TARGETING OF PROTEINS INTO PEROXISOMES

过氧化物酶体是普遍存在的亚细胞器， 真核细胞中的多种代谢途径。减值 过氧化物酶体蛋白输入和生物合成是许多人类 过氧化物酶体疾病（Zellweger综合征，高哌啶酸血症， 婴儿Refsum病和新生儿肾上腺脑白质营养不良）， 非常虚弱和致命我们的长期目标是了解 基质和膜蛋白从细胞中转运的机制 它们的合成位点，在细胞质中，到过氧化物酶体。两 参与输入的过氧化物酶体靶向信号，PTS1和PTS2 过氧化物酶体基质蛋白和PTS1受体已被鉴定 和表征了然而，其他细胞溶质和膜组分 参与过氧化物酶体蛋白质输入是目前未知的。我们希望 使用生物化学和遗传学策略的组合来识别 在这个进口过程中涉及的其他组件。这些研究将使 光的一个重要的亚细胞器的生物发生， 也与上述人类疾病有关。的具体目标 建议如下。 1.研究巴斯德毕赤酵母PAS8蛋白作为PTS1受体的作用 2.通过PTS1途径在体外定量过氧化物酶体输入 3.过氧化物酶体所需酵母胞浆因子的鉴定 进口 4.替代性细胞溶质依赖性体外输入系统的开发 酵母 5.研究过氧化物酶体膜的靶向性和拓扑结构 蛋白 6.为了研究巴斯德毕赤酵母PAS1和PAS5蛋白在细胞凋亡中的作用， 过氧化物酶体生物合成

Peroxisomes are ubiquitous subcellular organelles intimately involved in multiple metabolic pathways in eukaryotic cells. The impairment of peroxisomal protein import and biogenesis is responsible for many human peroxisomal disorders (Zellweger's syndrome, Hyperpipecolic acidaemia, infantile Refsum's disease and neonatal adrenoleukodystrophy) which can be very debilitating and lethal. Our long term interest is in understanding the mechanism by which matrix and membrane proteins are transported from their site of synthesis, in the cytosol, to the peroxisomes. Two of the peroxisomal targeting signals, PTS1 and PTS2, involved in the import of peroxisomal matrix proteins, and the PTS1 receptor, have been identified and characterized. However, the other cytosolic and membrane components involved in peroxisomal protein import are unknown at present. We hope to use a combination of biochemical and genetic strategies to identify the other components involved in this import process. These studies will shed light on the biogenesis of an important subcellular organelle, and are also relevant to the human disorders mentioned above. The specific aims of the proposal are listed below. 1. To study the role of the P. pastoris PAS8 protein as the PTS1 receptor 2. Quantitation of peroxisomal import in vitro via the PTS1 pathway 3. Identification of yeast cytosolic factors required for peroxisomal import 4. Development of alternative cytosol-dependent in vitro import systems in yeast 5. To investigate the targeting and topology of peroxisomal membrane proteins 6. To study the role of the P. pastoris PAS1 and PAS5 proteins in peroxisome biogenesis