PT - JOURNAL ARTICLE AU - Borislav Dejanovic AU - Guenter Schwarz TI - Neuronal Nitric Oxide Synthase-Dependent S-Nitrosylation of Gephyrin Regulates Gephyrin Clustering at GABAergic Synapses AID - 10.1523/JNEUROSCI.0531-14.2014 DP - 2014 Jun 04 TA - The Journal of Neuroscience PG - 7763--7768 VI - 34 IP - 23 4099 - http://www.jneurosci.org/content/34/23/7763.short 4100 - http://www.jneurosci.org/content/34/23/7763.full SO - J. Neurosci.2014 Jun 04; 34 AB - Gephyrin, the principal scaffolding protein at inhibitory synapses, is essential for postsynaptic clustering of glycine and GABA type A receptors (GABAARs). Gephyrin cluster formation, which determines the strength of GABAergic transmission, is modulated by interaction with signaling proteins and post-translational modifications. Here, we show that gephyrin was found to be associated with neuronal nitric oxide synthase (nNOS), the major source of the ubiquitous and important signaling molecule NO in brain. Furthermore, we identified that gephyrin is S-nitrosylated in vivo. Overexpression of nNOS decreased the size of postsynaptic gephyrin clusters in primary hippocampal neurons. Conversely, inhibition of nNOS resulted in a loss of S-nitrosylation of gephyrin and the formation of larger gephyrin clusters at synaptic sites, ultimately increasing the number of cell surface expressed synaptic GABAARs. In conclusion, S-nitrosylation of gephyrin is important for homeostatic assembly and plasticity of GABAergic synapses.