Hirai Kenshi, Idemoto Takuya, Kato Shiho, Ichiishi Akihiko, Fukumori Fumiyasu, Fujimura Makoto
Department of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Ora 374-0193, Gunma, Japan.
Department of Food and Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Ora 374-0193, Gunma, Japan.
J Fungi (Basel). 2022 Nov 6;8(11):1169. doi: 10.3390/jof8111169.
L-Sorbose induces hyperbranching of hyphae, which results in colonial growth in The gene, which encodes a glucose sensor that acts in carbon catabolite repression (CCR), has been identified as a sorbose resistance gene. In this study, we found that the deletion mutant of , which encodes an AmyR-like transcription factor that acts in CCR, displayed sorbose resistance. In contrast, the deletion mutants of other CCR genes, such as a hexokinase (), an AMP-activated S/T protein kinase (), and a transcription factor (), showed no sorbose resistance. Double mutant analysis revealed that the deletion of , , and did not affect the sorbose resistance of the mutant. Genes for a glucoamylase (), an invertase (), and glucose transporters ( and ) were highly expressed in the mutant, even in glucose-rich conditions, but this upregulation was suppressed in the Δ;Δ double-deletion mutant. Furthermore, we found that a (L1) mutant with a single amino-acid substitution, S11L, in the F-box protein EXO-1 displayed sorbose resistance, unlike the deletion mutants of , suggesting that the function of EXO-1 is crucial for the resistance. Our data strongly suggest that CCR directly participates in sorbose resistance, and that COL-26 and EXO-1 play important roles in regulating the amylase and glucose transporter genes during CCR.
L-山梨糖可诱导菌丝产生超分支，从而导致菌落生长。已鉴定出一个编码在碳源分解代谢阻遏（CCR）中起作用的葡萄糖传感器的基因，它是一个山梨糖抗性基因。在本研究中，我们发现编码在CCR中起作用的类AmyR转录因子的基因的缺失突变体表现出山梨糖抗性。相反，其他CCR基因的缺失突变体，如己糖激酶（）、AMP激活的丝氨酸/苏氨酸蛋白激酶（）和转录因子（），则未表现出山梨糖抗性。双突变分析表明，基因、和的缺失并不影响突变体的山梨糖抗性。葡糖淀粉酶（）、转化酶（）和葡萄糖转运蛋白（和）的基因在突变体中高表达，即使在富含葡萄糖的条件下也是如此，但在Δ；Δ双缺失突变体中这种上调受到抑制。此外，我们发现F-box蛋白EXO-1中具有单个氨基酸取代S11L的（L1）突变体表现出山梨糖抗性，这与基因的缺失突变体不同，表明EXO-1的功能对于抗性至关重要。我们的数据有力地表明，CCR直接参与山梨糖抗性，并且COL-26和EXO-1在CCR过程中对淀粉酶和葡萄糖转运蛋白基因的调控中发挥重要作用。
