TY - JOUR
T1 - Disruption of neuronal nitric oxide synthase dimerization contributes to the development of Alzheimer's disease
T2 - Involvement of cyclin-dependent kinase 5-mediated phosphorylation of neuronal nitric oxide synthase at Ser293
AU - Kwon, Kyoung Ja
AU - Park, Jung Hyun
AU - Jo, Inho
AU - Song, Kee Ho
AU - Han, Jung Soo
AU - Park, Seung Hwa
AU - Han, Seol Heui
AU - Cho, Du Hyong
N1 - Funding Information:
This work was supported by grants from Eulji University in 2014 to Du-Hyong Cho, from the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education , to Kyoung Ja Kwon ( NRF-2010-0023638 ), and from the Ministry of Science, ICT and Future Planning ( 2013R1A1A2074860 ) to Seol-Heui Han.
Publisher Copyright:
© 2016 Elsevier Ltd.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Although previous studies have suggested that neuronal nitric oxide synthase (nNOS)-derived NO has neuroprotective effects on the development of Alzheimer's disease (AD), the underlying molecular mechanisms are not fully elucidated. Here, we investigated whether and how disruption of nNOS dimerization contributes to the development of AD. No differences in synaptic number or expression of synaptic markers, including synaptophysin and postsynaptic density 95, were found in the cortex of 5 × FAD mice, which possess 5 familial AD mutations, at 6 months of age compared with control littermates. nNOS dimerization was disrupted in the 5 × FAD cortex, accompanied by an increase in reactive oxygen species (ROS) production. The subcellular distribution of cyclin-dependent kinase 5 (CDK5) shifted more diffusely toward a cytosolic compartment, but there was no change in total expression. Furthermore, the levels of p25, a CDK5 activator, increased significantly and it colocalized with nNOS in the 5 × FAD cortex. In silico analysis revealed that a new nNOS-specific GSP (glycine-serine-proline) motif was well-conserved across species at nNOS-Ser293, which is located ahead of the N-terminal hook. This motif was not present in the closely related isoform, endothelial NOS. Motif scan analysis also predicted that CDK5 can phosphorylate nNOS-Ser293 with a high likelihood. An in vitro phosphorylation assay clearly showed that CDK5/p25 does indeed phosphorylate nNOS-Ser293. Finally, nNOS-S293D mutant, a phosphomimetic form of nNOS-Ser293, and nNOS-S293A mutant, a neutral form of nNOS-Ser293, significantly decreased nNOS dimerization and NO production. Taken together, our results demonstrate that nNOS dimers are disrupted in the 5 × FAD cortex, and nNOS-Ser293, a potential site of CDK5 phosphorylation, may be involved in the decrease in nNOS dimerization and NO production, and the development of AD.
AB - Although previous studies have suggested that neuronal nitric oxide synthase (nNOS)-derived NO has neuroprotective effects on the development of Alzheimer's disease (AD), the underlying molecular mechanisms are not fully elucidated. Here, we investigated whether and how disruption of nNOS dimerization contributes to the development of AD. No differences in synaptic number or expression of synaptic markers, including synaptophysin and postsynaptic density 95, were found in the cortex of 5 × FAD mice, which possess 5 familial AD mutations, at 6 months of age compared with control littermates. nNOS dimerization was disrupted in the 5 × FAD cortex, accompanied by an increase in reactive oxygen species (ROS) production. The subcellular distribution of cyclin-dependent kinase 5 (CDK5) shifted more diffusely toward a cytosolic compartment, but there was no change in total expression. Furthermore, the levels of p25, a CDK5 activator, increased significantly and it colocalized with nNOS in the 5 × FAD cortex. In silico analysis revealed that a new nNOS-specific GSP (glycine-serine-proline) motif was well-conserved across species at nNOS-Ser293, which is located ahead of the N-terminal hook. This motif was not present in the closely related isoform, endothelial NOS. Motif scan analysis also predicted that CDK5 can phosphorylate nNOS-Ser293 with a high likelihood. An in vitro phosphorylation assay clearly showed that CDK5/p25 does indeed phosphorylate nNOS-Ser293. Finally, nNOS-S293D mutant, a phosphomimetic form of nNOS-Ser293, and nNOS-S293A mutant, a neutral form of nNOS-Ser293, significantly decreased nNOS dimerization and NO production. Taken together, our results demonstrate that nNOS dimers are disrupted in the 5 × FAD cortex, and nNOS-Ser293, a potential site of CDK5 phosphorylation, may be involved in the decrease in nNOS dimerization and NO production, and the development of AD.
KW - Alzheimer's disease
KW - Cyclin-dependent kinase 5
KW - Dimerization
KW - Neuronal nitric oxide synthase
KW - Phosphorylation
KW - p25
UR - http://www.scopus.com/inward/record.url?scp=84975471926&partnerID=8YFLogxK
U2 - 10.1016/j.neuint.2016.06.005
DO - 10.1016/j.neuint.2016.06.005
M3 - Article
C2 - 27296112
AN - SCOPUS:84975471926
SN - 0197-0186
VL - 99
SP - 52
EP - 61
JO - Neurochemistry International
JF - Neurochemistry International
ER -