Figure 7
From: Dynamic functional modules in co-expressed protein interaction networks of dilated cardiomyopathy
Hypothesis of the underlying molecular mechanism of DCM. In a normal myocardium cell, the dystrophin encoded by DMD builds a link between the intracellular microfilament network of actin and the dystrophin-associated protein complex (DAP) to protect the myocardium from long-term contraction-induced damage and necrosis. In the left panel, down-regulation of dystrophin (green rod-shaped protein) causes the collapse of the DAP and plasma membrane, leading to myocardium damage and possibly heart failure. To rescue this defect, utrophin (red rod-shaped protein) encoded by UTRN, which is the functional substitute for dystrophin, is up-regulated, as shown in the right panel. However, utrophin (UTRN) could not bind to the actin ACTC1 in cardiac cells. Hence, the connection between the actin and DAP is broken, leading to the disassociation of the DAP. As a result, cardiac cell membranes become permeable and gradually lyse, resulting in tissue destruction and heart failure.