The role of troponin C in determining the characteristic differences in contraction between fast-twitch skeletal and cardiac muscles was investigated with rabbit skinned psoas fibers and left ventricular trabeculae by exchanging their troponins C using a technique involving extraction and replacement. In both muscle types, skeletal troponin C conferred higher cooperativity on the Ca2+-activated tension development than cardiac troponin C, indicating that troponin C plays a crucial role in determining the cooperativity in Ca2+ activation of vertebrate striated muscle. Furthermore, the foreign type of troponin C was found to confer lower Ca2+sensitivity on the tension development in both fast-twitch skeletal and cardiac muscles than the native type of troponin C. This indicates that the Ca2+sensitivity of each muscle type is determined by troponin C interactions with other troponin subunits and not by troponin C alone.
|Number of pages||3|
|Journal||Journal of biochemistry|
|Publication status||Published - Jan 1994|
All Science Journal Classification (ASJC) codes
- Molecular Biology