Low reduction potential of Ero1alpha regulatory disulphides ensures tight control of substrate oxidation.
Low reduction potential of Ero1alpha regulatory disulphides ensures tight control of substrate oxidation.
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ERO1Alpha调节二硫化物的低还原电位可确保严格控制底物氧化。
DOI：
10.1038/emboj.2008.230
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发表时间：
2008-11-19
期刊：
影响因子：
11.4
通讯作者：
Bulleid, Neil J.
中科院分区：
文献类型：
--
作者：
Baker, Karl M.;Chakravarthi, Seema;Langton, Kevin P.;Sheppard, Alyson M.;Lu, Hui;Bulleid, Neil J.
哺乳动物内质网（ER）内二硫键的形成需要Ero 1 α和蛋白质二硫键异构酶（PDI）的联合活性。由于Ero 1 α在氧化过程中产生过氧化氢，因此调节其活性对于预防ER产生的氧化应激至关重要。在此，我们表达并纯化了重组人Ero 1 α，并显示其对硫氧还蛋白和PDI具有活性。对PDI的活性需要包含谷胱甘肽以确保持续氧化。通过对半胱氨酸残基进行定点突变，我们表明Ero 1 α受到非催化二硫键的调节。调节性二硫化物的中点还原电位（E°′）计算为约-275 mV，使其在ER中普遍存在的氧化还原条件下稳定。PDI仅部分减少了稳定的调节二硫键（E° '-180 mV），这表明这是防止Ero 1 α过度活性和PDI氧化的机制，或者哺乳动物ER内Ero 1 α激活需要额外的因素。
Formation of disulphide bonds within the mammalian endoplasmic reticulum (ER) requires the combined activities of Ero1α and protein disulphide isomerase (PDI). As Ero1α produces hydrogen peroxide during oxidation, regulation of its activity is critical in preventing ER-generated oxidative stress. Here, we have expressed and purified recombinant human Ero1α and shown that it has activity towards thioredoxin and PDI. The activity towards PDI required the inclusion of glutathione to ensure sustained oxidation. By carrying out site-directed mutagenesis of cysteine residues, we show that Ero1α is regulated by non-catalytic disulphides. The midpoint reduction potential (E°′) of the regulatory disulphides was calculated to be approximately −275 mV making them stable in the redox conditions prevalent in the ER. The stable regulatory disulphides were only partially reduced by PDI (E°′∼−180 mV), suggesting either that this is a mechanism for preventing excessive Ero1α activity and oxidation of PDI or that additional factors are required for Ero1α activation within the mammalian ER.
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影响因子：
11.4
作者：
Benham, AM;Cabibbo, A;Braakman, I
通讯作者：
Braakman, I
DOI：
10.1073/pnas.0506448103
发表时间：
2006-01-10
影响因子：
11.1
作者：
Gross, E;Sevier, CS;Fass, D
通讯作者：
Fass, D
影响因子：
11.4
作者：
Mezghrani, A;Fassio, A;Sitia, R
通讯作者：
Sitia, R
影响因子：
6.6
作者：
Appenzeller-Herzog, Christian;Ellgaard, Lars
通讯作者：
Ellgaard, Lars
影响因子：
4.8
作者：
Bertoli, G;Simmen, T;Sitia, R
通讯作者：
Sitia, R