Making waves: A proposed new role for myosin-binding protein C in regulating oscillatory contractions in vertebrate striated muscle

• DOI: 10.1085/jgp.202012729
• Publication Date: 2020-12-05T05:30:23Z
• Authors: Samantha P. Harris
• Keywords: Myofilament; Meromyosin

Myosin-binding protein C (MyBP-C) is a critical regulator of muscle performance that was first identified through its strong binding interactions with myosin, the force-generating muscle. Almost simultaneously discovery, MyBP-C soon found to bind actin, physiological catalyst for myosin's activity. However, two observations posed an apparent paradox, in part because myosin were on thick filament, whereas actin thin filament. Despite intervening decades since these initial discoveries, it only recently dual modes are becoming reconciled models place at central position between and where alternately stabilizes newly discovered super-relaxed state (SRX) filaments resting then prolongs "on" active Recognition dual, alternating functions reveals how regulation both contraction relaxation. The purpose this Viewpoint briefly summarize roles highlight possible new role inducing damping oscillatory waves Because contractile bear similarity cycles relaxation insect flight muscles, which evolved fast, energetically efficient contraction, ability damp so-called spontaneous contractions (SPOCs) has broad implications previously unrecognized regulatory mechanisms vertebrate striated While molecular by can function as wave maker or breaker just beginning be explored, likely will continue important understanding enigmatic protein.