PROTEIN FOLDING IN THE ENDOPLASMIC RETICULUM

虽然蛋白质折叠已经在体外进行了广泛的研究， 了解活细胞的过程。 我们的目标是阐明 糖蛋白在内质网（ER）的腔内折叠，和 折叠过程的结果如何决定它们在 cell. 分泌蛋白、膜糖蛋白和液泡蛋白， 在这个隔间里折叠，在ER中遇到一个环境， 在许多方面不同于细胞中的任何折叠隔室， 蛋白质折叠发生。 作为模型蛋白，我们将主要依赖于两个 病毒膜糖蛋白;流感血凝素 (HA)和水泡性口炎病毒（VSV）G蛋白。 我们的主要目标是确定在何种程度上的动力学和 共翻译和翻译后折叠效率取决于应激 蛋白质，折叠因子，伴侣蛋白，信号序列切割，N-连接 糖基化、氧化还原电位、翻译速率、钙浓度和 温度 由于折叠的大部分是共平移的，我们 将决定翻译速率和核糖体停顿是否调节 过程 我们将分离和表征新的ER因子， 用于蛋白质在ER中的折叠、错误折叠和保留， 相关的细胞器 我们将研究分子信号， 阻止错误折叠的蛋白质离开高尔基复合体，并诱导 他们的退化。 将分析发生降解的细胞器 与世隔绝 为了更好地了解ER的结构，我们将 最后研究了不溶性基质的组成和功能 ER膜和内腔中的蛋白质。 这个矩阵很可能是 参与ER的质量控制过程。 通过专注于细胞生物学方面的共同和后 翻译折叠i活细胞，我们希望了解更多关于 分泌的基本方面，细胞器生物发生和后 翻译调节 希望结果也能让一些 一些病理状态可以被归类为“ER 贮藏病”。

While protein folding has been extensively studied in vitro, little is known about the process in living cells. Our goal is to elucidate how glycoproteins fold within the lumen of the endoplasmic reticulum(ER), and how the outcome of the folding process determines their fate within the cell. Secretory proteins, membrane glycoproteins and vacuolar proteins, which fold in this compartment, encounter in the ER an environment which is different in many ways from any folding compartment in the cell where protein folding takes place. As model proteins, we will rely mainly on two well-characterized viral membrane glycoproteins; influenza hemagglutinin (HA) and vesicular stomatitis virus (VSV) G protein. Our main objectives are to determine to which extent the kinetics and efficiency of co- and post-translational folding depend on stress proteins, folding factors, chaperonins, signal sequence cleavage, N-linked glycosylation, redox potential, translation rate, calcium concentration and temperature. Since a large part of the folding is co-translational, we will determine whether the translation rate and ribosome pausing regulate the process. We will isolate and characterize new ER factors responsible for folding, misfolding and retention of proteins in the ER and in associated organelles. We will investigate the molecular signals that prevent misfolded proteins from exiting to the Golgi complex, and induce their degradation. The organelle where degradation occurs will be analyzed and isolated. To better understand the structure of the ER, we will finally study the composition and function of the matrix of insoluble proteins in the ER membrane and lumen. This matrix is likely to be involved in the quality control processes of the ER. By focussing on the cell biological aspects of the co- and post translational folding i living cells, we hope to learn more about the fundamental aspect of secretion, organelle biogenesis and post- translational regulation. Hopefully, the results will also throw some light on a number of pathological states which can be categorized as "ER storage diseases".