TNNC1

Description

The TNNC1 (troponin C1, slow skeletal and cardiac type) is a protein-coding gene located on chromosome 3.

Troponin C, also known as TN-C or TnC, is a protein that plays a vital role in muscle contraction. It resides within the troponin complex, which is located on the thin actin filaments of striated muscles, including cardiac and skeletal muscles. Troponin C is responsible for binding calcium, an essential step for triggering muscle contraction. It is encoded by the TNNC1 gene in humans, responsible for both cardiac and slow skeletal muscle troponin C production.

Troponin C consists of two domains: the regulatory N-terminal domain (cNTnC) and the structural C-terminal domain (cCTnC). Each domain contains two EF-hands, which are calcium-binding motifs. The C-terminal domain has two high-affinity calcium binding sites that are always occupied under physiological conditions. The N-terminal domain, however, has only one low-affinity calcium binding site. This means that calcium binding to the N-terminal domain is crucial for initiating muscle contraction.

In the absence of calcium, the N-terminal domain of troponin C is in a closed conformation. When calcium binds, the N-terminal domain undergoes a conformational change, transitioning between closed and open states. However, the closed form remains dominant even in the presence of calcium. This dynamic interplay between the closed and open states regulates the interaction of troponin C with other components of the troponin complex, ultimately controlling the contraction of muscle fibers.

TNNC1 is also known as CMD1Z, CMH13, TN-C, TNC, TNNC.

Associated Diseases

• Familial isolated dilated cardiomyopathy
• Cardiomyopathy, dilated, 1Z
• Cardiomyopathy, familial hypertrophic, 13