NDT80-like family genes are highly conserved across a large group of fungi, but the functions of each Ndt80 protein are diverse and have evolved differently among yeasts and pathogens. The unique NDT80 gene in budding yeast is required for sexual reproduction, whereas three NDT80-like genes, namely, NDT80, REP1, and RON1, found in Candida albicans exhibit distinct functions. Notably, it was suggested that REP1, rather than RON1, is required for N-acetylglucosamine (GlcNAc) catabolism. Although Candida tropicalis, a widely dispersed fungal pathogen in tropical and subtropical areas, is closely related to Candida albicans, its phenotypic, pathogenic and environmental adaptation characteristics are remarkably divergent. In this study, we focused on the Ron1 transcription factor in C. tropicalis. Protein alignment showed that C. tropicalis Ron1 (CtRon1) shares 39.7% identity with C. albicans Ron1 (CaRon1). Compared to the wild-type strain, the C. tropicalis ron1Δ strains exhibited normal growth in different carbon sources and had similar expression levels of several GlcNAc catabolic genes during GlcNAc treatment. In contrast, C. tropicalis REP1 is responsible for GlcNAc catabolism and is involved in GlcNAc catabolic gene expressions, similar to C. albicans Rep1. However, REP1 deletion strains in C. tropicalis promote hyphal development in GlcNAc with low glucose content. Interestingly, CtRON1, but not CaRON1, deletion mutants exhibited significantly impaired hyphal growth and biofilm formation. As expected, CtRON1 was required for full virulence. Together, the results of this study showed divergent functions of CtRon1 compared to CaRon1; CtRon1 plays a key role in yeast-hyphal dimorphism, biofilm formation and virulence.

中文翻译：

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热带念珠菌 RON1 是菌丝形成、生物膜发育和毒力所必需的，但对于 N-乙酰氨基葡萄糖分解代谢则不是必需的

NDT80样家族基因在一大群真菌中高度保守，但每种 Ndt80 蛋白的功能各不相同，并且在酵母和病原体之间进化不同。有性繁殖需要芽殖酵母中独特的NDT80基因，而在白色念珠菌中发现的三个NDT80样基因，即NDT80、REP1和RON1，表现出不同的功能。值得注意的是，有人提出N-乙酰葡糖胺 (GlcNAc) 分解代谢需要REP1而不是RON1。虽然热带念珠菌白色念珠菌是一种广泛分布于热带和亚热带地区的真菌病原体，与白色念珠菌密切相关，其表型、致病性和环境适应特征明显不同。在这项研究中，我们专注于热带念珠菌中的 Ron1 转录因子。蛋白质比对显示热带念珠菌Ron1 (CtRon1)与白色念珠菌Ron1 (CaRon1)具有 39.7% 的同一性。与野生型菌株相比，热带念珠菌 ron1Δ菌株在不同碳源中表现出正常生长，并且在 GlcNAc 处理期间具有相似的几种 GlcNAc 分解代谢基因的表达水平。相比之下，热带假丝酵母 REP1负责 GlcNAc 分解代谢并参与 GlcNAc 分解代谢基因表达，类似于白色念珠菌Rep1。然而，热带念珠菌中的 REP1缺失菌株促进了葡萄糖含量低的 GlcNAc 中的菌丝发育。有趣的是，Ct RON1而非Ca RON1缺失突变体表现出显着受损的菌丝生长和生物膜形成。正如预期的那样，完全毒力需要Ct RON1。总之，这项研究的结果表明，与 CaRon1 相比，CtRon1 具有不同的功能；CtRon1 在酵母菌丝二态性、生物膜形成和毒力中起关键作用。