Signaling mechanisms that detect stress and maintain homeostasis

项目摘要 布莱克威尔实验室研究维持代谢，蛋白质和脂质稳态的机制，主要是 通过利用模式生物C的优势。优雅我们的大部分工作涉及SKN-1，C。 线虫NRF（NF-E2相关因子）转录因子的直系同源物，其响应于氧化， 外源性物质、蛋白酶体和某些代谢应激。NIGMS支持我们的努力， 自1994年以来一直。在SKN-1作为NRF蛋白模型的开创性工作之后，我们已经证明， 这些蛋白质在促进长寿中发挥重要作用，并阐明了许多有趣和保守的 他们的职能方面。这个MIRA涵盖了我们在SKN-1上的大部分工作，除了一个单独的项目 研究SKN-1A同种型（NRF 1直系同源物）在脂质稳态中的特定功能。 在接下来的五年里，MIRA的研究将解决一系列令人兴奋和相互关联的问题， SKN-1功能，建立在我们最近的发现提供的机会。很明显， 描述两种主要SKN-1亚型（SKN-1A和SKN-1C）的功能至关重要， 因为它们直接对应于具有不同功能和调节的NRF蛋白（NRF 1和 NRF2）。为此，我们将产生必要的突变，并解决未满足的需求， 在skn-1至关重要的各种情况下鉴定SKN-1C功能。我们已经确定，当 内质网（ER）受到来自二硫键交联受损的应激， 与典型的ER未折叠蛋白反应不同，显然是因为活性氧簇 一代崛起。阐明这种反应，我们将其命名为ER二硫键中继反应 （DRRER），并直接涉及SKN-1亚型，将产生新的见解到ER的一个意想不到的方面 体内平衡没有任何压力反应的分析研究了它们对氧化还原体的影响， 氧化修饰的半胱氨酸残基和氧化还原调节过程。最近绘制了C。elegans 在前所未有的覆盖率的氧化还原体，我们将阐明DRRER和SKN-1的氧化还原作用 同种型。这项工作将揭示一个新的层面的压力反应的影响，确定机制， 氧化还原调节，并揭示了反应性氧物质意外增加的过程 寿命这些方法将有助于了解压力抵抗力或寿命是如何 增加任何干预。因此，我们还将研究抑制主生长调节剂的效果 mTORC 1（雷帕霉素的机制靶点）。C. elegans提供了一个无与伦比的系统， 压力防御机制的研究，我们将在未来五年内继续采用这种方法， 蛋白酶体应激如何调节SKN-1A。这些努力将产生新的生物学范式， 调节，并大大加深了我们对细胞和生物体如何抵御压力的理解。

Project Summary The Blackwell lab studies mechanisms that maintain metabolic, protein, and lipid homeostasis, primarily by leveraging the advantages of the model organism C. elegans. Much of our work involves SKN-1, the C. elegans ortholog of the NRF (NF-E2-related factor) transcription factors, which respond to oxidative, xenobiotic, proteasomal, and certain metabolic stresses. NIGMS has supported our efforts almost continuously since 1994. Having pioneered work on SKN-1 as an NRF protein model, we have shown that these proteins play important roles in promoting longevity and elucidated a number of intriguing and conserved aspects of their functions. This MIRA covers the majority of our work on SKN-1, aside from a separate project investigating specific functions of the SKN-1A isoform (NRF1 ortholog) in lipid homeostasis. During the next five years this MIRA research will address a set of exciting and interrelated aspects of SKN-1 functions, building upon opportunities provided by our recent findings. It has become clear that fully delineating the functions of the two major SKN-1 isoforms (SKN-1A and SKN-1C) is critical and will be very informative because they correspond directly to NRF proteins with distinct functions and regulation (NRF1 and NRF2, respectively). To this end, we will generate necessary mutations and address the unmet need of identifying SKN-1C functions in a variety of contexts where skn-1 is critical. We have determined that when the endoplasmic reticulum (ER) is subject to stress from impairment of disulfide crosslinking the response is distinct from the canonical ER unfolded protein response, apparently because reactive oxygen species generation is elevated. Elucidating this response, which we have named the ER disulfide relay response (DRRER), and which involves SKN-1 isoforms directly, will yield new insights into an unanticipated aspect of ER homeostasis. No analyses of stress responses have investigated their effects on the redoxome, the universe of oxidatively modified Cys residues and redox-regulated processes. Having recently mapped the C. elegans redoxome at unprecedented coverage, we will thereby elucidate the redox effects of the DRRER and SKN-1 isoforms. This effort will reveal a new dimension of stress response effects, identify mechanisms subject to redox regulation, and uncover processes through which reactive oxygen species can unexpectedly increase lifespan. These approaches will be informative for understanding how stress resistance or lifespan can be increased by any intervention. We will thereby also investigate effects of inhibiting the master growth regulator mTORC1 (mechanistic target of rapamycin). C. elegans provides an unparalleled system for unbiased genetic investigation of stress defense mechanisms, an approach we will continue during the next five years by focusing on how proteasomal stress regulates SKN-1A. These efforts will yield new paradigms of biological regulation and significantly deepen our understanding of how cells and organisms defend against stress.