Wei Qiou, Miskimins W Keith, Miskimins Robin
Division of Basic Biomedical Sciences, University of South Dakota School of Medicine, Vermillion, SD 57069, USA.
Gene. 2003 Aug 14;313:161-7. doi: 10.1016/s0378-1119(03)00675-9.
Expression of myelin basic protein in differentiating oligodendrocytes is mainly regulated at the transcriptional level. To better understand the regulation of myelin basic protein gene expression in mammalian cells, we cloned and characterized the rat myelin basic protein promoter by a genome walking technique. Extensive sequence homology has been found among mouse, rat and human MBP promoters. Alignment of the proximal core promoter of mouse and rat reveals highly conserved cis-elements that are important for regulating myelin basic protein gene transcription. One major transcription start site along with two minor sites have been identified in both mouse and rat myelin basic protein gene promoters using RNA ligase-mediated rapid amplification of 5' cDNA ends. The amplified rat myelin basic protein promoter was cloned into a luciferase reporter construct. Transient transfection experiments show that both mouse and rat myelin basic protein promoters yield increased expression when oligodendrocytes differentiate. The sequence and characterization of the rat MBP promoter provide a useful tool to investigate MBP gene regulation in mammalian cells.
髓鞘碱性蛋白在少突胶质细胞分化过程中的表达主要在转录水平受到调控。为了更好地理解哺乳动物细胞中髓鞘碱性蛋白基因表达的调控机制，我们通过基因组步移技术克隆并鉴定了大鼠髓鞘碱性蛋白启动子。在小鼠、大鼠和人类的髓鞘碱性蛋白启动子之间发现了广泛的序列同源性。小鼠和大鼠近端核心启动子的比对揭示了对髓鞘碱性蛋白基因转录调控很重要的高度保守的顺式元件。利用RNA连接酶介导的5' cDNA末端快速扩增技术，在小鼠和大鼠髓鞘碱性蛋白基因启动子中均鉴定出一个主要转录起始位点和两个次要位点。将扩增得到的大鼠髓鞘碱性蛋白启动子克隆到荧光素酶报告基因构建体中。瞬时转染实验表明，当少突胶质细胞分化时，小鼠和大鼠的髓鞘碱性蛋白启动子均能使表达增加。大鼠髓鞘碱性蛋白启动子的序列和鉴定为研究哺乳动物细胞中髓鞘碱性蛋白基因的调控提供了一个有用的工具。
