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

细胞内的遗传信息是由被称为转录因子的蛋白质管理的，转录因子对生命至关重要。“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，它们在细胞中参与广泛的生物学功能。为了发挥其功能，ETS蛋白必须在DNA中四种化学成分（A、C、G和T）序列确定的特定位点与DNA相互作用。这项研究将研究ETS蛋白如何识别它们的靶DNA位点，进而为细胞发育和适应其生物环境的更广泛过程提供信息。从这个项目中获得的知识将作为培训几名研究生和本科生的基础，并为华盛顿州立大学和佐治亚州立大学开发课程材料。这些机构的特殊人口结构将从美国国家科学基金会对STEM学科的支持中获益，特别是生物物理科学。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结合结构域（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高度分化。对PU.1和ETS -1这两个代表一阶序列分化极端的ETS成员的初步数据表明，这种多样性编码了ETS成员之间DNA识别的显著差异。本项目旨在通过动力学和位点识别热力学与溶液环境的耦合来描述ETS蛋白利用的序列识别机制。本提案的主要重点是系统地定义ETS成员之间的多样性，使用PU.1和ETS -1作为模型系统，在模拟细胞环境的溶液条件下，结合位点嵌入在非特异性DNA中，溶液环境是半稀释的。

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.