Complementation cloning identifies CDG-IIc, a new type of congenital disorders of glycosylation, as a GDP-fucose transporter deficiency
Complementation cloning identifies CDG-IIc, a new type of congenital disorders of glycosylation, as a GDP-fucose transporter deficiency
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DOI：
10.1038/ng0501-73
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发表时间：
2001-05-01
期刊：
影响因子：
30.8
通讯作者：
Körner, C
中科院分区：
文献类型：
--
作者：
Lübke, T;Marquardt, T;Körner, C
先天性糖基化障碍（CDG）包括一组快速增长的遗传性障碍，其中糖蛋白的糖基化由于组装脂质连接的寡糖、其转移至新生糖蛋白（CDG-I）或加工蛋白结合的聚糖1（1，2）（CDG-II）所需的基因突变而缺陷。以前，在患有CDG（A.C.）糖蛋白中岩藻糖基残基普遍缺乏（3）。该患者表现出II型白细胞粘附缺陷症（LAD II）的临床特征，包括精神发育迟滞、身材矮小、面部红斑和复发性外周细菌感染伴外周白细胞持续升高（4-7）。使用特定的岩藻糖。通过凝集素染色检测岩藻糖基化糖蛋白和逆转录病毒cDNA文库，我们分离出了一个补充患者成纤维细胞中岩藻糖基化缺陷的cDNA。该cDNA编码具有多个推定的跨膜结构域的364个氨基酸的高度疏水蛋白。从患者的成纤维细胞富含高尔基体的囊泡中的CDP-岩藻糖输入活性的恢复验证了该蛋白质的GDP-岩藻糖转运蛋白活性。我们在患者A.C.的GDP-岩藻糖转运蛋白cDNA中发现了两个错义突变。还有另外两个患有左前降支二型的人因此，互补克隆使我们能够确定人GDP-岩藻糖转运蛋白cDNA和GDP-岩藻糖转运蛋白缺陷作为一种新型CDG的原因。根据最近对CDG命名的建议（2，8），这种新类型被归类为CDG-IIc（以前称为LAD II）。
Congenital disorders of glycosylation (CDG) comprise a rapidly growing group of inherited disorders in which glycosylation of glycoproteins is defective due to mutations in genes required for the assembly of lipid-linked oligosaccharides, their transfer to nascent glycoproteins (CDG-I) or the processing of protein-bound glycansl(1,2) (CDG-II). Previously' a defect in the GDP-fucose import into the lumen of the Golgi was identified in a person with CDG (A.C.) with a general deficiency of fucosyl residues in glycoproteins(3). This patient presents the clinical features of leukocyte adhesion deficiency type II (LAD II) including mental retardation, short stature, facial stigmata, and recurrent bacterial peripheral infections with persistently elevated peripheral leukocytes(4-7). Using a fucose-specific. lectin-staining procedure for detection of fucosylated glycoproteins and a retroviral cDNA library, we isolated a cDNA complementing the fucosylation defect in the patient's fibroblasts. The cDNA encodes a highly hydrophobic protein of 364 amino acids with multiple putative transmembrane domains. Restoration of CDP-fucose import activity in Golgi-enriched vesicles from the patient's fibroblasts verified the GDP-fucose transporter activity of this protein. We identified two missense mutations in the GDP-fucose transporter cDNA of patient A.C. and of two other people with LAD II. Thus complementation cloning allowed us to identify the human GDP-fucose transporter cDNA and GDP-fucose transporter deficiency as a cause for a new type of CDG. Following the recent recommendations(2,8) for the nomenclature for CDG, this new type is classified as CDG-IIc (formerly LAD II).