Department of Genetics and Microbiology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic.
Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, Vestec, Czech Republic.
PLoS Genet. 2018 Jul 2;14(7):e1007495. doi: 10.1371/journal.pgen.1007495. eCollection 2018 Jul.
Yeast biofilms are complex multicellular structures, in which the cells are well protected against drugs and other treatments and thus highly resistant to antifungal therapies. Colony biofilms represent an ideal system for studying molecular mechanisms and regulations involved in development and internal organization of biofilm structure as well as those that are involved in fungal domestication. We have identified here antagonistic functional interactions between transcriptional regulators Cyc8p and Tup1p that modulate the life-style of natural S. cerevisiae strains between biofilm and domesticated mode. Herein, strains with different levels of Cyc8p and Tup1p regulators were constructed, analyzed for processes involved in colony biofilm development and used in the identification of modes of regulation of Flo11p, a key adhesin in biofilm formation. Our data show that Tup1p and Cyc8p regulate biofilm formation in the opposite manner, being positive and negative regulators of colony complexity, cell-cell interaction and adhesion to surfaces. Notably, in-depth analysis of regulation of expression of Flo11p adhesin revealed that Cyc8p itself is the key repressor of FLO11 expression, whereas Tup1p counteracts Cyc8p's repressive function and, in addition, counters Flo11p degradation by an extracellular protease. Interestingly, the opposing actions of Tup1p and Cyc8p concern processes crucial to the biofilm mode of yeast multicellularity, whereas other multicellular processes such as cell flocculation are co-repressed by both regulators. This study provides insight into the mechanisms regulating complexity of the biofilm lifestyle of yeast grown on semisolid surfaces.
酵母生物膜是一种复杂的多细胞结构，其中细胞受到很好的保护，免受药物和其他治疗方法的影响，因此对抗真菌治疗具有高度抗性。菌落生物膜是研究参与生物膜结构发育和内部组织以及真菌驯化的分子机制和调控的理想系统。我们在这里鉴定了转录调节因子 Cyc8p 和 Tup1p 之间的拮抗功能相互作用，这些相互作用调节了天然 S. cerevisiae 菌株在生物膜和驯化模式之间的生活方式。在这里，构建了具有不同 Cyc8p 和 Tup1p 调节剂水平的菌株，分析了参与菌落生物膜发育的过程，并用于鉴定关键黏附素 Flo11p 的调节模式，该蛋白在生物膜形成中起关键作用。我们的数据表明，Tup1p 和 Cyc8p 以相反的方式调节生物膜形成，是菌落复杂性、细胞-细胞相互作用和表面黏附的正、负调节剂。值得注意的是，对 Flo11p 黏附素表达的调控进行深入分析表明，Cyc8p 本身是 FLO11 表达的关键阻遏物，而 Tup1p 拮抗 Cyc8p 的抑制功能，此外，还通过细胞外蛋白酶拮抗 Flo11p 的降解。有趣的是，Tup1p 和 Cyc8p 的拮抗作用涉及到对酵母多细胞生物膜模式至关重要的过程，而其他多细胞过程，如细胞絮凝，两者都共同抑制。这项研究提供了对调节在半固体表面上生长的酵母生物膜生活方式复杂性的机制的深入了解。
