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.

项目摘要： 绝大多数哺乳动物基因通过 替代剪接和替代聚腺苷酸化（APA）。产生的不同mRNA同工型 从同一基因可以编码不同的蛋白质和/或它们可能受到不同调节。 最近的研究揭示了mRNA替代加工在许多生物学中的重要作用 替代剪接和APA的过程和错误调节已与宽阔的联系 疾病范围，包括癌症和神经退行性疾病。但是，机制 替代mRNA加工的功能仍然很少理解。 细胞是我们免疫响应和错误调节抗体反应的主要组成部分 构成了许多自动免疫疾病。 B细胞激活和分化需要复杂的 基因调控级联。以前的作品，包括我们的作品，已经提供了有关的见解 转录调节机制管理此过程。但是，很明显， 转录基因调节（例如替代剪接和APA）也起着重要作用。 1980年，一些具有里程碑意义的研究报道了替代RNA处理的第一个例子： 免疫球蛋白M（IgM）重链基因（IGHM）产生两个APA同工型，它们编码A 膜结合和分泌的IgM。此外，开发了IGHM APA 受监管。然而，随后的研究未能提供一致的机械模型 对于此APA开关。此外，尚不清楚APA法规如何广泛 网络是B细胞激活期间APA调控的功能影响和 分化。在我们的初步研究中，我们提供了证据，表明转录因子，核心 mRNA 3'加工因子和RNA结合蛋白调节IGHM APA。另外，我们 发现B细胞激活导致〜900个基因的APA模式发生了显着变化， 包括编码钥匙细胞命运调节剂和信号蛋白的那些。基于这些 初步结果，我们假设IGHM和大基因网络的APA受到调节 在多个级别上，APA调节在B细胞功能中起重要作用。测试这些 假设，我们设计了以下特定目的：1）确定B细胞的调节剂 激活诱导的IGHM APA开关使用生化和遗传方法； 2）系统地 表征B细胞激活诱导的IGHM APA开关的机制； 3）确定角色 B细胞激活和分化中APA调控的。成功完成拟议的 研究将提供对APA调节和功能的基本见解。更重要的是，我们的 结果将揭示转录后基因调节在B细胞发育和B细胞中的作用 介导的免疫响应，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。