TRANSLOCATION ACROSS GOLGI VESICLE MEMBRANES - A CHO GLYCOSYLATION MUTANT DEFICIENT IN CMP-SIALIC ACID TRANSPORT
TRANSLOCATION ACROSS GOLGI VESICLE MEMBRANES - A CHO GLYCOSYLATION MUTANT DEFICIENT IN CMP-SIALIC ACID TRANSPORT
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DOI：
10.1016/0092-8674(84)90007-2
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发表时间：
1984-01-01
期刊：
影响因子：
64.5
通讯作者：
HIRSCHBERG, CB
中科院分区：
文献类型：
--
作者：
DEUTSCHER, SL;NUWAYHID, N;HIRSCHBERG, CB
来自Lec2 CHO糖基化突变体的高尔基囊泡膜转运CMP-唾液酸的比率仅为野生型CHO细胞囊泡的2%。这种缺陷是特殊的，因为来自Lec2细胞的囊泡可以转运UDP-N-乙酰氨基葡萄糖、腺苷3‘’-磷酸5‘’-硫代磷酸和UDP-半乳糖，其速度与野生型细胞的囊泡相当。互补分析表明，Lec2突变体与表型相似的CHO突变体Clone 1021属于同一遗传互补群。这两个突变体之前被证明与野生型细胞相比，糖蛋白和神经节苷脂的唾液酸化减少了90%。细胞(1021)的唾液酸化能力、唾液酸转移酶活性和唾液酸化内源性受体水平均正常。Lec2和1021细胞的主要缺陷可能是它们不能将CMP-唾液酸转移到高尔基囊泡膜上。
Golgi vesicle membranes from the Lec2 CHO glycosylation mutant translocate CMP-sialic acid at only 2% the rate of vesicles from wild-type CHO cells. The deficiency is specific, because vesicles from Lec2 cells can translocate UDP-N-acetylglucosamine, adenosine 3''-phosphate 5''-phsophosulfate and UDP-galactose at rates comparable to those of vesicles from wild-type cells. Complementation analyses show that Lec2 mutants belong to the same genetic complementation group as clone 1021, a CHO mutant of similar phenotype. Both mutants were previously shown to have a 90% reduction in the sialylation of glycoproteins and gangliosides compared with wild-type cells. Cells (1021) appear to have normal levels of CMP-sialic acid, sialytransferase activity and endogenous acceptors for sialylation. The primary defect in Lec2 and 1021 cells may be their inability to translocate CMP-sialic acid across Golgi vesicle membranes.