GSK-3[beta] inhibits the activity of PP2A via upregulating the demethylation of PP2A catalytic subunit (PP2Ac) at Leu309.
We speculate that the mechanism of CIG's decreasing demethylation of PP2Ac at Leu309 might be through regulating the expression of PME-1 and LCMT.
The mechanism of CIG may be related to decreasing the ratio of PME-1/LCMT, thus reducing the demethylation of PP2Ac at Leu309.
They both can act as a calmodulin binding protein to interact with PP2AC in a calcium-dependent manner.
discovered that a novel apolipoprotein E-based peptide, COG112, can inhibit the interaction of SET with PP2AC, leading to increased PP2A activity.
It is reported to increase PP2A activity by upregulating PP2AC subunits, which results in the repression of Akt activation and the subsequent apoptosis .
Briefly, PP2Ac was immunoprecipitated from cell lysates with 4 [micro]g of anti-PP2Ac antibody, incubated with protein A agarose, and then washed with TBS.
Although we could not detect the expression changes of PP2Ac in fibroblasts, PP2A activity was significantly decreased on FC, compared to that on TC (Figure 4(a); p < 0.002).
First, we found that proliferation was increased by both OA treatment and PP2Ac knock-down (Figures 5(a) and 5(b)).