组蛋白乙酰转移酶(HAT)介导的表观遗传修饰对于真核生物的多种细胞过程至关重要。然而,人类病原体烟曲霉中HAT的功能仍然知之甚少。在这项研究中,我们表征了MOZ的功能,Ybf2/Sas3,Sas2和Tip60(MYST)家族组蛋白乙酰转移酶与烟曲霉沉默(Sas3)有关。表型分析显示,Sas3的丢失导致菌落生长显著受损,分生孢子,以及梅洛内拉模型中的毒力。亚细胞定位和Western印迹分析表明,Sas3定位于细胞核,能够在体内乙酰化组蛋白H3的赖氨酸9和14。重要的是,我们发现,Sas3对于烟曲霉的细胞壁完整性(CWI)途径至关重要,这可以通过对细胞壁干扰剂的超敏反应来证明,改变细胞壁厚度,和CWI蛋白激酶MpkA的异常磷酸化水平。此外,定点诱变研究表明,保守的甘氨酸残基G641和G643以及谷氨酸残基E664对Sas3的乙酰化活性至关重要。出乎意料的是,只有Sas3的三重突变(G641A/G643A/E664A)显示出与Δsas3突变体相似的缺陷表型,而双突变或单突变则没有。该结果暗示Sas3的作用可能超出组蛋白乙酰化。总的来说,我们的发现表明,MYST家族HATSas3在真菌发育中起重要作用,毒力,以及烟曲霉的细胞壁完整性。
目的:由HAT控制的表观遗传修饰对于真核生物的各种细胞过程是必不可少的。尽管如此,人类病原体烟曲霉中HAT的确切功能仍然难以捉摸。在这项研究中,我们揭示了MYST家族HATSas3在菌落生长中的作用,分生孢子,毒力,和烟曲霉细胞壁应激反应。特别是,我们的研究结果表明,Sas3可以通过与组蛋白乙酰化无关的机制发挥作用,如定点诱变实验所证明的。总的来说,这项研究拓宽了我们对真菌病原体中HATs调控机制的理解。
Histone acetyltransferase (HAT)-mediated epigenetic modification is essential for diverse cellular processes in eukaryotes. However, the functions of HATs in the human pathogen Aspergillus fumigatus remain poorly understood. In this study, we characterized the functions of MOZ, Ybf2/Sas3, Sas2, and Tip60 (MYST)-family histone acetyltransferase something about silencing (Sas3) in A. fumigatus. Phenotypic analysis revealed that loss of Sas3 results in significant impairments in colony growth, conidiation, and virulence in the Galleria mellonella model. Subcellular localization and Western blot analysis demonstrated that Sas3 localizes to nuclei and is capable of acetylating lysine 9 and 14 of histone H3 in vivo. Importantly, we found that Sas3 is critical for the cell wall integrity (CWI) pathway in A. fumigatus as evidenced by hypersensitivity to cell wall-perturbing agents, altered cell wall thickness, and abnormal phosphorylation levels of CWI protein kinase MpkA. Furthermore, site-directed mutagenesis studies revealed that the conserved glycine residues G641 and G643 and glutamate residue E664 are crucial for the acetylation activity of Sas3. Unexpectedly, only triple mutations of Sas3 (G641A/G643A/E664A) displayed defective phenotypes similar to the Δsas3 mutant, while double or single mutations did not. This result implies that the role of Sas3 may extend beyond histone acetylation. Collectively, our findings demonstrate that MYST-family HAT Sas3 plays an important role in the fungal development, virulence, and cell wall integrity in A. fumigatus.
OBJECTIVE: Epigenetic modification governed by HATs is indispensable for various cellular processes in eukaryotes. Nonetheless, the precise functions of HATs in the human pathogen Aspergillus fumigatus remain elusive. In this study, we unveil the roles of MYST-family HAT Sas3 in colony growth, conidiation, virulence, and cell wall stress response in A. fumigatus. Particularly, our findings demonstrate that Sas3 can function through mechanisms unrelated to histone acetylation, as evidenced by site-directed mutagenesis experiments. Overall, this study broadens our understanding of the regulatory mechanism of HATs in fungal pathogens.