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Updated: Jan 13, 2026

Analysis of Cardiac Contractile Dysfunction and Ca2+ Transients in Rodent Myocytes
Published on: May 25, 2022
Isoforms of troponin in normal and diseased myocardium
1Department of Physiology, Faculty of Medicine, Charles University, Hradec Králové, Czech Republic.
Abstract:
The regulatory protein troponin (Tn) located on actin filament consists of three subunits: TnT--binds troponin to tropomyosin, TnC--binds divalent calcium ions, and TnI--affects myosin-actin interactions. Tn subunits display several molecular and calcium binding variations. During ontogenetic development of cardiac and skeletal muscles the synthesis of multiple isoforms of Tn subunits was detected. Expression of Tn isoforms and the extent of phosphorylation of both TnT and TnI via protein kinase C or protein kinase A under different pathological situations (e.g. ischemia, congenital heart disease, heart failure) can affect the Ca2+-stimulated contraction function and the myofibrillar ATPase activity of the heart.
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