mRNA alternative polyadenylation in B cell development

B 细胞发育中的 mRNA 替代多腺苷酸化

• 批准号: 10629377
• 负责人: Roger Sciammas
• 金额: $ 77.68万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-26 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10629377
• 关键词: Alleles; Alternative Splicing; Antibodies; Antibody Response; Autoimmune Diseases; B-Cell Activation; B-Cell Development; B-Lymphocytes; Binding; Biochemical; Biological Process; CRISPR screen; Cell physiology; Cells; Complex; Data; Development; Disease; Gene Expression Regulation; Genes; Immune response; Immunoglobulin M; Individual; Link; Malignant Neoplasms; Membrane; Messenger RNA; Modeling; Neurodegenerative Disorders; Pattern; Play; Poly A; Polyadenylation; Post-Transcriptional Regulation; Process; Protein Isoforms; Proteins; RNA Processing; RNA-Binding Proteins; Regulation; Reporter; Reporting; Role; Signaling Protein; Testing; Transcript; Transcriptional Activation; Transcriptional Regulation; Work; cell mediated immune response; design; gene network; genetic approach; genome-wide; insight; novel; transcription factor; vaccine development

Project summary: The vast majority of mammalian genes produce alternatively processed mRNAs through alternative splicing and alternative polyadenylation (APA). Different mRNA isoforms produced from the same gene can encode distinct proteins and/or they may be differentially regulated. Recent studies have revealed essential roles of mRNA alternative processing in many biological processes and mis-regulation of alternative splicing and APA has been causally linked to a wide range of diseases, including cancer and neurodegenerative diseases. However, the mechanism and functions of alternative mRNA processing remain poorly understood.Antibody secretion by B cells is a major component of our immune response and mis-regulated antibody response underlies many auto-immune diseases. B cell activation and differentiation require a sophisticated gene regulation cascade. Previous works, including ours, have provided insights into the transcriptional regulation mechanisms governing this process. However, it is clear that post- transcriptional gene regulation, such as alternative splicing and APA, also play an important role. In 1980, several landmark studies reported the first example of alternative RNA processing: the Immunoglobulin M (IgM) heavy chain gene (IghM) produces two APA isoforms, which encode a membrane-bound and a secreted IgM respectively. Additionally the IghM APA is developmentally regulated. Subsequent studies, however, have failed to provide a consistent mechanistic model for this APA switch. Furthermore, it remains unknown how widespread the APA regulation network is and what the functional impact of APA regulation is during B cell activation and differentiation. In our preliminary studies, we provided evidence that transcription factors, core mRNA 3’ processing factors, and RNA-binding proteins regulate IghM APA. In addition, we discovered that B cell activation leads to a significantly change in the APA patterns of ~900 genes, including those encoding key cell fate regulators and signaling proteins. Based on these preliminary results, we hypothesize that the APA of IghM and a large gene network are regulated at multiple levels and that APA regulation plays an important role in B cell functions. To test these hypotheses, we have designed the following specific aims: 1) Identify regulators of B cell activation-induced IghM APA switch using a biochemical and genetic approach; 2) Systematically characterize the mechanisms of B cell activation-induced IghM APA switch; 3) Determine the role of APA regulation in B cell activation and differentiation. Successful completion of the proposed studies will provide fundamental insights into APA regulation and function. More importantly, our results will reveal the role of post-transcriptional gene regulation in B cell development and B cell- mediated immune response, which will pave the way for better strategies for developing vaccines and treatment for autoimmune diseases.

项目概要： 绝大多数哺乳动物的基因产生交替加工的mRNA， 选择性剪接和选择性聚腺苷酸化（阿帕）。产生的不同mRNA亚型 来自相同基因的基因可以编码不同的蛋白质和/或它们可以被差异调节。 最近的研究揭示了mRNA替代加工在许多生物学过程中的重要作用， 选择性剪接和阿帕的过程和错误调节与广泛的 一系列疾病，包括癌症和神经退行性疾病。然而，机制 和功能的替代mRNA加工仍然知之甚少。抗体分泌的B 细胞是我们免疫反应和错误调节抗体反应的主要组成部分 是许多自身免疫疾病的基础B细胞活化和分化需要复杂的 基因调控级联以前的作品，包括我们的作品， 转录调控机制控制这一过程。但很明显，后... 转录基因调控，如选择性剪接和阿帕，也发挥了重要作用。 1980年，几项具有里程碑意义的研究报道了替代RNA加工的第一个例子： 免疫球蛋白M（IgM）重链基因（IghM）产生两种阿帕亚型，编码一种 膜结合和分泌的IgM分别。此外，IghM阿帕在发育上 监管.然而，随后的研究未能提供一致的机制模型 这个阿帕开关。此外，还不清楚阿帕法规的适用范围有多大。 以及阿帕调节在B细胞活化过程中的功能影响， 分化在我们的初步研究中，我们提供了转录因子，核心 mRNA 3'加工因子和RNA结合蛋白调节IghM阿帕。另外我们 发现B细胞活化导致约900个基因的阿帕模式发生显著变化， 包括编码关键细胞命运调节因子和信号蛋白的那些。基于这些 初步结果，我们假设免疫球蛋白M的阿帕和一个大的基因网络受到调节， 阿帕调节在B细胞功能中起重要作用。测试这些 假设，我们设计了以下具体目标：1）确定调节B细胞 使用生物化学和遗传方法激活诱导的IghM阿帕开关; 2）系统地 表征B细胞活化诱导的IghM阿帕开关的机制; 3）确定 阿帕在B细胞活化和分化中的调节作用。圆满完成拟议的 这些研究将为阿帕的调节和功能提供基本的见解。更重要的是我们 结果将揭示转录后基因调控在B细胞发育和B细胞中的作用。 介导的免疫反应，这将为开发疫苗的更好策略铺平道路 和自身免疫性疾病的治疗。