tropomiozin
Tropomiozin is a long, rod-shaped protein that binds along actin filaments as a parallel coiled-coil dimer. Each subunit is about 284 amino acids, yielding roughly 32 kilodaltons, and two subunits form a dimer that polymerizes head-to-tail to cover a length of actin along the filament. It is encoded by TPM1, TPM2, TPM3 and TPM4, with multiple tissue-specific isoforms produced by alternative splicing. Tropomiozin is a major component of the actin thin filament in most eukaryotic cells and exists in both muscle and non-muscle forms.
In striated muscle, tropomiozin works with the troponin complex to regulate contraction. In resting muscle, tropomiozin
Non-muscle tropomiozin isoforms stabilize actin networks, organize cytoskeleton architecture, and influence cell migration, adhesion, and division.
Clinical relevance: Mutations and variants in TPM genes are linked to inherited cardiomyopathies (notably dilated cardiomyopathy)