Adhäsionsstellen

Adhäsionsstellen, also known as focal adhesions, are protein complexes that anchor the cell's actin cytoskeleton to the extracellular matrix. They are crucial for cell adhesion, migration, and signal transduction. These dynamic structures form at the cell's periphery and serve as a physical link between the intracellular environment and the external world.

The formation of adhäsionsstellen involves a complex interplay of various proteins. Integrins, transmembrane receptors, are key players. They bind to extracellular matrix components like fibronectin and collagen. Inside the cell, integrins connect to a network of adapter proteins, including talin, vinculin, and alpha-actinin. This network then links to the actin cytoskeleton, providing structural support and enabling cell movement.

Beyond their structural role, adhäsionsstellen are vital signaling hubs. They recruit and activate intracellular signaling pathways that regulate cell growth, survival, and differentiation. For instance, they can initiate signaling cascades that involve kinases like FAK (focal adhesion kinase) and Src. These signals are transmitted to the nucleus, influencing gene expression.

The assembly and disassembly of adhäsionsstellen are tightly regulated processes, allowing cells to adapt to their environment. This dynamic nature is essential for processes such as wound healing, immune cell trafficking, and embryonic development. Disruptions in adhäsionsstellen function have been implicated in various diseases, including cancer metastasis and fibrosis, highlighting their importance in cellular health and disease.