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-5 is a subunit of laminin-10 (laminin-511), laminin-11 (laminin-521) and laminin-15 (laminin-523). Major component. Expressed in heart, lung, kidney, skeletal muscle, pancreas, retina and placenta. Little or no expression in brain and liver. Domain G is globular and is part of the major cell-binding site located in the long arm of the laminin heterotrimer.