Genetic regulation of genome stability in yeast

酵母基因组稳定性的遗传调控

基本信息

批准号：
10646337
负责人：
THOMAS PETES
金额：
$ 70.69万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10646337
关键词：
ATR gene Accounting Aneuploidy Base Composition Biological Models Cells Centromere Chromosomes Cytosine DNA DNA Polymerase III DNA Repair DNA biosynthesis Data Deamination Enzymes Event Familial colorectal cancer GC gene Genes Genetic Genetic Nondisjunction Genetic Recombination Genome Genome Stability Genomic Instability Goals Guanine + Cytosine Composition Histone H2A Human Induced Mutation Maps Meclp Microsatellite Instability Mismatch Repair Modeling Molecular Chaperones Mutation Normal Cell Phenotype Phosphorylation Proteins Regulation Research Saccharomyces cerevisiae Single-Stranded DNA System TEL1 Gene Tandem Repeat Sequences Testing Yeasts ataxia telangiectasia mutated protein base cancer cell carcinogenesis causal variant experimental study neoplastic cell novel replication stress success telomere tumor yeast protein

项目摘要

Abstract Multiple genetic changes are necessary to convert a normal cell into a cancer cell. With a few exceptions, the mutations or conditions (for example, DNA replication stress) that initiate genetic instability and tumor formation are not understood. The goal of the proposed research is to use the yeast Saccharomyces cerevisiae as a model for investigating the mechanisms that generate the various types of genetic instability related to carcinogenesis. As an example of the success of this approach, our demonstration that DNA mismatch repair mutations in yeast produced the same rate of microsatellite instability observed in hereditary colorectal cancer cells was an important clue as to the causal mutation. 1. One of the proposed studies is the characterization of a novel mutator that is responsive to base composition. We showed that a gene with high GC content had a much-elevated mutation rate than genes with lower GC contents. We subsequently identified a mutation (met18) that elevated the mutation rate of a high-GC gene more than 100-fold, with a much smaller effect on other genes. The Met18 protein is a chaperone involved in the transport of Fe-S clusters into a variety of enzymes involved in DNA replication and DNA repair. Our current data suggest that DNA polymerase delta lacking the Fe-S cluster has substantially reduced processivity, accounting for the mutator phenotype of met18. This hypothesis will be tested by our proposed experiments. 2. Fusions between centromeres are commonly observed in tumor cells. We have developed a genetic system that allows the identification of recombination events occurring between the centromeres of different yeast chromosomes. We will use this system to examine the genetic regulation of centromere-centromere recombination. 3. We have recently used the mammalian APOBEC protein, which deaminates cytosine in single-stranded DNA, to map regions of single- stranded DNA in yeast cells undergoing DNA replication stress. Using APOBEC-induced mutations, we propose extending our studies to map deletions and duplications in arrays of tandemly-repeated genes. Such alterations are an important cause of genome instability. 4. Lastly, the Tel1p and Mec1p yeast proteins are related functionally to the human ATM and ATR proteins, respectively. Mutations in both human genes are associated with certain classes of tumors. Yeast cells with tel1 mec1 mutations have greatly elevated rates of chromosome rearrangements and chromosome non-disjunction. The chromosome rearrangements, but not the aneuploidy, are a consequence of a high rate of telomere fusions. We are testing the hypothesis that the high level of chromosome non-disjunction is a consequence of defective phosphorylation of histone H2A in tel1 mec1 strains.

抽象的将正常细胞转变为癌细胞需要多种基因变化。与几个异常、引发遗传不稳定的突变或条件（例如 DNA 复制压力）和肿瘤的形成尚不清楚。拟议研究的目标是使用酵母菌酿酒酵母作为研究产生各种遗传不稳定性的机制的模型与致癌有关。作为这种方法成功的一个例子，我们证明了 DNA 酵母中的错配修复突变产生的微卫星不稳定性与遗传中观察到的相同结直肠癌细胞是因果突变的重要线索。 1. 拟议的研究之一是对碱基组成有响应的新型突变子的表征。我们证明了一个基因具有高 GC含量的基因比GC含量较低的基因的突变率要高得多。我们随后确定一种突变 (met18)，使高 GC 基因的突变率提高了 100 倍以上，且突变率小得多对其他基因的影响。 Met18 蛋白是参与 Fe-S 簇转运至多种物质的伴侣蛋白。参与 DNA 复制和 DNA 修复的酶。我们目前的数据表明 DNA 聚合酶 delta 缺乏 Fe-S 簇会显着降低持续合成能力，从而解释了 met18 的突变表型。这个假设将通过我们提出的实验进行检验。 2. 着丝粒之间的融合通常是在肿瘤细胞中观察到。我们开发了一个遗传系统，可以识别重组不同酵母染色体着丝粒之间发生的事件。我们将使用这个系统来检查着丝粒-着丝粒重组的遗传调控。 3.我们最近使用了哺乳动物 APOBEC 蛋白，它使单链 DNA 中的胞嘧啶脱氨基，以绘制单链区域酵母细胞中的DNA链受到DNA复制压力。利用 APOBEC 诱导的突变，我们建议扩展我们的研究，以绘制串联重复基因阵列中的缺失和重复。这样的改变是基因组不稳定的重要原因。 4. 最后，Tel1p 和 Mec1p 酵母蛋白是分别与人类 ATM 和 ATR 蛋白功能相关。两个人类基因的突变都是与某些类型的肿瘤有关。具有 tel1 mec1 突变的酵母细胞的发生率大大提高染色体重排和染色体不分离。染色体重排，但不是非整倍体是端粒融合率高的结果。我们正在测试以下假设：高染色体不分离水平是 tel1 中组蛋白 H2A 磷酸化缺陷的结果 mec1 菌株。

项目成果

期刊论文数量（11）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Nanopore sequencing of complex genomic rearrangements in yeast reveals mechanisms of repeat-mediated double-strand break repair.

DOI：
10.1101/gr.228148.117
发表时间：
2017-12
期刊：
Genome research
影响因子：
7
作者：
McGinty RJ;Rubinstein RG;Neil AJ;Dominska M;Kiktev D;Petes TD;Mirkin SM
通讯作者：
Mirkin SM

Ribodysgenesis: sudden genome instability in the yeast Saccharomyces cerevisiae arising from RNase H2 cleavage at genomic-embedded ribonucleotides.

DOI：
10.1093/nar/gkac536
发表时间：
2022-07-08
期刊：
NUCLEIC ACIDS RESEARCH
影响因子：
14.9
作者：
Sui, Yang;Epstein, Anastasiya;Dominska, Margaret;Zheng, Dao-Qiong;Petes, Thomas D.;Klein, Hannah L.
通讯作者：
Klein, Hannah L.

Splitting the yeast centromere by recombination.