Characterization of the Sch9 -Longevity Pathway in Yeast

项目摘要/摘要 模式生物，如酿酒酵母，已被证明在阐明 调节寿命的基因和代谢物，这一知识构成了 了解人类的衰老和长寿。这些研究已经确定了Akt/PKB 蛋白激酶是衰老的保守调节剂。然而，目前还不完全清楚是如何 它们起作用了。我们研究的重点之一是酿酒酵母Sch9蛋白激酶，一种AKT 调节按时间顺序排列的寿命(CLS)的同源基因。从体外研究中我们发现 鞘磷脂长链碱基(LCB)和人磷脂酰肌醇依赖同系物Pkh1 蛋白激酶1(PDK1)，作为Sch9的第一个上游调控因子。此外, 我们鉴定了第一批参与翻译起始和核糖体的Sch9底物Rli1 生物发生和Ahp1，一种防止氧化的烷基过氧化氢还原酶 压力。我们将在这些新结果的基础上确定Rli1和Rli1的磷酸化是否 Ahp1by Sch9在CLS中发挥作用。我们还将在体内确定LCB和Pkh1是否起作用 上游调控Sch9在衰老过程中的作用。公布的数据表明， Tor蛋白在衰老过程中也调节Sch9，我们将确定这一假说是否 是真的。尽管我们已经成功地鉴定了Sch9底物，但很可能存在 其他人和我们建议通过经典的生化策略来寻找新的底物 以及更新的自动化但互为补充的战略。总而言之，这些工作的结果 研究将为Akt(Sch9)如何活动提供亟需的机械性理解 在酵母中被调节，以及它如何通过下游底物调节CLS。这 知识将有助于为理解人类衰老和 长寿。

Project Summary/Abstract Model organisms, such as Saccharomyces cerevisiae, have proven effective in elucidating genes and metabolites that modulate lifespan 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 phosphoinositidedependent protein kinase 1 (PDK1), as the first upstream regulators 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 Ahp1by Sch9 plays a role in CLS. We will also determine in vivo if LCBs and Pkh1 act upstream to regulate Sch9 during chronological aging. Published data suggest that the TOR proteins also regulate Sch9 during aging and we will determine if this hypothesis is true. 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 and newer automated but complementary strategies. 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.