The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components: microfilaments, intermediate filaments, and microtubules, and these are all capable of rapid growth or disassembly depending on the cell's requirements.
The cytoskeleton consists of (a) microtubules, (b) microfilaments, and (c) intermediate filaments.
Actin cytoskeleton of mouse embryo fibroblasts, stained with phalloidin
Microtubules in a gel-fixated cell
Cross section diagram through the cilium, showing the “9 + 2” arrangement of microtubules
In biology, a protein filament is a long chain of protein monomers, such as those found in hair, muscle, or in flagella. Protein filaments form together to make the cytoskeleton of the cell. They are often bundled together to provide support, strength, and rigidity to the cell. When the filaments are packed up together, they are able to form three different cellular parts. The three major classes of protein filaments that make up the cytoskeleton include: actin filaments, microtubules and intermediate filaments.
Developing wood cells in poplar showing microfilaments (in green) and cell nuclei (in red)
This is a representation of a microfilament breakdown in a muscle fiber. It shows the different zones and disks within the sarcolemma of this muscle fiber.
This helps depict the role that microtubules play in cellular division. In this fluorescent image, the microtubules are highlighted green and can be seen helping to pull the cells apart.
