Microfilaments, intermediate filaments and microtubules are three types of filaments that form the cytoskeleton. These filaments contribute to cell motility, cytokinesis, cell shape, and the movement of cargo and organelles within cells. While intermediate filaments primarily serve a structural role in the cell, both microfilaments and microtubules are involved in active processes which are facilitated by interactions with motor proteins. Actin motors, such as Myosin move along microfilaments and in doing so generate enough force to contract muscle tissue. In non-muscle cells, the interaction of Myosin with Actin microfilaments is responsible for cytokinesis. Microtubule motors such as Kinesins facilitate chromosomal separation during mitosis by walking along microtubule tracks. In contrast, Dynein molecules slide along microtubule tracks to facilitate the movement of cilia and flagella.
Small protein inhibitors and agonists are commonly used to better understand the role of each of these cytoskeletal components in processes such as intracellular transport of cargo. For example, small molecule inhibitors of Actin or Tubulin polymerization can reveal whether cargo is transported on microfilaments or microtubules, respectively. Tocris provides a wide range of small molecules to facilitate cytoskeletal and motor protein research.