Pharmacological chaperones facilitate the post-ER transport of recombinant N370S mutant β-glucocerebrosidase in plant cells: Evidence that N370S is a folding mutant
Pharmacological chaperones facilitate the post-ER transport of recombinant N370S mutant β-glucocerebrosidase in plant cells: Evidence that N370S is a folding mutant
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DOI：
10.1016/j.ymgme.2012.04.018
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发表时间：
2012-07-01
影响因子：
3.8
通讯作者：
Kermode, Allison R.
中科院分区：
文献类型：
--
作者：
Babajani, Gholamreza;Tropak, Michael B.;Kermode, Allison R.
Gaucher病是一种普遍的溶酶体储存疾病，其中受影响的个体在编码溶酶体酸β-葡萄糖苷酶（GCASEBEROSIDASE，GCASE，EC 3.2.1.45）的基因（GBA1）中遗传突变。人类最普遍的致病突变之一是Gcase蛋白中的N370错义突变。作为研究在植物细胞中表达的突变人类蛋白的命运的较大努力的一部分，N370S突变蛋白以及配备有信号肽的野生型 - （WT） - gase，在转基因烟草By2细胞中合成，不具有溶酶体。植物成年型N370S的酶活性明显低于WT-GCASE线的酶活性（81-95％）。与WT-GCASE蛋白有效地从烟草BY2细胞中分泌并在培养基中大量检测到的WT-GCASE蛋白相反，只有一小部分N370 GCASE被分泌。药理学伴侣，例如N-（N- nonyl）脱氧脂蛋白和Ambroxol增加了。植物细胞内部和培养基中的稳态突变蛋白水平。这些发现与这样的断言相矛盾：小分子伴侣伴侣通过稳定溶酶体中的酶来增加N370S的GCASE活性（如治疗的患者细胞裂解物所测定），并暗示突变蛋白在获得其功能折叠构象的能力方面受到了损害退出ER管腔的要求。 （c）2012 Elsevier Inc.保留所有权利。
Gaucher disease is a prevalent lysosomal storage disease in which affected individuals inherit mutations in the gene (GBA1) encoding lysosomal acid beta-glucosidase (glucocerebrosidase, GCase, EC 3.2.1.45). One of the most prevalent disease-causing mutations in humans is a N370S missense mutation in the GCase protein. As part of a larger endeavor to study the fate of mutant human proteins expressed in plant cells, the N370S mutant protein along with the wild-type- (WT)-GCase, both equipped with a signal peptide, were synthesized in transgenic tobacco BY2 cells, which do not possess lysosomes. The enzymatic activity of plant-recombinant N370S GCase lines was significantly lower (by 81-95%) than that of the WT-GCase lines. In contrast to the WT-GCase protein, which was efficiently secreted from tobacco BY2 cells, and detected in large amounts in the culture medium, only a small proportion of the N370S GCase was secreted. Pharmacological chaperones such as N-(n-nonyl) deoxynojirimycin and ambroxol increased the. steady-state mutant protein levels both inside the plant cells and in the culture medium. These findings contradict the assertion that small molecule chaperones increase N370S GCase activity (as assayed in treated patient cell lysates) by stabilizing the enzyme in the lysosome, and suggest that the mutant protein is impaired in its ability to obtain its functional folded conformation, which is a requirement for exiting the lumen of the ER. (C) 2012 Elsevier Inc. All rights reserved.