adhesioreseptorit

Adhesioreseptorit, or adhesion receptors, are transmembrane proteins that mediate binding between cells or between cells and the extracellular matrix. They are essential for maintaining tissue architecture, guiding cell migration, and enabling signaling that influences development, immune responses, wound healing, and homeostasis. The main families include integrins (cell–ECM adhesion), cadherins (cell–cell adhesion), selectins (cell–circulating-endothelium interactions), and members of the immunoglobulin superfamily such as ICAMs and VCAMs.

Structurally, most adhesion receptors are single-pass transmembrane proteins with an extracellular ligand-binding domain, a transmembrane helix, and a cytoplasmic tail that links to the cytoskeleton or signaling complexes. Activation can occur through inside-out signaling (changing receptor affinity from within the cell) or outside-in signaling (ligand binding triggering intracellular pathways). Adhesion receptor activity is modulated by divalent cations, conformational changes, and clustering into higher-order structures such as focal adhesions.

Key examples include integrins, which bind extracellular matrix components like collagen, laminin, and fibronectin; cadherins, which mediate calcium-dependent cell–cell contacts, with E-cadherin important in epithelial integrity and N-cadherin in neural tissues; selectins, which mediate leukocyte rolling on the endothelium via carbohydrate ligands such as sialyl Lewis antigens; and immunoglobulin superfamily members like ICAMs and VCAMs that participate in leukocyte trafficking and endothelial interactions.

Clinical relevance includes their roles as therapeutic targets in autoimmune diseases and cancer, where altered adhesion receptor expression or function affects metastasis, inflammation, and tissue repair.