Characterization of the Sch9 -Longevity Pathway in Yeast

描述（由申请人提供）：模式生物，如酿酒酵母，已被证明可有效阐明调节寿命的基因和代谢物，这些知识构成了理解人类衰老和长寿的基础。这些研究已经确定Akt/PKB蛋白激酶作为衰老的保守调节因子。然而，尚不完全清楚它们是如何工作的。我们的研究重点之一是S。cerevisiae Sch 9蛋白激酶，一种调节按时间顺序寿命（CLS）的AKT同源物。从体外研究中，我们确定了鞘脂长链碱基（LCB）和Pkh 1，人类磷酸肌醇依赖性蛋白激酶1（PDK 1）的同源物，作为Sch 9的第一个上游调节因子。此外，我们确定了第一个Sch 9底物，Rli 1，参与翻译起始和核糖体生物合成，和Ahp 1，一种烷基氢过氧化物还原酶，保护免受氧化应激。我们将建立在这些新的结果，并确定是否磷酸化的Rli 1和Ahp 1的Sch 9在CLS中发挥作用。我们还将在体内确定LCB和Pkh 1是否在时序老化过程中上游调节Sch 9。虽然我们已经成功地确定了Sch 9基板，有可能是其他人，我们建议寻找新的基板，经典的生化策略，更新的自动化，但互补的策略，和遗传筛选策略。总之，这些研究的结果将提供急需的机械理解Akt（Sch 9）活性如何在酵母中调节，以及它如何通过下游底物调节CLS。这些知识将有助于为理解人类衰老和长寿提供分子基础。公共卫生相关性：拟议的研究将确定Sch 9蛋白激酶，哺乳动物Akts/PKB的功能同源物，如何调节面包酵母酿酒酵母的时间寿命。包含Akt/PKB型蛋白激酶的信号转导通路在调节衰老和寿命方面起着重要作用，并且这些通路从酵母到哺乳动物都是保守的。因此，从这些研究中获得的信息应该为理解人类的衰老和寿命是如何调节的提供一个更机械的基础。

DESCRIPTION (provided by applicant): Model organisms, such as Saccharomyces cerevisiae, have proven effective in elucidating genes and metabolites that modulate life span and this knowledge forms a basis for understanding human aging and longevity. These studies have identified the Akt/PKB protein kinases as conserved regulators of aging. However, it is not entirely clear how they work. One focus of our research is the S. cerevisiae Sch9 protein kinase, an AKT homolog that regulates chronological life span (CLS). From in vitro studies we identified sphingolipid long chain bases (LCBs) and Pkh1, a homolog of human phosphoinositide-dependent protein kinase 1 (PDK1), as the first upstream regulator of Sch9. In addition, we identified the first Sch9 substrates, Rli1, involved in translation initiation and ribosome biogenesis, and Ahp1, an alkyl hydroperoxide reductase that protects against oxidative stress. We will build upon these novel results and determine if phosphorylation of Rli1 and Ahp1 by Sch9 plays a role in CLS. We will also determine in vivo if LCBs and Pkh1 act upstream to regulate Sch9 during chronological aging. Although we have successfully identified Sch9 substrates, there are likely to be others and we propose to search for new substrates by classical biochemical strategies, newer automated but complementary strategies, and a genetic screening strategy. In summary, the results of these studies will provide the much needed mechanistic understanding of how Akt (Sch9) activity is regulated in yeast and how it regulates CLS through downstream substrates. This knowledge will help to provide a molecular basis for understanding human aging and longevity. PUBLIC HEALTH RELEVANCE: The proposed research will determine how the Sch9 protein kinase, a functional homolog of mammalian Akts/PKBs, regulates chronological life span in the Baker's yeast Saccharomyces cerevisiae. Signal transduction pathways that contain Akt/PKB type protein kinases play important roles in regulating aging and life span, and these pathways have been conserved from yeast to mammals. Thus, information gained from these studies should provide a more mechanistic basis for understanding how aging and life span are regulated in humans.