The molecular basis of RECQ4-associated genetic disorders and cancer predispositi

RECQ4相关遗传性疾病和癌症易感性的分子基础

• 批准号: 8623102
• 负责人: Yilun Liu
• 金额: $ 33.81万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8623102
• 关键词: Aging-Related Process; Alleles; Amino Acids; Bacteria; Binding; Biochemical; CDC45L gene; Catalytic Domain; Cell Cycle; Cell Extracts; Cell Proliferation; Cell Survival; Cells; Chromatin; Chromosomes; Circadian Rhythms; Cisplatin; Complex; Cyclin-Dependent Kinases; DNA; DNA Binding; DNA Damage; DNA Repair; DNA Replication Factor; DNA Structure; DNA biosynthesis; Data; Defect; Development; Disease; Dissociation; Eukaryota; Evolution; Family; G1 Phase; Genes; Genome; Genomic Instability; Genomics; Genotoxic Stress; Goals; Health; Hereditary Disease; Homologous Gene; Human; In Vitro; Individual; Ionizing radiation; Knowledge; Lead; Lesion; Link; Lymphoma; MCM10 gene; MCM2 gene; Maintenance; Malignant Neoplasms; Maps; Metabolism; Methods; Molecular; Mutagenesis; Mutation; Organism; Outcome; Pathogenesis; Patients; Phenotype; Phosphorylation; Predisposition; Premature aging syndrome; Process; Prokaryotic Cells; Property; Protein Family; Proteins; RECQL4 gene; Regulation; Replication Initiation; Replication Origin; Reporting; Role; Set protein; Sister Chromatid; Tumor Suppressor Proteins; Vertebrates; Work; Yeasts; arm; base; biological adaptation to stress; cancer prevention; cancer therapy; cell growth; clinical phenotype; cohesion; helicase; in vitro activity; in vivo; metaplastic cell transformation; mouse model; osteosarcoma; polypeptide; prevent; protein complex; protein protein interaction; public health relevance; repaired; tumorigenesis

DESCRIPTION (provided by applicant): Functional machineries to prevent and repair DNA damages are required for maintaining genome integrity and preventing tumourigenesis. A set of proteins belonging to the RecQ family is among the cancer suppressors linked to repairing lesions caused by DNA damaging agents, such as ionizing radiation and cisplatin. During the course of evolution, RecQ genes appear to have been amplified and diverged from a single copy of the RecQ gene in bacteria and yeast to five RecQ homologs in humans. The clinical phenotypes caused by mutations in different RECQ proteins in humans and mouse models indicate that they have important and non-overlapping roles in maintaining genomic integrity and cancer prevention. Since RECQ helicases are highly interactive proteins and form large protein complexes in vivo, the unique functions of each of the RECQ proteins are likely defined and regulated by the specific protein-protein interactions they form in cells. To understand how the mammalian RECQ proteins act as tumor suppressors and caretakers for our genome, it is crucial to understand the unique functions of each of the RECQ protein complexes. Recently, our lab has several breakthroughs in the study of human RECQ4 helicase. First, we successfully reported ATP-dependent RECQ4 helicase activity in vitro. Surprisingly, domain analyses uncovered two distinct ATP binding and DNA unwinding activities within the RECQ4 protein. Secondly, we report the identification of a highly purified chromatin bound RECQ4 complex from human cell extracts. We found that essential replisome factors MCM10, MCM2-7 helicase, CDC45 and GINS are the primary interaction partner proteins of human RECQ4. Moreover, circadian proteins, TIMELESS and TIPIN important for cohesion establishment and DNA replication progression are part of the RECQ4 complex. Importantly, complex formation and the association of RECQ4 with the replication origin are cell cycle regulated. Our studies allow us to conclude that RECQ4 is an integral component of the MCM replicative helicase complex participating in DNA replication in human cells. Based on our work, the goal of this proposal is to define the exact function of RECQ4 complex in DNA replication, cohesion establishment and cancer avoidance. The Specific Aims are: (1) dissecting the role of human RECQ4 in DNA replication initiation; (2) Establishing the functional relationship between RECQ4 and TIM-TIPIN heterodimer in replication fork progression, genotoxic stress response and cohesion establishment; and (3) Analysis of the cancer-associated RECQ4 (c.1390+2delT) mutation.

描述（由申请人提供）：需要预防和修复DNA损伤的功能机械才能维持基因组完整性和预防肿瘤发生。属于RECQ家族的一组蛋白质是与DNA损伤剂（例如电离辐射和顺铂）引起的修复病变有关的癌症抑制剂之一。在进化过程中，RECQ基因似乎已扩增并与细菌中的RECQ基因的单个副本和酵母中的单个副本分歧，到了人类的五个RECQ同源物。由人类和小鼠模型中不同RECQ蛋白突变引起的临床表型表明它们在维持基因组完整性和预防癌症方面具有重要且不重叠的作用。由于RECQ解旋酶是高度相互作用的蛋白质，并在体内形成大蛋白复合物，因此每种RECQ蛋白的独特功能可能由它们在细胞中形成的特定蛋白质蛋白质相互作用来定义和调节。为了了解哺乳动物RECQ蛋白如何充当我们基因组的肿瘤抑制剂和看护人，了解每种RECQ蛋白复合物的独特功能至关重要。 最近，我们的实验室在人类RECQ4解旋酶的研究中有几个突破。首先，我们在体外成功报道了ATP依赖性RECQ4解旋酶活性。令人惊讶的是，域分析了RECQ4蛋白中发现的两种不同的ATP结合和DNA放松活性。其次，我们报告了从人类细胞提取物中高度纯化的染色质结合RECQ4复合物的鉴定。我们发现，必需的重建因子MCM10，MCM2-7解旋酶，CDC45和杜松子是人RECQ4的主要相互作用伴侣蛋白。此外，对于凝聚力的建立和DNA复制进程很重要的昼夜节律蛋白是RECQ4复合物的一部分。重要的是，复杂的形成和RECQ4与复制来源的关联受细胞周期的调节。我们的研究使我们得出结论，RECQ4是参与人类细胞中DNA复制的MCM复制性解旋酶复​​合物的组成部分。基于我们的工作，该提案的目的是定义RECQ4复合物在DNA复制，内聚力建立和避免癌症中的确切功能。具体目的是：（1）解剖人RECQ4在DNA复制启动中的作用； （2）在复制进展，遗传毒性应激反应和内聚力中建立RECQ4与Tim-Tipin异二聚体之间的功能关系； （3）分析癌症相关的RECQ4（C.1390+2DELT）突变。