Factors Controlling Minisatellite Stability in Yeast

控制酵母小卫星稳定性的因素

• 批准号: 7260488
• 负责人: David T. Kirkpatrick
• 金额: $ 23.99万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7260488
• 关键词: Affect; Alleles; Biological Models; Chromatin Loop; Class; Complement; DNA; DNA Repair; DNA Sequence Rearrangement; Data; Disease; Enhancers; Excision; Exhibits; Frequencies; Genes; Genetic; Genetic Recombination; Genetic Transcription; Genome; Genome Stability; Genomic Instability; Genomics; HRAS gene; Human; Length; Maintenance; Malignant Neoplasms; Mammalian Cell; Measures; Meiosis; Meiotic Recombination; Minisatellite Repeats; Mitotic; Mitotic Cell Cycle; Nucleotides; Numbers; Oncogenes; Pathway interactions; Phenotype; Predisposition; Proteins; Range; Research Personnel; Role; Saccharomyces cerevisiae; Screening procedure; Source; System; Tissue Sample; Transcription Initiation; Variant; Yeasts; base; clinical phenotype; endonuclease; genetic analysis; insight; malignant breast neoplasm; mammalian genome; mutant; novel; programs; repaired; research study; tumorigenesis

DESCRIPTION (provided by applicant): Maintenance of genome stability is of paramount importance; genome instability has been correlated with numerous disease states in humans, for example. Repetitive DNA is often the source of genomic rearrangements. One class of repetitive DNA, minisatellite sequences, have an approximate repeat unit length ranging from 15 to 100 nucleotides. Mammalian genomes contain a large number of different minisatellite tracts. While these tracts are stable during the mitotic cell cycle, they destabilize during meiosis, altering in both length and sequence composition. Unfortunately the genetic and physical factors controlling the stability of minisatellite tracts are unknown. Minisatellite tracts can have genetic functions; a human minisatellite tract associated with the HRAS1 oncogene acts as a transcription enhancer for HRAS1, and altered minisatellite alleles have been correlated with HRAS1 oncogenesis. We established a model system by introducing the HRAS1 minisatellite into the HIS4 locus in the yeast S. cerevisiae, where it exhibits all of the phenotypes observed in mammalian cells. The tract stimulates transcription and meiotic recombination, and undergoes meiosis-specific alterations in length. Removal of a recombination-initiating endonuclease eliminates tract alterations, while removal of a meiotic DNA loop repair pathway specifically reduces the frequency of tract expansions. These initial studies will be extended by determining the complete complement of genes governing stability of the HRAS1 minisatellite. Two general screens for minisatellite stability maintenance genes have been initiated, in addition to a directed screen of the Yeast Deletion Strain Bank. The screens will identify genes required for minisatellite stability as well as genes affecting DNA loop repair. Finally, we will determine the basis for an observed correlation between HRAS1 minisatellite allele state and breast cancer oncogenesis, through genetic analysis of native human HRAS1 minisatellite alleles. Many of 1he proposed experiments cannot be done in a mammalian system; the HIS4-HRAS1 minisatellite system is the only means to gain these important data. These studies will provide insights into genome maintenance, recombination, DNA repair, transcription initiation, and aspects of cancer predisposition.

描述（由申请人提供）：基因组稳定性的维持至关重要；例如，基因组不稳定性与人类的众多疾病状态相关。重复的DNA通常是基因组重排的来源。一类重复的DNA Minisatellite序列的重复单位长度在15至100个核苷酸范围内。哺乳动物的基因组包含大量不同的迷你卫生间。尽管这些区域在有丝分裂细胞周期中是稳定的，但它们在减数分裂过程中稳定，长度和序列组成都改变了。不幸的是，控制着迷你卫星区域稳定性的遗传和物理因素尚不清楚。迷你卫生馆可以具有遗传功能。与HRAS1致癌基因相关的人类迷你卫星道充当HRAS1的转录增强子，而改变的微型卫星等位基因已与HRAS1肿瘤发生相关。 我们通过将HRAS1微型卫星引入酵母菌S.酿酒酵母中的HIS4基因座来建立模型系统，在那里它表现出在哺乳动物细胞中观察到的所有表型。该道刺激了转录和减数分裂的重组，并经历了减数分裂特定的长度改变。去除重组发射核酸内切酶可以消除道的改变，而减数分裂DNA环修复途径的去除专门降低了道膨胀的频率。 这些初步研究将通过确定有关HRAS1迷你卫星稳定性的基因的完整补体来扩展。除了酵母缺失应变库的定向屏幕外，还启动了两个用于微型卫星稳定性维持基因的通用屏幕。屏幕将确定微型卫星稳定性所需的基因以及影响DNA环修复的基因。最后，我们将通过对天然人类HRAS1微型智能等位基因的遗传分析，确定HRAS1微型层等位基因状态与乳腺癌肿瘤之间观察到的相关性的基础。 1个提议的实验中的许多不能在哺乳动物系统中进行。 HIS4-HRAS1迷你卫星系统是获取这些重要数据的唯一手段。这些研究将提供有关基因组维持，重组，DNA修复，转录启动以及癌症易感方面的见解。