Characterization of MWS/DEN, a novel regulator of amino acid signaling to mTORC1

MWS/DEN 的表征，一种新型 mTORC1 氨基酸信号传导调节剂

基本信息

批准号：
8589837
负责人：
Lynne Chantranupong
金额：
$ 4.22万
依托单位：
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8589837
关键词：
Adverse effects Affect Amino Acids Autophagocytosis Biogenesis Biological Assay Biological Markers Breathing Catabolic Process Cell Culture Techniques Cells Clinical Clinical Trials Complex Cues Databases Development Diabetes Mellitus Energy Supply Exhibits FDA approved Frequencies GTPase-Activating Proteins Gene Silencing Genes Genetic Translation Genomics Goals Growth Growth Factor Guanosine Triphosphate Guanosine Triphosphate Phosphohydrolases Hydrolysis Immunofluorescence Immunologic Immunoprecipitation Institutes Insulin Knowledge Lead Malignant Neoplasms Manuscripts Mass Spectrum Analysis Mediating Molecular Mutation Nerve Degeneration Normal Cell Nutrient Pathway interactions Phosphotransferases Process Protein Kinase Protein Subunits Proteins Proteomics Regulation Renal Cell Carcinoma Reporting Research Training Ribosomes Role Signal Transduction Sirolimus Stimulus Stress Surface Techniques Therapeutic Translations Transplantation Tumor Suppressor Proteins Ubiquitination Work cancer cell carcinogenesis genetic analysis human disease in vivo inhibitor/antagonist insight loss of function novel novel therapeutics protein complex protein purification public health relevance response sarcoma scaffold stem tumor ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): The mechanistic target of rapamycin complex 1 (mTORC1) protein kinase is a master growth regulator. It integrates inputs from growth factors as well as nutrient and energy supplies to control key biosynthetic and catabolic processes, including protein translation, ribosome biogenesis and autophagy. As might be expected, this pathway is deregulated in a number of human diseases, ranging from neurodegeneration to cancer. Amongst the diverse inputs that impinge on mTORC1, amino acids are unique in that they are absolutely required for kinase activity, despite the presence of multiple activating stimuli. Amino acids utilize an independent mechanism from other cues to regulate mTORC1; however, this mechanism remains poorly characterized despite recent progress. By gaining a more complete understanding of how amino acids signal to mTORC1, we may also gain insight into more effective targets for pharmacological inhibition of mTORC1 with minimized side effects. We have used an unbiased proteomic approach to identify a novel octameric complex consisting of two interacting subcomplexes. The first subcomplex, MWS, is a positive regulator of the amino acid branch and contains Mios, WDR24, WDR59, Sec13, and Seh1L. The second subcomplex, DEN, contains DEPDC5, Nprl2, and Nprl3 and is the first negative regulator of the amino acid branch of mTORC1 to be identified. DEN's inhibitory role stems from its function as a GTPase activating protein (GAP) for the RagA/B GTPases, a key activator of the mTORC1 pathway. Importantly, as a negative regulator, DEN has the potential to be deregulated in cancer as a tumor suppressor. The goal of this project is to define and characterize the mechanisms of DEN and MWS in amino acid signaling to mTORC1 and to interrogate the possible role of DEN in carcinogenesis. To achieve this goal, we propose the following aims: 1. Further characterize the GAP activity of DEN towards RagA/B. 2. Determine the mechanism by which MWS regulates DEN in response to amino acids by exploring localization and a potential ubiquitin ligase function for MWS. 3. Interrogate the role for DEN as a tumor suppressor complex in cancer. Through a combination of hypothesis driven and unbiased approaches, our work will clarify how the amino acid pathway of mTORC1 functions in normal cells and how it can be deregulated in carcinogenesis. These insights may lead to the development of novel biomarkers and therapeutic strategies for cancer.

描述（由申请人提供）：雷帕霉素复合物 1 (mTORC1) 蛋白激酶的机制靶标是主要生长调节剂。它整合了生长因子以及营养和能量供应的输入，以控制关键的生物合成和分解代谢过程，包括蛋白质翻译、核糖体生物合成和自噬。正如所预料的那样，该通路在从神经退行性疾病到癌症等多种人类疾病中不受管制。在影响 mTORC1 的多种输入中，氨基酸的独特之处在于，尽管存在多种激活刺激，但它们对于激酶活性来说是绝对必需的。氨基酸利用独立于其他线索的机制来调节 mTORC1；然而，尽管最近取得了进展，但这一机制的特点仍然不明确。通过更全面地了解氨基酸如何向 mTORC1 发出信号，我们还可以深入了解 mTORC1 药理抑制的更有效靶点，同时将副作用降至最低。我们使用公正的蛋白质组学方法来鉴定由两个相互作用的子复合物组成的新型八聚体复合物。第一个子复合体 MWS 是氨基酸分支的正调节因子，包含 Mios、WDR24、WDR59、Sec13 和 Seh1L。第二个子复合体 DEN 包含 DEPDC5、Nprl2 和 Nprl3，是第一个待鉴定的 mTORC1 氨基酸分支的负调节因子。 DEN 的抑制作用源于其作为 RagA/B GTPases 的 GTPase 激活蛋白 (GAP) 的功能，RagA/B GTPase 是 mTORC1 通路的关键激活剂。重要的是，作为负调节因子，DEN 有可能在癌症中作为肿瘤抑制因子被解除调节。该项目的目标是定义和表征 DEN 和 MWS 在 mTORC1 氨基酸信号传导中的机制，并探讨 DEN 在致癌作用中的可能作用。为了实现这一目标，我们提出以下目标： 1. 进一步表征 DEN 针对 RagA/B 的 GAP 活动。 2. 通过探索 MWS 的定位和潜在的泛素连接酶功能，确定 MWS 调节 DEN 响应氨基酸的机制。 3. 探讨 DEN 作为肿瘤抑制复合物在癌症中的作用。通过结合假设驱动和公正的方法，我们的工作将阐明 mTORC1 的氨基酸途径如何在正常细胞中发挥作用，以及它如何在致癌过程中失调。这些见解可能会导致新型癌症生物标志物和治疗策略的开发。