A bacterial checkpoint protein for ribosome assembly moonlights as an essential metabolite-proofreading enzyme
A bacterial checkpoint protein for ribosome assembly moonlights as an essential metabolite-proofreading enzyme
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DOI：
10.1038/s41467-019-09508-z
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发表时间：
2019-04-04
影响因子：
16.6
通讯作者：
Heimann, John D.
中科院分区：
文献类型：
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作者：
Sachla, Ankita J.;Heimann, John D.
在真核生物中，赤藓糖-4-磷酸（戊糖磷酸途径（PPP）的中间体）的外源氧化产生4-磷酸葡糖酸（4PE），其抑制6-磷酸葡萄糖酸脱氢酶。4PE通过代谢物校正磷酸酶如酵母Phol 3解毒。在这里，我们报告了一个类似的功能是在枯草芽孢杆菌中进行的CpgA，一个检查点蛋白已知是重要的核糖体组装，细胞形态和耐药性细胞壁靶向抗生素。我们发现，三角洲cpgA细胞被葡萄糖或其他碳源，饲料到PPP中毒，CpgA具有高磷酸酶活性与4PE。6-磷酸葡萄糖酸脱氢酶（GndA）的抑制导致6-磷酸葡萄糖酸中毒，6-磷酸葡萄糖酸是磷酸葡萄糖异构酶（PGI）的强效抑制剂。PPP和糖酵解的协调关闭导致代谢僵局。GndA、PGI或酵母Pho 13的过表达抑制Delta cpgA细胞的葡萄糖中毒，但不抑制冷敏感性，这是一种与核糖体组装缺陷相关的表型。我们的研究结果表明，CpgA是一个多功能的蛋白质，在核糖体组装和代谢产物校正的遗传分离的作用。
In eukaryotes, adventitious oxidation of erythrose-4-phosphate, an intermediate of the pentose phosphate pathway (PPP), generates 4-phosphoerythronate (4PE), which inhibits 6-phosphogluconate dehydrogenase. 4PE is detoxified by metabolite-proofreading phosphatases such as yeast Phol3. Here, we report that a similar function is carried out in Bacillus subtilis by CpgA, a checkpoint protein known to be important for ribosome assembly, cell morphology and resistance to cell wall-targeting antibiotics. We find that Delta cpgA cells are intoxicated by glucose or other carbon sources that feed into the PPP, and that CpgA has high phosphatase activity with 4PE. Inhibition of 6-phosphogluconate dehydrogenase (GndA) leads to intoxication by 6-phosphogluconate, a potent inhibitor of phosphoglucose isomerase (PGI). The coordinated shutdown of PPP and glycolysis leads to metabolic gridlock. Overexpression of GndA, PGI, or yeast Pho13 suppresses glucose intoxication of Delta cpgA cells, but not cold sensitivity, a phenotype associated with ribosome assembly defects. Our results suggest that CpgA is a multifunctional protein, with genetically separable roles in ribosome assembly and metabolite proofreading.