Chapter 16: Cytoskeleton

Cytoskeleton

The cytoskeleton is a dynamic network of protein filaments found within the cytoplasm of cells.

Structural Support

The cytoskeleton provides structural support to the cell, giving it shape, strength, and stability.

Cell Motility

The cytoskeleton enables cellular movement by providing tracks for the transport of organelles, vesicles, and other cellular components.

Cell division

The cytoskeleton plays a critical role in cell division by forming the mitotic spindle and facilitating chromosome segregation.

Intracellular support

It aids in the transport of materials within the cell, allowing for the movement of organelles and vesicles along cytoskeletal tracks.

Cell adhesion

The cytoskeleton is involved in cell adhesion processes, including the formation of cell-cell junctions and anchoring cells to the extracellular matrix.

Intermediate filaments

The earliest cytoskeletal structures in eukaryotes were likely the intermediate filaments, providing mechanical support and stability.

Actin filaments

Actin filaments evolved later and are found in eukaryotes, providing cellular motility, shape changes, and intracellular transport.

Microtubules

Microtubules, composed of tubulin proteins, are believed to have emerged later in evolution and are involved in cell division, intracellular transport, and cell shape.

Cross-linking proteins

Crosslinking proteins, including spectrin and filamin, evolved to strengthen and stabilize the cytoskeletal network.

Actin

Actin is a highly conserved protein that forms filaments in eukaryotic cells.

Myosin

Myosin is a family of motor proteins found in eukaryotic cells that interact with actin filaments.

Microtubules

Microtubules are hollow cylindrical structures composed of protein subunits called tubulins.

Septins

Septins are a family of GTP-binding proteins that form filamentous structures and are involved in diverse cellular processes.

Cell polarization

Cell polarization refers to the asymmetric distribution of cellular components, such as proteins, organelles, and cytoskeletal elements, within a cell.

Cell migration

Cell migration refers to the movement of cells from one location to another within an organism.