Troponin C

It contains four calcium-binding EF hands, although different isoforms may have fewer than four functional calcium-binding subdomains.

It is a component of thin filaments, along with actin and tropomyosin.

The C lobe serves a structural purpose and binds to the N domain of troponin I (TnI).

The tissue specific subtypes are: 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 to dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM).