Desmosomes

Definition

Desmosomes are specialized cell structures that provide strong adhesion between adjacent cells, primarily in tissues subjected to mechanical stress. They consist of protein complexes that anchor intermediate filaments from the cytoskeleton of one cell to those of another, creating a robust connection that helps maintain tissue integrity. This adhesion plays a crucial role in cellular communication and transport, especially in epithelial and cardiac tissues, ensuring that cells can withstand stretching and shearing forces.

5 Must Know Facts For Your Next Test

1. Desmosomes are crucial in tissues like the heart and skin, where they help resist mechanical stress and prevent cells from being pulled apart.
2. The proteins involved in desmosome formation, such as desmogleins and desmocollins, belong to the cadherin family and play a vital role in intercellular adhesion.
3. Desmosomes connect to the cytoskeleton through intermediate filaments, providing tensile strength and structural stability to tissues.
4. In some diseases, such as pemphigus vulgaris, autoantibodies target desmosomal proteins, leading to loss of adhesion between skin cells and blister formation.
5. Desmosomes not only provide mechanical strength but also participate in signaling pathways that regulate cell behavior and response to stress.

Review Questions

• How do desmosomes contribute to tissue integrity under mechanical stress?
  • Desmosomes contribute to tissue integrity by providing strong adhesion between adjacent cells, particularly in areas subject to mechanical stress. They achieve this through a network of cadherin proteins that link intermediate filaments from one cell to another, creating a robust framework. This structure allows tissues such as cardiac and epithelial tissues to withstand stretching and shearing forces without losing cohesion.
• Discuss the molecular components of desmosomes and their roles in cellular adhesion.
  • Desmosomes are composed of cadherin family proteins, mainly desmogleins and desmocollins, which facilitate cell-to-cell adhesion. These proteins are anchored to the intermediate filaments within the cytoskeleton, providing structural support. The interaction between these components not only strengthens adhesion but also plays a role in signaling pathways that influence cell behavior. This molecular structure ensures that desmosomes can maintain tissue integrity while responding to mechanical forces.
• Evaluate the implications of dysfunctional desmosomes on tissue health and disease pathology.
  • Dysfunctional desmosomes can lead to significant tissue health issues as they compromise the mechanical integrity of tissues. Conditions such as pemphigus vulgaris arise when autoantibodies target desmosomal proteins, causing loss of adhesion between skin cells and resulting in blister formation. Additionally, impaired desmosome function has been linked to various cardiac diseases, where compromised connections between heart muscle cells can lead to arrhythmias or weakened heart function. Understanding these implications highlights the essential role desmosomes play in maintaining healthy tissues.

Related terms

Cadherins: Cadherins are a family of proteins that mediate cell-cell adhesion, playing a key role in the formation and function of desmosomes.

Intermediate Filaments: Intermediate filaments are a component of the cytoskeleton that provides structural support to cells and are anchored by desmosomes to maintain cell integrity.

Tight Junctions:

Tight junctions are another type of cell junction that create a barrier to prevent the passage of molecules between cells, complementing the mechanical strength provided by desmosomes.