Cell cortex

Diagram of the actin cortex in a cell.

The cell cortex is a specialized layer of cytoplasm on the inner face of the plasma membrane in eukaryotic cells. It is primarily composed of a network of actin filaments and associated proteins, which provide structural support and play a crucial role in various cellular processes.

Structure

The cell cortex is a dynamic structure that is closely associated with the plasma membrane. It consists of a dense meshwork of actin filaments, which are cross-linked by various actin-binding proteins. This network is often referred to as the actin cortex. The actin filaments are organized in a way that allows the cortex to maintain cell shape, resist mechanical stress, and facilitate cell movement.

Function

The cell cortex serves several important functions:

• Mechanical Support: The cortex provides mechanical strength to the cell, helping it maintain its shape and resist deformation.
• Cell Movement: The actin cortex is involved in cell motility, enabling processes such as amoeboid movement, cytokinesis, and cell migration.
• Signal Transduction: The cortex plays a role in signal transduction pathways, where it can influence the activity of membrane-bound receptors and other signaling molecules.
• Cell Division: During mitosis, the cortex is involved in the formation of the contractile ring that facilitates the separation of daughter cells.

Dynamics

The actin cortex is highly dynamic, with actin filaments constantly undergoing polymerization and depolymerization. This dynamic nature allows the cortex to rapidly reorganize in response to cellular signals and environmental changes. The regulation of actin dynamics is controlled by a variety of proteins, including formins, Arp2/3 complex, and cofilin.

Related pages

• Actin
• Cytoskeleton
• Plasma membrane
• Cell motility
• Cytokinesis