ARNT ISOFORMS FROM ONCORHYNCHUS MYKISS

描述：(改编自《调查者摘要》)The Aryl 烃类受体(AHR)和芳香烃受体核 转运蛋白(ARNT)被认为介导了许多作用 卤代芳香烃。虽然AHR介导的许多方面 信号转导系统在哺乳动物系统中已被阐明。 在过去的十年里，关于这一机制仍然存在许多问题 由此TCDD和相关的同系物介导毒性/生物效应和 参与该途径的各种蛋白质的功能。在……里面 此外，人们对参与其中的蛋白质只有一定的了解。 AHR在非哺乳动物系统中的信号转导。开始获益 对其中一些问题的洞察，这个实验室最近分离了 编码两种新的同源蛋白的Oncorhynchus mykis的cDNA 对哺乳动物阿诺特来说。重要的是，结果表明，(I)多个ARNT 成绩单在Oncorhynchus MyKISS中生成；(Ii)多个 转录产物可以通过替代的RNA剪接产生，(Iii) 两条信息表达的蛋白质在AHR介导的过程中具有相反的功能 信号转导和(Iv)功能改变可能与之有关 存在不同的COOH-末端结构域。有四个相互关联的 这项建议的具体目标是侧重于对假设的分析 选择性RNA剪接导致多个Arnt的表达 对AHR介导的信号起积极或消极作用的蛋白质 转导。目标1是Oncorhynchus的分子特征 MyKISS Arnt基因以确定交替剪接的程度。目标2是 确定不同的COOH-末端结构域的机制 Oncorhynchus mykis Arnt亚型在AHR依赖和非依赖中的作用 小路。目标3是建立稳定表达Oncorhynchus的细胞系 MYKISS ARNT异构体用于TCDD依赖性和非依赖性的功能分析 体内独立的基因表达。目标4是确定空间和 RtARNT信息和蛋白在小鼠特定组织中的时间表达 Oncorhynchus我的吻和发育过程中。乌骨鱼的使用 将使我们更好地理解 ARNT、其演变及其对TCDD依赖和独立的贡献 与细胞功能有关的机制。小说研究的现实意义 ARNT功能被最近的研究所强调，这些研究清楚地表明ARNT 独立于AHR的功能。此外，还详细研究了 ARNT的功能、表达和调控尚未完全完成 任何物种。

DESCRIPTION: (Adapted from the Investigator's Abstract) The aryl hydrocarbon receptor (AHR) and aryl hydrocarbon receptor nuclear translocator (ARNT) protein are thought to mediate many of the effects of halogenated aromatic hydrocarbons. While many aspects of AHR-mediated signal transduction system have been elucidated in mammalian systems over the past decade there are still numerous questions concerning the mechanism whereby TCDD and related congeners mediate toxic/biological effects and the function of the various proteins that contribute to the pathway. In addition, there is only a modest understanding of the proteins involved in AHR-mediated signal transduction in nonmammalian systems. To begin to gain insight into some of these issues, this laboratory has recently isolated cDNAs from Oncorhynchus mykiss that encode two novel proteins with homology to mammalian ARNT. Importantly, the results show that, (I) multiple ARNT transcripts are generated in Oncorhynchus mykiss; (ii) the multiple transcripts may be produced by alternative RNA splicing, (iii) that the proteins expressed from two messages have opposite functions in AHR-mediated signal transduction and (iv) that the change in function may be related to presence of distinct COOH-terminal domains. There are four interrelated specific aims in this proposal that focus on the analysis of the hypothesis that alternative RNA splicing results in the expression of multiple ARNT proteins that can act positively or negatively on AHR-mediated signal transduction. Aim 1 is the molecular characterization of the Oncorhynchus mykiss Arnt gene to determine the extent of alternate splicing. Aim 2 is to determine the mechanism whereby the distinct COOH-terminal domains of Oncorhynchus mykiss ARNT isoforms function in AHR-dependent and independent pathways. Aim 3 is to develop stable cell lines expressing Oncorhynchus mykiss ARNT isoforms for functional analysis of TCDD-dependent and independent gene expression in vivo. Aim 4 is to determine the spatial and temporal expression of rtARNT messages and proteins in specific tissues of Oncorhynchus mykiss and during development. The use of Oncorhynchus mykiss will provide a greater understanding of the fundamental significance of ARNT, its evolution and its contribution to TCDD-dependent and independent mechanisms involved in cellular function. The relevance of novel studies of ARNT function are highlighted by recent studies that clearly show ARNT function that is independent of the AHR. Additionally, a detailed study of the function, expression and regulation of ARNT has not been completed in any species.