Kume H, Maruyama K, Shinozaki K, Kuzume H, Obata K
Laboratory of Neurochemistry, National Institute for Physiological Sciences, Myodaiji, Okazaki, Aichi 444-8585, Japan.
Brain Res Mol Brain Res. 1998 Sep 18;60(1):107-14. doi: 10.1016/s0169-328x(98)00176-4.
KW8, a NeuroD family basic helix-loop-helix protein, was initially cloned during the course of screening for the genes related to long term potentiation in rat hippocampal slice. Its homologue NDRF/NeuroD was also reported. In this report its phosphorylation and spatiotemporal distribution was studied. KW8 was expressed not only during embryonic and neonatal periods but also in adults. In adult, KW8 was expressed only in brain tissues, such as the cerebral cortex, hippocampus and cerebellum. Immunohistological studies revealed that KW8 was localized in the nuclei of neurons. On immunoblotting of rat brain tissue, COS-1 cells and Neuro2A cells overexpressing KW8, this protein was detected as several diffuse bands. Alkaline phosphatase treatment reduced the molecular weights of these bands. Metabolic labeling with 32Pi in COS-1 cells confirmed that the KW8 protein was phosphorylated in vivo. Some of the physiological functions of KW8 might be regulated by this phosphorylation. In yeast, the GAL4 fusion protein containing the C-terminal region of KW8 activated transcription of the reporter gene, suggesting that KW8 had transcriptional activity.
KW8是一种神经D家族的碱性螺旋-环-螺旋蛋白，最初是在筛选与大鼠海马切片长期增强相关基因的过程中克隆出来的。其同源物NDRF/NeuroD也有相关报道。在本报告中，对其磷酸化及时空分布进行了研究。KW8不仅在胚胎期和新生儿期表达，在成体中也有表达。在成体中，KW8仅在脑组织中表达，如大脑皮层、海马体和小脑。免疫组织学研究表明，KW8定位于神经元细胞核。在大鼠脑组织、过表达KW8的COS-1细胞和Neuro2A细胞的免疫印迹中，该蛋白被检测为几条弥散条带。碱性磷酸酶处理降低了这些条带的分子量。在COS-1细胞中用32Pi进行代谢标记证实，KW8蛋白在体内被磷酸化。KW8的一些生理功能可能受这种磷酸化的调节。在酵母中，含有KW8 C末端区域的GAL4融合蛋白激活了报告基因的转录，表明KW8具有转录活性。
