Trafficking and Regulation of Drug/Xenobiotic Transporter OAT

描述（由申请人提供）：有机阴离子转运蛋白（OAT）家族介导多种环境毒素和临床重要药物的吸收、分布和排泄，包括抗hiv治疗药物、抗肿瘤药物、抗生素、降压药和抗炎药，因此对哺乳动物物种的生存至关重要。目前已鉴定出6种OAT1、OAT2、OAT3、OAT4、OAT5和OAT6，并在肾、肝、脑和胎盘中检测到表达。这些器官的OAT功能障碍显著地导致肾、肝、神经和胎儿的毒性和疾病。我们的长期目标是通过燕麦确定药物/毒素处置的分子机制。我们有强有力的初步数据表明，OAT受到细胞信号通路的急性调节，并且这种调节与OAT细胞表面呈现的动态变化相耦合，这表明膜运输是转运蛋白稳态和调节的基础。然而，这种调节的机制是完全未知的。本应用程序的主要目的是确定控制OAT1运输的细胞和分子机制，并评估这种调节形式的生理和病理生理相关性。概述了四个具体目标（SAs）。在SA-1中，我们将分析基础和调节的OAT1运输动力学。在SA-2中，我们将剖析涉及OAT1贩运的途径。在SA-3中，我们将确定OAT1序列中参与其贩运的结构基序。在SA-4中，我们将评估OAT1贩运在药物运输活性调节中的生理和病理生理相关性。生物化学和分子生物学的结合方法将被用于组织切片和培养细胞的拟议研究。了解OATs的运输和调控是药物运输领域的一个新焦点，将对未来设计旨在最大化治疗效果和最小化毒性的策略产生重大影响，并将使人们能够深入了解肾、肝、神经和胎儿毒性和疾病的分子、细胞和临床基础。公共卫生相关性：有机阴离子转运蛋白（OAT）家族介导多种环境毒素和临床重要药物的吸收、分布和排泄，包括抗hiv治疗药物、抗肿瘤药物、抗生素、降压药和抗炎药，因此对哺乳动物物种的生存至关重要。目前已鉴定出6种OAT1、OAT2、OAT3、OAT4、OAT5和OAT6，并在肾、肝、脑和胎盘中检测到表达。这些器官的OAT功能障碍显著地导致肾、肝、神经和胎儿的毒性和疾病。我们的长期目标是通过燕麦确定药物/毒素处置的分子机制。我们有强有力的初步数据表明，OAT受到细胞信号通路的急性调节，并且这种调节与OAT细胞表面呈现的动态变化相耦合，这表明膜运输是转运蛋白稳态和调节的基础。然而，这种调节的机制是完全未知的。本应用程序的主要目的是确定控制OAT1运输的细胞和分子机制，并评估这种调节形式的生理和病理生理相关性。了解OATs的运输和调控是药物运输领域的一个新焦点，将对未来设计旨在最大化治疗效果和最小化毒性的策略产生重大影响，并将使人们能够深入了解肾、肝、神经和胎儿毒性和疾病的分子、细胞和临床基础。

DESCRIPTION (provided by applicant): The organic anion transporter (OAT) family mediates the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti- inflammatories, and therefore is critical for the survival of mammalian species. Six OATs have been identified (OAT1, OAT2, OAT3, OAT4, OAT5, and OAT6) and their expression detected in kidney, liver, brain and placenta. OAT dysfunction in these organs significantly contributes to the renal, hepatic, neurological and fetal toxicity and disease. Our long-term goal is to define the molecular mechanisms underlying drug/toxin disposition through OATs. We have strong preliminary data to show that OATs are subjected to acute regulation by cellular signaling pathways and that such regulation is coupled to dynamic changes in OAT cell-surface presentation, suggesting that membrane trafficking is fundamental to transporter homeostasis and regulation. However, the mechanisms underlying this regulation are completely unknown. The major goal of this application is to determine the cellular and molecular mechanisms governing OAT1 trafficking, and to evaluate the physiological and pathophysiological relevance of this form of regulation. Four Specific Aims (SAs) are outlined. In SA-1, we will analyze basal and regulated OAT1 trafficking kinetics. In SA-2, we will dissect the pathways involved in OAT1 trafficking. In SA-3, we will identify the structural motifs in OAT1 sequence involved in their trafficking. In SA-4, we will evaluate the physiological and pathophysiological relevance of OAT1 trafficking in regulation of drug transport activity. Combined approaches of biochemistry and molecular biology will be employed for the proposed studies in tissue slices, and cultured cells. Understanding the trafficking and regulation of OATs, a novel focus in drug transport field, will have significant impact on the future design of strategies aimed at maximizing therapeutic efficacy and minimizing toxicity, and will permit insight into the molecular, cellular, and clinical bases of renal, hepatic, neurological and fetal toxicity and disease. PUBLIC HEALTH RELEVANCE: The organic anion transporter (OAT) family mediates the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti- inflammatories, and therefore is critical for the survival of mammalian species. Six OATs have been identified (OAT1, OAT2, OAT3, OAT4, OAT5, and OAT6) and their expression detected in kidney, liver, brain and placenta. OAT dysfunction in these organs significantly contributes to the renal, hepatic, neurological and fetal toxicity and disease. Our long-term goal is to define the molecular mechanisms underlying drug/toxin disposition through OATs. We have strong preliminary data to show that OATs are subjected to acute regulation by cellular signaling pathways and that such regulation is coupled to dynamic changes in OAT cell-surface presentation, suggesting that membrane trafficking is fundamental to transporter homeostasis and regulation. However, the mechanisms underlying this regulation are completely unknown. The major goal of this application is to determine the cellular and molecular mechanisms governing OAT1 trafficking, and to evaluate the physiological and pathophysiological relevance of this form of regulation. Understanding the trafficking and regulation of OATs, a novel focus in drug transport field, will have significant impact on the future design of strategies aimed at maximizing therapeutic efficacy and minimizing toxicity, and will permit insight into the molecular, cellular, and clinical bases of renal, hepatic, neurological and fetal toxicity and disease.