Beta-cardiac myosin heavy chain (MYH7) (MYH7)

Cardiac myosin is the fundamental motor protein of the thick filament in the cardiac sarcomere, primarily composed of the beta-cardiac myosin heavy chain (MYH7) in the adult human ventricle (UniProt: P12883) [1]. It consists of a globular head (S1 fragment) that contains the ATPase activity and actin-binding site, and a neck/tail region (S2 fragment) that acts as a lever arm (Spudich, 2014) [4]. This protein is responsible for converting chemical energy from ATP hydrolysis into mechanical force, driving myocardial contraction. Mutations in MYH7 are a primary cause of hypertrophic cardiomyopathy (HCM), often leading to hypercontractility and impaired relaxation (NIH: MedlinePlus) [5]. Therapeutic agents targeting cardiac myosin include inhibitors like mavacamten, which stabilize the super-relaxed state to treat HCM (Heitner et al., 2019) [2], and activators like omecamtiv mecarbil, which enhance force production in heart failure (Teerlink et al., 2021) [3].

Other names

Cardiac myosin heavy chain 7Myosin-7Beta-myosin heavy chainCardiac myosin S1 fragmentCardiac myosin S2 fragmentMYH7

Cardiac myosin inhibitors (e.g., mavacamten) reduce the number of myosin heads entering the force-generating state by stabilizing the super-relaxed (SRX) state [2]. Cardiac myosin activators (e.g., omecamtiv mecarbil) increase the rate of phosphate release, accelerating the transition to the force-generating state without increasing intracellular calcium [3].