Functional Proteomic Discovery of Slr0110 as a Central Regulator of Carbohydrate Metabolism in Synechocystis Species PCC6803
Functional Proteomic Discovery of Slr0110 as a Central Regulator of Carbohydrate Metabolism in Synechocystis Species PCC6803
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Slr0110 作为集胞藻 PCC6803 碳水化合物代谢中心调节剂的功能蛋白质组学发现
DOI：
10.1074/mcp.m113.033803
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发表时间：
2014-01-01
影响因子：
7
通讯作者：
Wang, Yingchun
中科院分区：
文献类型：
--
作者：
Gao, Liyan;Shen, Chunting;Wang, Yingchun
单细胞光合作用模型生物蓝藻集胞藻属 sp。 PCC6803 可以使用 CO2 进行光自养生长，也可以使用葡萄糖作为唯一碳源进行异养生长。集胞藻的碳代谢涉及多种途径，并且许多已知和未知基因对这些途径的协同调节对于生物体的生存和生长至关重要。在这里，我们报道了由开放阅读框 slr0110 编码的假设蛋白质对于集胞藻的异养生长是必需的。 slr0110缺失突变体在葡萄糖摄取、异养生长和暗生存能力方面存在缺陷，而在自养生长方面没有可检测到的缺陷，而光系统II的水平和氧气释放速率在突变体中增加。定量蛋白质组学分析表明，在突变体中，糖酵解和氧化戊糖磷酸途径中的几种蛋白质下调，而光系统 II 和藻胆体中的蛋白质显着上调。下调的蛋白包括葡萄糖转运蛋白、葡萄糖激酶、6-磷酸葡萄糖异构酶、6-磷酸葡萄糖脱氢酶及其组装蛋白OpcA，表明突变体中糖酵解、氧化戊糖磷酸和糖原合成途径受到显着抑制，这通过酶法测定和定量进一步证实。 糖原含量。这些发现确立了Slr0110作为集胞藻中碳代谢的新型中央调节剂，并揭示了一种复杂的机制，即当系统的一个或多个途径受损时，光合作用和碳代谢能够很好地协调以度过危机。
The unicellular photosynthetic model-organism cyanobacterium Synechocystis sp. PCC6803 can grow photoautotrophically using CO2 or heterotrophically using glucose as the sole carbon source. Several pathways are involved in carbon metabolism in Synechocystis, and the concerted regulation of these pathways by numerous known and unknown genes is critical for the survival and growth of the organism. Here, we report that a hypothetical protein encoded by the open reading frame slr0110 is necessary for heterotrophic growth of Synechocystis. The slr0110-deletion mutant is defective in glucose uptake, heterotrophic growth, and dark viability without detectable defects in autotrophic growth, whereas the level of photosystem II and the rate of oxygen evolution are increased in the mutant. Quantitative proteomic analysis revealed that several proteins in glycolysis and the oxidative pentose phosphate pathway are down-regulated, whereas proteins in photosystem II and phycobilisome are significantly up-regulated, in the mutant. Among the down-regulated proteins are glucose transporter, glucokinase, glucose-6-phosphate isomerase, and glucose-6-phosphate dehydrogenase and its assembly protein OpcA, suggesting that glycolysis, oxidative pentose phosphate, and glycogen synthesis pathways are significantly inhibited in the mutant, which was further confirmed by enzymatic assays and quantification of glycogen content. These findings establish Slr0110 as a novel central regulator of carbon metabolism in Synechocystis, and shed light on an intricate mechanism whereby photosynthesis and carbon metabolism are well concerted to survive the crisis when one or more pathways of the system are impaired.