Novel ARNT-mediated Regulatory Paradigm of AHR Signaling

新型 ARNT 介导的 AHR 信号调节范式

基本信息

批准号：
9477928
负责人：
Casey W Wright
金额：
$ 34.88万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-01 至 2021-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9477928
关键词：
ARNT gene Affect Affinity Alternative Splicing Amino Acids Antigen-Presenting Cells Aromatic Hydrocarbons Aryl Hydrocarbon Receptor Autoimmune Diseases Autoimmune Process Binding CD4 Positive T Lymphocytes CRISPR/Cas technology Cancer Cell Growth Cells Cellular biology Complex Cytoplasmic Receptors DNA Data Development Diet Dioxins EMSA Enhancers Environmental Pollution Event Exhibits Future Gatekeeping Gene Targeting Genetic Transcription Goals Hematopoiesis Immune Immune Tolerance Immune signaling Immunotherapy Individual Knock-out Laboratories Lentivirus Vector Ligand Binding Ligands Light Lymphocyte Lymphoma Malignant Neoplasms Malignant lymphoid neoplasm Mediating Molecular Mus Mutate NF-kappa B Nuclear Nuclear Translocation Organ Outcome Phosphorylation Phosphorylation Site Physiological Process Protein Isoforms RNA Polymerase II RNA Splicing Receptor Signaling Recruitment Activity Regulation Research Role Signal Pathway Signal Transduction Sum System T cell differentiation T-Lymphocyte Techniques Testing Tetrachlorodibenzodioxin Tissues Toxic Environmental Substances Transactivation Transgenic Mice Tryptophan Work Xenobiotics aryl hydrocarbon receptor ligand base cell growth cell type chromatin immunoprecipitation cofactor experimental study immunoregulation in vivo innovation mouse model mutant novel prevent public health relevance receptor binding receptor function receptor-mediated signaling reconstitution response therapy development transcription factor

ARNT gene Affect Affinity Alternative Splicing Amino Acids Antigen-Presenting Cells Aromatic Hydrocarbons Aryl Hydrocarbon Receptor Autoimmune Diseases Autoimmune Process Binding CD4 Positive T Lymphocytes CRISPR/Cas technology Cancer Cell Growth Cells Cellular biology Complex Cytoplasmic Receptors DNA Data Development Diet Dioxins EMSA Enhancers Environmental Pollution Event Exhibits Future Gatekeeping Gene Targeting Genetic Transcription Goals Hematopoiesis Immune Immune Tolerance Immune signaling Immunotherapy Individual Knock-out Laboratories Lentivirus Vector Ligand Binding Ligands Light Lymphocyte Lymphoma Malignant Neoplasms Malignant lymphoid neoplasm Mediating Molecular Mus Mutate NF-kappa B Nuclear Nuclear Translocation Organ Outcome Phosphorylation Phosphorylation Site Physiological Process Protein Isoforms RNA Polymerase II RNA Splicing Receptor Signaling Recruitment Activity Regulation Research Role Signal Pathway Signal Transduction Sum System T cell differentiation T-Lymphocyte Techniques Testing Tetrachlorodibenzodioxin Tissues Toxic Environmental Substances Transactivation Transgenic Mice Tryptophan Work Xenobiotics aryl hydrocarbon receptor ligand base cell growth cell type chromatin immunoprecipitation cofactor experimental study immunoregulation in vivo innovation mouse model mutant novel prevent public health relevance receptor binding receptor function receptor-mediated signaling reconstitution response therapy development transcription factor

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项目摘要

DESCRIPTION (provided by applicant): AHR is a cytoplasmic receptor that has affinity for numerous xenobiotic ligands, which include halogenated aromatic hydrocarbons such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), one of the most potent AHR activators, and AHR signaling mediates the detrimental effects of environmental contaminants on body tissues and organs. Ligand binding induces nuclear translocation of AHR and interaction with the AHR binding partner, aryl hydrocarbon receptor nuclear translocator (ARNT), allowing recognition of specific DNA enhancer sequences. More recently endogenous and natural AHR ligands, such as tryptophan metabolites and dietary compounds, have been identified. These ligands induce AHR-mediated immunomodulatory effects such as controlling normal T cell differentiation and immune tolerance. However, little is known about the role of ARNT in AHR immune signaling. Initial studies by our laboratory, and others, into the regulatory role of ARNT in AHR-mediated immunomodulation have suggested that ARNT is an integral cofactor in different immune signaling pathways, including AHR and NF-κB signaling. ARNT is often described in AHR signaling as a constitutively expressed, non-regulated, nuclear binding partner for AHR. However, our data challenge this assumption and show that the actual regulatory paradigm is more intricate. For instance, ARNT is expressed as two isoforms, isoform 1 and 3, which differ in only 15 amino acids present in isoform 1. Despite their sequence similarity, we have found that the ARNT isoforms appear to have opposing functions in AHR signaling. Intriguingly, the extra 15 amino acids in isoform 1 include a unique phosphorylation site, where we have observed TCDD-induced phosphorylation. Furthermore, we find that the phosphorylation of ARNT isoform 1 is crucial for the recruitment of RNA polymerase II and transactivation of AHR/ARNT target genes. We predict that ARNT activity is a function of both unique phosphorylation of isoform 1 and the given isoform ratio within a particular cell type, which in turn is likely important for regulating the magnitude/outcome of the AHR response. To investigate our hypothesis we propose to 1) Define a comprehensive molecular framework for AHR regulation by the ARNT isoforms, 2) Examine the role of AHR activity, as governed by the ARNT isoforms, in lymphoma cell growth, and 3) Characterize the regulation of AHR signaling by ARNT isoforms in vivo. Ultimately, these studies will lay the groundwork for ARNT-based therapies such as splice modulation as a means of manipulating the ARNT isoforms to control AHR signaling in autoimmune diseases and cancer.

DESCRIPTION (provided by applicable): AHR is a cytoplasmic receiver that has affinity for numerous xenobiotic ligands, which include halogenated aromatic hydrocarbons such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), one of the most potential AHR activators, and AHR signaling mediates the detrimental effects of environmental contaminants on body tissues and organs.配体结合诱导AHR的核易位以及与AHR结合伴侣，芳烃受体核转运剂（ARNT）的相互作用，从而识别了特定的DNA增强子序列。最近已经鉴定出了最近的内源性和天然AHR配体，例如色氨酸代谢产物和饮食化合物。这些配体诱导AHR介导的免疫调节作用，例如控制正常的T细胞分化和免疫耐受性。但是，关于ARNT在AHR免疫信号传导中的作用知之甚少。我们的实验室和其他研究对ARNT在ARR介导的免疫调节中的调节作用的初步研究表明，ARNT是不同免疫信号通路（包括AHR和NF-κB信号传导）中的积分辅助因子。 ARNT在AHR信号传导中通常被描述为AHR的组成型，不调节的核结合伴侣。但是，我们的数据挑战了这一假设，并表明同工型1中的15个额外的15个氨基酸包括一个独特的磷酸化位点，我们观察到TCDD诱导的磷酸化。此外，我们发现ARNT同工型1的磷酸化对于募集RNA聚合酶II和AHR/ARNT靶基因的反式激活至关重要。我们预测ARNT活性是同工型1的独特磷酸化和特定细胞类型内给定的同工型比的函数，这反过来又可能对调节AHR响应的幅度/结果很重要。为了研究我们的假设，我们提出提议1）定义ARNT同工型AHR调节的全面分子框架，2）检查由ARNT同工型在淋巴瘤细胞生长中的AHR活性的作用，以及3）表征ARNT INVO的ARNT信号的调节。最终，这些研究将为基于ARNT的疗法（例如分裂调制）奠定基础，以此作为操纵ARNT同工型控制自身免疫性疾病和癌症中AHR信号传导的方法。