College of Marine Life Sciences, Ocean University of China, Qingdao, China.
College of Marine Life Sciences, Ocean University of China, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Int J Biol Macromol. 2024 May;268(Pt 1):131820. doi: 10.1016/j.ijbiomac.2024.131820. Epub 2024 Apr 25.
In this study, an NSDD gene, which encoded a GATA-type transcription factor involved in the regulation and biosynthesis of melanin, pullulan, and polymalate (PMA) in Aureobasidium melanogenum, was characterized. After the NSDD gene was completely removed, melanin production by the Δnsd mutants was enhanced, while pullulan and polymalate production was significantly reduced. Transcription levels of the genes involved in melanin biosynthesis were up-regulated while expression levels of the genes responsible for pullulan and PMA biosynthesis were down-regulated in the Δnsdd mutants. In contrast, the complementation of the NSDD gene in the Δnsdd mutants made the overexpressing mutants restore melanin production and transcription levels of the genes responsible for melanin biosynthesis. Inversely, the complementation strains, compared to the wild type strains, showed enhanced pullulan and PMA yields. These results demonstrated that the NsdD was not only a negative regulator for melanin biosynthesis, but also a key positive regulator for pullulan and PMA biosynthesis in A. melanogenum. It was proposed how the same transcriptional factor could play a negative role in melanin biosynthesis and a positive role in pullulan and PMA biosynthesis. This study provided novel insights into the regulatory mechanisms of multiple A. melanogenum metabolites and the possibility for improving its yields of some industrial products through genetic approaches.
在这项研究中，鉴定了一个 NSDD 基因，该基因编码一个 GATA 型转录因子，参与调控和黑色素、普鲁兰和聚苹果酸（PMA）的生物合成，在出芽短梗霉中。完全敲除 NSDD 基因后，Δnsd 突变体的黑色素产量增加，而普鲁兰和聚苹果酸产量显著降低。黑色素生物合成相关基因的转录水平上调，而参与普鲁兰和 PMA 生物合成的基因表达水平下调。相反，在Δnsdd 突变体中过表达 NSDD 基因使过表达突变体恢复黑色素产量和黑色素生物合成相关基因的转录水平。相反，与野生型菌株相比，补料菌株显示出增强的普鲁兰和 PMA 产量。这些结果表明，NsdD 不仅是黑色素生物合成的负调控因子，也是出芽短梗霉中普鲁兰和 PMA 生物合成的关键正调控因子。提出了同一个转录因子如何在黑色素生物合成中起负作用，在普鲁兰和 PMA 生物合成中起正作用。本研究为多种出芽短梗霉代谢物的调控机制提供了新的见解，并为通过遗传方法提高某些工业产品的产量提供了可能性。
