ANTISILENCING OF PLP GENE EXPRESSION IN OLIGODENDROCYTES

少突胶质细胞中 PLP 基因表达的抗沉默

• 批准号: 2682018
• 负责人: Patricia A. Wight
• 金额: $ 15.88万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-15 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2682018
• 关键词: DNA footprinting; chimeric proteins; complementary DNA; developmental genetics; gel mobility shift assay; gene deletion mutation; gene induction /repression; molecular cloning; myelin proteolipid; neurogenetics; nucleic acid sequence; oligodendroglia; oligonucleotides; tissue /cell culture; transcription factor

DESCRIPTION: Myelin is produced by oligodendrocytes in the CNS, and its role in propagation of the action potential along the axon has been well studied. Myelin is an extension of the glial cell's plasma membrane, however, it is biochemically very different. Part of this difference can be attributed to the composition of proteins specifically targeted to the myelin membrane. One of these proteins, the myelin proteolipid protein (PLP) together with its alternatively spliced isoform DM-20 accounts for about 50% of the total protein found in adult CNS myelin. The ratio of the two isoforms changes during development with expression of DM-20 occurring well before myelination, however, as development proceeds, PLP becomes the major isoform. Mutation in the PLP gene cause X linked dysmyelination and in humans has been associated with Pelizaeus-Merzbacher disease (PMD) and some types of spastic paraplegia (SPG-2). Some people with PMD show perturbations in PLP gene expression; cases of no expression (deletion of the gene) or overexpression have been described. Thus, accurate expression of the PLP gene is critical and elucidation of its regulation will be helpful in deciphering critical regulatory elements that are mutated in some PMD/SPG-2 patients. Furthermore, it is important to understand how the gene is regulated, to help promote the remyelination process in people with demyelinating diseases. Multiple Sclerosis the most common demyelinating disease, generally occurs in adult substantially after the myelination period. Since PLP gene regulation is developmentally controlled and expression of the gene decreases after the age of two in humans, it is fundamental the regulation of the PLP gene be understood. Preliminary results presented in this application suggest that the PLP gene expression in oligodendrocytes is regulated by interplay of silencing and antisilencing mechanisms mediated through elements located within the first intron. One of these elements appears to function as and antisilencer upon binding with its cognate DNA-binding protein and together they override repression mediated by negative regulatory elements located elsewhere in PLP intron 1. The overall objectives of this proposal are to identify the antisilencer and negative regulatory elements by deletion transfection analysis with PLP-lacZ fusion genes and to characterize the DNA binding protein which promotes antisilencing in oligodendrocytes by biochemical approaches. These studies will increase our knowledge of antisilencing as a novel means of gene regulation which has been described for only a few other genes.

描述：髓磷脂由中枢神经系统中的少突胶质细胞产生，其 动作电位沿轴突传播的作用已得到很好的证实 研究过。 髓磷脂是神经胶质细胞质膜的延伸， 然而，它在生物化学上却截然不同。 这种差异的一部分可以是 归因于专门针对的蛋白质的组成 髓磷脂膜。 这些蛋白质之一，髓磷脂蛋白脂质蛋白 (PLP) 及其选择性剪接异构体 DM-20 解释了 约占成人中枢神经系统髓磷脂总蛋白的 50%。 的比例为 随着 DM-20 表达的发生，两种亚型在发育过程中发生变化 然而，早在髓鞘形成之前，随着发育的进行，PLP 就成为 主要亚型。 PLP 基因突变导致 X 连锁髓鞘形成障碍 人类与佩利扎乌斯-梅茨巴赫病 (PMD) 和 某些类型的痉挛性截瘫 (SPG-2)。 一些患有 PMD 的人表现出 PLP 基因表达的扰动；没有表达的情况（删除 基因）或过度表达已被描述。 因此，准确表达 PLP 基因的研究至关重要，其调控的阐明将是 有助于破译在某些情况下发生突变的关键调控元件 PMD/SPG-2 患者。 此外，了解基因如何 受到监管，以帮助促进患有以下疾病的人的髓鞘再生过程 脱髓鞘疾病。 多发性硬化症是最常见的脱髓鞘疾病 疾病，通常发生在成人髓鞘形成后 时期。 由于 PLP 基因调控是受发育控制的 人类两岁后该基因的表达量下降， 从根本上了解 PLP 基因的调控。 初步的 本申请中提出的结果表明 PLP 基因表达 少突胶质细胞中的沉默和反沉默的相互作用进行调节 通过位于第一个内含子内的元件介导的机制。 一 这些元素中的一些似乎在与结合后起到抗沉默剂的作用 它的同源 DNA 结合蛋白，它们一起克服抑制 由位于 PLP 内含子 1 中其他位置的负调控元件介导。 该提案的总体目标是确定抗消音器和 通过 PLP-lacZ 缺失转染分析获得负调控元件 融合基因并​​表征 DNA 结合蛋白，该蛋白促进 通过生化方法抑制少突胶质细胞的沉默。 这些研究 将增加我们对抗沉默作为一种新的基因手段的认识 仅对少数其他基因进行了描述的调节。