OPA1 and Atrophy: Thus, our findings that ASB2β induced an early activation of AMPK, a reduction in mitochondrial fusion-promoting Opa1 protein, an accumulation of cytoskeletal proteins and other proteins involved in regulating cytoskeletal dynamics, and increased the S616 phosphorylation of the fission mediator, Drp1 (Fig. 4H), provide compelling evidence that increased ASB2β expression may induce an imbalance in mitochondrial dynamics that could play a role in ASB2β-induced muscle atrophy.