Troponin C Cardiac (TnC) Protein

Troponin is a central regulatory protein of striated muscle contraction, and together with tropomyosin, is located on the actin filament. Troponin consists of 3 subunits: TnI, which is the inhibitor of actomyosin ATPase; TnT, which contains the binding site for tropomyosin; and TnC, the protein encoded by this gene. The binding of calcium to TnC abolishes the inhibitory action of TnI, thus allowing the interaction of actin with myosin, the hydrolysis of ATP, and the generation of tension. Mutations in this gene are associated with cardiomyopathy dilated type 1Z. [provided by RefSeq, Oct 2008]

TNNC1: 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. Defects in TNNC1 are the cause of cardiomyopathy dilated type 1Z (CMD1Z). Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death. Defects in TNNC1 are the cause of familial hypertrophic cardiomyopathy type 13 (CMH13). A hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death. Belongs to the troponin C family.

Protein type: Calcium-binding; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 3p21.1

Cellular Component: nucleoplasm; troponin complex; mitochondrion; cytosol; actin cytoskeleton

Molecular Function: troponin T binding; actin filament binding; protein binding; protein homodimerization activity; troponin I binding; calcium ion binding; calcium-dependent protein binding

Biological Process: regulation of ATPase activity; response to metal ion; regulation of muscle contraction; diaphragm contraction; regulation of muscle filament sliding speed; ventricular cardiac muscle morphogenesis; cardiac muscle contraction; muscle filament sliding

Disease: Cardiomyopathy, Dilated, 1z; Cardiomyopathy, Familial Hypertrophic, 13