Nitric oxide-mediated modulation of calcium/calmodulin-dependent protein kinase II.
The mechanisms of NO inhibition of CaMK [Ca(2+)/CaM (calmodulin)-dependent protein kinase] II activity were studied. In rat pituitary tumour GH3 cells, TRH [thyrotrophin (TSH)-releasing hormone]-stimulated phosphorylation of nNOS [neuronal NOS (NO synthase)] at Ser(847) was sensitive to an inhibitor of CaMKs, KN-93, and was enhanced by inhibition of nNOS with 7NI (7-nitroindazole). Enzyme activity of CaMKII following in situ treatment with 7NI was also increased. The in vitro activity of CaMKII was inhibited by co-incubation either with nNOS and L-arginine or with NO donors SNAP (S-nitroso-N-acetyl-DL-penicillamine) and DEA-NONOate [diethylamine-NONOate (diazeniumdiolate)]. Once inhibited by these treatments, CaMKII was observed to undergo full reactivation on the addition of a reducing reagent, DTT (dithiothreitol). In transfected cells expressing CaMKII and nNOS, treatment with the calcium ionophore A23187 further revealed nNOS phosphorylation at Ser(847), which was enhanced by 7NI and CaMKII S-nitrosylation. Mutated CaMKII (C6A), in which Cys(6) was substituted with an alanine residue, was refractory to 7NI-induced enhancement of nNOS phosphorylation or to CaMKII S-nitrosylation. Furthermore, we could identify Cys(6) as a direct target for S-nitrosylation of CaMKII using MS. In addition, treatment with glutamate caused an increase in CaMKII S-nitrosylation in rat hippocampal slices. This glutamate-induced S-nitrosylation was blocked by 7NI. These results suggest that inactivation of CaMKII mediated by S-nitrosylation at Cys(6) may contribute to NO-induced neurotoxicity in the brain.
Song
Tao
T
Department of Pharmacology, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan.
Hatano
Naoya
N
Kambe
Toshie
T
Miyamoto
Yoshiaki
Y
Ihara
Hideshi
H
Yamamoto
Hideyuki
H
Sugimoto
Katsuyoshi
K
Kume
Kodai
K
Yamaguchi
Fuminori
F
Tokuda
Masaaki
M
Watanabe
Yasuo
Y
D000818:Animals; D001596:Benzylamines / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D003545:Cysteine / Q000378:metabolism; D004789:Enzyme Activation; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D006834:Hydrazines / Q000378:metabolism; D007191:Indazoles / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000378:metabolism; D051381:Rats; D026423:S-Nitroso-N-Acetylpenicillamine / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013449:Sulfonamides / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000378:metabolism; D000096926:Benzenesulfonamides
D001596:Benzylamines; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D003545:Cysteine; D006834:Hydrazines; D007191:Indazoles; D009569:Nitric Oxide; D020030:Nitric Oxide Donors; D052248:Nitric Oxide Synthase Type I; D047428:Protein Kinase Inhibitors; D026423:S-Nitroso-N-Acetylpenicillamine; D012694:Serine; D013449:Sulfonamides; D013973:Thyrotropin-Releasing Hormone; C072105:KN 93; D000096926:Benzenesulfonamides; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; C080122:7-nitroindazole