Anti-Integrin beta4 Antibody

Integrin β4 (UniProt: P16144; also known as GP150, CD104) is encoded by the ITGB4 gene (Gene ID: 3691) in human. Integrins are heterodimeric cell surface receptors composed of a variable alpha subunit and a conserved beta subunit. The exact combination of various alpha and beta subunits dictates the binding specificity of integrins to different ECM components. Integrins are not constitutively active. Activation of an integrin from low ligand-binding affinity state to high ligand-binding affinity state requires conformational change that can originate from either from their cytoplasmic or extracellular interactions. The recognition site for most integrins that bind the ECM consists of an RGD (arginine-glycine-aspartic acid) sequence. Integrins bind to their ligands with low affinity and this binding occurs only when a certain minimum number of integrins are present at specific points known as focal contacts. Integrin β4 is a single-pass type I membrane protein that is synthesized with a signal peptide (aa 1-27), which is subsequently cleaved off to generate the mature form that contains an extracellular domain (aa 28-710), a transmembrane domain (aa 711-733), and a cytoplasmic domain (aa 734-1822). It contains four fibronectin type III domains. Integrin β4 heterodimerizes with a6 that serves as a receptor for laminin and plays a critical structural role in the hemidesmosome of epithelial cells. It undergoes palmitoylation by DHHC3 at several cysteines of the membrane-proximal region that enhances its stability and surface expression. Palmitoylation also promotes its secondary association with tetraspanins.