Binary reducing equivalent pathways using NADPH-thioredoxin reductase and ferredoxin-thioredoxin reductase in the cyanobacterium Synechocystis sp Strain PCC 6803
Binary reducing equivalent pathways using NADPH-thioredoxin reductase and ferredoxin-thioredoxin reductase in the cyanobacterium Synechocystis sp Strain PCC 6803
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DOI：
10.1093/pcp/pcm158
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发表时间：
2008-01-01
影响因子：
4.9
通讯作者：
Hisabori, Toru
中科院分区：
文献类型：
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作者：
Hishiya, Shoko;Hatakeyama, Wakako;Hisabori, Toru
硫氧还蛋白（Trx）是一种普遍存在的小蛋白，参与细胞和细胞器中发生的二硫二硫醇交换反应。在体内，Trx被Trx还原酶利用NADPH或光合作用产生的还原等效物还原，还原后的Trx具有生理功能。通过基因组分析，在蓝细菌Synechocystis sp. PCC6803中鉴定出2种Trx还原酶，即铁氧化还原酶-Trx还原酶（FTR）和NADPH-Trx还原酶（NTR），以及4种典型的Trx亚型。通过对Trx还原酶干扰物生理特性的分析，我们发现NTRTrx途径在抗氧化系统中发挥重要作用，而FTRTrx途径可能在控制细胞生长速率方面发挥更重要的作用。此外，通过对野生型和破坏型聚囊藻细胞中Trx丰度的定量分析，我们发现高等植物中m型Trx的同源基因slr0623的基因产物是最丰富的Trx，并且Trx亚型的积累依赖于其他氧化还原相关蛋白的表达。本文报道了蓝藻细胞中二元还原等效途径的研究。
Thioredoxin (Trx) is a small ubiquitous protein involved in the disulfidedithiol exchange reaction occurring in cells and organelles. In vivo, Trx is reduced by Trx reductase using NADPH or photosynthetically produced reducing equivalents, and the reduced form Trx takes on the physiological functions. In the cyanobacterium Synechocystis sp. PCC6803, two Trx reductases, ferredoxin-Trx reductase (FTR) and NADPH-Trx reductase (NTR), and four typical Trx isoforms have been identified by genomic analysis. Based on analysis of the physiological features of the Trx reductase disruptants, we found that the NTRTrx pathway is important for the antioxidant system, whereas the FTRTrx pathway may play a more important role in the control of cell growth rate. In addition, by quantification of Trx abundance in the wild-type and the disruptant Synechocystis cells, we found that the gene product of slr0623, the homolog of m-type Trx in higher plants, is the most abundant Trx, and that accumulation of Trx isoforms occurs dependent on the expression of the other redox-related proteins. A study of the binary reducing equivalent pathways in cyanobacterial cells is reported here.