ITGA

ITGA refers to the integrin alpha chain gene family, which encodes the alpha subunits of integrin receptors. Integrins are heterodimeric cell surface receptors formed by pairing one alpha and one beta subunit. The ITGA genes (including ITGA1 through ITGA11 and ITGAV) encode the alpha subunits that define the ligand specificity and tissue distribution of these receptors. When paired with beta subunits (ITGB), they mediate cell adhesion to extracellular matrix proteins and participate in bidirectional signaling that regulates cell survival, differentiation, and migration.

All ITGA-encoded proteins share a conserved architecture: a large extracellular domain containing a ligand-binding region, a single transmembrane segment, and a short cytoplasmic tail that interacts with the cytoskeleton and signaling proteins. The exact extracellular conformation and binding preferences are determined by the specific alpha subunit, which in turn dictates which beta subunit it partners with and which ligands are recognized.

Ligand specificity and function vary among alpha subunits. Examples include α1β1 and α2β1, which bind collagen; α3β1 and α6β1, which interact with laminin; α5β1, which binds fibronectin; and alphaV-containing integrins (such as αVβ3 and αVβ5), which recognize vitronectin and related ligands. Integrins mediate adhesion to the extracellular matrix, regulate cell movement, and activate intracellular signaling pathways involving focal adhesion kinase (FAK), PI3K, and MAPK cascades.

Regulation of ITGA proteins occurs through inside-out and outside-in signaling, with activation modulated by intracellular adaptor proteins like talin and kindlins, as well as divalent cations. Altered expression or function of ITGA subunits is associated with development, immune responses, wound healing, and diseases such as cancer, fibrosis, and inflammatory disorders. ITGA genes are active research targets for understanding tissue biology and exploring therapeutic interventions.