Protein filament

Compared to the other parts of the cytoskeletons, the microfilaments contain the thinnest filaments, with a diameter of approximately 7 nm.

Two strands of actin intertwined together form a filamentous structure allowing for the movement of motor proteins.

They are found in several places in the body including the microvilli, contractile rings, stress fibers, cellular cortex, etc.

Elongation is the next step in this process, and it is the rapid addition of actin monomers at both the plus and minus end of the microfilament.

This movement of myosin along the microfilament can cause muscle contraction, membrane association, endocytosis, and organelle transport.

The Z disk is the part of the microfilament that characterizes the overall end of each side of the sarcomere, a structural unit of a myofibril.

Tropomodulin is a protein that will cap the ends of the actin filaments causing the overall stability of the structure.

[citation needed] Microtubules are the largest type of filament, with a diameter of 25 nm wide, in the cytoskeleton.

Microtubules have the ability to play a significant role in the organization of organelles and vesicles, beating of cilia and flagella, nerve and red blood cell structure, and alignment/ separation of chromosomes during mitosis and meiosis.

The basal body found within the cell helps the microtubule to orient in this specific fashion.

The positive end of these microtubules will attach to the kinetochore on the chromosome allowing for cellular division when applicable.

Taxol is another drug often times used to help treat breast cancer through targeting microtubules.

These deposits are determined via polarity cues, growth and differentiation factors, or adhesion contacts.

NDC80 is a protein found at this binding point that will help with the stabilization of this interaction during cellular division.

[citation needed] Intermediate filaments are part of the cytoskeleton structure found in most eukaryotic cells.

Intermediate filaments contain an average diameter of 10 nm, which is smaller than that of microtubules, but larger than that of microfilaments.

They can also help with the linkage of actin and microtubules to the cytoskeleton which will lead to the eventual movement and division of cells.

Lastly these intermediate filaments have the ability to help with vascular permeability through organizing continuous adherens junctions through plectin cross-linking.

Type 1 and 2 intermediate filaments are those that are composed of keratins, and they are mainly found in epithelial cells.

Type 6 intermediate filaments are involved with nestin that interact with the stem cells of central nervous system.

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.
A human cell showing the tubulin component of the cytoskeleton in green and the nucleus in red. The blue staining is a single cytoplasmic protein.
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.
Human neural stem cells stained for Sox2, in green, and vimentin, in red. Vimentin is a type III intermediate filament (IF) protein.