Role of HELLS chromatin remodeler in genome maintenance

HELLS 染色质重塑剂在基因组维护中的作用

基本信息

批准号：
10629966
负责人：
Wioletta Czaja
金额：
$ 1.21万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2022-10-04
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10629966
关键词：
Alkylating Agents Alkylation Animal Model Area Biological Assay Cause of Death Cell Death Cell Survival Cells Centromere Chromatin Chromosomal Breaks Chromosomal Rearrangement Chromosome abnormality Cytoprotection DNA DNA Alkylation DNA Damage DNA Methylation DNA Repair DNA Repair Pathway DNA replication fork Data Development Diagnosis Disease Etiology Eukaryota Event Exhibits Exposure to Face Gametogenesis Genetic Genome Genome Stability Genomic Instability Genomic approach Genomics Genotoxic Stress Goals HELLS gene Heterochromatin Human Hypersensitivity Immune system Immunofluorescence Immunologic Immunologic Deficiency Syndromes Knowledge Link Maintenance Malignant Neoplasms Measures Mediating Metabolism Modeling Molecular Mus Mutagens Mutation Neurospora Neurospora crassa Nonhomologous DNA End Joining Organism Pathway interactions Phenotype Play Proteins Proteomics Regulation Reporter Research Role Toxic effect base chromatin remodeling disorder prevention epigenomics genome-wide genomic locus human disease immunodeficiency-centromeric instability-facial anomalies syndrome insight member mutant novel novel strategies prevent repaired response

项目摘要

Project Summary Robust and tightly regulated DNA repair is critical to maintain genome stability and prevent disease development. Eukaryotic DNA is packaged into chromatin that has a profound, yet not well understood regulatory influence on DNA repair, replication and genome maintenance. There is a fundamental gap in understanding how DNA repair pathways are regulated and coordinated within structurally diverse chromatin, and across the heterogeneous genomic landscape. The HELLS (Helicase Lymphoid Specific) is a poorly understood chromatin-associated protein, with an emerging new role in genome maintenance. Mouse HELLS is essential for gametogenesis and proper development of the immune system. Mutations in human HELLS cause severe immunodeficiency syndrome ICF (Immunodeficiency Centromeric Instability Facial anomalies). Despite substantial progress in understanding the molecular functions of the mammalian HELLS in DNA methylation and chromatin remodeling, its role in DNA repair and genome maintenance is poorly understood and remains elusive. The unresolved questions remain whether HELLS regulates multiple DNA repair pathways, and whether it has specialized roles in the repair and maintenance of a distinct genomic loci or domains. We have established and validated fungal model, Neurospora crassa to advance the fundamental understanding of HELLS-mediated mechanisms of genome stability. Our studies reveal a new, previously unrecognized link between HELLS proteins and cellular responses to DNA alkylation damage in fungal and human cells. We hypothesize that HELLS protects cells form alkylation-induced toxicity and plays important roles in the repair and stability of the constitutive heterochromatin domains. This hypothesis is founded based on a strong preliminary data in the fungal model Neurospora and in human cells demonstrating that cells deficient in HELLS exhibit sensitivity to DNA alkylation damage and are deficient in the repair of the constitutive heterochromatin. In addition, we discovered that loss of fungal WDR76 protein in HELLS mutant cells leads to the synthetic rescue of the alkylation sensitivity phenotype, implying that WDR76 acts as genetic suppressor of HELLS deficiency. In Aim 1 we will determine the role of fungal and human HELLS remodelers in the repair of alkylation DNA damage. In Aim 2 we will define precise genomic and chromatin contexts that depend on HELLS for genome maintenance. In Aim 3 we will determine the functional relationship between HELLS and WDR76, a WD40 protein implicated in response to DNA alkylation. Successful completion of the proposed research will define HELLS-mediated mechanisms of genome maintenance, and identify additional regulators and pathways cooperating with HELLS in protecting the cells from detrimental consequences of genotoxic stress. These studies will provide important insights into the origin of the disease- causing chromosomal rearrangements and breaks found in many human diseases, including the ICF syndrome.

项目概要强大且严格调控的 DNA 修复对于维持基因组稳定性和预防疾病发展至关重要。真核 DNA 被包装成染色质，对染色质具有深远但尚未充分理解的调节影响。 DNA 修复、复制和基因组维护。对 DNA 修复方式的理解存在根本性差距通路在结构多样的染色质内以及跨异质性的区域内受到调节和协调基因组景观。 HELLS（淋巴解旋酶特异性）是一种人们知之甚少的染色质相关蛋白蛋白质，在基因组维护中发挥着新兴的新作用。 Mouse HELLS 对于配子发生至关重要免疫系统的正常发育。人类 HELLS 突变导致严重免疫缺陷 ICF 综合征（免疫缺陷着丝粒不稳定面部异常）。尽管取得了实质性进展了解哺乳动物 HELLS 在 DNA 甲基化和染色质重塑中的分子功能，人们对它在 DNA 修复和基因组维护中的作用知之甚少，而且仍然难以捉摸。未解决的问题仍然存在：HELLS 是否调节多种 DNA 修复途径，以及它是否具有专门的作用修复和维护不同的基因组位点或结构域。我们已经建立并验证了真菌粗糙脉孢菌模型，以促进对 HELLS 介导机制的基本理解基因组稳定性。我们的研究揭示了 HELLS 蛋白与细胞之间新的、以前未被认识的联系真菌和人类细胞中对 DNA 烷基化损伤的反应。我们假设 HELLS 可以保护细胞形成烷基化诱导的毒性，在组成型异染色质的修复和稳定性中发挥重要作用域。这一假设是基于真菌模型脉孢菌和真菌模型中强有力的初步数据而建立的。人类细胞证明，HELLS 缺陷的细胞对 DNA 烷基化损伤表现出敏感性，并且组成型异染色质修复缺陷。此外，我们发现真菌 WDR76 的丢失 HELLS 突变细胞中的蛋白质导致烷基化敏感性表型的合成拯救，这意味着 WDR76 充当 HELLS 缺陷的基因抑制因子。在目标 1 中，我们将确定真菌和人类的作用 HELLS 重塑剂修复烷基化 DNA 损伤。在目标 2 中，我们将定义精确的基因组和依赖于 HELLS 进行基因组维护的染色质环境。在目标 3 中，我们将确定函数 HELLS 和 WDR76 之间的关系，WDR76 是一种与 DNA 烷基化反应有关的 WD40 蛋白。成功的拟议研究的完成将定义 HELLS 介导的基因组维护机制，以及确定与 HELLS 合作的其他调节因子和途径，以保护细胞免受有害影响遗传毒性应激的后果。这些研究将为了解该疾病的起源提供重要的见解—— 导致许多人类疾病中发现的染色体重排和断裂，包括 ICF 综合征。