MeHg augments Nrf2 activation by downregulation of the Src family kinase Fyn. MeHg activates Akt, which in turn inhibits GSK-3β. Thus, GSK-3β does not signal Fyn nuclear import. ROS generation consequent to MeHg exposure promotes Nrf2 nuclear localization, which upregulates Hmox1 and Nqo1 transcription. Further, MeHg reduces Sp1 protein, which results in decreased Fyn gene expression. Blue arrows indicate the effects of MeHg, while red arrows designate processes disrupted subsequent to MeHg exposure.