Regulation of B Cell Development and Function by Zfp521

Zfp521 对 B 细胞发育和功能的调节

• 批准号: 8683097
• 负责人: James R. Hagman
• 金额: $ 39.43万
• 依托单位: NATIONAL JEWISH HEALTH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-03 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8683097
• 关键词: Antibodies; Antibody Formation; B-Cell Development; B-Lymphocytes; Binding; Binding Sites; Biochemical; Biochemistry; Bioinformatics; Bone Marrow; Calorimetry; Cell Lineage; Cellular biology; ChIP-seq; Chromatin; Chronic Lymphocytic Leukemia; Commit; Complex; Consensus; Crystallography; DNA; DNA Binding; Development; Epigenetic Process; Flow Cytometry; Gene Expression Profiling; Gene Rearrangement; Gene Targeting; Generations; Genes; Genetic Transcription; Genome; Glean; Hematopoietic stem cells; Immature B-Lymphocyte; Immune response; Immunoglobulin Genes; In Vitro; Knockout Mice; Laboratories; Location; Lymphopoiesis; Mature B-Lymphocyte; Measures; Modeling; Molecular; Mus; Nuclear Protein; Process; Proteins; Proto-Oncogenes; Reagent; Regulation; Regulator Genes; Relative (related person); Research; Site; Structural Models; Structure; Surface Plasmon Resonance; System; Testing; Time; Titrations; Transcriptional Regulation; base; chromatin modification; design; experience; in vitro activity; in vivo; leukemia/lymphoma; mutant; novel; progenitor; programs; promoter; protein protein interaction; protein structure; transcription factor; transcriptome sequencing

DESCRIPTION (provided by applicant): Summary B cell development in the bone marrow proceeds in a stepwise process from multipotent hematopoietic stem cells (HSCs) to committed immature B lymphocytes. Research has elucidated a B cell-specific regulatory network of transcription factors necessary for the development of early B cells. These proteins include Early B cell Factor 1 (EBF1), which drives B lineage specification and commitment. Although much is known about EBF1, there are many unanswered questions concerning its regulation in B cells and its potential for protein- protein interactions. Several lines of evidence point to Zfp521 (Evi3/ZNF521/EHZF) as a co-regulator of gene transcription with EBF1. Zfp521 interacts physically with EBF1 and can repress its activity in vitro. Zfp521 is co- expressed with EBF1 in developing B cells. However, little is known concerning functions of Zfp521 in B cell development. Specifically, the mechanisms by which Zfp521 modulates activities of EBF1 and the basis and consequences of physical interactions between Zfp521 and EBF1 are unknown. We have demonstrated that early B cell development is perturbed greatly in the absence of Zfp521. This is evidenced by a lack of expression of markers of late pro-B cells and pre-B cells and decreased immature B cells in bone marrow of Zfp521-deficient mice. As a mechanism that integrates the activities of both Zfp521 and EBF1, recent studies in our laboratory using newly developed antibody reagents detected Zfp521 binding to promoters that also bind EBF1. Co-occupancy of Zfp521 and EBF1 on these genes suggests a new model for co-regulation of B lymphopoiesis. In this manner, EBF1, the B lineage determination factor, is regulated by Zfp521 in developing B cells. Hypotheses: Zfp521 is critically important for B cell lymphopoiesis and function. We propose that it regulates the B cell program via EBF1-dependent and -independent mechanisms. Zfp521 interacts with EBF1 to limit its DNA binding, but Zfp521 also assembles complexes with EBF1 on target gene DNA. Determining the basis of interactions between EBF1 and Zfp521 at the molecular level is critical for understanding how the B cell regulatory network generates mature B cells capable of secreting antibodies in humoral immune responses. Therefore, we will: Determine how Zfp521 regulates gene transcription in developing B cells. Determine how Zfp521 functions in the B cell regulatory network by identifying its binding sites in pro- B cells. Define structural requirements and functional consequences of Zfp521 interactions with EBF1.

描述（由申请人提供）： 概述 骨髓中的 B 细胞发育是从多能造血干细胞 (HSC) 到定型的未成熟 B 淋巴细胞的逐步过程。研究阐明了早期 B 细胞发育所必需的 B 细胞特异性转录因子调控网络。这些蛋白质包括早期 B 细胞因子 1 (EBF1)，它驱动 B 谱系规范和承诺。尽管人们对 EBF1 了解很多，但关于它在 B 细胞中的调节及其蛋白质-蛋白质相互作用的潜力，还有许多未解答的问题。多条证据表明 Zfp521 (Evi3/ZNF521/EHZF) 与 EBF1 一起作为基因转录的共同调节因子。 Zfp521 与 EBF1 发生物理相互作用，并可在体外抑制其活性。 Zfp521 在发育中的 B 细胞中与 EBF1 共表达。然而，关于 Zfp521 在 B 细胞发育中的功能知之甚少。具体而言，Zfp521 调节 EBF1 活性的机制以及 Zfp521 和 EBF1 之间物理相互作用的基础和后果尚不清楚。 我们已经证明，在 Zfp521 缺失的情况下，早期 B 细胞发育会受到极大干扰。 Zfp521 缺陷小鼠的骨髓中缺乏晚期 pro-B 细胞和前 B 细胞标记物的表达以及减少的未成熟 B 细胞就证明了这一点。作为整合 Zfp521 和 EBF1 活性的机制，我们实验室最近使用新开发的抗体试剂进行的研究检测到 Zfp521 与也结合 EBF1 的启动子结合。 Zfp521 和 EBF1 在这些基因上的共同占用表明了 B 淋巴细胞生成共同调节的新模型。通过这种方式，EBF1（B 谱系决定因子）在发育中的 B 细胞中受到 Zfp521 的调节。假设：Zfp521 对于 B 细胞淋巴细胞生成和功能至关重要。我们认为它通过 EBF1 依赖和独立机制调节 B 细胞程序。 Zfp521 与 EBF1 相互作用以限制其 DNA 结合，但 Zfp521 也在靶基因 DNA 上与 EBF1 组装复合物。在分子水平上确定 EBF1 和 Zfp521 之间相互作用的基础对于了解 B 细胞调节网络如何生成能够在体液免疫反应中分泌抗体的成熟 B 细胞至关重要。因此，我们将： 确定 Zfp521 如何调节发育中 B 细胞的基因转录。通过识别 Zfp521 在原 B 细胞中的结合位点，确定 Zfp521 如何在 B 细胞调节网络中发挥作用。定义 Zfp521 与 EBF1 相互作用的结构要求和功能后果。