Fig. 9.

Proposed mechanism of H₂O₂ and ethanol effects on AMPK phosphorylation and activity. In this study, we found that H₂O₂ activates AMPK via LKB1 and CaMKK. We have previously shown that the inhibitory effect of ethanol on AMPK requires its metabolite, acetaldehyde (denoted by dashed line). We proposed that such effects of ethanol on AMPK phosphorylation are secondary to 1) inhibition of AMPK upstream kinase, LKB1, and 2) increasing AMPK dephosphorylation through PP2A (activation, inhibition).