Troponin

Troponin together with tropomyosin, regulate the binding of myosin to actin. Troponin is a trimeric protein composed of Troponin subunits I, C and T. Troponin C binds calcium ions, Troponin T binds to tropomyosin and troponin I binds to actin. This calcium-dependent interaction serves to position the tropomyosin along the actin filament during muscle contraction. Troponins are used as diagnostic biomarkers for cardiac injury.