Okadaic acid

Okadaic acid, a marine toxin, is an inhibitor of protein phosphatases (PP). Okadaic acid has a significantly higher affinity for PP2A (IC50=0.1-0.3 nM), and inhibits PP1 (IC50=15-50 nM), PP3 (IC50=3.7-4 nM), PP4 (IC50=0.1 nM), PP5 (IC50=3.5 nM), but does not inhibit PP2C. Okadaic acid increases of phosphorylation of a number of proteins by inhibiting PP, and acts a tumor promoter. Okadaic acid induces tau phosphorylation[1][2].

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[1]Kleppe R, et al. Cell Death Inducing Microbial Protein Phosphatase Inhibitors--Mechanisms of Action. Mar Drugs. 2015 Oct 22;13(10):6505-20.|[2]Valdiglesias V, et al. Okadaic acid: more than a diarrheic toxin. Mar Drugs. 2013 Oct 31;11(11):4328-49.|[3]del Campo M, et al. Okadaic acid toxin at sublethal dose produced cell proliferation in gastric and colon epithelial cell lines. Mar Drugs. 2013;11(12):4751-4760.|[4]Cho MH, et al. Increased phosphorylation of dynamin-related protein 1 and mitochondrial fission in okadaic acid-treated neurons. Brain Res. 2012 May 15;1454:100-10.|[5]Baker S, et al. A local insult of okadaic acid in wild-type mice induces tau phosphorylation and protein aggregation in anatomically distinct brain regions. Acta Neuropathol Commun. 2016;4:32.|[6]Natalia Dos Santos Tramontin, et al. Gold Nanoparticles Treatment Reverses Brain Damage in Alzheimer's Disease Model . Mol Neurobiol. 2020, 57, 2.