Characterization of Long-lived Asymmetrically Retained Proteins (LARPs) in aging

这项资助的重点是了解基因组不稳定性增加的现象， 杂合性缺失（洛），随着芽殖酵母复制年龄的增加，S.啤酒。在工作 在R37资助期开始之前，我们发现与年龄相关的线粒体 功能障碍导致我们观察到的洛缺失事件。我们有证据表明，这种联系是由于减少 功能失调的线粒体产生铁硫簇（ISCs）。ISCs是许多 核DNA复制和修复酶，我们假设ISC辅因子的减少导致 受损的旧细胞DNA修复。 在过去的3.5年中，因为这个赠款被授予，我们已经取得了重大进展，发展一个 更好地理解老化过程中洛上游的早期事件（Hughes和Gottschling， 2012），以及年龄相关的洛缺失可能发生的其他途径（Lindstrom et al.，2011年）。两 这些研究之所以成为可能，是因为我们开发了母亲富集计划技术 这使我们能够充分利用S.酿酒酵母 研究衰老（Lindstrom和Gottschling，2009）。在描述与年龄相关的现象时， 洛，我们作出了意外和令人兴奋的发现一类新的蛋白质（长寿命的不对称 保留蛋白（LARP），我们认为这些蛋白与理解衰老过程高度相关。 细胞水平。事实上，其中一个LARP（Pmal）参与了年龄相关性衰老的最早阶段。 表型，并似乎影响线粒体功能障碍的后期年龄相关表型（参见 进度报告）。 这些发现和我们为研究它们而开发的工具现在使我们能够探索衰老的各个方面， 以前是站不住脚的。我们相信LARP的研究不仅与酵母复制有关， 衰老，但也可能影响我们如何看待其他细胞的衰老过程， 细胞分裂-例如后生动物中的干细胞。在接下来的5年里，我建议剖析这些 不寻常的蛋白质，并了解它们在衰老过程中扮演的角色。

This grant has been focused on understanding the phenomenon of increased genomic instability, manifested as loss-of-heterozygosity (LOH), with advancing replicative age in the budding yeast, S. cerevisiae. In work leading up to the initiation of this R37 grant period, we had discovered that age-associated mitochondrial dysfunction led to the LOH events we observed. We had evidence that this link was the result of reduced production of iron-sulfur clusters (ISCs) by the dysfunctional mitochondria. ISCs are a cofactor for a number of nuclear DNA replication and repair enzymes and we hypothesized that reduction of the ISC cofactor led to impaired DNA repair in old cells. In the past 3.5 years since this grant was awarded, we have made significant progress toward developing a better understanding of early events in the aging process that are upstream of LOH (Hughes and Gottschling, 2012), as well as additional pathways by which age-associated LOH can occur (Lindstrom et al., 2011). Both of these studies were made possible because of the Mother Enrichment Program technology we developed which has allowed us to apply the full potential of tools and breadth of scientific knowledge from S. cerevisiae to study aging (Lindstrom and Gottschling, 2009). While characterizing age-associated phenomena linked to LOH, we made the unexpected and exciting discovery of a new class of proteins (long-lived asymmetrically retained proteins - LARPs) that we believe are highly relevant to understanding the aging process at the cellular level. In fact, one of these LARPs (Pmal) is involved in the earliest steps of the age-associated phenotypes and appears to impact the later age-associated phenotypes of mitochondrial dysfunction (see Progress Report). These findings and the tools we have generated to study them now allow us to explore aspects of aging that have not been tenable before. We believe that study of the LARPs will not only be relevant to yeast replicative aging, but may also affect how we consider the aging process in other cells that undergo repeated asymmetric cell divisions - e.g. stem cells in metazoa. In the next 5 years, I propose to dissect the properties of these unusual proteins and understand what roles they play in the aging process.