The Glycomics Center, Division of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA.
Glycobiology. 2012 Jun;22(6):863-75. doi: 10.1093/glycob/cws053. Epub 2012 Feb 28.
The conserved oligomeric Golgi complex (COG) is a hetero-octomeric peripheral membrane protein required for retrograde vesicular transport and glycoconjugate biosynthesis within the Golgi. Mutations in subunits 1, 4, 5, 6, 7 and 8 are the basis for a rare inheritable human disease termed congenital disorders of glycosylation type-II. Defects to COG complex function result in aberrant glycosylation, protein trafficking and Golgi structure. The cellular function of the COG complex and its role in protein glycosylation are not completely understood. In this study, we report the first detailed structural analysis of N-glycans from a COG complex-deficient organism. We employed sequential ion trap mass spectrometry of permethylated N-glycans to demonstrate that the COG complex is essential for the formation of fucose-rich N-glycans, specifically antennae fucosylated structures in Caenorhabditis elegans. Our results support the supposition that disruption to the COG complex interferes with normal protein glycosylation in the medial and/or trans-Golgi.
保守寡聚高尔基体复合物（COG）是一种异八聚体的外周膜蛋白，对于高尔基体中的逆行囊泡运输和糖缀合物生物合成是必需的。亚基 1、4、5、6、7 和 8 的突变是一种罕见的遗传性人类疾病，称为 II 型先天性糖基化障碍的基础。COG 复合物功能的缺陷导致糖基化、蛋白质运输和高尔基体结构异常。COG 复合物的细胞功能及其在蛋白质糖基化中的作用尚未完全阐明。在这项研究中，我们报告了第一个 COG 复合物缺陷生物体的 N-聚糖的详细结构分析。我们采用顺序离子阱质谱法对甲基化 N-聚糖进行分析，证明 COG 复合物对于富含岩藻糖的 N-聚糖的形成是必需的，特别是在秀丽隐杆线虫中的天线岩藻糖基化结构。我们的结果支持这样的假设，即 COG 复合物的破坏干扰了中间和/或跨高尔基的正常蛋白质糖基化。
