Integrin

An integrin, or integrin receptor, is a receptor in the plasma membrane of biological cells. Integrins play an important role in:

• Integration of the cell into the surrounding tissue by
  • cell-cell-interaction
  • adhesive interaction
• Embryonal development
• Tumor development
• Apoptosis
• Connection between intracellular and extracellular scaffolding

Among the ligands of integrins are fibronectin and collagen, both part of the extracellular matrix. Ligand binding leads to clustering (cross-connection) of the multivalent components of the integrin to a functional protein complex. Integrins have no intrinsic kinase activity, but associate kinases (for example, focal adhesion kinase, FAK) on the cytoplasmic side of the membrane.