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: 9097469
• 负责人: James R. Hagman
• 金额: $ 39.44万
• 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/9097469
• 关键词: Antibodies; Antibody Formation; B-Cell Development; B-Cell Leukemia; B-Lymphocytes; Binding; Binding Sites; Biochemical; Biochemistry; Bioinformatics; Bone Marrow; Calorimetry; Cell Lineage; Cellular biology; ChIP-seq; Chromatin; 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; 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细胞发育是一个从多能造血干细胞（hsc）到成熟B淋巴细胞的逐步过程。研究已经阐明了早期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谱系的规范和承诺。尽管我们对EBF1了解甚多，但关于其在B细胞中的调控及其在蛋白-蛋白相互作用中的潜力仍有许多未解之谜。一些证据表明Zfp521 （Evi3/ZNF521/EHZF）是EBF1基因转录的共同调节因子。Zfp521与EBF1物理相互作用，可以抑制其体外活性。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。具体来说，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，在缺乏Zfp521的情况下，早期B细胞的发育受到极大的干扰。zfp521缺陷小鼠骨髓中晚期前B细胞和前B细胞标记物的表达缺乏以及未成熟B细胞的减少证明了这一点。作为一种整合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作用提示了一种共同调控B淋巴生成的新模式。通过这种方式，B谱系决定因子EBF1在发育中的B细胞中受到Zfp521的调控。假设：Zfp521对B细胞淋巴生成和功能至关重要。我们认为它通过依赖和不依赖ebf1的机制调节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，对于理解B细胞调控网络如何在体液免疫反应中产生能够分泌抗体的成熟B细胞至关重要。因此，我们将：确定Zfp521如何调节发育中的B细胞的基因转录。通过鉴定Zfp521在前B细胞中的结合位点，确定Zfp521在B细胞调节网络中的功能。定义Zfp521与EBF1相互作用的结构要求和功能后果。