Control of Yeast Life Span

描述（由申请人提供）：人类衰老的标志之一是线粒体功能随着年龄的增长而下降。模型系统已经证明了一种信号通路，该信号通路将线粒体的功能状态传达给细胞核以协调转录反应。使用一个独特的报告系统，监测核转录的变化，我们发现了一个新的细胞核信号通路，揭示了F1 F0-ATP合酶复合物的b-亚基的重要性，在酿酒酵母中由ATP 2基因编码。我们发现缺乏ATP 2基因的细胞寿命短，这是令人惊讶的，因为在秀丽隐杆线虫中的RNAi实验表明，减少其他F1 F0- ATP合酶亚基的表达可以延长寿命。我们有了一个令人兴奋的发现，即ATP 2表达的适度减少或增加都会延长S。酿酒酵母寿命。我们推测，b亚基水平的失调导致ATP水平下降。由于F1 F0-ATP合酶从细菌到人类都是保守的，因此了解它如何延长酵母寿命以及这种效应是否在进化上保守将对我们对衰老的理解产生广泛影响。为了确定额外的长寿途径，我们在裂殖酵母中开发了一种新的衰老测定法，该测定法概括了长寿细胞通过热量限制和抗应激延长寿命的进化保守特性。该测定允许从随机突变体群体中直接和无偏地选择长寿突变体。我们已经建立了一个大银行的S。粟酒裂殖酵母DNA插入突变体，这将允许长寿命的突变体的分离和受影响的基因的快速鉴定。我们的长期目标是了解控制衰老的遗传途径，我们将通过描述模型系统中进化保守的途径来实现这一目标。我们的具体目标将回答以下问题：1. F1 F0-ATP合成酶b亚基调控不当的突变体寿命延长是否与产生ATP的能力降低有关？我们将确定长寿突变体是否改变了ATP水平和线粒体功能，并测试b亚基是否必须定位于线粒体以延长寿命。2. F1 F0-ATP合酶b亚基的错误调节延长寿命的作用在进化上是保守的吗？我们将测试是否错误调节b亚单位增加果蝇或S。粟酒寿命3.在我们独特的S。粟酒酵母老化试验揭示了延长时间寿命的新途径？我们将描述S.通过热量限制和使用这个系统来识别新的延长寿命的突变。我们的研究结果将为进化上保守的途径提供新的见解，这些途径将影响对人类衰老生物学的理解。公共卫生相关性：人体中的所有细胞都依赖线粒体来产生能量并进行生命所需的各种过程。使用酵母作为人类细胞的模型，我们发现线粒体蛋白质的小幅增加可以增加20%的寿命。我们还发现了一种方法，可以发现许多新的突变，延长酵母的寿命，这可以揭示延长人类细胞寿命的类似方法。

DESCRIPTION (provided by applicant): One of the hallmarks of human aging is the decline in mitochondrial function with advancing years. Model systems have demonstrated a signaling pathway that communicates the functional state of the mitochondria to the nucleus to coordinate a transcriptional response. Using a unique reporter system that monitors changes in nuclear transcription, we uncovered a new mitochondrial-nuclear signaling pathway that revealed the importance of the b-subunit of the F1F0-ATP synthase complex, encoded in Saccharomyces cerevisiae by the ATP2 gene. We found that cells lacking the ATP2 gene had a short lifespan, which was surprising since RNAi experiments in Caenorhabditis elegans indicated that reducing expression of other F1F0- ATP synthase subunits extends lifespan. We made the exciting discovery that either a modest decrease or increase in ATP2 expression extends S. cerevisiae lifespan. We hypothesize that misregulation of b-subunit levels causes a decrease in ATP levels. As the F1F0-ATP synthase is conserved from bacteria to humans, understanding how it can extend yeast lifespan and if this effect is evolutionarily conserved will have wide impact on our understanding of aging. To identify additional longevity pathways, we developed a new aging assay in Schizosaccharomyces pombe that recapitulates the evolutionarily conserved properties of lifespan extension by caloric restriction and stress resistance of long-lived cells. This assay allows the direct and unbiased selection of long-lived mutants from populations of random mutants. We have constructed a large bank of S. pombe DNA insertion mutants that will allow an isolation of long-lived mutants and rapid identification of the affected genes. Our long-term goals are to understand the genetic pathways that control aging, which we will approach by characterizing evolutionarily conserved pathways in model systems. Our specific aims will answer the following questions: 1. Is the lifespan extension of mutants misregulated in the F1F0-ATP synthase b-subunit related to a reduction in the ability to produce ATP? We will determine if the long-lived mutants have altered ATP levels and mitochondrial functions, and test whether the b-subunit must be localized to mitochondria to extend lifespan. 2. Are the lifespan extending effects of misregulating the b-subunit of the F1F0-ATP synthase evolutionarily conserved? We will test if misregulating the b-subunit increases Drosophila or S. pombe lifespan. 3. Does the unbiased isolation of long-lived mutants in our unique S. pombe aging assay reveal new pathways to extend chronological lifespan? We will characterize the mechanism of lifespan extension in S. pombe by caloric restriction and use this system to identify new lifespan extending mutations. Our results will provide new insights into evolutionarily conserved pathways that will impact the understanding of the biology of human aging. PUBLIC HEALTH RELEVANCE: All cells in the human body rely on mitochondria to produce energy and to carry out a wide variety of processes required for life. Using yeast as a model for human cells, we found that a small increase in a mitochondrial protein can increase lifespan by 20%. We have also discovered a way to find many new mutations that prolong life in yeast that can reveal similar ways to prolong life in human cells.