Plant Peroxisome Biogenesis: Acquisition/Function of Membrane Proteins

植物过氧化物酶体生物发生：膜蛋白的获取/功能

• 批准号: 9728935
• 负责人: Richard Trelease
• 金额: $ 36.39万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9728935&HistoricalAwards=false
• 关键词: Plant; Peroxisome; Biogenesis; Acquisition; Function

9728935 Trelease Eukaryotic cells contain membrane-enclosed compartments (organelles) in which various cellular functions are carried out. This isolation of various functions within physical boundaries is critical to the life of the cell: it allows the cell to regulate the functions of each compartment separately; and it prevents the contents of each compartment from interfering with others. However, it does require that the cells have mechanisms for sorting and translocating individual proteins to their proper subcellular locations. One type of intracellular compartment is the peroxisome, which occurs in virtually all eukaryotic cells. Peroxisomes participate in a very wide range of metabolic pathways, depending on the cell or tissue type in which they function. The overall goal of this project is to understand the complicated means by which peroxisomal membrane proteins (PMPs) become selectively integrated into the boundary membrane of peroxisomes (glyoxysomes) in oilseed seedlings, and to understand the functions of such PMPs within the membrane as the seedlings develop. Three specific objectives are proposed relative to the biogenesis of plant peroxisomes. The first aim is to discover the putative membrane peroxisomal targeting signal (mPTS) responsible for targeting peroxisomal ascorbate peroxidase (pAPX) to glyoxysomes, and define the topographic orientation of the protein within the membrane. This information is particularly relevant for oilseed glyoxysomes, to understand how the membrane is protected from abundant reactive oxygen species and to understand the pathway for regeneration of NAD+ required for conversion of storage oils into carbohydrates. The second aim is to test the hypothesis that a 73 kilodalton membrane-bound polypeptide, PMP73, is a novel "peroxin" which functions at the boundary membrane as a molecular chaperone in the uptake of proteins from the cytosol. The third aim is to try to discover additional plant PM Ps, using polyclonal rabbit antisera raised previously and already used successfully to discover PMP73 and pAPX. It is likely that, in addition to the overall goal of understanding peroxisomal biogenesis and function in developing oilseed seedlings, the results of these studies will provide more general insight into peroxisomal biogenesis that will be applicable to diverse species and tissues.

9728935释放真核细胞含有膜封闭的室（细胞器），各种细胞功能在其中执行。这种物理边界内各种功能的隔离对细胞的生命至关重要：它允许细胞分别调节每个隔室的功能；它可以防止每个隔间的内容物相互干扰。然而，它确实要求细胞具有将单个蛋白质分选和转运到适当的亚细胞位置的机制。一种类型的细胞内隔室是过氧化物酶体，它存在于几乎所有真核细胞中。过氧化物酶体参与非常广泛的代谢途径，这取决于它们发挥作用的细胞或组织类型。该项目的总体目标是了解油籽幼苗中过氧化物酶体膜蛋白（pmp）选择性整合到过氧化物酶体（glyoxysomes）边界膜中的复杂途径，并了解随着幼苗发育，膜内pmp的功能。关于植物过氧化物酶体的生物发生，提出了三个具体目标。第一个目的是发现假定的膜过氧化物酶体靶向信号（mPTS），负责将过氧化物酶体抗坏血酸过氧化物酶（pAPX）靶向到乙氧基小体上，并确定膜内蛋白质的地形取向。这一信息对油籽glyoxysome特别重要，有助于了解膜是如何免受丰富活性氧的保护的，也有助于了解储存油转化为碳水化合物所需的NAD+再生途径。第二个目的是验证一个假设，即73千道尔的膜结合多肽PMP73是一种新型的“过氧化物”，它在边界膜上作为分子伴侣从细胞质溶胶中摄取蛋白质。第三个目的是利用兔多克隆抗血清发现更多的植物pmps，这些抗血清已经成功地用于发现PMP73和pAPX。很可能，除了了解过氧化物酶体在油籽幼苗发育中的生物发生和功能的总体目标外，这些研究的结果将提供更全面的了解过氧化物酶体的生物发生，这将适用于不同的物种和组织。