Desmin: molecular interactions and putative functions of the muscle intermediate filament protein

Abstract

Desmin is the intermediate filament (IF) protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin, and vimentin, besides the ubiquitous lamins, but they are not unique to muscle. Desmin was purified in 1977, the desmin gene was characterized in 1989, and knock-out animals were generated in 1996. Several isoforms have been described. Desmin IFs are present throughout smooth, cardiac and skeletal muscle cells, but can be more concentrated in some particular structures, such as dense bodies, around the nuclei, around the Z-line or in costameres. Desmin is up-regulated in muscle-derived cellular adaptations, including conductive fibers in the heart, electric organs, some myopathies, and experimental treatments with drugs that induce muscle degeneration, like phorbol esters. Many molecules have been reported to associate with desmin, such as other IF proteins (including members of the membrane dystroglycan complex), nebulin, the actin and tubulin binding protein plectin, the molecular motor dynein, the gene regulatory protein MyoD, DNA, the chaperone αB-crystallin, and proteases such as calpain and caspase. Desmin has an important medical role, since it is used as a marker of tumors' origin. More recently, several myopathies have been described, with accumulation of desmin deposits. Yet, after almost 30 years since its identification, the function of desmin is still unclear. Suggested functions include myofibrillogenesis, mechanical support for the muscle, mitochondrial localization, gene expression regulation, and intracellular signaling. This review focuses on the biochemical interactions of desmin, with a discussion of its putative functions.

Reductive Stress Linked to Small HSPs, G6PD, and Nrf2 Pathways in Heart Disease

“…Along with the molecular link between R120G-and G6PD-mediated GSH production, HSPB1 was upregulated at the transcriptional and translational levels. Mitochondria, by far the most vital organelle for energy production and redox adaptation (56,120), are organized spatially at the A and I bands of the sarcomere, thereby providing proximity of ATP production to the proximal contractile apparatus (28,84). Independently, Maloyan and coworkers demonstrated severely compromised mitochondrial function and disrupted mitochondrial organization of mouse R120G compared with HSPB5 WT littermates, suggesting that the mutant R120G expression might disrupt ROS production during progressive heart failure (80).…”

Immunohistochemistry and antigenic expression of four proteins in Kaposi Sarcoma

“…23 and is present in higher amounts during embryogenesis. This suggests that there may be some interaction between the two in determining muscle cell differentiation 13 . This also suggests that 10(67%) of the samples were obtained from relatively advanced sarcoma lesions.…”

“…It is a 52 kD protein that is a subunit of intermediate filaments in skeletal muscle tissue, smooth muscle tissue, and cardiac muscle tissue. Its presence in vascular smooth muscle is variable 13 . The muscle cell matures only if desmin is present.…”

“…Vimentin is present in higher amounts during embryogenesis while desmin is present in higher amounts after differentiation. This suggests that there may be some interaction between the two in determining muscle cell differentiation 13 . Desmin is detected in rhabdomyosarcoma of all subtypes, benign smooth muscle tumours, benign skeletal muscle tumours and leiomyosarcoma (50%) 14 .…”

Knockdown of Lmo7 inhibits chick myogenesis

“…Cells were grown in 2 mL of medium (minimum essential medium with the addition of 10% horse serum, 0.05% chick embryo extract, 1% L-glutamine and 1% penicillin-streptomycin) under humidified 5% CO 2 atmosphere at 37°C. The percentage of myoblasts in these cell cultures was calculated by the double labeling of 24-h cultures with both DAPI (nuclear staining) and anti-desmin antibodies (applied herein to define a muscle-specific marker) [4] and subsequently counting the number of desmin-positive cells out of the total number of cells in the field. A rabbit polyclonal antibody against desmin (Sigma) was used.…”