Post-synaptic density-95 promotes calcium/calmodulin-dependent protein kinase II-mediated Ser847 phosphorylation of neuronal nitric oxide synthase.
Post-synaptic density-95 (PSD-95) is a neuronal scaffolding protein that associates with N -methyl-D-aspartate (NMDA) receptors and links them to intracellular signalling molecules. In neurons, neuronal nitric oxide synthase (nNOS) binds selectively to the second PDZ domain (PDZ2) of PSD-95, thereby exhibiting physiological activation triggered via NMDA receptors. We have demonstrated previously that Ca(2+)/calmodulin-dependent protein kinase IIalpha (CaM-K IIalpha) directly phosphorylates nNOS at residue Ser(847), and can attenuate the catalytic activity of the enzyme in neuronal cells [Komeima, Hayashi, Naito and Watanabe (2000) J. Biol. Chem. 275, 28139-28143]. In the present study, we examined how CaM-K II participates in the phosphorylation by analysing the functional interaction between nNOS and PSD-95 in cells. The results showed that PSD-95 directly promotes the nNOS phosphorylation at Ser(847) induced by endogenous CaM-K II. In transfected cells, this effect of PSD-95 required its dual palmitoylation and the PDZ2 domain, but did not rely on its guanylate kinase domain. CaM-K Ialpha and CaM-K IV failed to phosphorylate nNOS at Ser(847) in transfected cells. Thus PSD-95 mediates cellular trafficking of nNOS, and may be required for the efficient phosphorylation of nNOS at Ser(847) by CaM-K II in neuronal cells.
Watanabe
Yasuo
Y
Department of Cell Physiology, Kagawa Medical University, 1750-1 Ikenobe, Miki-cho, Kida-gun, Japan. yasuwata@kms.ac.jp
Song
Tao
T
Sugimoto
Katsuyoshi
K
Horii
Mariko
M
Araki
Nobukazu
N
Tokumitsu
Hiroshi
H
Tezuka
Tohru
T
Yamamoto
Tadashi
T
Tokuda
Masaaki
M
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured / Q000166:cytology / Q000378:metabolism; D000076122:Disks Large Homolog 4 Protein; D007124:Immunoenzyme Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000302:isolation & purification / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D010766:Phosphorylation; D010957:Plasmids; D011233:Precipitin Tests; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012694:Serine / Q000378:metabolism*
D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D016194:Receptors, N-Methyl-D-Aspartate; C033652:postsynaptic density proteins; D012694:Serine; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D011494:Protein Kinases; C106686:(CaM)-dependent protein kinase Ia kinase; D017346:Protein Serine-Threonine Kinases; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517675:Camk2a protein, rat; D002118:Calcium