Genetics of DNA methylation patterning of arabidopsis.

拟南芥 DNA 甲基化模式的遗传学。

基本信息

批准号：
9196358
负责人：
STEVEN E JACOBSEN
金额：
$ 30.8万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-01-01 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9196358
关键词：
Arabidopsis Binding Biological Assay Cancer Biology Cancer Etiology Chemicals Chromosomes Collaborations Cytosine DNA DNA Methylation DNA Modification Methylases DNA Sequence DNA-Binding Proteins Defect Epigenetic Process Eukaryota Gene Expression Regulation Gene Silencing Genes Genetic Genetic Screening Genomics Grant Hereditary, Type III, Motor and Sensory Neuropathy Histone H3 Homologous Gene Hypermethylation Individual Instruction Laboratories Lead Light Maintenance Mammals Methods Methylation Methyltransferase Modification Molecular Genetics Pathway interactions Plant Model Play Process Proteins RNA Recruitment Activity Regulator Genes Research Role Series Site Small Interfering RNA System Techniques Tissues Tumor Suppressor Genes Work X Inactivation demethylation experimental study gene function genome-wide histone methylation histone methyltransferase imprint methylation pattern mutant prevent reverse genetics structural biology tumor

项目摘要

Cytosine DNA methylation is an epigenetic mark for gene silencing that is important in many gene regulatory systems including mammalian imprinting, X-chromosome inactivation, and the silencing of transposons and other DNA sequences containing either direct or inverted repeats. Methylation is important in cancer biology, as tumors often show both genome wide demethylation and hypermethylation of specific tumor suppressor genes. We are studying the mechanisms of DNA methylation control in the model plant Arabldopsis, which has methylation systems that have much in common with mammalian systems. In Arabldopsis, the initial establishment of methylation (de novo methylation) requires the activity of DRM2, a homolog of mammalian DnmtS, which is guided to appropriate targets, at least in part, by small interfering RNAs. Once established, DNA methylation is maintained by three different systems for methylation of cytosines in three different sequence contexts, CG, CHG and CHH (asymmetric). CG methylation is maintained by MET1, a homolog of mammalian Dnmtl CHG methylation is maintained by the CMT3 DNA methyltransferase, which is guided to appropriate targets by the methylation of histone H3. CHH methylation is maintained by the persistent activity of DRM2, which is targeted by small interfering RNAs. In this proposal, we plan to further study these DNA methylation control mechanisms. Genetic screens are being used to identify genes required for proper de novo DNA methylation, and we plan to perform a detailed molecular genetic characterization of these genes to understand more about the mechanism by which they contribute to de novo methylation. We have also begun using structural biology, in collaboration with Dinshaw Patel's laboratory, to help in our understanding of individual components of the de novo DNA methylation pathway. We are also applying genomics techniques the study of RNA-directed DNA methylation in order to assist in our understanding the genome wide functions of DNA methylation. These studies should shed new light on DNA methylation systems in Arabldopsis and have implications for related systems in mammals and other eukaryotes.

胞嘧啶DNA甲基化是基因沉默的表观遗传标记，在许多基因调节中很重要包括哺乳动物印记，X染色体灭活以及转座和沉默的系统其他包含直接重复或反向重复序列的DNA序列。甲基化在癌症中很重要生物学，因为肿瘤经常显示基因组广泛的脱甲基化和特定肿瘤的高甲基化抑制基因。我们正在研究模型植物中DNA甲基化控制的机制 Arabldopsis，其具有与哺乳动物系统有很多共同点的甲基化系统。在 Arabldopsis，最初的甲基化建立（从头甲基化）需要DRM2的活性，A 哺乳动物DNMT的同源物，至少部分通过小干扰来指导适当的靶标 RNA。一旦建立，DNA甲基化将通过三种不同的系统维持 CG，CHG和CHH（不对称）的三种不同序列上下文中的细胞选择。 CG甲基化是通过Met1维持，CMT3 DNA维持了哺乳动物DNMTL CHG甲基化的同源物甲基转移酶，通过组蛋白H3的甲基化引导到适当的靶标。 CHH甲基化由DRM2的持续活动维护，DRM2由小型干扰RNA靶向。在这个提案，我们计划进一步研究这些DNA甲基化控制机制。遗传屏幕正在用于识别适当的从头DNA甲基化所需的基因，我们计划执行详细的这些基因的分子遗传表征，以更多地了解它们的机制有助于从头甲基化。我们还开始与结构生物学合作使用结构生物学 Dinshaw Patel的实验室，以帮助我们理解从头DNA的单个组件甲基化途径。我们还应用了基因组技术研究RNA指导DNA的研究甲基化以帮助我们理解DNA甲基化的基因组广泛功能。这些研究应为Arabldopsis中的DNA甲基化系统提供新的启示，并对相关的影响哺乳动物和其他真核生物的系统。