Fast skeletal myosin binding protein-C regulates fast skeletal muscle contraction

Myosin-binding protein C (MyBP-C) is a thick filament regulatory protein found exclusively in the C-zone of the A band in the sarcomeres of vertebrate striated muscle. Cardiac, slow skeletal and fast skeletal MyBP-C (fMyBP-C) paralogs perform different functions. However, the functional role of fMyBP-C in fast skeletal muscle is completely unknown. Genetic mutations in human fMyBP-C lead to skeletal myopathies. All three isoforms share similar protein structures, but likely differ substantially in terms of expression and function, which may serve the distinct physiologies of fast and slow muscle fibers. In the present study, we developed a novel fMyBP-C global knockout (KO) mouse model (C2-/-) to investigate the structural, functional, molecular, cellular and physiological roles of fMyBP-C in skeletal muscle.