Characterization of genes isolated in a novel screen for mutants with altered mitotic lifespan in yeast

在酵母中有丝分裂寿命改变的突变体的新型筛选中分离的基因的表征

• 批准号: 239239-2012
• 负责人: Harkness, Troy
• 金额: $ 2.91万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570592
• 关键词: Characterization; genes; isolated; novel; screen

INTRODUCTION: Why all living organisms age has been a most intriguing question for centuries. Using simple model systems, such as flies, worms, and yeast, single conserved genes have been identified that greatly impact cellular and whole animal lifespan. The health of single cell and multicellular organisms is a measure of cellular capacity to maintain lifespan. Every cell undergoes a series of divisions until a differentiated or senescent state is reached. RECENT PROGRESS: We have designed and implemented the first genome-wide screen for yeast mutants that experience an altered number of cell divisions prior to senescence. The screen yielded 48 mutants with increased lifespan and 87 with reduced lifespan. Many of the identified mutants define cellular processes that have not been previously linked with regulating lifespan, and implicate genes involved in protein trafficking and iron transport. OBJECTIVES: This proposal will focus on testing our central hypotheses that i) protein trafficking is an integral determinant of cellular lifespan in yeast, and ii) that impaired iron uptake and cellular transport results in premature aging in yeast. METHODS: The lifespan phenotypes of mutants identified in the screen will be confirmed using the replicative lifespan assay (RLS). The initial characterization will involve a genetic analysis of interactions to work out functional pathways. Characterizing genetic interactions and potential epistasis is utilized for placement of factors within hierarchical pathways, an approach that we have extensively relied on in the past. The synchrotron at the Canadian Light Source (CLS) will be employed in studies aimed at determining whether free iron accumulates in the mutants and to characterize the iron species that normally accumulate with age. IMPACT: The genes we have identified in yeast are also found in humans, suggesting that our findings in yeast will allow new avenues of research to be explored in aging studies in higher eukaryotic systems.

简介：为什么所有生物年龄都成为数百年来最有趣的问题。使用简单的模型系统（例如苍蝇，蠕虫和酵母），已经确定了单一保守基因，从而极大地影响了细胞和整个动物的寿命。单细胞和多细胞生物的健康是维持寿命的细胞能力的量度。每个细胞都会经历一系列分裂，直到达到差异化或衰老状态为止。 最近的进展：我们为酵母突变体设计并实施了第一个全基因组筛选，这些筛子经历了衰老之前的细胞分裂数量变化。屏幕产生了48个突变体，寿命增加，寿命降低。许多已鉴定的突变体定义了以前尚未与调节寿命相关的细胞过程，并暗示了与蛋白质运输和铁转运有关的基因。 目的：该提案将重点介绍我们的中心假设：i）蛋白运输是酵母中细胞寿命不可或缺的决定因素，而ii）II）损害了铁的摄取和细胞运输会导致酵母的过早衰老。 方法：将使用复制寿命测定（RLS）确认在屏幕上鉴定出的突变体的寿命表型。最初的表征将涉及对相互作用的遗传分析，以解决功能途径。表征遗传相互作用和潜在上毒的特征用于将因子放置在层次途径中，这是我们过去广泛依赖的一种方法。加拿大光源（CLS）的同步加速器将用于旨在确定突变体中的自由铁积聚并表征通常随着年龄增长而积累的铁物种的研究。 影响：在人类中也发现了我们在酵母中发现的基因，这表明我们在酵母中的发现将允许在高等真核系统的衰老研究中探索新的研究途径。