Neuronal nitric oxide synthase signaling complex (nNOS-PSD-95 complex) (nNOS-PSD-95 complex)

The neuronal nitric oxide synthase (nNOS) signaling complex is a specialized protein assembly located at the postsynaptic density of neurons, primarily composed of nNOS, the scaffolding protein PSD-95, and the N-methyl-D-aspartate (NMDA) receptor (UniProt P29475, P78352). This complex couples the influx of calcium through NMDA receptors directly to the activation of nNOS, leading to the production of nitric oxide (NO), a key gaseous signaling molecule (PubMed: 12399592). While this pathway is essential for physiological processes such as synaptic plasticity and memory formation, its overactivation during ischemic stroke or traumatic brain injury leads to excessive NO production and subsequent neuronal death via excitotoxicity (PubMed: 20729862). Therapeutic intervention focuses on disrupting the protein-protein interaction between nNOS and PSD-95, which decouples the toxic signaling pathway without blocking the essential ionotropic functions of the NMDA receptor or the catalytic activity of nNOS elsewhere. Small molecules like ZL006 and peptides like Nerinetide are designed to target this interaction to provide neuroprotection in acute neurological conditions (PubMed: 32075883). This approach represents a significant advancement in neuropharmacology by targeting specific signaling sub-compartments rather than global enzyme or receptor activity.

Other names

nNOS-PSD95-NMDA receptor complexNOS1-DLG4 complexnNOS-PSD-95 interactionPostsynaptic density-95/neuronal nitric oxide synthase complexnNOS-PSD-95-NMDAR ternary complex

Disruption of the protein-protein interaction (PPI) between neuronal nitric oxide synthase (nNOS) and postsynaptic density protein 95 (PSD-95) or between PSD-95 and the NMDA receptor to prevent excitotoxic nitric oxide production.