methods” (C,E). The relative intensity was normalized against DM1A (to α-tubulin) and expressed by setting pSUP as 1. The data were presented as mean ± SD of at least three independent experiments. **p < 0.01 vs. pSUP.