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Contraction of vertebrate striated muscles is regulated via switch-like activation of the thin filament due to Ca 2+ binding to the troponin C (TnC) subunit of troponin, which together with tropomyosin comprise the thin filament regulatory strand. This mechanism has been known for nearly 50 years, dating to the initial publication by Ebashi and Endo (1968)(More)
SLControl is a computerized data acquisition and analysis system that was developed in our laboratory to help perform mechanical experiments using striated muscle preparations. It consists of a computer program (Windows 2000 or later) and a commercially available data acquisition board (16-bit resolution, DAP5216a, Microstar Laboratories, Bellevue, WA).(More)
Cardiac myosin binding protein-C (cMyBP-C) is a thick filament accessory protein that binds tightly to myosin, but despite evidence that mutations in the cMyBP-C gene comprise a frequent cause of hypertrophic cardiomyopathy, relatively little is known about the role(s) of cMyBP-C in myocardium. Based on earlier studies demonstrating the potential importance(More)
The Ca2+ sensitivities of the rate constant of tension redevelopment (ktr; Brenner, B., and E. Eisenberg. 1986. Proceedings of the National Academy of Sciences. 83:3542-3546) and isometric force during steady-state activation were examined as functions of myosin light chain 2 (LC2) phosphorylation in skinned single fibers from rabbit and rat fast-twitch(More)
Beta-adrenergic agonists induce protein kinase A (PKA) phosphorylation of the cardiac myofilament proteins myosin binding protein C (cMyBP-C) and troponin I (cTnI), resulting in enhanced systolic function, but the relative contributions of cMyBP-C and cTnI to augmented contractility are not known. To investigate possible roles of cMyBP-C in this response,(More)
Myosin binding protein C (MyBP-C) is a component of the thick filament of striated muscle. The importance of this protein is revealed by recent evidence that mutations in the cardiac gene are a major cause of familial hypertrophic cardiomyopathy. Here we investigate the distribution of MyBP-C in the A-bands of cardiac and skeletal muscles and compare this(More)
Transgenic mice expressing an allele of cardiac troponin T (cTnT) with a COOH-terminal truncation (cTnT(trunc)) exhibit severe diastolic and mild systolic dysfunction. We tested the hypothesis that contractile dysfunction in myocardium expressing low levels of cTnT(trunc) (i.e., <5%) is due to slowed cross-bridge kinetics and reduced thin filament(More)
Familial hypertrophic cardiomyopathy (FHC) is an inherited autosomal dominant disease caused by mutations in sarcomeric proteins. Among these, mutations that affect myosin binding protein-C (MyBP-C), an abundant component of the thick filaments, account for 20% to 30% of all mutations linked to FHC. However, the mechanisms by which MyBP-C mutations cause(More)
C-protein, a substantial component of muscle thick filaments, has been postulated to have various functions, based mainly on results from biochemical studies. In the present study, effects on Ca(2+)-activated tension due to partial removal of C-protein were investigated in skinned single myocytes from rat ventricle and rabbit psoas muscle. Isometric tension(More)
In skinned myocardium, cyclic AMP-dependent protein kinase A (PKA)-catalyzed phosphorylation of cardiac myosin-binding protein C (cMyBP-C) and cardiac troponin I (cTnI) is associated with a reduction in the Ca(2+) responsiveness of myofilaments and an acceleration in the kinetics of cross-bridge cycling, although the respective contribution of these two(More)