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

描述（由申请人提供）：所附提案描述了一项为期5年的研究计划，旨在利用遗传学、转基因动物和RNAi研究秀丽隐杆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。对蛋白质组的损害有助于环境和职业暴露的有害影响，包括神经退行性疾病、癌症和糖尿病在内的特定疾病的发病机制，甚至可能导致衰老过程本身。蛋白质组损伤的来源包括氧化应激、不稳定蛋白、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，一些亲电酪氨酸代谢物是蛋白质毒性应激的一个强有力的内源性来源。此外，这些代谢物还诱导AIRAP/aip-1的表达，AIRAP/aip-1是最近发现的一个由砷暴露诱导的蛋白家族，通过蛋白体增强对受损蛋白的清除。我们的发现使酪氨酸降解产物成为aip-1途径的第一个内源性激活物。AIRAP/aip-1基因也很有趣，因为它们是由暴露诱导的，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，产生更有限的损伤，不能诱导AIRAP/aip-1。因此，AIRAP/aip-1的诱导具有很大的特异性，目前尚不清楚。我们确定了三个转录因子，skn-1， elt-2和F57B10.1，是酪氨酸代谢物诱导aip-1所必需的。我们的建议旨在了解如何感知AIRAP/aip-1诱导剂的存在，并将其传达给这些转录因子，并导致aip-1和其他共同调节的应激反应基因的激活。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是如何被调节的；利用遗传学寻找参与识别蛋白质组损伤的基因，并将这些信息传递给产生aip-1表达的基因；并使用RNAi来观察其他诱导剂，如砷，是否利用类似的途径诱导aip-1的表达。

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.