title: Neuronal nitric oxide synthase (nNOS) modulates the JNK1 activity through redox mechanism: a cGMP independent pathway.
abstract: Nitric oxide (NO) is a small, uncharged molecule, which is primarily generated by the nitric oxide synthase (NOS) family of proteins, including neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). NO has been implicated in diverse roles in biological systems, such as the regulation of cell death and survival signaling pathways of a variety of cell types, including neuronal cells. In this study, we determined that the NO generated from l-arginine by ectopically overexpressed nNOS in HEK293 cells exerted an inhibitory effect against the activity of c-Jun N-terminal kinase (JNK), an important modulator of neuronal cell death and survival signaling pathways. NO repressed the activation of JNK, but exerted no significant effects on the activities of SEK1/MKK4 and MEKK1, which are the upstream MAPKK and MAPKKK of JNK1, respectively. This NO-mediated inhibition of JNK1 was not affected by the addition of ODQ, a guanylyl cyclase inhibitor, indicating that the effect is independent of the level of cyclic GMP. In an in vitro kinase assay, SNAP, a NO donor, was shown to directly suppress JNK1 activity, thereby indicating that NO is a direct modulator of JNK1. Moreover, the NO-mediated suppression of JNK1 was demonstrated to be redox-sensitive and dependent on the cysteine-116 in JNK1. Finally, according to the results of an immunohistochemical study using rat striatal neurons, we were able to determine that nNOS-expressing neurons evidenced significantly reduced JNK1 activation. Collectively, these data suggest that JNK1 is regulated by nNOS-mediated NO production in neurons, via a thiol-redox-sensitive mechanism.
authors.affiliation: Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Yongbong-dong, Buk-ku, Gwangju, Republic of Korea.
authors.forename: Hee-Sae
authors.initials: HS
authors.lastname: Park
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Huh
authors.forename: Mi-Sung
authors.initials: MS
authors.lastname: Kim
authors.forename: Doo Yeon
authors.initials: DY
authors.lastname: Kim
authors.forename: Byoung Joo
authors.initials: BJ
authors.lastname: Gwag
authors.forename: Ssang-Goo
authors.initials: SG
authors.lastname: Cho
authors.forename: Eui-Ju
authors.initials: EJ
authors.lastname: Choi
mesh_terms: D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D001120:Arginine / Q000378:metabolism; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000037:antagonists & inhibitors / Q000502:physiology*; D004789:Enzyme Activation; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D048728:MAP Kinase Kinase Kinase 1 / Q000378:metabolism; D048055:Mitogen-Activated Protein Kinase 8 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I / Q000096:biosynthesis / Q000502:physiology*; D010084:Oxidation-Reduction; D051381:Rats; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D015398:Signal Transduction
chemical_list: D009569:Nitric Oxide; D000841:Anisomycin; D026423:S-Nitroso-N-Acetylpenicillamine; D001120:Arginine; D052248:Nitric Oxide Synthase Type I; D009252:NADPH Dehydrogenase; D048055:Mitogen-Activated Protein Kinase 8; D048728:MAP Kinase Kinase Kinase 1; D048670:MAP Kinase Kinase 4; D006152:Cyclic GMP