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]

  • Vasculogenesis
  • Regulation of systemic arterial blood pressure by ischemic conditions
  • Skeletal muscle contraction
  • Cellular calcium ion homeostasis
  • Muscle contraction
  • Cardiomyopathy, dilated, 2a
  • Cardiomyopathy, familial hypertrophic, 7
  • Cardiomyopathy, familial restrictive, 1
  • Cardiomyopathy, dilated, 1ff
  • Restrictive cardiomyopathy

Emw. Structure of the TNNI3 protein. Based on PyMOL rendering of PDB 1j1d.

Gene Location