Starke Stephan, Velleman Laura, Dobbert Birgit, Seibert Luis, Witte Jordi, Jung Sascha, Meyer Vera
Chair of Applied and Molecular Microbiology, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany.
Front Microbiol. 2025 Jan 24;15:1490293. doi: 10.3389/fmicb.2024.1490293. eCollection 2024.
Antifungal peptides are promising drug candidates to fight fungal infections in the clinics and agriculture. However, recent data suggest that antifungal peptides might also play a role within their own producing organism to survive nutrient limiting conditions. We have therefore studied the function of the antifungal AnAFP in in more detail. To achieve this, we established a Tet-on controlled expression system, which allowed us to study a null and an overexpression phenotype in the same isolate. We observed that increased intracellular AnAFP expression reduces growth of and prematurely activates autophagy. Comparative transcriptome analyses of glucose-starving mycelium demonstrated that increased expression strongly impacts expression of genes important for cell wall integrity and remodeling, as well as genes with a predicted function in metabolism and transport of carbohydrates, proteins, and lipids. Notably, genes encoding regulators of conidiophore development such as and became induced upon overexpression. Fluorescent analyses of a Tet-on driven AnAFP::eGFP fusion protein congruently unraveled that AnAFP localizes to cell walls and septa of . Moreover, AnAFP::eGFP expression is spatially restricted to selected compartments only and affected cells displayed a sudden reduction in hyphal diameter. From these data we conclude that AnAFP is important to drive vegetative growth and sporulation in during nutrient limitation through autophagic recycling. We predict that AnAFP drives nutrient mobilization through selective cell lysis to ensure the survival of the whole colony during phases of starvation.
抗真菌肽是有望用于临床和农业领域对抗真菌感染的候选药物。然而，最近的数据表明，抗真菌肽在其自身产生的生物体中可能也发挥着作用，使其能够在营养限制条件下存活。因此，我们更详细地研究了抗真菌肽AnAFP的功能。为此，我们建立了一个四环素诱导型表达系统，该系统使我们能够在同一菌株中研究缺失和过表达表型。我们观察到细胞内AnAFP表达的增加会降低其生长并过早激活自噬。对葡萄糖饥饿菌丝体的比较转录组分析表明，AnAFP表达的增加强烈影响对细胞壁完整性和重塑重要的基因的表达，以及在碳水化合物、蛋白质和脂质代谢及转运中具有预测功能的基因的表达。值得注意的是，编码分生孢子梗发育调节因子的基因，如[具体基因名称1]和[具体基因名称2]，在AnAFP过表达时被诱导。对四环素诱导型AnAFP::eGFP融合蛋白的荧光分析一致表明，AnAFP定位于[具体真菌名称]的细胞壁和隔膜。此外，AnAFP::eGFP的表达仅在空间上局限于选定的隔室，受影响的细胞显示菌丝直径突然减小。从这些数据中我们得出结论，AnAFP在营养限制期间通过自噬循环对[具体真菌名称]的营养生长和孢子形成很重要。我们预测，AnAFP通过选择性细胞裂解驱动营养物质的动员，以确保整个菌落在饥饿阶段的存活。
