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Protein phosphatase-2A (PP2A) activity is significantly suppressed in Alzheimer's disease. We have reported that glycogen synthase kinase-3β (GSK-3β) inhibits PP2A via upregulating the phosphorylation of PP2A catalytic subunit (PP2A(C)). Here we studied the effects of GSK-3β on the inhibitory demethylation of PP2A at leucine-309 (dmL309-PP2A(C)). We found(More)
GSK-3β (glycogen synthase kinase-3β), a crucial tau kinase, negatively regulates PP2A (protein phosphatase 2A), the most active tau phosphatase that is suppressed in the brain in AD (Alzheimer's disease). However, the molecular mechanism is not understood. In the present study we found that activation of GSK-3β stimulates the inhibitory phosphorylation of(More)
Pesticides are widely used in agriculture, and epidemiological studies suggest that pesticide exposure is a risk factor for Alzheimer's disease (AD), but the mechanisms are elusive. Here, we studied the effects of pesticide exposure on the cognitive ability and the underlying mechanisms in rats. Deltamethrin and carbofuran were administered respectively(More)
Phosphotyrosyl phosphatase activator (PTPA) is decreased in the brains of Alzheimer's disease (AD) and the AD transgenic mouse models. Here, we investigated whether down-regulation of PTPA affects cell viability and the underlying mechanisms. We found that PTPA was located in the integral membrane of mitochondria, and knockdown of PTPA induced cell(More)
Increase of inhibitor-2 of protein phosphatase-2A [Formula: see text] is associated with protein phosphatase-2A (PP2A) inhibition and tau hyperphosphorylation in Alzheimer's disease (AD). Down-regulating [Formula: see text] attenuated amyloidogenesis and improved the cognitive functions in transgenic mice expressing amyloid precursor protein (tg2576). Here,(More)
Zinc induces protein phosphatase 2A (PP2A) inactivation and tau hyperphosphorylation through PP2A (tyrosine 307) phosphorylation in cells and the brain, but whether Zn2+ has a direct inhibitory effect on PP2A is not clear. Here we explored the effect of Zn2+ on PP2A and their direct interaction in vitro. The results showed that Zn2+ mimicked the inhibitory(More)
We have used ultraviolet laser crosslinking to characterize the DNA-binding properties of highly purified yeast topoisomerase II in the absence of ATP. A single 5 ns, 20 mJ pulse of 266 nm light produced optimal crosslinking to a short DNA duplex, with an efficiency of 0.25%. An equilibrium binding constant (Keq) of 1.2 +/- 0.5 x 10(8) M(-1) was determined(More)
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