Troponin C, slow skeletal and cardiac muscles is a protein in humans that is encoded by TNNC1 gene. Troponin C, slow skeletal and cardiac muscles is a protein in humans that is encoded by TNNC1 gene. Troponin is the central regulatory protein of striated muscle contraction. Tn consists of three components: Tn-I which is the inhibitor of actomyosin ATPase, Tn-T which contains the binding site for tropomyosin and Tn-C. The binding of calcium to Tn-C abolishes the inhibitory action of Tn on actin filaments.