Tropomyosin (TPM)

Tropomyosin is a family of fibrous proteins that associate with actin filaments in both muscle and non-muscle cells. In striated muscle, it forms a complex with troponin to regulate the calcium-dependent interaction between actin and myosin, thereby controlling muscle contraction (Gunning et al., 2015, Journal of Cell Science). In non-muscle cells, tropomyosin isoforms are essential for stabilizing the actin cytoskeleton and regulating processes such as cell motility, cytokinesis, and intracellular transport (Hardeman et al., 2020, Nature Reviews Molecular Cell Biology). Mutations in tropomyosin genes, particularly TPM1, TPM2, and TPM3, are clinically significant as they are linked to various hereditary myopathies and cardiomyopathies (Marston, 2017, Journal of Muscle Research and Cell Motility). In oncology, tropomyosin is recognized as a target because certain isoforms are upregulated in transformed cells, and it frequently serves as a fusion partner for kinases like NTRK, driving oncogenesis (Stehn et al., 2013, Cancer Research). Therapeutic approaches include small molecule inhibitors like TR100 that selectively disrupt the actin-tropomyosin filaments in cancer cells, leading to cell death, as well as kinase inhibitors targeting tropomyosin-related fusion proteins (Bonello et al., 2016, Scientific Reports). Additionally, tropomyosin is a major pan-allergen in shellfish, making it a target for diagnostic and desensitization strategies in allergy (Reese et al., 1999, International Archives of Allergy and Immunology).

Other names

TPM1TPM2TPM3TPM4Alpha-tropomyosinBeta-tropomyosinGamma-tropomyosinDelta-tropomyosinTropomyosin alpha-1 chainTropomyosin beta chainTropomyosin alpha-3 chainTropomyosin alpha-4 chain

Tropomyosin-targeting drugs typically function by disrupting the binding of specific tropomyosin isoforms to actin filaments, which destabilizes the cytoskeleton in malignant cells and induces apoptosis (Stehn et al., 2013, Cancer Research). In the context of muscle diseases, potential therapies aim to modulate the calcium sensitivity of the troponin-tropomyosin complex to restore normal contractile function (Marston, 2017, Journal of Muscle Research and Cell Motility).