State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300453, China.
State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Biomolecules. 2023 Feb 4;13(2):295. doi: 10.3390/biom13020295.
Sugar transporters play an important role in the cellulase production of lignocellulose-degrading fungi. Nevertheless, the role and function of these transporters are still unclear. Here we first report intracellular sugar transporters assisting cellulase production in () using lactose. The mRNA levels of sugar transporter genes , , and were substantially upregulated in cultivated on lactose, with the most abundant mRNA levels at 24 h as compared to glucose. Moreover, the individual deletion of these sugar transporters significantly inhibited cellulase production, solid cell growth, and sporulation of , suggesting they play a supporting role in cellulase production when grown in lactose. Surprisingly, MFS, GST, and LAC1 were mainly localized in the cytoplasm, with MFS and LAC1 in the endoplasmic reticulum (ER), representing the first discovery of intracellular sugar transporters involved in cellulase biosynthesis in lactose culture. The absence of the gene noticeably inhibited most of the crucial genes related to cellulase production, including cellulase-encoding genes, transcription factors, and sugar transporters, at 24 h, which was fully relieved at 48 h or 72 h, indicating that affects cellulase production more at the early step. This research advances the understanding of the function of intracellular sugar transporters in fungi, particularly for fungal cellulase production.
糖转运蛋白在木质纤维素降解真菌的纤维素酶生产中起着重要作用。然而，这些转运蛋白的作用和功能仍不清楚。在这里，我们首次报道了利用乳糖辅助木质纤维素降解真菌 () 生产纤维素酶的细胞内糖转运蛋白。在乳糖上培养时，糖转运蛋白基因 、 、 的 mRNA 水平显著上调，与葡萄糖相比，24 h 时的 mRNA 水平最高。此外，这些糖转运蛋白的单独缺失显著抑制了纤维素酶的产生、固体细胞的生长和 的孢子形成，表明它们在乳糖生长时在纤维素酶生产中起支持作用。令人惊讶的是，MFS、GST 和 LAC1 主要定位于细胞质中，MFS 和 LAC1 位于内质网 (ER) 中，这代表了首次发现参与乳糖培养中纤维素生物合成的细胞内糖转运蛋白。基因 的缺失显著抑制了 24 h 时大多数与纤维素酶生产相关的关键基因，包括纤维素酶编码基因、转录因子和糖转运蛋白，这在 48 h 或 72 h 时得到完全缓解，表明 在早期阶段对纤维素酶生产的影响更大。这项研究推进了对细胞内糖转运蛋白在真菌中的功能的理解，特别是对真菌纤维素酶生产的理解。
