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Analysis of Ah Receptor Ligand Binding Specificity

Ah 受体配体结合特异性分析

基本信息

批准号：
9753237
负责人：
MICHAEL STEVEN DENISON
金额：
$ 30万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9753237
关键词：
ARNT gene Affect Affinity Antineoplastic Agents Aromatic Hydrocarbons Aryl Hydrocarbon Receptor Binding Binding Sites Biochemical Biological CYP1A1 gene Cells Chemicals Complex DNA DNA Binding DNA Sequence Development Developmental Process Dimerization Dissociation Docking Gene Expression Gene Expression Profiling Genes Goals Heterodimerization Homology Modeling Human IL8 gene Immune Immunologics Lead Ligand Binding Ligand Binding Domain Ligands Link Measures Mediating Methods Modeling Molecular Molecular Analysis Mus Mutation Pathway interactions Physiological Physiological Processes Process Property Proteins Proteolysis Protocols documentation Receptor Activation Reporting Role SERPINB2 gene Series Signal Transduction Site-Directed Mutagenesis Specificity Structural Protein Structure Testing Tetrachlorodibenzodioxin Therapeutic Tissues Transfection Work base cell type chromatin immunoprecipitation dimer experimental study gene induction hepatoma cell human model inhibitor/antagonist insight molecular dynamics mouse model promoter protein complex protein structure receptor receptor binding receptor function receptor structure function recruit reproductive response transcription factor

项目摘要

The Ah receptor (AhR) is a ligand-dependent transcription factor known to regulate the toxic and biological effects of a variety of exogenous chemicals and these effects result from AhR-dependent gene expression. The AhR is also involved in endogenous developmental and physiological processes, although the responsible endogenous ligand(s) is unknown. While toxic halogenated aromatic hydrocarbons are the prototypical and highest affinity ligands, the AhR can bind and be activated by a diverse range of structurally dissimilar compounds and these ligands can produce distinctly different AhR-dependent responses, both in magnitude and specificity of gene induction. Site-directed mutagenesis and functional analysis studies based on our homology model of the AhR ligand binding domain (LBD) revealed significant differences in the interactions of these diverse ligands with residues within the AhR LBD, providing new insights into how ligands can activate the AhR. It is currently assumed that the diversity in AhR-dependent gene expression response of diverse ligands results from ligand-specific differences in structure and function of the AhR and/or ARNT that leads to differential coactivator recuitment, but this has not been demonstrated. While the classical AhR mechanism involves AhR dimerization with ARNT and binding of this complex to DNA to regulate gene expression, the AhR can also heterodimerize with other proteins (KLF6 and RelB), bind to distinctly different DNA sequences and regulate other genes. Thus, a given ligand can differentially regulate AhR-dependent gene expression in a given cell or tissue by multiple mechanisms. We hypothesize that the structure of the AhR complex can be altered in a ligand-selective manner, resulting in distinct differences in AhR functionality when bound by structurally diverse ligands and this can contribute to the diversity in AhR response. We propose to examine whether differential AhR binding and activation by structurally diverse ligands alters the structure and function of the AhR and/or its heterodimeric partners (ARNT, KLF6 or RelB), as measured by ligand and DNA binding, limited proteolysis and gene expression analysis and interpreted by Molecular Docking. Ligand-selective differences in AhR heterodimer-specific coactivator recruitment to the CYP1A1, PAI2 or IL8 gene promoters in human and mouse hepatoma cells will be determined using chromatin immunoprecipitation and will link ligand- induced alterations in receptor structure to changes in functional analysis in intact cells. The newly developed homology model of the AhR:ARNT bHLH-PASA-PASB dimer will provide an avenue to examine both the molecular mechanisms involved in ligand-dependent transformation/AhR:ARNT dimerization as well as the effect of diverse ligands on this process by Molecular Dynamics methods. The studies proposed here will provide detailed analysis of the molecular mechanisms by which structurally diverse ligands can differentially affect the AhR and its associated factors and will yield insights into the mechanisms of ligand-dependent AhR transformation, the influence of ligand structure on these processes and the diversity of AhR responsiveness.

Ah受体（AhR）是一种已知的依赖配体的转录因子，用于调节毒性和生物学

项目成果

期刊论文数量（36）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Deciphering Dimerization Modes of PAS Domains: Computational and Experimental Analyses of the AhR:ARNT Complex Reveal New Insights Into the Mechanisms of AhR Transformation.

DOI：
10.1371/journal.pcbi.1004981
发表时间：
2016-06
期刊：
PLoS computational biology
影响因子：
4.3
作者：
Corrada D;Soshilov AA;Denison MS;Bonati L
通讯作者：
Bonati L

Transitional States in Ligand-Dependent Transformation of the Aryl Hydrocarbon Receptor into Its DNA-Binding Form.

芳基烃受体配体依赖性转化为其 DNA 结合形式的过渡状态。

DOI：
10.3390/ijms21072474
发表时间：
2020
期刊：
International journal of molecular sciences
影响因子：
5.6
作者：
Soshilov,AnatolyA;Motta,Stefano;Bonati,Laura;Denison,MichaelS
通讯作者：
Denison,MichaelS

Computational approaches to shed light on molecular mechanisms in biological processes.

揭示生物过程中分子机制的计算方法。

DOI：
10.1007/s00214-006-0203-4
发表时间：
2007
期刊：
Theoretical chemistry accounts
影响因子：
1.7
作者：
Moro,Giorgio;Bonati,Laura;Bruschi,Maurizio;Cosentino,Ugo;DeGioia,Luca;Fantucci,PierCarlo;Pandini,Alessandro;Papaleo,Elena;Pitea,Demetrio;Saracino,GloriaAA;Zampella,Giuseppe
通讯作者：
Zampella,Giuseppe

Detection of the TCDD binding-fingerprint within the Ah receptor ligand binding domain by structurally driven mutagenesis and functional analysis.

DOI：
10.1021/bi900259z
发表时间：
2009-06-30
期刊：
BIOCHEMISTRY
影响因子：
2.9
作者：
Pandini, Alessandro;Soshilov, Anatoly A.;Song, Yujuan;Zhao, Jing;Bonati, Laura;Denison, Michael S.
通讯作者：
Denison, Michael S.

Structural modeling of the AhR:ARNT complex in the bHLH-PASA-PASB region elucidates the key determinants of dimerization.

BHLH-PASA-PASB区域中AHR：ARNT复合物的结构建模阐明了二聚化的关键决定因素。