Cardiac Troponin, I Subunit (TNNI3) Human Native Protein

Troponin I (TnI), along with troponin T (TnT) and troponin C (TnC), is one of 3 subunits that form the troponin complex of the thin filaments of striated muscle. TnI is the inhibitory subunit; blocking actin-myosin interactions and thereby mediating striated muscle relaxation. The TnI subfamily contains three genes: TnI-skeletal-fast-twitch, TnI-skeletal-slow-twitch, and TnI-cardiac. This gene encodes the TnI-cardiac protein and is exclusively expressed in cardiac muscle tissues. Mutations in this gene cause familial hypertrophic cardiomyopathy type 7 (CMH7) and familial restrictive cardiomyopathy (RCM). [provided by RefSeq, Jul 2008]

TNNI3: Troponin I is the inhibitory subunit of troponin, the thin filament regulatory complex which confers calcium-sensitivity to striated muscle actomyosin ATPase activity. Binds to actin and tropomyosin. Interacts with TRIM63. Interacts with STK4/MST1. Belongs to the troponin I family.

Protein type: Actin-binding; Motility/polarity/chemotaxis; Motor

Chromosomal Location of Human Ortholog: 19q13.42

Cellular Component: cytosol; sarcomere; troponin complex

Molecular Function: actin binding; calcium channel inhibitor activity; calcium-dependent protein binding; protein binding; protein domain specific binding; protein kinase binding; troponin C binding; troponin T binding

Biological Process: cardiac muscle contraction; cellular calcium ion homeostasis; heart contraction; heart development; muscle filament sliding; negative regulation of ATPase activity; regulation of systemic arterial blood pressure by ischemic conditions; skeletal muscle contraction; vasculogenesis; ventricular cardiac muscle morphogenesis

Disease: Cardiomyopathy, Dilated, 1ff; Cardiomyopathy, Dilated, 2a; Cardiomyopathy, Familial Hypertrophic, 7; Cardiomyopathy, Familial Restrictive, 1