Nikaido Takuya, Iseki Ken, Mori Tetsuji, Takaki Hiromi, Yokoya Sachihiko, Hagino Seita, Takeda Junko, Zhang Yuxiang, Takeuchi Mayumi, Kikuchi Shin-ichi, Wanaka Akio
Department of Cell Science, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Japan.
Brain Res Mol Brain Res. 2002 Dec;108(1-2):129-38. doi: 10.1016/s0169-328x(02)00521-1.
We reported the expression patterns of a novel member of the CREB/ATF family, OASIS, in central nervous system (CNS) lesions and its transcriptional activity. OASIS gene expression was upregulated in the stab-injured spinal cord. Double labeling experiments revealed that the distribution of OASIS mRNA-positive cells overlapped with a population of GFAP-immunoreactive cells. This finding suggested that OASIS might regulate expression of important downstream molecules in certain subset of the reactive astrocytes (e.g. inhibitory substances in injured brain). In gel shift assays, OASIS was able to specifically bind to CRE as CREB family members were. We then examined transcriptional activity of full-length OASIS with GAL4-UAS-luciferase reporter assay in COS7 cells. OASIS protein activated transcription, but did not inhibit basal transcription driven by AdML promoter. To determine critical portion(s) of the OASIS protein in transcriptional activation, we examined the activity of various deletion constructs of OASIS gene. The assay revealed that a strong transcriptional activation domain lay in the N-terminal region where acidic amino acids clustered and a possible repression domain, which had not been reported for other CREB/ATF family members, lay in the more C-terminal region. We therefore proposed that OASIS protein positively regulated gene transcription in a subset of reactive astrocytes, and thereby influenced the reaction of injured CNS tissues.
我们报道了CREB/ATF家族的一个新成员OASIS在中枢神经系统（CNS）损伤中的表达模式及其转录活性。在脊髓刺伤损伤中，OASIS基因表达上调。双重标记实验显示，OASIS mRNA阳性细胞的分布与一组GFAP免疫反应性细胞重叠。这一发现表明，OASIS可能调节反应性星形胶质细胞特定亚群中重要下游分子的表达（例如损伤脑中的抑制性物质）。在凝胶迁移实验中，与CREB家族成员一样，OASIS能够特异性结合CRE。然后，我们在COS7细胞中用GAL4-UAS-荧光素酶报告基因检测法检测了全长OASIS的转录活性。OASIS蛋白激活转录，但不抑制由AdML启动子驱动的基础转录。为了确定OASIS蛋白在转录激活中的关键部分，我们检测了OASIS基因各种缺失构建体的活性。检测结果显示，一个强大的转录激活域位于N端区域，此处酸性氨基酸聚集，而一个可能的抑制域位于更靠C端的区域，这是其他CREB/ATF家族成员未曾报道过的。因此，我们提出OASIS蛋白在反应性星形胶质细胞的一个亚群中正向调节基因转录，从而影响受损CNS组织的反应。
