Enzymatic characterization of four new mutations in the glucose-6 phosphatase (G6PC) gene which cause glycogen storage disease type 1a
Enzymatic characterization of four new mutations in the glucose-6 phosphatase (G6PC) gene which cause glycogen storage disease type 1a
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DOI：
10.1046/j.1469-1809.1999.6320141.x
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发表时间：
1999-03-01
影响因子：
1.9
通讯作者：
Mithieux, G
中科院分区：
文献类型：
--
作者：
Bruni, N;Rajas, F;Mithieux, G
糖原累积病Ia型（GSD 1a）是由葡萄糖-6磷酸酶（G6 PC）基因突变引起的，该基因编码糖原生成和糖原分解的最后一种酶。为了研究先前在法国GSD 1a患者中鉴定的但尚未酶促表征的突变的影响，我们使用了人葡萄糖-6磷酸酶（hGlc 6 beta）cDNA的体外表达系统。在COS-7细胞中表达的野生型hGlc 6 β表现出与来自正常人肝脏和肾脏的微粒体Glc 6 β相当的动力学特征。通过定点突变的方法将新的突变体W77 R、A124 T、G184 E和L211 P插入Glc 6 β cDNA中，并在COS-7细胞中进行瞬时表达。所有四种突变完全消除Glc 6 β活性。
Glycogen storage disease type la (GSD1a) is caused by mutations in the gene of glucose-6 phosphatase (G6PC), encoding the last enzyme of gluconeogenesis and glycogenolysis. To study the effect of mutations previously identified, but not yet enzymatically characterized, in French GSD1a patients, we used an in vitro expression system of the human glucose-6 phosphatase (hGlc6Pase) cDNA. Wild type hGlc6Pase expressed in COS-7 cells exhibited kinetic features comparable to microsomal Glc6Pase from normal human liver and kidney. Pour new mutations inducing aminoacid changes in the coding sequence, e.g. W77R, A124T, G184E and L211P, were inserted into the Glc6Pase cDNA by site-directed mutagenesis, and studied after transient expression in COS-7 cells. All four mutations totally abolished Glc6Pase activity.