Phosphoproteomic Analysis of Rhodopseudomonas palustris Reveals the Role of Pyruvate Phosphate Dikinase Phosphorylation in Lipid Production
Phosphoproteomic Analysis of Rhodopseudomonas palustris Reveals the Role of Pyruvate Phosphate Dikinase Phosphorylation in Lipid Production
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DOI：
10.1021/pr300582p
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发表时间：
2012-11-01
影响因子：
4.4
通讯作者：
Wu, Shih-Hsiung
中科院分区：
文献类型：
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作者：
Hu, Chia-Wei;Lin, Miao-Hsia;Wu, Shih-Hsiung
沼泽红假单胞菌（R. palustris）是具有代谢多样性的紫色非硫不产氧光合细菌，并且能够在光异养和化能异养状态下生长。它可用于碳管理、碳循环、制氢和脂质生产;因此，它具有生物能源生产和生物降解的潜力。本研究首次鉴定了沼生铁藻在化能异养和光能异养生长条件下的磷酸化蛋白质组，包括来自54种磷酸化蛋白的100个磷酸肽和来自42种磷酸化蛋白的74个磷酸肽。在鉴定的磷酸化蛋白质组中，发现丙酮酸磷酸二激酶（PPDK，RPA 1051）的苏氨酸残基Thr 487处的磷酸化参与碳代谢的调节。在这里，我们表明，PPDK酶活性较高的光合异养生长，与Thr 487磷酸化作为一个可能的调解人。在相同的光合异养条件下，过表达野生型PPDK的沼泽地藻比突变型PPDK（T487 V）的沼泽地藻表现出更高的总脂积累。这项研究揭示了PPDK在生物柴油材料，脂质含量的生产中的作用，与苏氨酰磷酸化作为一个可能的调节事件，在光异养生长在沼泽。
Rhodopseudomonas palustris (R. palustris) is a purple nonsulfur anoxygenic phototrophic bacterium with metabolic versatility and is able to grow under photoheterotrophic and chemoheterotrophic states. It has uses in carbon management, carbon recycling, hydrogen generation, and lipid production; therefore, it has the potential for bioenergy production and biodegradation. This study is the first to identify the phosphoproteome of It palustris including 100 phosphopeptides from 54 phosphoproteins and 74 phosphopeptides from 42 phosphoproteins in chemoheterotrophic and photoheterotrophic growth conditions, respectively. In the identified phosphoproteome, phosphorylation at the threonine residue, Thr487, of pyruvate phosphate dikinase (PPDK, RPA1051) was found to participate in the regulation of carbon metabolism. Here, we show that PPDK enzyme activity is higher in photoheterotrophic growth, with Thr487 phosphorylation as a possible mediator. Under the same photoheterotrophic conditions, it palustris with overexpressed wild-type PPDK showed an enhanced accumulation of total lipids than those with mutant PPDK (T487V) form. This study reveals the role of the PPDK in the production of biodiesel material, lipid content, with threonyl-phosphorylation as one of the possible regulatory events during photoheterotrophic growth in It palustris.