Obscurin, a giant protein of striated muscles, is emerging as an important player in a wide range of processes including myofibril assembly and maintenance, muscle protein degradation and intracellular signaling. Accordingly, obscurin participates to the mechanisms by which muscles adapt to physiological requirements or to pathological cues associated with cardiac and skeletal muscle diseases. Areas covered: The structure of the different obscurin isoforms identified so far, their tissue distribution and the most recent findings on obscurin in invertebrates and mammals will be reviewed. We will provide a synopsis of known molecular interactions between obscurin and other proteins and the biological relevance of these interactions for striated muscle function. The involvement of obscurin in protein degradation mechanisms and intracellular signaling will be also discussed along with initial evidence of a role of obscurin in the pathophysiology of human diseases. Expert opinion: Although still much remains to be discovered about the role of obscurin either as a structural component of the sarcomere or as a mediator of signaling pathways within muscle cells, it can be envisioned that this protein represents an interesting novel pharmacological target for the prevention and treatment of cardiac and skeletal muscle diseases.
Keywords: Mechanotransduction; RhoGEF; cardiomyopathy; intracellular signaling; muscle adaptation; muscle atrophy & hypertrophy; muscular dystrophy; protein kinase.