Molecular Mechanisms of Myotonic Dystrophy

强直性肌营养不良的分子机制

• 批准号: 7270076
• 负责人: Andrew Berglund
• 金额: $ 24.77万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7270076
• 关键词: 3' Splice Site; Adopted; Adult; Alternative Splicing; Amino Acids; Binding; Biochemical; Bioinformatics; Biological Assay; Cell physiology; Complex; Disease; Fingers; Functional RNA; Genes; Goals; Helix (Snails); Heterogeneous Nuclear RNA; In Vitro; Introns; Lead; Methods; Molecular; Molecular Conformation; Muscular Dystrophies; Myotonia; Myotonic Dystrophy; Normal Cell; Nucleotides; Outcome; Patients; Protein Kinase; Proteins; RNA; RNA Binding; RNA Conformation; RNA Splicing; RNA-Binding Proteins; Regulation; Resolution; Role; Standards of Weights and Measures; Structure; Symptoms; Transcript; Work; cellular targeting; comparative; ear helix; gain of function; in vivo; mRNA Precursor; stem; therapy development

DESCRIPTION (provided by applicant): Myotonic dystrophy (DM) is caused by nucleotide expansions of CUG and CCUG in the non-coding regions of the dystrophia myotonia protein kinase gene (DMPK) and the Zn finger 9 gene (ZNF9) respectively. Patients with the CUG expansions have type I myotonic dystrophy (DM1) and patients with the CCUG expansions have type II myotonic dystrophy (DM2). Patients with DM1 and DM2 display the same symptoms, suggesting both CUG and CCUG expansions cause DM through the same mechanism. The hypothesis for how these non-coding expansions cause DM is through an RNA gain-of-function mechanism; the expanded CUG and CCUG repeat RNAs sequester the MBNL RNA binding protein and also indirectly increase the protein levels of another RNA binding protein (CUG-BP), which disrupts the normal cellular function of MBNL and CUG-BP. MBNL and CUG-BP are pre-mRNA splicing factors that appear to function antagonistically. Changing their "active" concentration results in the mis-regulation of alternative splicing of multiple transcripts with a final outcome of DM for people with CUG and CCUG expansions. The focus of this proposal is to determine the role of MBNL in the disease state (DM) as well as in normal cells. To accomplish these goals we are using a combination of bioinformatics, biochemical, biophysical and structural methods. Aim 1. Identify cellular targets of MBNL and determine the mechanisms through which MBNL regulates pre- mRNA splicing. Aim 2. Biochemical and structural characterization of CUG and CCUG repeats alone and in complex with MBNL. Our goal is to understand the molecular mechanisms that cause DM. This understanding will help lead to the development of therapies to help the many people (1 in 8000) that have this most common form of adult onset muscular dystrophy.

描述（由申请人提供）：强直性肌营养不良（DM）是由肌强直性肌营养不良蛋白激酶基因（DMPK）和锌指9基因（ZNF9）的非编码区中的CUG和CCUG分别的核苷酸扩增引起的。患有 CUG 扩张的患者患有 I 型强直性肌营养不良 (DM1)，患有 CCUG 扩张的患者患有 II 型强直性肌营养不良 (DM2)。 DM1 和 DM2 患者表现出相同的症状，表明 CUG 和 CCUG 扩张通过相同的机制导致 DM。关于这些非编码扩展如何导致 DM 的假设是通过 RNA 功能获得机制实现的；扩增的CUG和CCUG重复RNA会隔离MBNL RNA结合蛋白，并间接增加另一种RNA结合蛋白（CUG-BP）的蛋白水平，从而破坏MBNL和CUG-BP的正常细胞功能。 MBNL 和 CUG-BP 是前 mRNA 剪接因子，其功能似乎是拮抗的。改变它们的“活性”浓度会导致多个转录本选择性剪接的错误调节，最终导致 CUG 和 CCUG 扩增患者出现 DM。该提案的重点是确定 MBNL 在疾病状态 (DM) 以及正常细胞中的作用。为了实现这些目标，我们结合使用生物信息学、生物化学、生物物理和结构方法。目标 1. 鉴定 MBNL 的细胞靶标并确定 MBNL 调节前 mRNA 剪接的机制。目标 2. 单独的 CUG 和 CCUG 重复序列以及与 MBNL 复合的 CUG 和 CCUG 重复序列的生化和结构表征。我们的目标是了解导致 DM 的分子机制。这种理解将有助于开发治疗方法，以帮助许多患有这种最常见的成人发病型肌营养不良症的人（八千分之一）。