Troponin C is a protein which is part of thetroponin complex. It contains four calcium-bindingEF hands, although different isoforms may have fewer than four functional calcium-binding subdomains. It is a component ofthin filaments, along withactin andtropomyosin. It contains an N lobe and a C lobe. The C lobe serves a structural purpose and binds to the N domain oftroponin I (TnI). The C lobe can bind either Ca²⁺ or Mg²⁺. The N lobe, which binds only Ca²⁺, is the regulatory lobe and binds to the C domain of troponin I after calcium binding.

The tissue specific subtypes are:

• Slow troponin C,TNNC1 (3p21.1Online Mendelian Inheritance in Man (OMIM):191040)
• Fast troponin C,TNNC2 (20q12-q13.11,Online Mendelian Inheritance in Man (OMIM):191039)

Point mutations can occur in troponin C inducing alterations to Ca²⁺ and Mg²⁺ binding and protein structure,^[1] leading to abnormalities in muscle contraction.^[2][3] In cardiac muscle, they are related todilated cardiomyopathy (DCM) andhypertrophic cardiomyopathy (HCM).

These known point mutations are:

• A8V
• D145E
• A31S
• C84Y
• E134D
• Y5H
• I148V

• Troponin
• Troponin T
• Troponin I
• Calcium-binding protein
• Sliding filament model

• Troponin+C at the U.S. National Library of MedicineMedical Subject Headings (MeSH)

• Genes on human chromosome 3
• Genes on human chromosome 20
• Troponin

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