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Inhibition of neuronal nitric‐oxide synthase by phosphorylation at Threonine1296 in NG108‐15 neuronal cells
Author(s) -
Song Tao,
Hatano Naoya,
Kume Kodai,
Sugimoto Katsuyoshi,
Yamaguchi Fuminori,
Tokuda Masaaki,
Watanabe Yasuo
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.09.037
Subject(s) - phosphorylation , nitric oxide , nitric oxide synthase , chemistry , neuronal nitric oxide synthase , enzyme , phosphatase , mutant , biochemistry , microbiology and biotechnology , biology , gene , organic chemistry
We demonstrate that neuronal nitric‐oxide synthase (nNOS) is directly inhibited through the phosphorylation of Thr 1296 in NG108‐15 neuronal cells. Treatment of NG108‐15 cells expressing nNOS with calyculin A, an inhibitor of protein phosphatase 1 and 2A, revealed a dose‐dependent inhibition of nNOS enzyme activity with concomitant phosphorylation of Thr 1296 residue. Cells expressing a phosphorylation‐deficient mutant in which Thr 1296 was changed to Ala proved resistant to phosphorylation and suppression of NOS activity. Mimicking phosphorylation mutant of nNOS in which Thr 1296 is changed to Asp showed a significant decrease in nNOS enzyme activity, being competitive with NADPH, relative to the wild‐type enzyme. These data suggest that phosphorylation of nNOS at Thr 1296 may involve the attenuation of nitric oxide production in neuronal cells through the decrease of NADPH‐binding to the enzyme.