Cardiac myosin-binding protein C (cMyBP-C) (cMyBP-C)

Cardiac myosin-binding protein C (cMyBP-C) is a critical regulatory and structural protein located in the C-zones of the cardiac sarcomere's thick filaments. It acts as a molecular brake on muscle contraction by binding to both myosin and actin, thereby modulating the kinetics of cross-bridge cycling and the calcium sensitivity of the myofilament (UniProt P12847; PubMed 1.3.1). Mutations in the MYBPC3 gene are the most common genetic cause of hypertrophic cardiomyopathy (HCM), typically leading to protein haploinsufficiency and hypercontractility (PubMed 1.1.1, 1.4.3). Therapeutically, cMyBP-C is the primary target for novel gene replacement therapies like TN-201, which aim to restore functional protein levels via AAV-mediated delivery (Tenaya Therapeutics). Additionally, cMyBP-C serves as a highly sensitive blood-based biomarker for acute myocardial injury, often appearing in the circulation more rapidly than traditional cardiac troponins (PubMed 1.2.2, 1.2.5). Its phosphorylation state is also a key determinant of cardiac output, making it a focal point for research into heart failure treatments.

Other names

MYBPC3C-protein, cardiac muscle isoformCardiac MyBP-CMyosin-binding protein C, cardiac-type

Adeno-associated virus (AAV)-mediated gene replacement therapy designed to deliver a functional MYBPC3 gene to cardiomyocytes to restore normal protein levels and sarcomere function (Tenaya Therapeutics).