Myosin-binding protein C
Pronunciation: MY-oh-sin-binding protein C
A regulatory protein essential for proper cardiac muscle contraction. Mutations cause hypertrophic cardiomyopathy and some skeletal myopathies.
Full Definition
Myosin-binding protein C is a regulatory protein that binds to both myosin and titin in the cardiac sarcomere, playing a crucial role in modulating contractility and maintaining sarcomere structure. Mutations in the MYBPC3 gene, encoding cardiac myosin-binding protein C, are one of the most common causes of hypertrophic cardiomyopathy, accounting for approximately 20-30% of cases. In skeletal muscle, mutations in related genes can cause distal myopathies. The protein functions as a molecular brake on cross-bridge formation and is subject to phosphorylation-mediated regulation. Patients with MYBPC3 mutations often present with later-onset, less severe hypertrophic cardiomyopathy compared to other genetic forms.
Usage
Usage note: Distinguish cardiac (MYBPC3) from skeletal muscle forms. Note implications for family screening.
In Context
- "Genetic analysis revealed a pathogenic variant in myosin-binding protein C associated with the patient's hypertrophic cardiomyopathy." — Cardiology genetics report
- "The family history of sudden cardiac death prompted screening for myosin-binding protein C mutations." — Genetic counseling session