Emerin functions in transcriptional regulation

艾默林在转录调控中的功能

• 批准号: 6584099
• 负责人: JAMES Michael HOLASKA
• 金额: $ 4.16万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6584099
• 关键词: binding proteins; gene mutation; genetic regulation; genetic transcription; membrane proteins; muscular dystrophy; nuclear membrane; protein protein interaction; protein sequence; protein structure function; site directed mutagenesis; thymopoietin

DESCRIPTION (provided by applicant): The presence of the nuclear envelope in eukaryotes functionally separates the processes of transcription and translation. The ability to have these processes disjoined serves to establish greater transcriptional and translational regulation. The nuclear envelope consists of an outer nuclear membrane, which is contiguous with the endoplasmic reticulum, and an inner nuclear membrane (INM). The INM contains numerous integral membrane proteins that bind to both lamins and chromatin-associated proteins. One of these proteins, emerin, directly binds the nuclear lamina and a chromatin associated protein named Barrier-to-Autointegration (BAF). Interestingly, mutation or deletion of emerin causes the recessive form of Emery-Dreifuss muscular dystrophy (EDMD). Although emerin is expressed in most cell types tested, EDMD specifically targets muscle and adipose tissue, suggesting a role for emerin in tissue-specific functions. Recently it has been demonstrated that another INM protein, Lap213, interacts with a transcriptional repressor, germ-cell-less (GCL). Since Lab2beta and emerin share a significant region of homology, I tested whether emerin could interact with transcriptional repressors. Both GCL and EBP1, another transcriptional regulator, bind emerin. I propose that emerin may recruit transcriptional regulators to the nuclear envelope and form functional repressor or activator complexes here. To test this model, I will fine-map the functional domains within emerin, GCL, and EBP1 necessary for this interaction. Using mutational analysis, I will identify the domain(s) in emerin that interact(s) with GCL and EBP1. Mutations will also be made in GCL and EBP in order to map the 'emerin binding domain' in each of these proteins. Once identified, the(se) emerin binding domain(s) will be used to identify other emerin binding proteins. The initial characterization of these interactions will serve as the foundation for studying the role of the nuclear envelope in transcriptional regulation in my own laboratory.

描述（由申请人提供）： 真核生物中核膜的存在在功能上将转录和翻译过程分开。将这些过程分开的能力有助于建立更好的转录和翻译调控。核膜由与内质网相邻的外核膜和内核膜（INM）组成。 INM 包含许多与核纤层蛋白和染色质相关蛋白结合的整合膜蛋白。其中一种蛋白质艾默林 (emerin) 直接结合核纤层和一种名为自动整合屏障 (BAF) 的染色质相关蛋白。有趣的是，Emerin 的突变或缺失会导致隐性形式的 Emery-Dreifuss 肌营养不良症 (EDMD)。尽管 emerin 在大多数测试的细胞类型中表达，但 EDMD 专门针对肌肉和脂肪组织，这表明 emerin 在组织特异性功能中发挥作用。最近，已证明另一种 INM 蛋白 Lap213 与转录抑制因子、无生殖细胞 (GCL) 相互作用。由于 Lab2beta 和 emerin 具有显着的同源性区域，我测试了 emerin 是否可以与转录抑制因子相互作用。 GCL 和另一种转录调节因子 EBP1 均与 emerin 结合。我认为艾默林可能会将转录调节因子招募到核膜并在此形成功能性阻遏物或激活物复合物。为了测试这个模型，我将精细映射此交互所需的 emerin、GCL 和 EBP1 内的功能域。通过突变分析，我将识别 emerin 中与 GCL 和 EBP1 相互作用的结构域。 GCL 和 EBP 也将发生突变，以便绘制这些蛋白质的“emerin 结合域”图谱。一旦鉴定，emerin结合结构域将用于鉴定其他emerin结合蛋白。这些相互作用的初步表征将作为我自己实验室研究核膜在转录调控中的作用的基础。