Binding to cells via a high affinity receptor, laminin is thought to mediate the attachment, migration and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. Laminin is a complex glycoprotein, consisting of three different polypeptide chains (alpha, beta, gamma), which are bound to each other by disulfide bonds into a cross-shaped molecule comprising one long and three short arms with globules at each end. Alpha-1 is a subunit of laminin-1 (laminin-111 or EHS laminin) and laminin-3 (laminin-121 or S-laminin). Major component. The alpha-helical domains I and II are thought to interact with other laminin chains to form a coiled coil structure. Domains VI, IV and G are globular. Tyrosine phosphorylated by PKDCC/VLK.