The Role of Molecular Chaperones in Foreign Protein Secretion in Yeast

首席调查员(PI)建议研究蛋白质折叠伴侣在酵母分泌外源蛋白质中的作用。文献中有证据表明，内质网腔内的蛋白质折叠可能是整个分泌过程中的限速步骤，而蛋白二硫键异构酶(PDI)和KAR2(哺乳动物重链结合蛋白的酵母同源物)等伴侣蛋白在细胞内蛋白质折叠。PI计划通过使用受调控的启动子来改变细胞内PDI和KAR2的水平，并确定由此产生的对外来蛋白质分泌的影响。PI还计划通过筛选过量表达增强外源基因的重组DNA文库来分离新的伴侣蛋白质分泌或补充基因导致的蛋白质转位到分泌途径的缺陷。

The Principal Investigators (PIs) propose to study the role of protein folding chaperones in the secretion of foreign proteins from yeast. There is evidence in the literature that protein folding in the lumen of the endoplasmic reticulum may be the rate-limiting step in the overall process of secretion, and that chaperones such as protein disulfide isomerase (PDI) and KAR2 (the yeast homolog of mammalian heavy chain binding protein) play a key role in intracellular protein folding. The PIs plan to vary intracellular levels of PDI and KAR2 by use of regulated promoters, and to determine the resulting effects on foreign protein secretion. The PIs also plan to isolate novel chaperones by screening recombinant DNA libraries for genes whose overexpression enhances foreign protein secretion or complements a genetically induced defect in protein translocation into the secretory pathway.