Search for the Structural Basis of Biomacromolecular Fun

寻找生物大分子乐趣的结构基础

• 批准号: 7291757
• 负责人: Yun Xing m wang
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7291757
• 关键词: Search; Structural; Basis; Biomacromolecular; Fun

The general research interests of our group are to study fundamental mechanism that governs biological process from structural biology point of view. We study the systems that include nucleic acids, enzymes and RNA-protein-drug complexes using NMR and various other biophysical and biochemical methods. Our current research focuses are the following.1. RAP project. Of the more than 140,000 genes in the human genome, roughly 20-30% code for integral membrane proteins. These proteins have a vast array of functions ranging from receptors of cellular signals to channels for transporting ions and small molecules. Most importantly, membrane proteins represent the cellular targets for approximately 60% of all drugs currently manufactured. The low density lipoprotein receptor-related protein (LRP) is a large endocytic receptor that involved in several biological pathways, including Wint pathway, and plays prominent roles in lipoprotein metabolism and in the catabolism of proteinases involved in coagulation. LRP is also the cellular entry gateway for several viruses and toxins. The protein that is responsible for the well-being of this important class of the receptor is called the receptor associated protein (RAP). In the ER, RAP acts like a molecular chaperone by interacting with newly synthesized receptor to help it fold. In the meantime, RAP serves as an antagonist to prevent other ligands from binding to the receptors prematurely in the secretory pathway, and escorts the receptors from the ER to the Golgi where it dissociates from the receptors before recycling back to the ER. The aim of the project is to study the structure biology of RAP and its interaction with LRP. The first phase of the project is to determine the solution structure of the protein and is to reveal the structure basis for RAP's biological function using various methods and tools. At this point, we are completing the first phase study. We are also planning study the complex structure formed between RAP and the LRP fragment.2. L11 and L11-rRNA-thiostrepton project. High resolution X-ray crystal structures of ribosome together with the accumulative knowledge from previous investigation have tremendously enhanced our understanding the structure and the function of this protein synthesis machinery. In addition to its central role in protein synthesis, ribosome biogenesis and translation control are also essential cellular processe. Several tumor suppressors and proto-oncogenes have been found either to affect the formation of the mature ribosome or to regulate the activity of proteins known as translation factors. Furthermore, several ribosome proteins have been implicated in inactivating HDM2/MDM2, a p53 inhibitor and inducing p53 activity in response to cellular stress. The findings revealed a new pathway of regulating HDM2/p53 activity under stress cellular environment. These newly revealed roles for ribosome proteins necessitate a need to study these proteins from a fresh angle in the context of both ribosome protein synthesis as well as their potential regulatory roles. L11 is recognized to play an important role in the elongation and translocation cycle of protein synthesis, during which the activities of EF-TU and EF-G at both GTP and GDP stages require coordinated movement between the factors and the L11 N-terminal domain. L11 is absent from the 2.4 resolution X-ray map of 50 S subunit, and its orientation between the two domains in the cryo EM density map of 50 S ribosome is different by ca. 40 degrees from that in the binary complex formed between L11 and rRNA. Hence, there is a need for a clear understanding of the L11 structure and its role. The aim of the project is to study the dynamics of L11 in free and the ternary complex forms, and the mechanism of inhibition of protein synthesis by thiostrepton.

我们课题组的总体研究兴趣是从结构生物学的角度研究控制生物过程的基本机制。我们使用 NMR 和各种其他生物物理和生化方法研究包括核酸、酶和 RNA-蛋白质-药物复合物的系统。我们目前的研究重点如下： 1． RAP 项目。在人类基因组的 140,000 多个基因中，大约 20-30% 编码整合膜蛋白。这些蛋白质具有广泛的功能，从细胞信号受体到运输离子和小分子的通道。最重要的是，膜蛋白代表了目前生产的所有药物中约 60% 的细胞靶点。低密度脂蛋白受体相关蛋白（LRP）是一种大型内吞受体，参与包括Wint途径在内的多种生物途径，并在脂蛋白代谢和参与凝血的蛋白酶的分解代谢中发挥重要作用。 LRP 也是多种病毒和毒素的细胞进入网关。负责这一类重要受体健康的蛋白质称为受体相关蛋白 (RAP)。在 ER 中，RAP 通过与新合成的受体相互作用来帮助其折叠，从而发挥分子伴侣的作用。同时，RAP 作为拮抗剂，防止其他配体在分泌途径中过早地与受体结合，并将受体从 ER 护送至高尔基体，在高尔基体中与受体解离，然后再循环回 ER。该项目的目的是研究 RAP 的结构生物学及其与 LRP 的相互作用。该项目的第一阶段是确定蛋白质的溶液结构，并利用各种方法和工具揭示RAP生物功能的结构基础。至此，我们正在完成第一阶段的研究。我们还计划研究RAP和LRP片段之间形成的复杂结构。 2． L11 和 L11-rRNA-硫链丝菌肽项目。核糖体的高分辨率 X 射线晶体结构以及之前研究中积累的知识极大地增强了我们对这种蛋白质合成机制的结构和功能的理解。除了在蛋白质合成中发挥核心作用外，核糖体生物发生和翻译控制也是重要的细胞过程。已发现几种肿瘤抑制因子和原癌基因可以影响成熟核糖体的形成或调节称为翻译因子的蛋白质的活性。此外，几种核糖体蛋白与 p53 抑制剂 HDM2/MDM2 失活以及响应细胞应激而诱导 p53 活性有关。研究结果揭示了应激细胞环境下调节 HDM2/p53 活性的新途径。这些新揭示的核糖体蛋白的作用需要从核糖体蛋白合成及其潜在调节作用的背景下以全新的角度研究这些蛋白。 L11被认为在蛋白质合成的延伸和易位循环中发挥重要作用，在此期间EF-TU和EF-G在GTP和GDP阶段的活性需要因子和L11 N端结构域之间的协调运动。 L11 在 50 S 亚基的 2.4 分辨率 X 射线图上不存在，并且在 50 S 核糖体的冷冻电镜密度图中两个结构域之间的方向相差约 10%。与 L11 和 rRNA 之间形成的二元复合物的角度成 40 度。因此，需要清楚地了解 L11 结构及其作用。该项目的目的是研究L11游离形式和三元复合物形式的动力学，以及硫链丝菌素抑制蛋白质合成的机制。