Investigating the molecular mechanisms in controlling the aryl hydrocarbon recept

研究控制芳烃受体的分子机制

• 批准号: 8671598
• 负责人: WILLIAM K CHAN
• 金额: $ 36.71万
• 依托单位: UNIVERSITY OF THE PACIFIC-STOCKTON
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8671598
• 关键词: AHR gene; Address; Affect; Applications Grants; Aromatic Polycyclic Hydrocarbons; Aryl Hydrocarbon Receptor; Cancer cell line; Cell Proliferation; Cell physiology; Cells; Cervical; Complex; Dendritic Cells; Development; Dioxins; Embryo; Environmental Pollutants; Event; Exposure to; Geldanamycin; Gene Expression; Genes; Grant; Hela Cells; Helix-Turn-Helix Motifs; Hematopoietic stem cells; Hepatocyte; Human; Human Cell Line; Immune; Immune response; Investigation; Knockout Mice; Knowledge; Lead; Ligand Binding; Ligands; Literature; Lung; MG132; Malignant Neoplasms; Mediating; Molecular; Molecular Conformation; Mus; Nature; Organ; Pathway interactions; Physiologic pulse; Polychlorinated Biphenyls; Precipitation; Primary carcinoma of the liver cells; Proteasome Inhibitor; Proteins; Proteolysis; Publishing; Reporting; Role; Stem Cell Development; Stem cells; Structure; Subfamily lentivirinae; T cell differentiation; T-Lymphocyte; Tetrachlorodibenzodioxin; Transfection; Ubiquitination; aryl hydrocarbons; carcinogenesis; environmental chemical; human AHR protein; interest; multicatalytic endopeptidase complex; mutant; protein degradation; public health relevance; receptor; receptor expression; research study; response; screening; small hairpin RNA; stable cell line; tool; transcription factor

DESCRIPTION (provided by applicant): The aryl hydrocarbon receptor (AhR) is a ligand-activated basic-helix-loop-helix-PAS transcription factor. This receptor is responsible for our bodily response to exposure of environmental pollutants such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and dioxins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most studied and best known ligand of AhR. Expression of AhR is up-regulated in human cancers and during T cell differentiation. Malfunction of the events affecting the AhR gene expression would undoubtedly cause problems in cancer, aberrant immune response, stem cell development, and our response to toxic environmental chemicals. However, our knowledge of how the AhR protein levels are maintained in the absence of ligand is very limited. Recently, we generated p23-knockdown stable cells and discovered that compromised p23 levels in human hepatoma (Hep3B) and cervical (HeLa) cells suppress the AhR protein levels by reducing its protein degradation in the absence of ligand. In this grant proposal, we wil ultilize these stable cells to investigate the molecular mechanisms that regulate the human AhR protein levels in the absence of ligand. Specifically, we will perform the following experiments: (1) investigate whether conformation of the unliganded AhR complex governs the AhR protein stability (Aim 1) and (2) investigate whether and how p23 acts locally at the AhR complex level to control AhR protein stability (Aim 2) and (3) investigate the involvement of non-proteasomal degradation mechanisms and identify and characterize new protein target(s) which are responsible for controlling the human AhR protein degradation (Aim 3).

描述（由申请人提供）：芳烃受体（AhR）是一种配体激活的碱性-螺旋-环-螺旋-PAS转录因子。这种受体负责我们身体对暴露于环境污染物（如多环芳烃、多氯联苯和二恶英）的反应。2，3，7，8-四氯二苯并对二恶英（TCDD）是AhR的研究最多和最知名的配体之一。AhR的表达在人类癌症和T细胞分化过程中上调。影响AhR基因表达的事件的故障无疑会导致癌症，异常免疫反应，干细胞发育以及我们对有毒环境化学品的反应等问题。然而，我们的知识如何AhR蛋白水平维持在配体的情况下是非常有限的。最近，我们产生了p23敲低的稳定细胞，并发现在人肝癌（Hep 3B）和宫颈（HeLa）细胞中受损的p23水平通过在配体不存在的情况下减少其蛋白降解来抑制AhR蛋白水平。在这项资助计划中，我们将最终利用这些稳定的细胞来研究在缺乏配体的情况下调节人类AhR蛋白水平的分子机制。具体来说，我们将进行以下实验：（1）研究未配体AhR复合物的构象是否控制AhR蛋白质稳定性（目的1）和（2）研究p23是否和如何在AhR复合物水平局部作用以控制AhR蛋白质稳定性（目的2）和（3）研究非蛋白酶体降解机制的参与并鉴定和表征新的蛋白质靶标其负责控制人AhR蛋白降解（目的3）。