Molecular Basis of DNA Specific and Non-Specific Site Recognition by ETS Transcription Factors

细胞内的遗传信息由被称为转录因子的蛋白质管理，转录因子是生命所必需的。Ets(E-26的缩写)是在所有多细胞动物中发现的一个相关转录因子家族，它们参与细胞中广泛的生物功能。为了发挥它们的功能，ETS蛋白必须在DNA中四种化学成分(A、C、G和T)的序列所确定的特定位置与DNA相互作用。这项研究将研究ETS蛋白质如何识别它们的目标DNA位点，并反过来告知细胞发育和适应其生物环境的更广泛的过程。该项目的知识将作为培训几名研究生和本科生以及华盛顿州立大学和佐治亚州立大学编写课程材料的基础。这些机构的特殊人口统计学特征将显著受益于NSF在STEM学科特别是生物物理科学方面的支持。ETS转录因子家族在动物(后生动物)中普遍存在，并调节大型基因网络的转录。它们的生物学功能依赖于由结构保守的DNA结合域(称为Ets结构域)决定的位点特异性DNA识别。虽然Ets结构域具有很强的结构保守性，但它们的氨基酸序列也具有高度的差异性。关于代表初级序列分歧极端的两个ETS成员PU.1和ETS-1的初步数据表明，这种多样性编码了ETS成员在DNA识别方面的显著差异。这个项目的目的是通过位点识别的热力学与溶液环境的动力学和耦合来描述ETS蛋白质利用的序列识别的机制。这项建议的一个主要重点是以PU.1和ETS-1为模型系统，在模拟细胞环境的溶液条件下，系统地定义ETS成员之间的多样性，其中结合位点嵌入在非特异性DNA中，溶液环境为半稀释。

Genetic information inside the cell is managed by proteins known as transcription factors, which are essential to life. 'ETS' (short for E-26) is a family of related transcription factors found in all multi-celled animals and they participate in a wide range of biological functions in the cell. To perform their functions, ETS proteins must interact with DNA at specific sites identified by the sequence of four chemical constituents in DNA (A, C, G, and T). This research will investigate how ETS proteins recognize their target DNA sites, and in turn inform the broader process by which cells develop and adapt to their biological environment. Knowledge from this project will serve as the basis for training several graduate and undergraduate students, as well as for developing curricular material at Washington State University and Georgia State University. The particular demographics of these institutions stand to benefit significantly from NSF support in STEM disciplines in general and biophysical science in particular.The ETS family of transcription factors is ubiquitous in animals (the Metazoa) and regulates the transcription of large networks of genes. Their biological functions depend on site-specific DNA recognition as determined by a structurally conserved DNA-binding domain (known as the ETS domain). Although ETS domains share strong structural conservation, their amino acid sequences are also highly divergent. Preliminary data on PU.1 and Ets-1, two ETS members that represent the extremes of primary sequence divergence, indicate that this diversity encodes distinctive differences in DNA recognition by ETS members. This project is aimed at delineating the mechanisms of sequence recognition utilized by ETS proteins through the kinetics and coupling of the thermodynamics of site recognition to the solution environment. A major focus of this proposal is to systematically define the diversity among ETS members, using PU.1 and Ets-1 as model systems, under solution conditions that mimic the cellular environment, in which binding sites are embedded within nonspecific DNA and the solution environment is semi-dilute.