Maintaining the Fully Differentiated Cardiac Sarcomere
The contractile proteins of the fully differentiated muscle cell are arranged in a highly ordered three-dimensional lattice. The functional interactions among these proteins are optimized to produce force and motion in response to rapid changes in intracellular calcium. In the muscle sarcomere, the structural interactions among different contractile proteins are complex, in some cases forming multimeric complexes (troponin, myosin), micron-long filaments (thick and thin filaments), or multicomponent anchoring networks (Z-line). The de novo formation of the muscle sarcomere (myofibrillogenesis) in a differentiating muscle cell is a very dynamic process, with coordinate regulation of muscle protein isoform gene expression, localization of the newly synthesized protein to the myofibrillar structures, and the organization of these structures into sarcomeres. The process of myofibrillogenesis is well documented in the chapters of this book and has been markedly advanced by recent genetic and immunocytochemistry approaches applied to embryonic, neonatal, and other types of differentiating muscle cells.
KeywordsPolyacrylamide Cardiomyopathy Dodecyl Barb Onic
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