白念珠菌胞质分裂关键蛋白Hof1在Rad53相关DNA损伤应答和毒力调控中的新功能研究

DNA损伤应答对于细胞抵御内源或外源的DNA损伤胁迫至关重要，否则会引发癌变或凋亡等。白念珠菌是一种最重要的人体病原真菌，其致病机理与形态转换等相关，但近期发现其DNA损伤应答与毒力也存在密切联系。前期研究中，我们通过文库筛选发现一个新的DNA损伤应答分子，即胞质分裂蛋白Hof1，其缺失对遗传毒性试剂敏感，引起基因组不稳定性增加，且与检验点激酶Rad53处于同一个DNA损伤应答信号通路，提示了Hof1在DNA损伤应答中的新功能。预实验还发现HOF1缺失显著影响细胞毒力，且与巨噬细胞产生的ROS有关。本课题中，我们拟采用蛋白互作、遗传互作及转录组测序等方法，具体解析Hof1在Rad53相关DNA损伤应答中的作用；并通过白念珠菌-宿主细胞互作和动物实验揭示Hof1及相关DNA损伤应答调控毒力的作用与机制。本课题的研究有望为深入理解白念珠菌DNA损伤应答、胞质分裂及相关致病机制提供新的实验依据。

DNA damage response plays crucial roles in resisting the internal or external DNA damage stress which may lead to mutantion or apoptosis. Candida albicans remains one of the most important human fungal pathogen. Recent studies revealed that DNA damage response is involved in maintaining cell virulence. In our previous research, we screened a collection of conditional gene inactivation strains of C. albicans and found HOF1, a cytokinesis related gene, plays a novel role in DNA damage response. We have identified that deletion of HOF1 renders genotoxic sensitivity and genome instability. Through genetic interaction assay, Hof1 is assigned to the main checkpoint kinase Rad53 circuit, suggesting a novel role in Rad53 related DNA damage response. Besides, Hof1 is also involved in maintaining cell virulence which is probably related with the ROS secreted by macrophages. In this project, we plan to further specify the function of Hof1 in DNA damage response through protein interaction and genetic interaction assays, as well as the target genes of Hof1 in DNA damage response through RNA-seq assays; and to identify the role and regulating mechanism of Hof1 as well as the related DNA damage response genes in virulence regulation. We aim to supply new sights for understanding the DNA damage response pathway and its connection with cytokinesis as well as pathogenic mechanism of C. albicans cells.