Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Academy of Science, Royal Society of Thailand, Bangkok 10300, Thailand.
Plant Sci. 2020 Jan;290:110287. doi: 10.1016/j.plantsci.2019.110287. Epub 2019 Sep 27.
A pathway for polyamine-derived GABA synthesis in Synechocystis sp. PCC 6803 was explored by disrupting both the glutamate decarboxylase and α-ketoglutarate decarboxylase genes. The generated Δgad:Δkgd strain had increased intracellular α-ketoglutarate and polyamine levels compared to the wild type. Gene transcript analysis using RT-PCR indicated that the Δgad:Δkgd strain had up-regulated expression of a putative gadbh whose gene product, γ-aminobutanal dehydrogenase, would catalyze the conversion of γ-aminobutanal to GABA. A strain with disrupted gabdh showed an increase in GABA, glutamate, succinate and spermidine levels. These findings provide evidence for a link between spermidine degradation and GABA synthesis in cyanobacteria. This study highlights the role of γ-aminobutanal dehydrogenase in maintaining an intact tricarboxylic acid cycle in Synechocystis.
通过敲除谷氨酸脱羧酶和α-酮戊二酸脱羧酶基因，探索了集胞藻 PCC 6803 中多胺衍生 GABA 合成的途径。与野生型相比，生成的Δgad:Δkgd 菌株具有更高的细胞内α-酮戊二酸和多胺水平。使用 RT-PCR 的基因转录分析表明，Δgad:Δkgd 菌株上调了一个假定的 gadbh 的表达，其基因产物γ-氨基丁醛脱氢酶将催化γ-氨基丁醛转化为 GABA。具有gabdh 缺失的菌株 GABA、谷氨酸、琥珀酸和亚精胺水平增加。这些发现为蓝藻中多胺降解与 GABA 合成之间的联系提供了证据。本研究强调了γ-氨基丁醛脱氢酶在维持集胞藻完整三羧酸循环中的作用。
