Regulation of Gene Expression By The Exon Junction Complex

外显子连接复合物对基因表达的调节

• 批准号: 1051022
• 负责人: Jessica Treisman
• 金额: $ 72万
• 依托单位: New York University Medical Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1051022&HistoricalAwards=false
• 关键词: Regulation; Gene; Expression; Exon; Junction

Intellectual Merit:Gene expression is the process of decoding the information stored in DNA to produce functional proteins or RNA. This process occurs in multiple steps. First, the DNA sequence is transcribed into RNA. The RNA may then be spliced to remove non-coding intron sequences, and transported to specific regions of the cell, before it is translated into protein. Finally, the RNA is degraded into nucleotides to terminate its expression. Each of these stages can be independently regulated, but they can also be linked by markers that reveal the history of an RNA molecule. One such marker is the exon-junction complex (EJC), a set of four core proteins that bind to RNA molecules during splicing and identify them as having been spliced. The presence of a bound EJC can alter RNA stability, localization and translation. This project is based on the discovery of a novel function for EJC subunits in the splicing process itself. The MAP kinase protein is an important mediator of many developmental signaling pathways that regulate cell survival, proliferation and differentiation. However, the cell faces challenges in expressing the MAP kinase gene, which is located in a repressive chromatin region and has very large introns that must be spliced out to produce the protein-coding transcript. Three subunits of the EJC (Mago, Y14 and eIF4AIII) are specifically required to splice MAP kinase as well as RNAs transcribed from other genes that have similar features. In contrast, the fourth subunit, Btz, has no effect on MAP kinase, but is required for the normal expression of a neuronal RNA-binding protein, Elav. This project will take a genome-wide approach to identify all the genes that are regulated by each subunit of the EJC and to determine the common features of each group. This analysis is likely to reveal new molecular functions for the complex as a whole and for its individual subunits. In addition, the project will investigate two potentially new biological functions for subunits of the EJC. One set of experiments will test whether Btz affects synapse formation by controlling the ability of Elav to regulate alternative splicing. Another set will test whether Mago and Y14 allow normal egg production by generating small RNAs used as a defense mechanism against mobile genetic elements. The results will give us a deeper understanding of the connection between splicing and other modes of RNA-based regulation. Broader impacts:The results of these studies will be published in scientific journals and presented at scientific meetings, and will also reach a broad audience through the Treisman lab web site. The project will provide advanced training to individuals at the graduate and postgraduate levels, and undergraduate students and high school students, including under-represented minorities, are also expected to participate during the summers. In addition, a former colleague and collaborator, Dr. Helen Sink, is now a science teacher at PS 7, a middle school in Harlem. The PI will provide Dr. Sink materials and equipment for scientific activities at PS 7 and will host interested students from Dr. Sink?s classes in the laboratory at NYU to carry out small projects related to the research. These outreach activities will increase awareness of scientific research among minority students at an early stage of their education.

智力优势：基因表达是解码储存在DNA中的信息以产生功能蛋白质或RNA的过程。此过程分多个步骤进行。首先，DNA序列被转录成RNA。然后，RNA可以被剪接以去除非编码内含子序列，并在其被翻译成蛋白质之前被转运到细胞的特定区域。最后，RNA被降解为核苷酸以终止其表达。 这些阶段中的每一个都可以独立调节，但它们也可以通过揭示RNA分子历史的标记联系起来。一种这样的标记是外显子连接复合物（EJC），一组四个核心蛋白，在剪接过程中与RNA分子结合，并将其识别为已被剪接。结合的EJC的存在可以改变RNA稳定性、定位和翻译。该项目是基于EJC亚基在剪接过程本身中的新功能的发现。MAP激酶蛋白是调节细胞存活、增殖和分化的许多发育信号通路的重要介质。然而，细胞在表达MAP激酶基因方面面临挑战，该基因位于抑制性染色质区域，具有非常大的内含子，必须将其拼接出来才能产生蛋白质编码转录本。EJC的三个亚基（Mago、Y14和eIF4AIII）是剪接MAP激酶以及从具有类似特征的其他基因转录的RNA所特别需要的。相反，第四个亚基Btz对MAP激酶没有影响，但对神经元RNA结合蛋白Elav的正常表达是必需的。该项目将采用全基因组方法来识别由EJC的每个亚基调控的所有基因，并确定每组的共同特征。这种分析可能揭示复合物作为一个整体及其单个亚基的新分子功能。此外，该项目还将研究EJC亚基的两种潜在的新生物学功能。一组实验将测试Btz是否通过控制Elav调节选择性剪接的能力来影响突触形成。另一组将测试Mago和Y14是否通过产生小RNA作为对抗移动的遗传元件的防御机制来允许正常的卵子生产。这些结果将使我们更深入地了解剪接与其他基于RNA的调控模式之间的联系。更广泛的影响：这些研究的结果将发表在科学期刊上，并在科学会议上发表，还将通过Treisman实验室网站向广大受众传播。该项目将为本科生和研究生提供高级培训，预计本科生和高中生，包括代表人数不足的少数群体，也将在夏季参加。此外，一位前同事和合作者海伦·辛克博士现在是哈莱姆一所中学PS 7的科学教师。PI将为PS7的科学活动提供Sink博士的材料和设备，并将接待Sink博士感兴趣的学生。他在纽约大学的实验室里上课，进行与这项研究有关的小项目。这些外联活动将提高少数群体学生在教育早期阶段对科学研究的认识。