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Molecular and Genetic Dissection of Ultraviolet-B Signaling in Arabidopsis

拟南芥中 UV-B 信号传导的分子和遗传解析

基本信息

批准号：
8437232
负责人：
Zheng-Hui HE
金额：
$ 22.22万
依托单位：
SAN FRANCISCO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-01 至 2014-12-28
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): All sun-exposed organisms have to encounter ultraviolet-B (UV-B, 280-320 nm), an integral part of solar radiation. Depending on its energy levels, UV-B can be harmful or beneficial to biological organisms. High- level UV-B causes direct harms including DNA damage, eye cataracts, skin cancer, and immune system suppression in animals, as well as retarded growth and depressed photosynthesis in plants. On the other hand, low-level UV-B can provide beneficial effects including serving as developmental signals in plants and aiding vitamin D synthesis in human. Opposing effects of UV-B on human cancers have also been reported. While UV-B is a known carcinogen that causes skin cancer, it can help suppress prostate cancer development. The damaging effects of high-level UV-B have been intensively studied in many organisms, but little is known about the molecular mechanism of how cells sense low-level UV-B and transduce its specific signals. Low-level UV-B perception and signaling are well-documented physiological phenomena in plants, but the molecular nature of the involved UV-B-specific receptor(s) remains elusive. Understanding the molecular mechanism of how cells sense and respond to UV-B at all levels is fundamentally important to both agriculture and human health. It has been difficult to genetically pin down a specific pathway that is activated by low-level UV-B because of the lack of unambiguous screenable phenotypes specifically associated with low-level UV-B. We have identified an Arabidopsis mutant, rus1 that is specifically hypersensitive to low- level UV-B. The striking phenotypes and extreme UV-B sensitivities of rus1 provide a feasible platform to identify genetic components that can be good candidates for UV-B specific receptors and signaling components. Our long-term goal is to delineate the molecular mechanism of low-level UV-B signaling in Arabidopsis. Our objective in this application is to characterize signaling components that genetically and biochemically interact with RUS1. Our central hypothesis is that RUS1 and its partners function as key players in low-level UV-B perception. We propose the following two specific aims: Aim 1: Characterize specific UV-B signaling components by mapping and cloning extragenic rus1 suppressor genes; Aim 2: Investigate functional roles of RUS1-interacting proteins in UV-B signaling. These studies are innovative in that the dissection of the UV-B signaling pathway would provide vital information of how cells sense and respond to low-level UV-B. At the completion of these studies we expect to know the molecular mechanism of how RUS1 works with other components to respond to environmental low-level UV-B. The successful completion of these studies will help bring a more profound understanding of how cells sense and respond to UV-B at different levels and what is learned can be ultimately used to develop enhanced agricultural practices and better health recommendations for both animals and human.

描述(申请人提供)：所有暴露在阳光下的生物都必须遇到紫外线-B(UV-B，280-320 nm)，这是太阳辐射的组成部分。根据其能量水平的不同，UV-B对生物有机体可能有害，也可能有益。高水平的UV-B对动物造成直接伤害，包括DNA损伤、眼白内障、皮肤癌和免疫系统抑制，以及植物生长迟缓和光合作用减弱。另一方面，低水平的UV-B可以提供有益的效果，包括作为植物的发育信号和帮助人类合成维生素D。UV-B对人类癌症的相反作用也有报道。虽然UV-B是一种已知的致癌物质，会导致皮肤癌，但它可以帮助抑制前列腺癌的发展。高强度UV-B的损伤效应在许多生物体中已经得到了深入的研究，但对于细胞如何感知低水平UV-B并转导其特定信号的分子机制知之甚少。低水平的UV-B感知和信号是植物中公认的生理现象，但涉及的UV-B特异性受体(S)的分子性质仍然不清楚。了解细胞在各个水平上如何感知和响应UV-B的分子机制对农业和人类健康都是至关重要的。由于缺乏明确的与低水平UV-B相关的可筛选表型，从基因上很难确定低水平UV-B激活的特定途径。我们已经确定了一个拟南芥突变体rus1，它对低水平的UV-B特别敏感。Rus1惊人的表型和对UV-B的极端敏感性为鉴定遗传成分提供了一个可行的平台，这些遗传成分可能是UV-B特异性受体和信号成分的良好候选者。我们的长期目标是阐明低水平UV-B信号在拟南芥中的分子机制。我们在这项应用中的目标是表征与RUS1在遗传和生化上相互作用的信号成分。我们的中心假设是RUS1及其伙伴在低水平的UV-B感知中发挥关键作用。我们提出了以下两个特定的目标：目的1：通过定位和克隆基因外抑制基因rus1来鉴定特定的UV-B信号成分；目标2：研究RUS1相互作用蛋白在UV-B信号中的功能。这些研究具有创新性，因为对UV-B信号通路的剖析将提供细胞如何感知和响应低水平UV-B的重要信息。在这些研究完成后，我们希望了解RUS1如何与其他成分一起对环境低水平UV-B做出反应的分子机制。这些研究的成功完成将有助于更深刻地理解细胞如何在不同水平上感知和响应UV-B，所学到的最终可以用于改进农业实践和为动物和人类提供更好的健康建议。