What functions does the cytoskeleton perform?
All eukaryotes in the cytoplasm have a complex supporting system – the cytoskeleton. It consists of three elements: microtubules, intermediate filaments and microfilaments.
Microtubules penetrate the entire cytoplasm and are hollow tubes with a diameter of 20–30 nm. Their walls are formed by specially twisted threads built from tubulin protein. The assembly of microtubules from tubulin occurs in the cell center. Microtubules are strong and form the supporting base of the cytoskeleton. Often they are positioned so as to counteract the stretching and contraction of the cell. In addition to the mechanical function, microtubules also perform a transport function, participating in the transfer of various substances through the cytoplasm.
Intermediate filaments have a thickness of about 10 nm and also have a protein nature. Their functions are currently poorly understood.
Microfilaments are protein filaments with a diameter of only 4 nm. Their basis is actin protein. Sometimes actin filaments are bundled. Microfilaments are most often located close to the plasma membrane and are able to change its shape, which is very important, for example, for the processes of phagocytosis and pinocytosis.
Thus, the cytoplasm is penetrated by the structures of the cytoskeleton, supporting the shape of the cell and providing intracellular transport. The cytoskeleton can quickly “disassemble” and “assemble.” When it is assembled, organoids can move through its structures with the help of special proteins, getting to the places of the cell where they are needed at the moment.
