Expression Pattern of a Chloroplast NADPH-Dependent Thioredoxin Reductase in Chlorella vulgaris during Hardening and Its Interaction with 2-Cys Peroxiredoxin
Expression Pattern of a Chloroplast NADPH-Dependent Thioredoxin Reductase in Chlorella vulgaris during Hardening and Its Interaction with 2-Cys Peroxiredoxin
复制标题
DOI：
10.1271/bbb.80761
复制
发表时间：
2009-03-01
影响因子：
1.6
通讯作者：
Miyamoto, Takahisa
中科院分区：
文献类型：
--
作者：
Machida, Takeshi;Kato, Eri;Miyamoto, Takahisa
从小球藻中鉴定出叶绿体NADPH依赖性硫氧还蛋白还原酶基因，命名为CvNTRC。在大肠杆菌中表达了成熟的CvNTRC蛋白（mCvNTRC），该蛋白具有NADPH依赖的硫氧还蛋白还原酶（NTR）和硫氧还蛋白（Trx）样二硫醇二硫化物氧化还原酶活性。CvNTRC的转录增加整个24小时硬化，而编码的蛋白量和总NTR活性下降一次，然后增加硬化过程中。通过体外pull-down分析，分离出与mCvNTRC结合的21.2-kDa蛋白，并基于N-末端序列鉴定为2-Cys过氧化物氧还蛋白（2-Cys Prx）。这些数据表明，CvNTRC在硬化过程中保持在恒定的水平，并且在小球藻的抗冻性的获得中与2-Cys Prx一起用作抗氧化剂。
A chloroplastic NADPH-dependent thioredoxin reductase gene was identified from Chlorella vulgaris and designated CvNTRC. Mature CvNTRC protein (mCvNTRC) was expressed in Escherichia coli, and it showed both NADPH-dependent thioredoxin reductase (NTR) and thioredoxin (Trx)-like dithiol-disulfide oxidoreductase activities. The transcript of CvNTRC increased throughout 24-h hardening, whereas the encoded protein amount and total NTR activity decreased once and then increased during hardening. By in vitro pull-down assay, a 21.2-kDa protein bound to mCvNTRC was isolated and identified as a 2-Cys peroxiredoxin (2-Cys Prx) based on the N-terminal sequence. These data suggest that CvNTRC is maintained at a constant level during hardening and functions as an antioxidant with 2-Cys Prx in the acquisition of freezing tolerance of Chlorella.