Investigation of the molecular chaperone HSP90 in arabidopsis: its function in plant development, organelle physiology and biogenesis

地球上的所有生物体都不断地暴露在各种环境压力下。植物等生物体没有移动和逃避压力的能力，更经常受到不利影响。自然地，植物像大多数其他生物一样发展出复杂的机制来感知和科普环境压力。分子伴侣是一组蛋白质，其中大多数是高度诱导的热休克蛋白（HSP），因此被称为热休克蛋白，以帮助其他蛋白质在应激条件下正常发挥功能。分子伴侣在正常生长条件下维持其他蛋白质的适当活性方面也很重要，并在细胞蛋白质质量控制系统中起关键作用。我提出了一个研究计划，研究一个特定的一组分子伴侣称为热休克蛋白90在模式植物拟南芥，并探讨其他蛋白质的帮助下，拟南芥热休克蛋白90在正常和压力条件下的适当功能。拟南芥含有7个HSP90基因。本研究将探讨定位于叶绿体和内质网的两种拟南芥HSP 90的生化特性及其作为环境胁迫传感器的作用机制，并通过蛋白质组学方法确定可用于未来作物抗生物或非生物胁迫育种的靶标。拟议的研究计划还将补充哺乳动物细胞中HSP90的研究，该蛋白目前被用作癌症研究的靶点。

All living organisms on the earth are continuously exposed to a variety of environmental stresses. Organisms such as plants do not have the ability to move and escape from the stresses and are more frequently affected adversely. Naturally, plants like most other organisms develop complex mechanisms to sensor and cope with environmental stresses. Molecular chaperones are a group of proteins, most of which are highly induced by heat shock and therefore termed as heat shock proteins (HSP), to help other proteins to function properly under stress conditions. Molecular chaperones are also important in the maintenance of proper activities of other proteins under normal growth conditions and serve as critical players in the cellular protein quality control system. I am proposing a research program to study a particular set of molecular chaperones termed HSP90 in the model plant Arabidopsis and to explore what other proteins are aided by Arabidopsis HSP90 for their proper functions under both normal and stress conditions. Arabidopsis contains seven HSP90 genes. This study will investigate the biochemical properties of two Arabidopsis HSP90s which are localized in chloroplast and endoplasmic reticulum and the mechanism of action of plant HSP90s as sensors of environmental stresses, and will identify, by proteomics approaches, targets which can be potentially used for future breeding of crops with better resistance to biotic or abiotic stresses. The proposed research program will also complement the research on HSP90 in mammalian cells, where this protein is currently used as a target for cancer research.