Ras, Cycling and Inhibition.

Ras，循环和抑制。

• 批准号: 7775011
• 负责人: Nicolas Nassar
• 金额: $ 7.19万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-04 至 2010-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7775011
• 关键词: Adopted; Affinity; Area; Biochemical; Biological Models; Biology; Bladder; Cancer Model; Cell physiology; Colon; Computer Simulation; Databases; Differentiation and Growth; Disease; Enzymes; Family member; GTP Binding; GTP-Binding Proteins; Goals; Guanine Nucleotides; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Hydrolysis; In Vitro; Knowledge; Lung; Malignant Neoplasms; Malignant neoplasm of pancreas; Molecular; Molecular Conformation; Normal Cell; Nucleotides; Oncogenic; Outcome; Pancreas; Pharmaceutical Preparations; Physiological; Preclinical Drug Evaluation; Protein Conformation; Proteins; Reaction; Regulation; Research; Research Project Grants; Research Proposals; Screening procedure; Sequence Homology; Signal Pathway; Signal Transduction; Signaling Protein; Site-Directed Mutagenesis; Specificity; Structure; Techniques; Testing; base; cell growth; design; fight against; flexibility; human disease; improved; in vivo; inhibitor/antagonist; metaplastic cell transformation; molecular dynamics; mutant; prototype; rho; small molecule

DESCRIPTION (provided by applicant): GTP-binding proteins are key switches in signaling pathways that regulate critical cellular functions such as growth and differentiation. Ras, which serves as a prototype for GTP-binding is constitutively activated in a large number of cancers including those of the pancreas, bladder, colon, and lung. The long-term goal of this research is to interfere with the oncogenic forms of Ras in human disease by understanding its cycling. Because oncogenic Ras relies on its intrinsic ability to hydrolyze and exchange GTP, the primary goal of this research proposal is to better our understanding of Ras cycling between the active and inactive states by revealing structures of intermediates of the reactions of GTP hydrolysis and guanine nucleotide exchange. Screening of drugs that will stabilize a non-signaling conformation of oncogenic Ras will be also performed. This proposal is based on findings that altering the flexibility of a hinge region stabilizes structures of Ras that are normally transient. Using this approach, two structures of intermediates along the path for GTP hydrolysis were stabilized as well as an open non-signaling conformation, which is also adopted by the native protein. The first aim of this proposal tests the hypothesis that the open conformation of Ras mimics the structure of an intermediate for nucleotide exchange and the structu-e of an unappreciated native conformation. Additional structures of intermediates for Ras cycling will be generated by altering the flexibility of another hinge region. The generated mutants will be studied using a combination of structural, molecular dynamics, biochemical, and in vivo techniques. The second aim tests the hypothesis that Rho- family members and trimeric G-proteins do not follow the Ras path of GTP hydrolysis and nucleotide exchange despite strong sequence homology. The third aim uses biophysical, structural, and cellular approaches to study how small molecules identified by screening the NCI database interact with the open non-signaling conformation and inhibit oncogenic Ras in a pancreatic cancer model system. The outcome of the proposed research should improve our understanding of the regulation of key signaling proteins and our ability to interfere with their action in human diseases.

描述（由申请人提供）：GTP结合蛋白是信号通路中的关键开关，这些开关调节关键细胞功能，例如生长和分化。用作GTP结合原型的RA在包括胰腺，膀胱，结肠和肺部在内的大量癌症中被组成式激活。这项研究的长期目标是通过了解其循环来干扰人类疾病中的RA的致癌形式。由于致癌性RAS取决于其水解和交换GTP的固有能力，因此该研究建议的主要目标是通过揭示GTP水解和鸟嘌呤核苷酸交换的中间体结构来更好地理解我们对主动状态和非活性状态之间的RAS循环。还将进行筛查将稳定致癌性RA的非信号构象的药物。该建议基于发现铰链区域的灵活性稳定通常是短暂的RAS结构的发现。使用这种方法，稳定了沿GTP水解路径的中间体的两个结构以及开放的非信号构象，这也是天然蛋白也采用的。该提案的第一个目的检验了以下假设：RAS的开放构象模仿了核苷酸交换中间体的结构和未批准的本机构象的结构。通过改变另一个铰链区域的柔韧性，将产生用于RAS循环的中间体的其他结构。将使用结构，分子动力学，生化和体内技术的组合研究产生的突变体。第二个目的检验了以下假设：尽管序列同源性很强，但Rho-家族成员和三聚体G蛋白仍未遵循GTP水解和核苷酸交换的RAS路径。第三目的使用生物物理，结构和细胞方法来研究小分子如何通过筛选NCI数据库与开放的非信号构象相互作用，并抑制胰腺癌模型系统中的致癌性RAS。拟议研究的结果应提高我们对关键信号蛋白的调节的理解，以及我们干扰其在人类疾病中的作用的能力。