Figure 5. Simplified illustration of a laminin heterotrimer. Schematic of a prototypical laminin heterotrimer. Each chain is comprised of six domains (I-VI). The α-helical coiled-coil regions in domains I and II of the "long arm" regions of all three chains are covalently linked to one another by disulfide bonds., The self-assembly domain of each chain is responsible for self-polymerization required for basement membrane assembly. The terminal globular domain of the α chain interacts with cell surface receptors, and is responsible for communication between cells and the basement membrane. The sites for interaction of laminins with other basement membrane molecules such as nidogens (in domain III of the γ1 chain) and agrin (in the laminin "long arm" consisting of α, β and γ chains) are shown.