Regulation and Function of DNA Demethylation in Arabidopsis

拟南芥DNA去甲基化的调控和功能

基本信息

批准号：
7626739
负责人：
ROBERT L FISCHER
金额：
$ 30.69万
依托单位：
UNIVERSITY OF CALIFORNIA BERKELEY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-02-01 至 2012-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7626739
关键词：
Acetylation Address Affect Alleles Amino Acids Animals Arabidopsis Arabidopsis DEMETER protein Binding Binding Proteins Biochemical Biological Assay Cell Nucleus Cells Chimeric Proteins Chromatin Chromatin Structure Cis-Acting Sequence Cytosine DNA DNA Methylation DNA Repair DNA Repair Pathway DNA glycosylase Data Disease Disease Resistance Embryonic Development Enzymes Epigenetic Process Excision Family Family member Gene Expression Gene Expression Regulation Gene Proteins Gene Silencing Gene Targeting Genes Genetic Transcription Genome Genomics Heterochromatin Histones Hydrolysis Hypermethylation In Vitro Infection Insertion Mutation Length Link Mammals Maps Measures Mediating Methylation Molecular Mutation Nucleosomes Placenta Plant Diseases Plants Play Polycomb Predisposition Process Protein Binding Proteins Pseudomonas syringae RNA Polymerase II Regulation Reproduction Research Resistance Retroviridae Role Stem cells Structure Substrate Specificity System T-DNA Testing Trans-Activators Transcription factor genes Vertebral column X ray diffraction analysis X-Ray Crystallography X-Ray Diffraction bacterial resistance base defense response demethylation density enzyme activity gene function genome-wide histone modification homeodomain imprint insight member mutant novel pathogen polypeptide promoter research study sperm cell tumor progression

项目摘要

DESCRIPTION (provided by applicant): DNA methylation (5-methylcytosine) in mammals and plants silences transposons, retroviruses, and regulates gene imprinting. In mammals, DNA hypermethylation is associated with certain diseases including the onset and progression of cancer. We discovered that the Arabidopsis DEMETER (DME) protein regulates imprinting by DNA demethylation. DME is related to DNA glycosylases that excise damaged/mispaired bases in the base excision DNA repair pathway. DME excises 5-methylcytosine that is replaced with cytosine. DME is expressed primarily in the central cell, the progenitor of the placenta-like endosperm that supports embryo development. DME demethylates and activates maternal allele expression of genes that are imprinted in the endosperm. Arabidopsis has three DME-LIKE (DML) genes: ROS1, DML2, and DML3, which are broadly expressed in the plant. Like DME, they excise 5-methylcytosine and have a DNA glycosylase domain flanked by additional conserved domains that are essential for activity. DME and DML proteins specifically demethylate the 5' and 3' ends of at least 180 genes. ROS1 demethylates disease resistance genes and is required for resistance to a bacterial pathogen, Pseudomonas syringae. We will carry out the following experiments to understand the mechanisms and functions of DNA demethylation in the regulation of gene imprinting. 1) We will elucidate how expression of DME is restricted to the central cell, identify new genes imprinted by DME, and isolate mutations in genes that regulate DME expression, targeting, and/or DNA demethylation. 2) To understand the molecular mechanisms of DNA demethylation, we will identify and analyze the function of DME-binding proteins, determine if DME directly demethylates DNA by physical association with its target genes, and elucidate what changes in chromatin structure accompany DNA demethylation. 3) To understand how DNA demethylation regulates disease resistance, we will elucidate the function of plant defense genes that are demethylated by ROS1. Plants and animals have related mechanisms for controlling DNA methylation. Information about the basic mechanisms of DNA demethylation will provide valuable insights into the critical role DNA methylation plays in the regulation of gene imprinting and disease

描述（由申请人提供）：哺乳动物和植物沉默的转座子，逆转录病毒和调节基因印记的DNA甲基化（5-甲基胞嘧啶）。在哺乳动物中，DNA高甲基化与某些疾病有关，包括癌症的发作和进展。我们发现拟南芥（DME）蛋白通过DNA脱甲基化调节。 DME与在碱基切除DNA修复途径中损坏/误导碱的DNA糖基酶有关。 DME摄取5-甲基胞嘧啶，被胞嘧啶取代。 DME主要在中央细胞中表达，这是支持胚胎发育的胎盘样胚乳的祖细胞。 DME脱甲基化并激活印在胚乳中的基因的母体等位基因表达。拟南芥具有三个DME样（DML）基因：ROS1，DML2和DML3，它们在植物中广泛表达。像DME一样，它们会消除5-甲基胞嘧啶，并具有DNA糖基酶结构域的侧面，其侧面是其他对活性必不可少的保守域。 DME和DML蛋白特别脱甲基化至少180个基因的5'和3'末端。 ROS1脱甲基化疾病抗性基因，是对细菌病原体假单胞菌的抗性所必需的。我们将进行以下实验，以了解基因印记调节DNA脱甲基的机制和功能。 1）我们将阐明DME的表达如何仅限于中心细胞，鉴定由DME印记的新基因以及调节DME表达，靶向和/或DNA脱甲基化的基因中的分离基因。 2）要了解DNA脱甲基化的分子机制，我们将识别和分析DME结合蛋白的功能，确定DME是否通过物理与其靶基因的物理关联直接脱甲基脱甲基，并阐明染色质结构伴随DNA脱甲基化的变化。 3）了解DNA脱甲基化如何调节疾病抗性，我们将阐明由ROS1脱甲基化的植物防御基因的功能。植物和动物具有控制DNA甲基化的相关机制。有关DNA脱甲基化基本机制的信息将为DNA甲基化在调节基因印记和疾病中的关键作用提供有价值的见解