ROLE OF N-LINKED GLYCANS AND PROTEIN FOLDING

N 连接聚糖和蛋白质折叠的作用

基本信息

批准号：
2459641
负责人：
ARI H HELENIUS
金额：
$ 11.14万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-08-01 至 1998-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2459641
关键词：
chemical binding conformation endoplasmic reticulum gel electrophoresis glycoprotein biosynthesis glycosylation hexosyltransferase laboratory mouse laboratory rabbit molecular chaperones polymerase chain reaction protein folding protein structure function tissue /cell culture

项目摘要

Protein folding is a fundamental but still poorly understood process in living cells. The experiments proposed in this application are designed to evaluate the molecular basis of a novel concept in the folding field: the direct role of N-linked glycans as appendages for chaperone-binding during glycoprotein folding and assembly in the ER. Preliminary results indicate that calnexin, a ubiquitous ER chaperone, associates with its ligands by lectin-like affinity to partially glucose-trimmed N-linked oligosaccharides(Glc1Man9-7GlcNAc2). For many glycoproteins, this association (modulated by glucosidases and the lumenal UDP- Glc:glycoprotein glucosyltransferase) is likely to determine the rate of folding and the efficiency of export to the Golgi complex. Our overall goal is to analyze the role of calnexin and its soluble homologue calreticulin in the conformational maturation and quality control of newly synthesized glycoproteins. We will analyze the specificity and structural basis for glycoprotein binding to calnexin and calreticulin, a soluble homologue in the ER lumen. We will also determine the functional significance of the calnexin and calreticulin association in glycoprotein biogenesis. Finally, we will investigate the role of UDP- glucose: glycoprotein glucosyl transferase, and the mechanisms involved in the re-and deglucosylation cycle that it supports in the ER. The experiments will utilize biochemical, cell biological, genetic and structural approaches. The results will throw light on the mechanisms by which a variety of glycoproteins acquire heir transport-competent three-dimensional structure in the ER of living cell. The results will have direct relevance to a variety of diseases with ER storage/quality control etiology including cystic fibrosis and alpha1-antitrypsin deficiency. The need for cotranslational glycosylation and trimming of core glycans may, moreover, find their explanation in the link between glycosylation and folding, oligomeric assembly, degradation and quality control.

蛋白质折叠是一个基本的，但在活细胞。本应用程序中提出的实验是设计的评估折叠场中新型概念的分子基础： N连锁聚糖作为伴侣结合的附属物的直接作用在ER中的糖蛋白折叠和组装过程中。初步结果表明无处不在的ER伴侣钙粘蛋白与之相关配体通过凝集素样亲和力，与部分葡萄糖修剪的N连接寡糖（GLC1MAN9-7GLCNAC2）。对于许多糖蛋白，这个关联（由葡萄糖酶和腔内UDP-调节 GLC：糖蛋白葡萄糖基转移酶）可能确定折叠和向高尔基体配合物的出口效率。我们的总体目标是分析钙钙蛋白的作用及其可溶性构象成熟和质量中的同源钙元素对新合成的糖蛋白的控制。我们将分析糖蛋白与钙结合蛋白结合的特异性和结构基础钙网蛋白，ER管腔中的可溶性同源物。我们还将确定钙钙蛋白和钙网蛋白关联的功能意义在糖蛋白生物发生中。最后，我们将研究UDP-的作用葡萄糖：糖蛋白葡萄糖基转移酶和涉及的机制在其在ER中支持的重新葡萄糖基化循环中。这实验将利用生化，细胞生物学，遗传和结构方法。结果将阐明各种机制糖蛋白获得继承人交通运输的三维活细胞的ER结构。结果将直接与ER存储/质量控制的各种疾病有关病因包括囊性纤维化和α1-抗抗蛋白酶缺乏症。这核心聚糖的共转糖基化和修剪的需求可能此外，在糖基化和折叠，寡聚组件，降解和质量控制。