title: The PSD95-nNOS interface: a target for inhibition of excitotoxic p38 stress-activated protein kinase activation and cell death.
abstract: The stress-activated protein kinase p38 and nitric oxide (NO) are proposed downstream effectors of excitotoxic cell death. Although the postsynaptic density protein PSD95 can recruit the calcium-dependent neuronal NO synthase (nNOS) to the mouth of the calcium-permeable NMDA receptor, and depletion of PSD95 inhibits excitotoxicity, the possibility that selective uncoupling of nNOS from PSD95 might be neuroprotective is unexplored. The relationship between excitotoxic stress-generated NO and activation of p38, and the significance of the PSD95-nNOS interaction to p38 activation also remain unclear. We find that NOS inhibitors reduce both glutamate-induced p38 activation and the resulting neuronal death, whereas NO donor has effects consistent with NO as an upstream regulator of p38 in glutamate-induced cell death. Experiments using a panel of decoy constructs targeting the PSD95-nNOS interaction suggest that this interaction and subsequent NO production are critical for glutamate-induced p38 activation and the ensuing cell death, and demonstrate that the PSD95-nNOS interface provides a genuine possibility for design of neuroprotective drugs with increased selectivity.
authors.affiliation: Department of Neurobiology, A.I. Virtanen Institute, University of Kuopio, Kuopio FIN 70211, Finland.
authors.forename: Jiong
authors.initials: J
authors.lastname: Cao
authors.forename: Jenni I
authors.initials: JI
authors.lastname: Viholainen
authors.forename: Caroline
authors.initials: C
authors.lastname: Dart
authors.forename: Helen K
authors.initials: HK
authors.lastname: Warwick
authors.forename: Mark L
authors.initials: ML
authors.lastname: Leyland
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Courtney
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology; D004594:Electrophysiology; D004789:Enzyme Activation; D031541:Fluorescence Resonance Energy Transfer; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D017434:Protein Structure, Tertiary; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D009419:Nerve Tissue Proteins; D020030:Nitric Oxide Donors; D016194:Receptors, N-Methyl-D-Aspartate; D011993:Recombinant Fusion Proteins; C033652:postsynaptic density proteins; D009569:Nitric Oxide; D018698:Glutamic Acid; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D048051:p38 Mitogen-Activated Protein Kinases; D002118:Calcium