Cadherins

Definition

Cadherins are a family of transmembrane proteins that play a critical role in cell adhesion by mediating calcium-dependent cell-cell interactions. These proteins are essential for the formation and maintenance of tissue structure and integrity, as they help cells stick together in various tissues, influencing their shape, organization, and overall function during development.

5 Must Know Facts For Your Next Test

1. Cadherins require calcium ions to maintain their adhesive properties, which is why they're often referred to as calcium-dependent adhesion molecules.
2. There are different types of cadherins, including classical cadherins (like E-cadherin found in epithelial tissues) and non-classical cadherins (such as N-cadherin found in neural tissues), each serving specific functions.
3. The interaction of cadherins with the cytoskeleton is essential for their role in maintaining cell shape and structural integrity within tissues.
4. Cadherins not only mediate adhesion but also play a role in signaling pathways that regulate cellular processes such as proliferation, differentiation, and apoptosis.
5. Alterations or loss of cadherin function can lead to various diseases, including cancer, where decreased expression of E-cadherin is often associated with increased tumor invasiveness and metastasis.

Review Questions

• How do cadherins contribute to the overall organization of tissues during development?
  • Cadherins contribute to tissue organization by mediating cell-cell adhesion, which helps maintain proper spatial relationships between cells. During development, this adhesion is crucial for processes like morphogenesis, where cells need to move and reorganize into structured forms. By forming adherens junctions through cadherin interactions, cells can communicate and coordinate their behavior, ensuring that tissues develop correctly and maintain their integrity.
• Discuss the differences between classical and non-classical cadherins and their respective roles in specific tissue types.
  • Classical cadherins, like E-cadherin, are primarily found in epithelial tissues and are vital for maintaining the integrity of epithelial cell layers. They promote adhesion between adjacent epithelial cells, influencing tissue structure. Non-classical cadherins, such as N-cadherin, are commonly found in neural tissues and are important for neural development and synaptic connections. These differences illustrate how various cadherins are adapted to fulfill specific roles in maintaining the function and architecture of different tissue types.
• Evaluate the implications of altered cadherin function in cancer progression and metastasis.
  • Altered cadherin function significantly impacts cancer progression by affecting cell adhesion properties. For instance, loss or decreased expression of E-cadherin is frequently observed in invasive tumors, leading to reduced intercellular adhesion. This allows cancer cells to detach from the primary tumor site and invade surrounding tissues or enter the bloodstream, promoting metastasis. Understanding these changes highlights potential therapeutic targets for preventing tumor spread and emphasizes the importance of cadherins in maintaining normal tissue homeostasis.

Related terms

Integrins:

Integrins are transmembrane receptors that facilitate cell-extracellular matrix adhesion, playing a vital role in cellular signaling and communication with the surrounding environment.

Desmosomes: Desmosomes are specialized structures that provide strong adhesion between adjacent cells, mainly through cadherins, contributing to the mechanical strength of tissues.

Epithelial Tissue: Epithelial tissue consists of layers of cells that line surfaces and cavities throughout the body, where cadherins are crucial for maintaining the structural integrity and function of these layers.