Abstract 40: Discovery and Characterization of the Novel Muscle-Specific Membrane Protein Smco1
Mutations in numerous membrane proteins cause debilitating myopathies. The discovery of novel muscle-specific, membrane proteins would likely provide insight into mechanisms of disease and potentially yield new therapeutic targets. Through bioinformatics screening for muscle-specific membrane proteins with unknown function, we identified C3orf43 or single-pass membrane protein with coiled-coil domains 1 (Smco1). Consistent with bioinformatics predictions, Smco1 is expressed exclusively in cardiac and skeletal muscle. We demonstrate with chromatin immunoprecipitation and luciferase promoter assays that Smco1 is a Mef2-regulated gene with robust expression occurring shortly after birth. Immunofluorescent analysis demonstrates Scmo1 localizes to the cardiomyocyte sarcolemma and intercalated disks. Talen-mediated disruption of Smco1 in mice results in stunted postnatal growth, cardiac hypoplasia and skeletal muscle myopathy as early as postnatal day 15. While studies are on going to determine the function of Smco1, our findings reveal an essential role of Smco1 in striated muscle structure and function. The identification of heart- and muscle-specific membrane proteins will likely illuminate the mechanisms of muscular membrane diseases.