Protein Phosphatase 2A and the Toxic Effects of Microcystin

Abstract: Protein phosphatase 2A (PP2A) is a main serine/threonine protein phosphatase responsible for a major portion of the total phosphatase activity， playing an equally important role in the regulation of protein phosphorylation as protein kinases. Microcystin-LR (MC-LR)， one of the great deal of natural occurring toxins targeting PP2A， has been highly concerned due to its acute hepatotoxicity and potent tumor promotion activity. Although extensive studies indicate that oxidative stress， DNA damage， cytoskeleton disruption and apoptosis play pivotal role in the toxic effects of MC-LR， the exact mechanisms of MC-LR toxicity need to be fully elucidated. Due to the important functions of PP2A in the processes of oxidative stress， repair of DNA damage， cytoskeleton organization and the regulation of apoptosis related kinase CaMKII and Bcl-2 family members， we propose that MC-LR induces toxic effects by interacting with PP2A， which will shed lights on the molecular toxicity mechanisms of MC-LR.

CSTR: 32200.14.cjcb.2010.01.0003