<P> A large - scale example of an action performed by the cytoskeleton is muscle contraction . In the muscle , there are groups of highly specialized cells that work together to perform a function known as muscle contraction . A main component in the cytoskeleton that helps show the true function of this muscle contraction is known as a microfilament . Microfilaments are composed of the most abundant cellular protein known as actin . During contraction of a muscle , within each muscle cell , myosin molecular motors collectively exert forces on parallel actin filaments . Muscle contraction starts from nerve impulses which then causes increased amounts of calcium to be released from the sarcoplasmic reticulum . Increases in calcium in the cytosol allows muscle contraction to begin with the help of two proteins , tropomyosin and troponin . Tropomyosin inhibits the interaction between actin and myosin , while troponin senses the increase in calcium and releases the inhibition . This action contracts the muscle cell , and through the synchronous process in many muscle cells , the entire muscle . </P>
the part of the cytoskeleton made from the protein actin is called
microfilament