Thioredoxin targets are regulated in heterocysts of cyanobacterium Anabaena sp. PCC 7120 in a light-independent manner
Thioredoxin targets are regulated in heterocysts of cyanobacterium Anabaena sp. PCC 7120 in a light-independent manner
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DOI：
10.1093/jxb/erz561
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发表时间：
2020-03-25
影响因子：
6.9
通讯作者：
Hisabori, Toru
中科院分区：
文献类型：
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作者：
Mihara, Shoko;Sugiura, Kazunori;Hisabori, Toru
在固氮蓝藻Anabaena sp. PCC 7120中，葡萄糖6-磷酸脱氢酶（G6 PDH）在光条件下产生还原固氮酶的动力中起重要作用。我们以前的研究表明，硫氧还蛋白抑制G6 PDH通过减少其激活蛋白OpcA，这意味着G6 PDH在光照条件下失活，因为硫氧还蛋白减少光合电子传递系统在蓝藻。为了解决鱼腥藻PCC 7120如何保持G6 PDH活性，即使在光条件下，当固氮发生，我们调查了营养细胞和特定的固氮细胞命名为异形胞的氧化还原调节系统，分别。我们发现硫氧还蛋白靶蛋白在光条件下在异形胞中比在营养细胞中氧化得更多。异形胞氧化还原调节机制的改变可能会影响硫氧还蛋白靶蛋白（包括OpcA）的氧化还原状态，因此即使在光照条件下，异形胞中的G6 PDH也会被激活。
In the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, glucose 6-phosphate dehydrogenase (G6PDH) plays an important role in producing the power for reducing nitrogenase under light conditions. Our previous study showed that thioredoxin suppresses G6PDH by reducing its activator protein OpcA, implying that G6PDH is inactivated under light conditions because thioredoxins are reduced by the photosynthetic electron transport system in cyanobacteria. To address how Anabaena sp. PCC 7120 maintains G6PDH activity even under light conditions when nitrogen fixation occurs, we investigated the redox regulation system in vegetative cells and specific nitrogen-fixing cells named heterocysts, individually. We found that thioredoxin target proteins were more oxidized in heterocysts than in vegetative cells under light conditions. Alterations in the redox regulation mechanism of heterocysts may affect the redox states of thioredoxin target proteins, including OpcA, so that G6PDH is activated in heterocysts even under light conditions.