摘要：SummaryGephyrin is critical for the structure, function, and plasticity of inhibitory synapses. Gephyrin mutations have been linked to various neurological disorders; however, systematic analyses of the functional consequences of these mutations are lacking. Here, we performed molecular dynamics simulations of gephyrin to predict how six reported point mutations might change the structural stability and/or function of gephyrin. Additionalin silicoanalyses revealed that the A91T and G375D mutations reduce the binding free energy of gephyrin oligomer formation. Gephyrin A91T and G375D displayed altered clustering patterns in COS-7 cells and nullified the inhibitory synapse-promoting effect of gephyrin in cultured neurons. However, only the G375D mutation reduced gephyrin interaction with GABAAreceptors and neuroligin-2 in mouse brain; it also failed to normalize deficits in GABAergic synapse maintenance and neuronal hyperactivity observed in hippocampal dentate gyrus-specific gephyrin-deficient mice. Our results provide insights into biochemical, cell-biological, and network-activity effects of the pathogenic G375D mutation.Graphical AbstractDisplay OmittedHighlights•Gephyrin G375D reduces the formation of E- domain-mediated gephyrin oligomers•Gephyrin G375D impairs GABAergic synapse maintenancein vivo•Gephyrin G375D increases susceptibility to kainic acid-induced seizuresin vivo•Gephyrin G375D displays reduced interactions with GABAAreceptors and Nlgn2in vivoMolecular Biology; Neuroscience; Structural Biology
