The role of laminins in the organization and function of neuromuscular junctions

The synaptic cleft between a motor neuron and a muscle fiber is filled with the basal lamina. Laminin α4, α5, and β2 chains specifically localize to neuromuscular junctions (NMJs), and these laminin isoforms play a critical role in the maintenance of NMJs and organization of synaptic vesicle release sites known as active zones. These individual laminin chains exert their role in organizing NMJs by binding to their receptors including integrins, dystroglycan, and voltage-gated calcium channels (VGCCs). Disruption of these laminins or the laminin-receptor interaction occurs in neuromuscular diseases including Pierson syndrome and Lambert–Eaton myasthenic syndrome (LEMS).