Sequestration and clearance of age-induced damage in gametogenesis

生物体在1岁、2岁时就会受到损害。与衰老细胞相关的共同特征是 蛋白质聚集、核仁异常和功能失调的细胞器2、3、5。 仍然很难区分哪些特征直接促进细胞衰老，哪些是由于 衰老的后果。生成一个解决这个问题的模型系统将使我们能够更好地开发 对抗衰老和提高健康寿命的治疗策略。 与后生动物相似，萌芽酵母积累蛋白质聚集体、核仁异常和 衰老过程中细胞器功能失调。令人惊讶的是，随着老化的酵母细胞经历配子发生，结果 配子不再包含与年龄相关的轨迹6。此外，配子的寿命通过以下方式恢复 这一过程表明，年龄相关特征的消除会导致细胞恢复活力。我的目标是剖析 配子发生过程中抗AGE损伤的分子机制及其影响 按寿命计算。 目标1中的实验将确定萌芽酵母中的哪些基因导致配子避免 年龄相关性状的遗传。到目前为止的分析表明，细胞内容受到年龄诱导的影响 损伤，包括核孔复合体、蛋白质聚集体和核仁，局限于一个小室。 在配子发生过程中核膜的变化。这个隔室不是由配子继承的，因为它们 这些观察表明，年龄诱导的特征与年龄相关 核包膜亚室通过特定的适配器，导致它们被排除在配子之外。如果是真的， 每个候选接头的破坏应该导致一种不同类型的年龄诱导损伤的保留。在……里面 同时，将采用一种无偏见的遗传方法来筛选将年龄诱导特征传递给 他们的游戏30。通过微流控系谱分析对每个突变体的进一步评估将揭示哪些性状 都是限制寿命的。 Aim 2中的实验将确定衰老细胞中积累的长寿蛋白质有多长 在发芽酵母和线虫配子发生过程中被破坏。萌芽酵母配子不继承 祖细胞的液泡，最终被破坏。当液泡溶解时，它会释放出 正常情况下会降解长寿蛋白7、13、14。因此，抑制空泡蛋白水解酶以及其他因素 与蛋白质质量控制相关的可能会导致在老化细胞中发现的长寿命蛋白质在 配子发生。最近在线虫生殖系中也报告了类似的现象，这将 结果将通过酵母菌遗传学、蠕虫遗传学和荧光来验证 活细胞成像。识别消除长寿命蛋白所需的基因将有助于产生 消除蛋白毒素损伤的新策略。

Organisms acquire damage as they age1, 2. Common traits that are associated in aged cells are the accumulation of protein aggregates, nucleolar abnormalities and dysfunctional organelles2, 3,5. However, it remains difficult to distinguish which traits directly promote cellular aging, versus those that arise as a consequence of aging. Generating a model system that addresses this issue will allow us to develop better therapeutic strategies to combat aging and improve health span. Similar to metazoans, budding yeast accumulates protein aggregates, nucleolar abnormalities and dysfunctional organelles during aging. Surprisingly, as aged yeast cells undergo gametogenesis, the resulting gametes no longer contain the age-associated traits6. Furthermore, the longevity of the gametes is restored by this process, suggesting that elimination of age-associated traits causes cellular rejuvenation6. I aim to dissect the molecular mechanisms that counteract age-induced damage during gametogenesis and test their impact on lifespan. The experiments in Aim 1 will determine which genes in budding yeast cause gametes to avoid the inheritance of age-associated traits. Analyses so far indicate that cellular contents subject to age-induced damage, including nuclear pore complexes, protein aggregates and the nucleoli, localize to a subcompartment of the nuclear envelope during gametogenesis. This compartment is not inherited by the gametes as they regenerate contents de novo 8, 12. These observations suggest that age-induced traits are associated with the nuclear envelope subcompartment via specific adaptors, which cause their exclusion from the gametes. If true, disruption of each candidate adaptor should lead to retention of a distinct type of age-induced damage. In parallel, an unbiased genetic approach will be taken to screen for mutants that pass on age-induced traits to their gametes30. Further assessment of each mutant by microfluidic pedigree analyses will reveal which traits are limiting for lifespan39. The experiments in Aim 2 will determine how long-lived proteins that accumulate in aged cells are destroyed during budding yeast and C.elegans gametogenesis. Budding yeast gametes do not inherit the vacuole of the progenitor cell, which is ultimately destroyed. When the vacuole lyses, it releases proteases that normally degrade long-lived proteins7, 13, 14. Therefore, inhibiting vacuolar proteases, as well as other factors associated with protein quality control may cause long-lived proteins found in aged cells to persist during gametogenesis. Similar phenomena have been recently reported in the C.elegans germline, which will additionally be explored17, 18. The results will be verified by yeast genetics, worm genetics and fluorescence live-cell imaging. Identifying the genes required to eliminate long-lived proteins will facilitate the generation of new strategies to remove proteotoxic damage.