Finally, Adenylosuccinate is cleaved by the enzyme adenylosuccinate lyase to release fumarate and regenerate the starting material of AMP: .
A recent study conducted by Sridharan et al. (AJP Cell Physiology, 2008, 295:C29-C37) showed that activation of HIF-1α allows cardiomyocytes to sustain mitochondrial membrane potential during anoxic stress by utilizing fumarate produced by adenylosuccinate lyase as an alternate terminal electron acceptor in place of oxygen.