PRKAA2 and infection: To verify the specificity of the AMPK signal pathway in the enhancement of glucose uptake induced by treatment with Xn and Xc, we used two different methods: (1) treatment with a chemical AMPK-specific inhibitor, compound C, and (2) infection with a dominant negative AMPKa2 virus in which Asp157 was replaced with alanine, an abundant isoform of the AMPKa subunit found in skeletal muscle.