Structure/Function of CBFbeta

描述(申请人提供)：核心结合因子(CBF)是一个小的转录因子家族，由RUNX1、Runx2或Runx3基因编码的DNA结合亚基组成，以及由Cbfb基因编码的共同的非DNA结合CBF2亚基组成。我们发现，CBF2水平降低(正常的15%)的小鼠产生除T和NK细胞外的所有血细胞系。在CBF2缺乏的小鼠中，T细胞的发育在规范阶段流产，因为T细胞分化的最早标志无法表达。NK细胞的发育也很早就失败了，在NK祖细胞和未成熟NK细胞之间的过渡阶段。我们建议通过确定哪些DNA结合的RUNX亚基是NK祖细胞向未成熟NK细胞发展所必需的，来进一步表征CBF2不足引起的NK细胞缺陷。我们还将使用T细胞和NK细胞的体外发育分析来探索这些血统中CBF的生化功能。具体地说，我们将鉴定和表征CBF在T和NK细胞中招募到其靶基因的染色质重塑蛋白，并评估这些蛋白与T和NK细胞发育的相关性。我们将评估CBF相互作用蛋白的染色质占有率，以确定它们是否与CBF结合的全部或部分基因相关，以及它们的占有率是否与活性或非活性染色质状态相关。 项目简介：这些研究旨在了解对淋巴细胞形成至关重要的蛋白质是如何发挥其功能的。这是一个重要的研究领域，因为淋巴细胞发育受阻会导致免疫紊乱、白血病和淋巴瘤。

DESCRIPTION (provided by applicant): The core binding factors (CBFs) are a small family of transcription factors that consist of a DNA binding subunit encoded by the Runx1, Runx2, or Runx3 genes, and a common non-DNA binding CBF2 subunit encoded by the Cbfb gene. We showed that mice with reduced (15% of normal) CBF2 levels generate all blood cell lineages with the exception of T and NK cells. T cell development in CBF2-insufficient mice aborts at the specification stage, as the very earliest markers of T cell differentiation fail to be expressed. NK cell development also fails very early, at the transition between NK progenitors and immature NK cells. We propose to further characterize the NK cell defect caused by CBF2 insufficiency by determining which DNA-binding Runx subunit (or subunits) are required for the progression of NK progenitors to immature NK cells. We will also use in vitro assays of T and NK cell development to probe the CBF's biochemical functions in these lineages. Specifically, we will identify and characterize chromatin-remodeling proteins recruited by the CBFs to their target genes in T and NK cells, and assess the relevance of these proteins for T and NK cell development. We will assess chromatin occupancy by the CBF-interacting proteins to determine whether they associate with all or a subset of genes bound by the CBFs, and if their occupancy correlates with active or inactive chromatin states. Project Narrative: These studies aim to understand how proteins that are essential for lymphocyte formation perform their functions. This is an important area of research because disruption of lymphocyte development can lead to immune disorders, leukemia, and lymphoma.