Figure 1.

Schematic representation of the desmin intermediate filament network and its association with myofibrils, sarcolemma, mitochondria and the nucleus, in a skeletal myofiber. Desmin is a key protein of the intermediate filaments of the cytoskeleton in myofibers of skeletal muscle. Desmin’s main function is transmission of the forces produced by myofibrils. Desmin IFs link myofibrils into bundles through the Z-discs (dark blue) and connect them to specialized sites of adhesion (costameres) (green) in the sarcolemma. Myofibrillar forces are then transmitted from the costameres to the extracellular matrix and then to the tendons. In addition, Desmin provides a three-dimensional organization of the mitochondrial system (pink), connects the contractile apparatus to the myonuclei (purple), and may contribute to mechano-chemical signaling between the various compartments of the myofiber.