Molecular analyses of RECQ1 functions in genome maintenance

RECQ1 在基因组维护中的功能的分子分析

基本信息

批准号：
8323668
负责人：
Sudha Sharma
金额：
$ 14.84万
依托单位：
HOWARD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8323668
关键词：
Affinity Chromatography Aging Amino Acids Binding Biochemical Biological Biological Process Bloom Syndrome Catalytic Domain Cell Extracts Cell physiology Cells Characteristics Chromosomal Instability Clinical Complex Cruciform DNA DNA DNA Damage DNA Double Strand Break DNA Repair DNA Repair Pathway DNA Structure Defect Development Disease Educational Curriculum Ensure Event Family Foundations Frequencies Future Genetic Recombination Genome Genome Stability Genomic Instability Genotoxic Stress Goals Grant Growth Health Hela Cells Hereditary Disease Homologous Gene Human Immunoprecipitation In Vitro Individual Ionizing radiation Knock-out Knockout Mice Letters Life Link Maintenance Malignant Neoplasms Mass Spectrum Analysis Metabolism Mismatch Repair Modeling Molecular Mus Mutation Nature Organism Pathway interactions Patients Play Predisposition Premature aging syndrome Productivity Property Proteins Publishing RECQL gene RECQL4 gene RECQL5 gene Rare Diseases RecQ protein Recombinants Regulation Research Research Personnel Resources Role Rothmund-Thomson syndrome Sister Chromatid Exchange Site-Directed Mutagenesis Small Interfering RNA Testing United States National Institutes of Health Werner Syndrome Work cancer prevention clinical phenotype early onset helicase high risk homologous recombination in vitro activity insight member metaplastic cell transformation migration novel prevent public health relevance recombinational repair repaired response tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): The RecQ helicase family is a group of highly conserved DNA unwinding enzymes critical in guarding genome stability in all kingdoms of life. Human RecQ homologs include RECQ1, BLM, WRN, RECQL4, and RECQ5. Although the five human RecQ proteins are similar in their catalytic core and share certain biochemical properties in vitro, they are clearly not redundant. Mutations in BLM, WRN and RecQ4 are associated with distinct genetic disorders of Bloom, Werner, and Rothmund-Thomson syndromes, respectively. Thus, a defect in one RecQ protein is sufficient to cause genomic instability that cannot be compensated by other RecQ homologs. However, what makes each RecQ protein unique is not understood. Dissecting the functions of each human RecQ helicase, and comparing the similarities and differences among them, will reveal which aspects of RecQ functions in DNA metabolism are essential for genome maintenance. The goal of this proposal is to examine molecular functions of RECQ1, the most abundant but least characterized human RecQ helicase homolog. Recently, we have shown that RECQ1 is essential for genome stability maintenance; its deficiency induces accumulation of DNA damage and chromosomal instability. RECQ1 binds and unwinds DNA structures that represent intermediates of DNA recombination repair, and interacts physically and functionally with proteins involved in regulating genetic recombination. Moreover, RECQ1-deficient cells are more sensitive to DNA damage and display spontaneously elevated sister chromatid exchanges reminiscent of aberrant repair of stalled replication forks. We hypothesize that RECQ1 plays critical roles in ensuring genome stability by virtue of its catalytic actions and specific interactions with cellular protein partners. To test this hypothesis, we are proposing systematic analyses of the biochemical and cellular characteristics of RECQ1. We will elucidate how biochemical activities of RECQ1 allow it to achieve its putative functions in genome stability maintenance by: 1) elucidating role(s) of RECQ1 in DNA repair pathways of genome stability maintenance; 2) determining critical amino acid residues of RECQ1 essential for specific catalytic and cellular functions; and 3) identifying novel protein interactions of RECQ1 using unbiased biochemical approaches and investing their functional significance. Results from these studies will be important to establish biological roles of RECQ1. This should facilitate dissecting the molecular details that explain similarities and differences in the biological functions of human RecQ helicases in pathways of genome stability maintenance to prevent cancer and premature aging. PUBLIC HEALTH RELEVANCE: RECQ1 belongs to the RecQ family of DNA helicases members of which are associated with rare diseases of premature aging and cancer predisposition in humans. Thus, the functions of RecQ helicases have a direct impact on human health. The presence of multiple RecQ homologs in humans indicates functional specialization; elucidating the molecular function(s) of RECQ1 helicase should, therefore, provide important insights to the mechanisms of genome stability maintenance that prevent development of cancer and early onset of aging.

描述（由申请人提供）：RECQ解旋酶家族是一组高度保守的DNA，放松酶，这对于保护所有王国的基因组稳定性至关重要。人RECQ同源物包括RECQ1，BLM，WRN，RECQL4和RECQ5。尽管五种人RECQ蛋白在其催化核心上是相似的，并且在体外具有某些生化特性，但它们显然不是冗余。 BLM，WRN和RECQ4中的突变分别与Bloom，Werner和Rothmund-Thomson综合征的不同遗传疾病有关。因此，一种RECQ蛋白的缺陷足以引起基因组不稳定性，而其他RECQ同源物无法补偿。但是，使每个RECQ蛋白独特的原因尚不清楚。解剖每个人RECQ解旋酶的功能，并比较它们之间的相似性及其差异，将揭示DNA代谢中RECQ功能的哪些方面对于维持基因组维持至关重要。该提案的目的是检查RECQ1的分子功能，RECQ1是最丰富但最不含的人类RECQ解旋酶同源物。最近，我们表明RECQ1对于基因组稳定性维持至关重要。它的缺乏会导致DNA损伤和染色体不稳定性的积累。 RECQ1结合并解开代表DNA重组修复中间体的DNA结构，并与参与调节遗传重组的蛋白质在物理和功能上相互作用。此外，RECQ1缺陷型细胞对DNA损伤更敏感，并显示出自发升高的姐妹染色单体交换，让人联想到失速复制叉的异常修复。我们假设RECQ1凭借其催化作用和与细胞蛋白伴侣的特定相互作用在确保基因组稳定性方面起关键作用。为了检验这一假设，我们提出了RECQ1生化和细胞特征的系统分析。我们将阐明RECQ1的生化活性如何允许其在基因组稳定性维持中实现其假定的功能：1）RECQ1在基因组稳定性维持DNA修复途径中阐明RECQ1的作用； 2）确定对特定催化和细胞功能必不可少的RECQ1的关键氨基酸残基； 3）使用公正的生化方法鉴定RECQ1的新型蛋白质相互作用并投入其功能意义。这些研究的结果对于建立RECQ1的生物学作用将很重要。这应该有助于解剖分子细节，以解释人类RECQ解旋酶在基因组稳定性维持途径中的生物学功能中的相似性和差异，以预防癌症和过早衰老。公共卫生相关性：RECQ1属于DNA解旋酶成员的RECQ家族，其成员与人类的罕见过早衰老和癌症易感性有关。因此，RECQ解旋酶的功能对人类健康有直接影响。人类中多个RECQ同源物的存在表明功能专业化。因此，阐明RECQ1解旋酶的分子功能应为基因组稳定性维持的机制提供重要的见解，以防止癌症的发展和衰老的早期发作。