Zheng Xianyao, Li Aifeng, Qiu Jiangbing, Yan Guowang
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China.
Mar Pollut Bull. 2024 Dec;209(Pt B):117197. doi: 10.1016/j.marpolbul.2024.117197. Epub 2024 Oct 31.
The neurotoxin β-N-methylamino-L-alanine (BMAA) produced by marine diatoms has been implicated in some neurological disorders, and there is a need to elucidate the biological processes involved in the production of BMAA-containing proteins. In this study, growth of seven diatoms was suppressed under nitrogen limitation, however the production of BMAA-containing proteins was significantly increased in six of them, up to 5.22-fold increase in Thalassiosira andamanica. These variations were associated with reduced concentration of dissolved inorganic nitrogen (DIN) and changes in photosynthetic efficiency. Analytical results of non-targeted metabolomics showed that the obvious changes in amino acids, lipids and sugars may help diatoms to adjust growth and physiological parameters. Combined with previous transcriptomic data, a decrease in N-acetyl-D-glucosamine (GlcNAc) leads to an increase in N-glycan terminal modifications, which in turn increases protein misfolding. In addition, the reduced efficiency of vesicular transport in the COPII system may have exacerbated the accumulation of BMAA-containing proteins.
海洋硅藻产生的神经毒素β-N-甲基氨基-L-丙氨酸（BMAA）与某些神经系统疾病有关，因此有必要阐明含BMAA蛋白质产生过程中涉及的生物学过程。在本研究中，七种硅藻的生长在氮限制条件下受到抑制，然而其中六种硅藻中含BMAA蛋白质的产量显著增加，安达曼海链藻中增加了5.22倍。这些变化与溶解无机氮（DIN）浓度降低和光合效率变化有关。非靶向代谢组学分析结果表明，氨基酸、脂质和糖类的明显变化可能有助于硅藻调整生长和生理参数。结合之前的转录组数据，N-乙酰-D-葡萄糖胺（GlcNAc）的减少导致N-聚糖末端修饰增加，进而增加蛋白质错误折叠。此外，COPII系统中囊泡运输效率的降低可能加剧了含BMAA蛋白质的积累。
