Structural biololgy of tumor suppressor PP2A and its regulatory proteins

肿瘤抑制因子PP2A及其调节蛋白的结构生物学

• 批准号: 7554132
• 负责人: YIGONG SHI
• 金额: $ 22.12万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7554132
• 关键词: Active Sites; Applications Grants; Baculoviruses; Binding; Biochemical; Biology; Brain; Catalytic Domain; Cattle; Cells; Classification; Complex; DNA Viruses; Enzymes; Foundations; Holoenzymes; Human; In Vitro; Insecta; Investigation; Mammalian Cell; Methylation; Molecular; Molecular Conformation; Molecular Structure; Oncogenic; Phosphoric Monoester Hydrolases; Phosphorylation; Play; Principal Investigator; Property; Protein Dephosphorylation; Protein Phosphatase 2A Regulatory Subunit PR53; Protein phosphatase; Proteins; Recombinants; Regulation; Resolution; Roentgen Rays; Role; Simian virus 40; Solutions; Structure; Structure-Activity Relationship; Substrate Specificity; System; Transferase; Tumor Antigens; Tumor Suppressor Proteins; Viral Proteins; Work; design; dimer; enzyme mechanism; esterase; genetic regulatory protein; inhibitor/antagonist; insight; reconstitution; scaffold

Reversible protein phosphorylation, namely protein phosphorylation and dephosphorylation, is a fundamental regulatory mechanism in all aspects of biology. Protein phosphatase 2A (PP2A) is a dominant Ser/Thr protein phosphatase in mammalian cells and a principal tumor suppressor protein against oncogenic transformation. The core component of PP2A consists of the scaffolding subunit (A subunit) and the catalytic ubunit (C subunit). The methylation of the C subunit, controlled by the PP2A methyl transferase (PMT) and the PP2A methyl esterase (PME), is essential to the function of PP2A. The PP2A A-C hetero-dimer and the regulatory subunit (B subunit) assemble into a functional holoenzyme. The DMAvirus SV40 Small Tumor Antigen (ST) antagonizes the function of PP2A at least in part by competing with the B subunit for binding to the PP2A A-C hetero-dimer. The Dlpha4 protein antagonizes the normal function of PP2A by forming a complex with the C subunit of PP2A. Despite intense investigation, the structure and mechanisms of PP2A remain largely unknown. Systematic X-ray crystallographic and biochemical analyses of the PP2A core component, its regulatory proteins, and its modifying enzymes have been initiated. Significant progress has been achieved; the work proposed here will build on the preliminary results with the following specific aims: (1) Determination of the crystal structures of PME, PMT, and their cognate complexes with substrate/inhibitor. (2) Determination of the structure of the core component A-C hetero-dimer of PP2A. (3) Determination of the structure of a PP2A holoenzyme involving A-C hetero-dimer and a B subunit. (4) Determination of the structure of a PP2A A-C hetero-dimer bound to Small Tumor Antigen (ST). (5) Determination of the structure of Dlpha4 alone and in complex with the C subunit of PP2A. The proposed specific aims in this grant application represent an important and systematic effort to unravel the structural mechanisms of PP2A regulation. The generally excellent solution properties of the proteins and their cognate complexes make this undertaking feasible.

可逆的蛋白质磷酸化，即蛋白质磷酸化和去磷酸化， 生物学各个方面的调节机制。蛋白磷酸酶2A（PP 2A）是一种显性的Ser/Thr 哺乳动物细胞中的蛋白磷酸酶和一种主要的肿瘤抑制蛋白， 转型PP 2A的核心组分由支架亚基（A亚基）和催化亚基（B亚基）组成。 亚基（C亚基）。C亚基的甲基化，由PP 2A甲基转移酶（PMT）控制， PP 2A甲基酯酶（PME）是PP 2A功能所必需的。PP 2A A-C异源二聚体和PP 2A A-C异源二聚体的结构域。 调节亚基（B亚基）组装成功能性全酶。DMA病毒SV 40小肿瘤 抗原（ST）至少部分地通过与B亚基竞争结合PP 2 A来拮抗PP 2 A的功能。 PP 2A A-C异源二聚体。Dlpha 4蛋白通过形成一种抑制PP 2A的蛋白质来拮抗PP 2A的正常功能。 与PP 2A的C亚基复合。尽管进行了大量的研究，PP 2A的结构和机制， 但基本上仍不为人所知。PP 2A核心的系统X射线晶体学和生物化学分析 它的组成部分，它的调节蛋白和它的修饰酶已经启动。重大进展 在此提出的工作将以初步成果为基础，具体目标如下： (1)PME、PMT及其同源配合物的晶体结构测定 底物/抑制剂。(2)PP 2A的核心组分A-C杂二聚体的结构测定。（三） 涉及A-C异源二聚体和B亚基的PP 2A全酶的结构的测定。（四） 与小肿瘤抗原（ST）结合的PP 2A A-C异源二聚体的结构的测定。（五） 单独的Dlpha 4和与PP 2A的C亚基复合的Dlpha 4的结构的确定。拟议 在这个赠款申请的具体目标是一个重要的和系统的努力，以解开结构性的 PP 2A的调节机制。蛋白质及其同源物的一般优异的溶液性质 综合体使这项工作切实可行。