Troponin I serines 43/45 and regulation of cardiac myofilament function.

@article{Pyle2002TroponinIS,
  title={Troponin I serines 43/45 and regulation of cardiac myofilament function.},
  author={W. Glen Pyle and Marius P. Sumandea and R. John Solaro and Pieter P de Tombe},
  journal={American journal of physiology. Heart and circulatory physiology},
  year={2002},
  volume={283 3},
  pages={
          H1215-24
        }
}
We studied Ca(2+) dependence of tension and actomyosin ATPase rate in detergent extracted fiber bundles isolated from transgenic mice (TG), in which cardiac troponin I (cTnI) serines 43 and 45 were mutated to alanines (cTnI S43A/S45A). Basal phosphorylation levels of cTnI were lower in TG than in wild-type (WT) mice, but phosphorylation of cardiac troponin T was increased. Compared with WT, TG fiber bundles showed a 13% decrease in maximum tension and a 20% increase in maximum MgATPase activity… 

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