Regulation on of the AIRAP/aip-1 pathway by metabolic stress

描述(由申请人提供)：所附的建议书描述了一项5年研究计划，旨在利用遗传学、转基因动物和RNAi研究线虫对细胞代谢或特定外源毒素引起的蛋白质组损伤的反应。蛋白质组的损伤会导致环境和职业暴露的有害影响，导致特定疾病的发病，包括神经退行性疾病、癌症和糖尿病，甚至可能是衰老过程本身。蛋白质组损伤的来源包括氧化应激、不稳定的蛋白质、感染和外源化学物质，如重金属和亲电有机化合物。我们最近发现，几种亲电酪氨酸代谢物是蛋白毒性应激的有效内源性来源。此外，这些代谢物还诱导AIRAP/AIP-1的表达，AIRAP/AIP-1是最近被描述的一个蛋白质家族，由砷暴露诱导，并通过蛋白小体增强受损蛋白质的清除。我们的发现使酪氨酸降解产物成为第一个被发现的AIP-1途径的内源性激活剂。AIRAP/AIP-1基因也很有趣，因为它们由暴露诱导，如砷或酪氨酸代谢物，对受影响的细胞产生氧化、内质网和热休克样应激，但经典暴露，如热、过氧化氢或衣霉素，产生更有限的损害谱，未能诱导AIRAP/AIP-1。因此，AIRAP/AIP-1的诱导具有很大的特异性，这一点目前尚不清楚。我们鉴定了三个转录因子SKN-1、ELT-2和F57B10.1，它们是酪氨酸代谢产物诱导AIP-1所必需的。我们的建议试图了解AIRAP/AIP-1诱导物的存在是如何被感知的，如何与这些转录因子沟通，并导致AIP-1的激活，或许还导致其他共同调节的应激反应基因的激活。这些实验包括使用转基因动物、酵母单杂交筛选和RNAi来研究AIP-1是如何调控的；使用遗传学来寻找与识别蛋白质组损伤相关的基因并传递这些信息来产生AIP-1表达；以及使用RNAi来查看其他诱导剂，如砷，是否利用类似的途径来诱导AIP-1的表达。 公共卫生相关性：我们的项目旨在利用非寄生蠕虫线虫研究细胞如何对外部毒素或细胞新陈代谢造成的损害做出反应。我们希望对这些反应提供新的见解，这可能会导致预防糖尿病等疾病的新疗法。

DESCRIPTION (provided by applicant): The attached proposal describes a 5 year research plan designed to investigate responses in C.elegans to proteome damage resulting from cellular metabolism or specific exogenous toxins using genetics, transgenic animals, and RNAi. Damage to the proteome contributes to the harmful effects of environmental and occupational exposures, the pathogenesis of specific diseases including neurodegenerative diseases, cancer, and diabetes, and likely even the aging process itself. Sources of proteome damage include oxidative stress, unstable proteins, infections, and exogenous chemicals such as heavy metals and electrophilic organic compounds. We have recently found that several electrophilic tyrosine metabolites are a potent endogenous source of proteotoxic stress. Further, these metabolites also induce the expression of AIRAP/aip-1 which is a recently described family of proteins that are induced by arsenic exposure and serve to augment the clearance of damaged proteins via the proteosome. Our finding makes tyrosine degradation products the first identified endogenous activator of the aip-1 pathway. The AIRAP/aip-1 genes are also interesting in that they are induced by exposures, like arsenic or tyrosine metabolites, that produce oxidative, ER, and heat shock-like stresses to affected cells, but classic exposures, like heat, peroxide, or tunicamycin, that produce a more limited spectrum of damage fail to induce AIRAP/aip-1. Hence, the induction of AIRAP/aip-1 has a great deal of specificity which is currently not understood. We identified three transcription factors, skn-1, elt-2, and F57B10.1, as being required for the induction of aip-1 by tyrosine metabolites. Our proposal seeks to understand how the presence of AIRAP/aip-1 inducers is perceived, is communicated to these transcription factors, and leads to the activation of aip-1 and perhaps additional co-regulated stress response genes. The experiments involve using transgenic animals, a yeast one-hybrid screen, and RNAi to study how aip-1 is regulated; using genetics to find genes involved in identifying proteome damage and relaying this information to produce aip-1 expression; and using RNAi to see if other inducers, such arsenic, utilize similar pathways to induce aip-1 expression. PUBLIC HEALTH RELEVANCE: Our project aims to study how cells respond to damage from external toxins or cellular metabolism using the non-parasitic worm C. elegans. We hope to provide new insights into these responses which might lead to new treatments to prevent diseases like diabetes.