Integrin in autoimmune disease is a transmembrane focal adhesion protein that plays an indispensable role in these immune cell mechanisms.
The most common integrins are laminin receptors (α6β4 and α3β1), the collagen receptor (α2β1) and less abundantly the vitronectin receptor αvβ5.
When integrins are activated it leads to the recruitment of a protein complex that is composed of kindlin, vinculin and talin.
The examples of integrin proteins are αIIbβ3 integrin and β2 integrin that predominantly exist in the inactive state.
The examples of integrin receptors are receptors for collagens, laminin-1 and laminin-5, fibronectin, tenascin, thrombospondin, vitronectin, and VCAM-1.
The family of integrins are a family of ubiquitous αβ heterodimeric receptors which exist in multiple conformations and also interact with a diverse group of ligands.
These molecules also mediate interactions between cells and of these cells with the extracellular matrix (ECM) and also serve a critical role in signaling and homeostasis.
Integrins contribute to blood clotting by binding to the adhesive proteins, the integrins mediate platelet adhesion to injured vascular wall and platelet aggregation which is important for the maintenance of hemostasis which prevents excessive bleeding.
In inflammation integrins regulate the cellular growth, migration, proliferation, signaling and cytokine activation and release and play important roles in cell proliferation and migration as well as tissue repair, apoptosis and processes that are critical to inflammation, angiogenesis and infection.
Integrin does bind to collagen and has been reported to be one of the main collagen binding integrins that are present in skin, bone and other internal organs which comprise epithelial cells, platelets, immune cells, fibroblasts, mesenchymal cells and chondrocytes.
The roles of integrin are to function as transmembrane linkers (or “integrators”), mediating the interactions between the cytoskeleton and the extracellular matrix that are required for cells to grip the matrix and they are activated by cytoplasmic tail ligands.
There are 24 different integrins which include 18 subunits and 8 subunits that generate 24 different integrins.
The cells that express integrin are all nucleated cells of multicellular animals and are essential for cell-matrix adhesion and, in vertebrates, cell-cell interactions.
Integrins are activated by cytoplasmic tail ligands.
Talin PTB domain (the head F3 subdomain) binds the first β-NPXY and the membrane proximal helix, whereas kindlin binds the second NPXY.
In skin integrin binds to numerous ligands that are present in the provisional wound ECM which includes the fibronectin (α5β1, α9β1, αvβ6), vitronectin (αvβ5), and tenascin (α9β1, αvβ6), as well as laminin-332 (α3β1, α6β4) that is deposited by migrating keratinocytes.
The integrin binds to the extracellular matrix (ECM) glycoproteins such as laminins and collagens in basement membranes or connective tissue components like fibronectin.
Other integrins also bind to what are known as counterreceptors on neighboring cells, bacterial polysaccharides, or viral coat proteins.
The examples of integrins are αIIbβ3 to platelets; α6β4 to keratinocytes; αEβ7 to T cells, dendritic cells and mast cells in mucosal tissues; α4β1 to leukocytes; α4β7 to a subset of memory T cells; and the β2 integrins to leukocytes.
In mammals some integrins are limited to certain cell types and or tissue types.
In regard to ligand specificity, the mammalian integrins can be broadly grouped into laminin-binding integrins (α1β1, α2β1, α3β1, α6β1, α7β1, and α6β4), collagen-binding integrins (α1β1, α2β1, α3β1, α10β1, and α11β1), leukocyte integrins (αLβ2, αMβ2, αXβ2, and αDβ2), and RGD-recognizing integrins (α5β1, αVβ1, αVβ3.
The function of integrins are to act as transmembrane linkers (or “integrators”), mediating the interactions between the cytoskeleton and the extracellular matrix which are required for the cells to grip the matrix.
Integrins regulate cellular growth, proliferation, migration, signaling, and cytokine activation and release and thereby play important roles in cell proliferation and migration, apoptosis, tissue repair, as well as in all processes critical to inflammation, infection, and angiogenesis.
Cell surface receptors for the extracellular matrix (ECM), such as the integrins, play key roles in the regulation of normal and tumour cell migration and survival.
The integrin family of cell adhesion proteins controls cell attachment to the ECM.
Integrins are the principal receptors used by animal cells to bind to the extracellular matrix.
They are heterodimers and function as transmembrane linkers between the extracellular matrix and the actin cytoskeleton.
A cell can regulate the adhesive activity of its integrins from within.
Integrins are formed through noncovalent association of two type I transmembrane glycoproteins, the α- and the β subunit.
The extracellular parts are approximately 700 amino acids for α - and 1000 amino acids for β subunits and form elongated stalks and a globular ligand-binding head region6.
Examples of integrin ligands are ICAM-1, which is present at the plasma membrane of antigen-presenting cells and binds to the integrin receptor LFA-1 to promote cell–cell adhesion.
Mutations in integrin genes are associated with various human disorders, including epidermolysis bullosa with pyloric atresia, congenital muscular dystrophy, leukocyte adhesion deficiency, and Glanzmann's thrombasthenia.
The epidermal integrins can bind numerous ligands present in the provisional wound ECM, including fibronectin (α5β1, α9β1, αvβ6), vitronectin (αvβ5), and tenascin (α9β1, αvβ6), as well as laminin-332 (α3β1, α6β4) that is deposited by migrating keratinocytes.
Integrin activation in leukocytes is a central event in many leukocyte processes.
Leukocyte integrins are key elements for both innate and adaptive immune responses, which have emerged as promising therapeutic targets for patients with inflammation and autoimmune diseases.
Genetic and other disorders which are caused by mutations in human DNA include.
Genetic Disorders. Sickle Cell Disease.
Cystic fibrosis. Cystic Fibrosis Liver Disease.
Brain, Nerves and Spine. Huntington's Disease.
Cleft lip and palate. Cleft Lip and Palate.