The neurotransmitters GABA and glycine mediate fast synaptic inhibition by activating ligandgated chloride channels-namely, type A GABA (GABA(A)) and glycine receptors. Both types of receptors are anchored postsynaptically by gephyrin, which self-assembles into a scaffold and interacts with the cytoskeleton. Current research indicates that postsynaptic gephyrin clusters are dynamic assemblies that are held together and regulated by multiple protein-protein interactions. Moreover, post-translational modifications of gephyrin regulate the formation and plasticity of GABAergic synapses by altering the clustering properties of postsynaptic scaffolds and thereby the availability and function of receptors and other signalling molecules. Here, we discuss the formation and regulation of the gephyrin scaffold, its role in GABAergic and glycinergic synaptic function and the implications for the pathophysiology of brain disorders caused by abnormal inhibitory neurotransmission. Shiva Tyagarajan graduated as a molecular virologist at the Pennsylvania State University (USA) and later trained as a neurobiologist during his post-doctoral studies at the University of Zurich. He is currently a group leader and the research focus of his group is to elucidate molecular and cellular mechanisms that couple transcriptional and post-transcriptional programs to regulate GABAergic synaptic plasticity.
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AbstractThe neurotransmitters GABA and glycine mediate fast synaptic inhibition by activating ligand-gated Cl channels, namely the GABA A and glycine receptors. Both types of receptors are anchored postsynaptically by gephyrin, which self-assembles into a scaffold and interacts with the cytoskeleton. Current research indicates that gephyrin postsynaptic clusters are dynamic assemblies that are held together and regulated by multiple protein-protein interactions. Moreover, posttranslational modifications of gephyrin regulate the formation and plasticity of GABAergic synapses, by altering the clustering properties of postsynaptic scaffolds and thereby the availability and function of receptors and other signalling molecules.Here, we discuss the formation and regulation of the gephyrin scaffold, its role in GABAergic and glycinergic synaptic function and the implications for the pathophysiology of brain disorders caused by abnormal inhibitory neurotransmission.On-line summary Gephyrin is a multi-functional protein, responsible for Moco biosynthesis in all organisms, and for postsynaptic clustering of glycine receptors and GABAA receptors in vertebrate CNS Gephyrin forms a protein scaffold by self-assembly from trimeric complexes, which interacts with numerous, structurally different proteins, in order to form a high ordered signalling complex in glycinergic and GABAergic synapses Gephyrin function as a scaffolding protein is regulated by alternate mRNA splicing and by multiple post-transcriptional and posttranslational modifications, which only begin to be understood. Regulation of gephyrin scaffold by multiple signallin...