AMP-activated protein kinase (AMPK) is activated by upstream kinases and negatively
regulated by protein phosphatases. Intracellular calcium mediates protein phosphatase 2A
(PP2A), which is in a heterotrimeric complex with the PR72 subunit. The PR72 subunit
contains two calcium-binding sites formed by EF hands. Our previous study has shown that
chronic calcium exposure decreases AMPK activity. To define the specific molecular
mechanism whereby calcium can deactivate AMPK, activities of AMPK and PP2A were …