Troponin T gene

Fast skeletal troponin T gene and spliced mRNAs... 

Cooper, T.A. Ordahl, C.P. (1985). A single cardiac troponin T gene generates embryonic and adult isoforms via develop-mentally regulated alternate splicing. ]. Biol. Chem., 260, 11140-8. 

The contractile proteins of the myofibril include three troponin regulatory proteins. The troponin complex includes three protein subunits, troponin C (the calcium-binding component), troponin I (the inhibitory component), and troponin T (the tropomyosin-binding component). The subunits exist in a number of isoforms. The distribution of these isoforms varies between cardiac muscle and slow- and fast-twitch skeletal muscle. Only two major isoforms of troponin C are found in human heart and skeletal muscle. These are characteristic of slow- and fast-twitch skeletal muscle. The heart isoform is identical with the slow-twitch skeletal muscle isoform. Isoforms of cardiac-specific troponin T (cTnT) and cTnl also have been identified and are the products of unique genes. All cardiac troponins are localized primarily in the myofibrils (94%-97%), with a smaller cytoplasm fraction (3%-6%). 

Cardiac troponin subunits I and T are encoded by different genes than the respective skeletal muscle isoforms and have different amino acid sequences, giving them unique cardiac specificity. cTnl has never been shown to be expressed in normal, regenerating, or diseased human or animal skeletal muscle. By contrast, small amounts of cTnT are expressed as one of four identified isoforms in skeletal muscle during human fetal development, in regenerating rat skeletal muscle, and in diseased human skeletal muscle. cTnT isoform expression has been demonstrated in skeletal muscle specimens... 

Cardiac troponin subunits I and T have different amino acid sequences encoded by different genes. Human cTnl has an additional post translational 31-amino acid residue on the amino terminal end compared with skeletal muscle Tnl,... 

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