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)：B细胞在骨髓中的发育经历了一个从多能造血干细胞(HSCs)到承诺的未成熟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血统的规范和承诺。虽然人们对EBF1了解很多，但关于它在B细胞中的调控以及它在蛋白质-蛋白质相互作用中的潜力，仍有许多未解的问题。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在物理上相互作用，在体外可以抑制其活性。Zfp521在发育中的B细胞中与EBF1共表达。然而，Zfp521在B细胞发育中的作用却鲜为人知。具体来说，Zfp521调控EBF1活性的机制以及Zfp521和EBF1之间物理相互作用的基础和结果尚不清楚。我们已经证明，在缺乏Zfp521的情况下，早期B细胞的发育受到很大的干扰。Zfp521基因缺陷小鼠骨髓中晚期Pro-B细胞和Pre-B细胞的标志物缺乏表达，幼稚B细胞减少，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进行的研究检测到Zfp521与启动子结合，该启动子也与EBF1结合。Zfp521和EBF1在这些基因上的共同存在为B淋巴细胞的共同调控提供了一种新的模式。通过这种方式，B谱系决定因子EBF1在B细胞发育过程中受到Zfp521的调节。假设：Zfp521对B细胞的淋巴生成和功能至关重要。我们认为它通过EBF1依赖和非依赖机制来调节B细胞程序。Zfp521与EBF1相互作用限制其与DNA的结合，但Zfp521也与EBF1在靶基因DNA上组装复合体。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细胞调控网络如何产生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如何调控发育中的B细胞的基因转录。通过确定Zfp521在Pro-B细胞中的结合位点，确定Zfp521如何在B细胞调控网络中发挥作用。定义Zfp521与EBF1相互作用的结构要求和功能后果。