State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China.
Mar Drugs. 2020 Jul 13;18(7):360. doi: 10.3390/md18070360.
Glyceroglycolipids, abundant in cyanobacteria's photosynthetic membranes, present bioactivities and pharmacological activities, and can be widely used in the pharmaceutical industry. Environmental factors could alter the contents and compositions of cyanobacteria glyceroglycolipids, but the regulation mechanism remains unclear. Therefore, the glyceroglycolipids contents and the transcriptome in PCC 7942 were analyzed under phosphate starvation. Under phosphate starvation, the decrease of monogalactosyl diacylglycerol (MGDG) and increases of digalactosyl diacylglycerol (DGDG) and sulfoquinovosyl diacylglycerol (SQDG) led to a decrease in the MGDG/DGDG ratio, from 4:1 to 5:3, after 12 days of cultivation. However, UDP-sulfoquinovose synthase gene , and the SQDG synthase gene , were down-regulated, and the decreased MGDG/DGDG ratio was later increased back to 2:1 after 15 days of cultivation, suggesting the regulation of glyceroglycolipids on day 12 was based on the MGDG/DGDG ratio maintaining glyceroglycolipid homeostasis. There are 12 differentially expressed transcriptional regulators that could be potential candidates related to glyceroglycolipid regulation, according to the transcriptome analysis. The transcriptome analysis also suggested post-transcriptional or post-translational regulations in glyceroglycolipid synthesis. This study provides further insights into glyceroglycolipid metabolism, as well as the scientific basis for glyceroglycolipid synthesis optimization and cyanobacteria glyceroglycolipids utilization via metabolic engineering.
甘油糖脂大量存在于蓝藻的光合膜中，具有生物活性和药理活性，可广泛应用于制药工业。环境因素可以改变蓝藻甘油糖脂的含量和组成，但调控机制尚不清楚。因此，在磷饥饿条件下分析了 PCC 7942 的甘油糖脂含量和转录组。在磷饥饿条件下，经过 12 天的培养，单半乳糖二酰甘油（MGDG）的减少和双半乳糖二酰甘油（DGDG）和硫酸奎诺糖二酰甘油（SQDG）的增加导致 MGDG/DGDG 比值从 4:1 降低至 5:3。然而，UDP-硫酸奎诺糖合酶基因和 SQDG 合酶基因下调，在 15 天的培养后，降低的 MGDG/DGDG 比值又增加到 2:1，这表明甘油糖脂在第 12 天的调控是基于维持甘油糖脂的平衡来调节 MGDG/DGDG 比值。根据转录组分析，有 12 个差异表达的转录调控因子可能是与甘油糖脂调控相关的潜在候选因子。转录组分析还表明甘油糖脂合成存在转录后或翻译后调控。本研究进一步深入了解了甘油糖脂代谢，为通过代谢工程优化甘油糖脂合成和利用蓝藻甘油糖脂提供了科学依据。
