Troponin isoform switching in the developing heart and its functional consequences.
The subunits of the troponin complex-troponin C, troponin T, and troponin I-are responsible for the Ca(2+)-dependent regulation of contractile activity in heart and skeletal muscle. Distinct troponin T and I isoforms, generated by different genes or by alternative splicing from the same gene, are expressed during cardiac development. Troponin switching affects the Ca(2+) sensitivity of the contractile system and may account for the greater resistance to hypoxia and acidosis, and the impaired responsiveness to adrenergic stimulation of the fetal and neonatal heart.
Department of Biomedical Sciences, CNR Unit for Muscle Biology and Physiopathology, University of Padova, 35121 Padova, Italy.
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Schiaffino
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Gorza
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Ausoni