Muscle-specific type III intermediate filament essential for proper muscular structure and function. Plays a crucial role in maintaining the structure of sarcomeres, inter-connecting the Z-disks and forming the myofibrils, linking them not only to the sarcolemmal cytoskeleton, but also to the nucleus and mitochondria, thus providing strength for the muscle fiber during activity. In adult striated muscle they form a fibrous network connecting myofibrils to each other and to the plasma membrane from the periphery of the Z-line structures. May act as a sarcomeric microtubule-anchoring protein: specifically associates with detyrosinated tubulin-alpha chains, leading to buckled microtubules and mechanical resistance to contraction. Contributes to the transcriptional regulation of the NKX2-5 gene in cardiac progenitor cells during a short period of cardiomyogenesis and in cardiac side population stem cells in the adult. Plays a role in maintaining an optimal conformation of nebulette (NEB) on heart muscle sarcomeres to bind and recruit cardiac alpha-actin. Homomer. Interacts with DST. Interacts with MTM1. Interacts with EPPK1; interaction is dependent of higher-order structure of intermediate filament. Interacts with CRYAB. Interacts with NEB (via nebulin repeats 160-164). Interacts (via rod region) with NEBL (via nebulin repeats 1-5). Interacts with ASB2; the interaction targets DES for proteasomal degradation (By similarity). Localizes in the intercalated disks which occur at the Z line of cardiomyocytes. Localizes in the nucleus exclusively in differentiating cardiac progenitor cells and premature cardiomyocytes. ADP-ribosylation prevents ability to form intermediate filaments. Phosphorylation at Ser-7, Ser-28 and Ser-32 by CDK1 and phosphorylation at Ser-60 by AURKB contribute to efficient separation of desmin intermediate filaments during mitosis. Ubiquitination by a SCF-like complex containing ASB2 leads to proteasomal degradation. Belongs to the intermediate filament family.