,Brain ischemia induces serine phosphorylation of neuronal nitric oxide synthase by Ca2+/calmodulin-

• 作 者: Xue-bo YAN Fan-jie MENG Bo SONG Guang-yi ZHANG
• 机 构: Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou 221002, China
• 出 处: 中国药理学报（英文版）
• 发表日期: 2004年5期
• 关键词: serine phosphorylation nitric oxide synthase calmodulin kinase KN 62 brain ische

AIM: To investigate whether brain ischemia induces serine phosphorylation of neuronal nitric oxide synthase (nNOS) by Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKII) and the interaction between CaMKIIα and nNOS in rat hippocampus. METHODS: Brain ischemia was induced by bilateral carotid artery occlusion procedure.Phosphorylation and the interaction of proteins were studied by immunoprecipitation and immunoblotting. We investigated during brain ischemia serine phosphorylation and amount of nNOS in crude membranes fraction (P)and cytosolic fraction (S), interaction between CaMKIIα and nNOS, and the effects of 1-[N,O-bis-(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62, a selective inhibitor of CaMKII) on phosphorylation and the interaction of proteins in P. RESULTS: Serine phosphorylation of nNOS in P increased persistently during brain ischemia, and 15 min ischemia-induced serine phosphorylation of nNOS was attenuated significantly by KN-62. But there was no serine phosphorylation of nNOS in S. The distributions of nNOS were not affected by ischemia and KN-62. However, the binding levels of both CaMKIIα with nNOS and Thr286 autophosphorylated CaMKIIα with nNOS increased after ischemia, and were diminished by KN-62. CONCLUSION:CaMKII interacted with nNOS and regulated serine phosphorylation of nNOS during brain isehemia.