Troponin C1, slow skeletal and cardiac type (TNNC1)

Troponin C1, slow skeletal and cardiac type (TNNC1) encodes a calcium-binding regulatory protein crucial for striated muscle contraction, specifically in cardiac and slow-twitch skeletal muscle[1][4]. It forms part of the troponin complex, together with troponin I and troponin T, on the actin filament. Troponin C's core function is to sense and bind calcium ions via its EF-hand motifs—calcium binding induces structural changes that release inhibitory constraints on actin-myosin interaction, thereby triggering muscle contraction[2][3][4]. TNNC1 is implicated in the pathogenesis of both familial dilated and hypertrophic cardiomyopathy when mutated[1][2][4]. Drugs that interact with or modulate TNNC1 (e.g., calcium sensitizers like levosimendan) are being developed to treat certain cardiac diseases by enhancing myocardial contractility without increasing intracellular calcium load[2]. This protein is highly conserved, and its proper regulation is essential for coordinated heartbeat and skeletal muscle contraction[2][3].

Other names

Troponin C, slow skeletal and cardiac musclesTNNC1TNNCTnCTN-CCMD1ZCMH13cardiac troponin Cslow twitch skeletal/cardiac muscle troponin Ctroponin C type 1 (slow)

Calcium sensitization (drugs like levosimendan increase calcium sensitivity of cTnC, enhancing contractility)[2]; modulation of calcium binding affinity (affecting troponin conformation and thus muscle contraction)[2]