Troponin T type 3 (TNNT3) - Marker for fast skeletal muscles

Troponin T is the subunit of troponin, which confers the binding of the troponin complex to the tropomyosin complex. The troponin complex (consisting of troponin -C, -I, and -T) is responsible for Ca2 sensitive muscle contractions. Troponin T has 3 subtypes, each with their own tissue type specific expression. Type 1 is expressed in slow twitch (red) muscle fibers, type 2 is expressed in cardiac muscle, and type 3 is expressed in fast twitch (white) skeletal muscles.