Study on physiological function of a brainspecific 14 kDa protein (PNP 14)

脑特异性14 kDa蛋白（PNP 14）的生理功能研究

• 批准号: 04671370
• 负责人: NAKAJO Shigeo
• 金额: $ 0.51万
• 依托单位: Showa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04671370/
• 关键词: phosphoneuroprotein; PNP 14; brain-specific protein; tyrosine phosphorylation; axonal transport; tyrosine kinase; calmodulin kinase II; pp60^<src>; in situハイブリダイゼーション; 神経特異的タンパク質

A novel brain-specific protein with a molecular mass of 14 kDa was found and purified from bovine crebral cortex. In the present work, the primary structure of PNP 14 was determined. This protein is composed of 134 amino acid residues (molecularmass = 14,122 Da). We found that the protein was phosphorylated in*2+*vivo as well as in vitro. In vitro experiments showed that Ca*, calmodulin-dependent protein kinase II is responsible for the phosphorylation of Ser118, and tyrosine kinases such as EGF receptors and pp60^<v-src> catalyze tyrosine phosphorylation of PNP 14. The phosphorylation site of PNP 14 phosphorylated by EGF receptors was Tyr39. PNP 14 formed complex with phosphtidylinositol 3-kinase or pp60^<c-src>. Localization of PNP 14 and its mRNA expression in rat brain were investigated by immunohistochemistry and in situ hybridization. PNP 14 immunoreactivity was detected in cerebellar cortex. No PNP 14 immunoreactivity was detected in cerebellar medulla. In cerebrum, the immunoreactivity was found throughout cerebral cortex, especially in the layr V.It was also found in hippocampus and striatum. Electron microscopic observation revealed that the immunoreactivity was detected in the cytoplasmic matrix in the presynaptic axon terminals. PNP 14 mRNA was observed in granular layr of cerbellar cortex, hippocampus and cerebral cortex. These findings suggested that PNP 14 play important role in presynaptic axon terminals and the function is regulated by phosphorylation reaction.

从牛脑皮层中发现并纯化了一种分子质量为14 kDa的新型脑特异性蛋白。在本工作中，确定了PNP 14的主要结构。该蛋白由134个氨基酸残基组成（分子质量= 14,122 Da）。我们发现该蛋白在*2+*体内和体外都被磷酸化。体外实验表明，钙调素依赖性蛋白激酶II （Ca*）负责Ser118的磷酸化，EGF受体和pp60^<v-src>等酪氨酸激酶催化PNP 14的酪氨酸磷酸化。EGF受体磷酸化的PNP - 14的磷酸化位点为Tyr39。PNP 14与磷脂酰肌醇3-激酶或pp60^<c-src>形成复合物。采用免疫组织化学和原位杂交技术研究PNP - 14在大鼠脑中的定位及其mRNA表达。小脑皮层检测PNP - 14免疫反应性。小脑髓质未检测到PNP - 14免疫反应性。在大脑中，免疫反应性遍及整个大脑皮层，特别是在v层，海马和纹状体也有。电镜观察发现，突触前轴突末端的细胞质基质中存在免疫反应性。小脑皮层、海马和大脑皮层颗粒层均可见PNP - 14 mRNA表达。提示PNP - 14在突触前轴突终末起重要作用，其功能受磷酸化反应调控。

项目成果

Nakajo, S., Tsukada, K., Omata, K., Nakamura, Y., and Nakaya, K.: "A new brain-apecific 14-kDa protein is a phosphoprotein Its complete amino acid sequence and evidence for phosphorylation." Eur. J.biochem.217. 1057-1063 (1993)

Nakajo, S.、Tsukada, K.、Omata, K.、Nakamura, Y. 和 Nakaya, K.：“一种新的脑特异性 14-kDa 蛋白是一种磷蛋白，它具有完整的氨基酸序列和磷酸化的证据。”

Nakajo,S.: "A new brain-specific 14-kDa protein is a phosphoprotein Its complete amino acid sequence and evidence for phosphorylation" Eur.J.Biochem.217. 1057-1063 (1993)

Nakajo,S.：“一种新的大脑特异性 14-kDa 蛋白是一种磷蛋白，其完整的氨基酸序列和磷酸化的证据”Eur.J.Biochem.217。