TPM2

Tropomyosin alpha-1 chain
Structure of Tropomyosin
Identifiers
Symbol	?

Tropomyosin alpha-1 chain (TPM1) is a protein that in humans is encoded by the TPM1 gene. Tropomyosin is a two-stranded alpha-helical coiled coil protein found in cell cytoskeletons. It is an integral component of the actin filament system and plays a crucial role in muscle contraction and other cellular processes.

Structure

Tropomyosin is a dimeric protein that forms a coiled coil structure. Each tropomyosin molecule is approximately 40 nm in length and binds along the length of the actin filament. The TPM1 gene encodes the alpha isoform of tropomyosin, which is predominantly expressed in cardiac muscle tissue.

Function

Tropomyosin is involved in the regulation of muscle contraction. It binds to actin filaments and, in conjunction with the troponin complex, regulates the interaction of actin and myosin. In the absence of calcium ions, tropomyosin blocks the myosin-binding sites on actin filaments, preventing contraction. When calcium ions are present, they bind to troponin, causing a conformational change that moves tropomyosin away from the myosin-binding sites, allowing contraction to occur.

Clinical Significance

Mutations in the TPM1 gene have been associated with various cardiomyopathies, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). These conditions can lead to heart failure and are characterized by abnormal heart muscle structure and function.

Research and Applications

Research on TPM1 and its role in muscle contraction has implications for understanding heart diseases and developing therapeutic interventions. Studies often focus on the molecular mechanisms by which TPM1 mutations lead to cardiomyopathy and how these pathways can be targeted in treatment.

Also see

• Actin
• Myosin
• Troponin
• Hypertrophic cardiomyopathy
• Dilated cardiomyopathy