Molecular analyses of RECQ1 functions in genome maintenance

RECQ1 在基因组维护中的功能的分子分析

• 批准号: 8724514
• 负责人: Sudha Sharma
• 金额: $ 32.97万
• 依托单位: HOWARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8724514
• 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

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.

描述（由申请人提供）：RecQ解旋酶家族是一组高度保守的DNA解旋酶，在所有生命王国中对保护基因组稳定性至关重要。人类RecQ同源物包括RECQ 1、BLM、WRN、RECQL 4和RECQ 5。虽然这五种人类RecQ蛋白在催化核心上是相似的，并且在体外共享某些生化特性，但它们显然不是多余的。BLM、WRN和RecQ 4中的突变分别与Bloom、Werner和Rothmund-Thomson综合征的不同遗传疾病相关。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。然而，是什么使每种RecQ蛋白独特尚不清楚。剖析每个人类RecQ解旋酶的功能，并比较它们之间的相似性和差异，将揭示RecQ在DNA代谢中的哪些功能对基因组的维持至关重要。该提案的目标是研究RECQ 1的分子功能，RECQ 1是最丰富但特征最少的人类RecQ解旋酶同源物。最近，我们发现RECQ 1对基因组稳定性的维持至关重要;它的缺陷会导致DNA损伤和染色体不稳定性的积累。RECQ 1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，RECQ 1缺陷细胞对DNA损伤更敏感，并显示自发升高的姐妹染色单体交换，这让人想起停滞的复制叉的异常修复。我们假设RECQ 1通过其催化作用和与细胞蛋白质伴侣的特异性相互作用在确保基因组稳定性方面发挥关键作用。为了验证这一假设，我们建议对RECQ 1的生化和细胞特征进行系统分析。我们将阐明RECQ 1的生物化学活性如何使其在基因组稳定性维持中实现其假定的功能：1）阐明RECQ 1在基因组稳定性维持的DNA修复途径中的作用; 2）确定RECQ 1的关键氨基酸残基对特定的催化和细胞功能至关重要;和3）使用无偏的生物化学方法鉴定RECQ 1的新蛋白质相互作用并研究其功能意义。这些研究的结果对于确定RECQ 1的生物学作用非常重要。这将有助于解剖分子细节，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的相似性和差异，以防止癌症和过早衰老。