RUI: Mechanisms of Aging in Saccharomyces cerevisiae

RUI：酿酒酵母的衰老机制

• 批准号: 0113937
• 负责人: Laura Hoopes
• 金额: $ 32.29万
• 依托单位: Pomona College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0113937&HistoricalAwards=false
• 关键词: RUI; Mechanisms; Aging; Saccharomyces; cerevisiae

In research funded by an NSF POWRE grant awarded to the investigator, the yeast DNA2 gene was found to be essential for normal life span. DNA2 encodes a replicative and post replication repair helicase distantly related to SGS1 and Werner syndrome helicases. Four dna2 mutants have average life spans from 4.9 to 8.9 generations, while wild type is 23.8 generations. The sgs1 and dna2 mutants do not appear to be epistatic. Other replication mutants also have short life spans. Two strains with all rDNA deleted and rDNA supplied by plasmids have shortened life spans. These results led to the replication block model of DNA aging in yeast, suggesting that replicative senescence can result from accumulation of blocked replication forks. In addition, Y55 diploids were recently found to reset their aging clocks in meiosis. This project tests the model of replicative aging resulting from blocked replication forks and will begin a search for genes involved in resetting the yeast aging clock. The replication fork block hypothesis is being tested by observing the aging phenotypes of size increases, sterility, nucleolar fragmentation, and rDNA amplification in replication and post replication repair mutants other than dna2 and in ribosomal deletion strains, to see whether or not aspects of normal aging are accelerated in these mutants. If so, the particular process may be related to aging pacesetting. If the rDNA deletions appear to age faster, then epistasis with mutants of the silent information regulators and helicases will be tested. The structures of the DNA, with particular emphasis on structures that would result from stalled replication forks, will be examined using fiber-FISH, 2D gels, and pulsed field and normal electrophoresis combined with nuclease digestion. In addition, resetting of the aging clock is being examined in mutants affecting budding asymmetry. Whether meiosis affects clock resetting in a different meiosis strain, BR3604, will be determined. If the clock is reset in meiosis, sporulation mutants will be used to test the involvement of specific steps in meiosis in the resetting.This novel research promises to further our understanding at the molecular level of the process of aging. The use of the yeast system enhances the promise of the project because of the many molecular tools available for yeast and the extensive existing body of knowledge about the system. This research will be carried out at Pomona College, an undergraduate institution. The active involvement of students there in this research is an especially attractive feature of the project.

在由NSF POWRE基金资助的研究中，酵母DNA 2基因被发现对正常寿命至关重要。 DNA 2编码一种复制和复制后修复解旋酶，与SGS 1和Werner综合征解旋酶远缘。 4个dna 2突变体的平均寿命为4.9 - 8.9代，而野生型为23.8代。 sgs 1和dna 2突变体似乎没有上位性。 其他的复制突变体也有很短的寿命。 两个rDNA全缺失、由质粒提供rDNA的菌株寿命缩短。 这些结果导致了酵母中DNA老化的复制阻断模型，表明复制性衰老可能是由被阻断的复制叉的积累引起的。 此外，最近发现Y55二倍体在减数分裂中重置其衰老时钟。 这个项目测试了由复制叉受阻导致的复制性衰老模型，并将开始寻找参与重置酵母衰老时钟的基因。 复制叉块假说正在测试通过观察老化表型的大小增加，不育，核仁片段化，并在复制和复制后修复突变体以外的dna 2和核糖体缺失株rDNA扩增，看看是否正常老化的方面在这些突变体加速。 如果是这样的话，该特定过程可能与老化起搏有关。 如果rDNA缺失似乎老化更快，则将测试与沉默信息调节子和解旋酶的突变体的上位性。 DNA的结构，特别强调的结构，将导致停滞的复制叉，将使用纤维FISH，2D凝胶，脉冲场和正常电泳结合核酸酶消化检查。 此外，正在研究影响出芽不对称性的突变体的衰老时钟重置。 将确定减数分裂是否影响不同减数分裂株BR 3604中的时钟重置。 如果在减数分裂中时钟被重置，孢子形成突变体将被用来测试减数分裂中的特定步骤在重置中的参与。这项新的研究有望在分子水平上加深我们对衰老过程的理解。 酵母系统的使用增强了该项目的前景，因为有许多可用于酵母的分子工具和关于该系统的广泛现有知识。 这项研究将在波莫纳学院，一个本科院校进行。 该项目的一个特别吸引人的特点是学生积极参与这项研究。