Effect of exogenous glucose on the expression and activity of NADPH dehydrogenase complexes in the cyanobacterium Synechocystis sp. strain PCC 6803.
Effect of exogenous glucose on the expression and activity of NADPH dehydrogenase complexes in the cyanobacterium Synechocystis sp. strain PCC 6803.
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DOI：
10.1016/j.plaphy.2008.04.019
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发表时间：
2008-08
期刊：
影响因子：
--
通讯作者：
Weimin Ma;H. Mi
中科院分区：
文献类型：
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作者：
Weimin Ma;H. Mi
活性NADPH脱氢酶超复合体和中复合体是新近在蓝藻中发现的，它们分别对光合循环系统I（PSI）的活性、呼吸作用和CO2的吸收至关重要。用外源葡萄糖（Glc）处理集胞藻PCC 6803细胞不同时间。采用NADPH-硝基四氮唑蓝氧化还原酶活性染色和western blot方法，测定P700+暗还原起始速率。NADPH脱氢酶超复合物的表达和酶活性逐渐受到抑制，并被发现与环PSI活性的降低密切相关，如P700+暗还原的初始速率所反映的。相比之下，NADPH脱氢酶介质复合物的那些和由NdhD 3和NdhF 3的表达水平反映的CO2摄取活性不受添加外源Glc的培养物的显著影响;然而，发现该介质复合物的表达和酶活性受CO2浓度的变化的显著影响。这些结果表明：（1）两种藻NADPH脱氢酶复合物对外源Glc的表达和活性反应不同，（2）这些反应与它们各自的生理作用密切相关。
Active NADPH dehydrogenase super- and medium-complexes were newly identified in cyanobacteria and are essential to cyclic photosystem I (PSI) activity and respiration and to CO2uptake, respectively. Synechocystis sp. strain PCC 6803 cells were treated with exogenous glucose (Glc) for different times. Active staining of NADPH–nitroblue tetrazolium oxidoreductase and western blot were conducted, and the initial rate of P700+dark reduction was measured. The expression and enzyme activity of the NADPH dehydrogenase super-complex were gradually inhibited and were found to be closely associated with the decrease in cyclic PSI activity, as reflected by the initial rate of P700+dark reduction. By contrast, those of the NADPH dehydrogenase medium-complex and the activity of CO2uptake reflected by the expression levels of NdhD3 and NdhF3 were not significantly affected by the addition of exogenous Glc to the cultures; however, the expression and enzyme activity of this medium-complex were found to be significantly influenced by the changes in CO2concentration. These results indicated that (1) the responses of the 2 cyanobacterial NADPH dehydrogenase complexes to exogenous Glc in terms of their expression and activity differed and that (2) these responses were closely associated with their respective physiological roles.