Reduced Length-Dependent Activation in Human Cardiomyocytes Harboring the Troponin I Mutation R145W
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چکیده
منابع مشابه
Familial Hypertrophic Cardiomyopathy Related Cardiac Troponin C L29Q Mutation Alters Length-Dependent Activation and Functional Effects of Phosphomimetic Troponin I*
The Ca(2+) binding properties of the FHC-associated cardiac troponin C (cTnC) mutation L29Q were examined in isolated cTnC, troponin complexes, reconstituted thin filament preparations, and skinned cardiomyocytes. While higher Ca(2+) binding affinity was apparent for the L29Q mutant in isolated cTnC, this phenomenon was not observed in the cTn complex. At the level of the thin filament in the p...
متن کاملFunctional effects of a restrictive-cardiomyopathy-linked cardiac troponin I mutation (R145W) in transgenic mice.
The human cardiac troponin I (hcTnI) mutation R145W has been associated with restrictive cardiomyopathy. In this study, simultaneous measurements of ATPase activity and force in skinned papillary fibers from hcTnI R145W transgenic mice (Tg-R145W) were explored. Tg-R145W fibers showed an approximately 13-16% increase in maximal Ca(2+)-activated force and ATPase activity compared to hcTnI wild-ty...
متن کاملA dominantly negative mutation in cardiac troponin I at the interface with troponin T causes early remodeling in ventricular cardiomyocytes.
We previously reported a point mutation substituting Cys for Arg(111) in the highly conserved troponin T (TnT)-contacting helix of cardiac troponin I (cTnI) in wild turkey hearts (Biesiadecki et al. J Biol Chem 279: 13825-13832, 2004). This dominantly negative TnI-TnT interface mutation decreases the binding affinity of cTnI for TnT, impairs diastolic function, and blunts the β-adrenergic respo...
متن کاملLength-dependent activation is modulated by cardiac troponin I bisphosphorylation at Ser23 and Ser24 but not by Thr143 phosphorylation.
Frank-Starling's law reflects the ability of the heart to adjust the force of its contraction to changes in ventricular filling, a property based on length-dependent myofilament activation (LDA). The threonine at amino acid 143 of cardiac troponin I (cTnI) is prerequisite for the length-dependent increase in Ca(2+) sensitivity. Thr143 is a known target of protein kinase C (PKC) whose activity i...
متن کاملTroponin and Titin Coordinately Regulate Length-dependent Activation in Skinned Porcine Ventricular Muscle
We investigated the molecular mechanism by which troponin (Tn) regulates the Frank-Starling mechanism of the heart. Quasi-complete reconstitution of thin filaments with rabbit fast skeletal Tn (sTn) attenuated length-dependent activation in skinned porcine left ventricular muscle, to a magnitude similar to that observed in rabbit fast skeletal muscle. The rate of force redevelopment increased u...
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ژورنال
عنوان ژورنال: Biophysical Journal
سال: 2012
ISSN: 0006-3495
DOI: 10.1016/j.bpj.2011.11.860