PEROXISOME BIOGENESIS--A GENETIC APPROACH

真核细胞拥有各种细胞器，每个细胞器都致力于 执行一组特定的代谢功能。细胞必须保持 这些细胞器中的每一个都正确地引导特定的蛋白质组 到它们合适的亚细胞位置。细胞如何管理这些 一些细胞器的操作，如线粒体、叶绿体和 内质网一直是深入研究的主题。 相对于这些，人们对过氧酶体知之甚少，这是一种 无处不在的细胞器，由单一的膜包围，包含 酶参与多种重要的代谢途径。在……里面 人类，过氧化物酶在脂肪中特别重要 代谢(例如，血浆蛋白原和胆汁酸合成；脂肪酸， 胆固醇和前列腺素降解)和遗传。产品中的缺陷 细胞器会导致一种致命的人类疾病，称为齐薇格综合征。 该计划的主要长期目标是了解 分子水平，控制过氧化物体生物发生和 功能。该计划的目标是启动一种遗传方法 为此，使用利用甲醇的毕赤酵母作为 模特。之所以选择这种酵母，是因为过氧化物体绝对是 在甲醇上生长所需，这是一种很容易观察到的表型 因为经典的和分子的基因操作方法 生物体是完全发育的。全面收集 巴氏杆菌过氧化物酶缺陷型(PER)突变体将被分离并 以遗传、生化和细胞生物学研究为目标 在阐明它们主要缺陷的分子基础上。The PER 然后将利用突变体来克隆受影响的特定基因和 每个基因的DNA序列将被确定和分析。这个 从每个基因推导出的氨基酸序列以及生化 对每个基因突变的影响的分析应该有助于阐明 每种蛋白质在过氧酶体功能中的作用并制定一种 过氧核糖体操作的总体情况。 该计划的第二个长期目标是利用所获得的知识 从这项研究中了解人类的疾病状况并帮助 尤其是齐薇格受害者。预计一些酵母菌 已鉴定的过氧化物体基因将是下列基因的同源基因 在齐薇格患者身上都会受到影响。如果是这样的话，关于酵母的信息 PER基因及其产物可用于鉴定和分离 人类的同源基因。这些人类PER基因将是有价值的 诊断探针，并最终可能用于基因治疗。

Eukaryotic cells possess a variety of organelles, each devoted to performing a specific set of metabolic functions. The cell must maintain each of these organelles and correctly direct specific sets of proteins to their proper subcellular locations. How the cell manages these operations for some organelles such as the mitochondrion, chloroplast and endoplasmic reticulum has been the subject of intensive investigations. Relative to these, little is known about peroxisomes, a family of ubiquitous organelles, surrounded by a single membrane and containing enzymes involved in a variety of important metabolic pathways. In humans, peroxisomal enzymes are particularly important in lipid metabolism (e.g., plasmalogen and bile acid synthesis; fatty acid, cholesterol and prostaglandin degradation) and genetic. defects in the organelles result in a lethal human disorder, termed Zellweger syndrome. The primary long-term goal of this program is to understand, at the molecular level, the mechanisms which control peroxisome biogenesis and function. The objective of the program is to initiate a genetic approach toward this end using the methanol-utilizing yeast Pichia pastoris as a model. This yeast was selected because peroxisomes are absolutely required for its growth on methanol, an easily observed phenotype, and because methods for classical- and molecular-genetic manipulation of the organism are fully developed. A comprehensive collection of peroxisome-deficient (per) mutants of P. pastoris will be isolated and subjected to genetic, biochemical and cellular biological studies aimed at elucidating the molecular basis of their primary defects. The per mutants will then be utilized to clone the specific genes affected and the DNA sequence of each PER gene will be determined and analyzed. The amino acid sequence deduced from each gene along with the biochemical analysis of the effect of mutations in each gene should help to elucidate the role of each protein in peroxisome function and to formulate an overall picture of peroxisomal operations. A second long-term goal of this program is to utilize knowledge gained from this research to understand the human disease state and to aid Zellweger victims, specifically. It is expected that some of the yeast peroxisomal genes that are identified will be homologues of genes that are affected in Zellweger patients. If so, information obtained on yeast PER genes and their products could be useful in identifying and isolating the human homologues. These human PER genes would be valuable as diagnostic probes and eventually may be used in gene therapy treatments.