Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Korea.
Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.
Mol Plant Pathol. 2019 Nov;20(11):1491-1505. doi: 10.1111/mpp.12856. Epub 2019 Jul 30.
Histone acetylation has been established as a principal epigenetic regulatory mechanism in eukaryotes. Sas3, a histone acetyltransferase belonging to the largest family of acetyltransferase, MYST, is the catalytic subunit of a conserved histone acetyltransferase complex. To date, the functions of Sas3 and its orthologues have been extensively studied in yeast, humans and flies in relation to global acetylation and transcriptional regulation. However, its precise impact on development and pathogenicity in fungal plant pathogens has yet to be elucidated. Considering the importance of Sas3 in H3K14 acetylation, here we investigate the roles of its orthologue in the rice blast fungus, Magnaporthe oryzae (Pyricularia oryzae). Unlike a previously reported Sas3 deletion in yeast, which led to no remarkable phenotypic changes, we found that MoSAS3 deletion alone had a profound effect on fungal growth and development, including asexual reproduction, germination and appressorium formation in M. oryzae. Such defects in pre-penetration development resulted in complete loss of pathogenicity in the deletion mutant. Furthermore, genetic analysis of MoSAS3 and MoGCN5 encoding a Gcn5-related N-acetyltransferase family histone acetyltransferase suggested that two conserved components of histone acetylation are integrated differently into epigenetic regulatory mechanisms in the yeast and a filamentous fungus. RNA-seq analysis of ΔMosas3 showed two general trends: many DNA repair and DNA damage response genes are up-regulated, while carbon and nitrogen metabolism genes are down-regulated in ΔMosas3. Our work demonstrates the importance of MYST family histone acetyltransferase as a developmental regulator and illuminates a degree of functional variation in conserved catalytic subunits among different fungal species.
组蛋白乙酰化已被确立为真核生物中主要的表观遗传调控机制。Sas3 是一种组蛋白乙酰转移酶，属于最大的乙酰转移酶家族 MYST，是保守的组蛋白乙酰转移酶复合物的催化亚基。迄今为止，Sas3 及其同源物在酵母、人类和果蝇中的功能已被广泛研究，涉及全局乙酰化和转录调控。然而，其在真菌植物病原体中的发育和致病性的确切影响尚未阐明。考虑到 Sas3 在 H3K14 乙酰化中的重要性，我们在这里研究了其在稻瘟病菌（Magnaporthe oryzae）中的同源物的作用。与酵母中先前报道的 Sas3 缺失没有明显表型变化的情况不同，我们发现 MoSAS3 缺失单独对真菌的生长和发育有深远的影响，包括无性繁殖、萌发和稻瘟病菌分生孢子的附着胞形成。这些在穿透前发育中的缺陷导致缺失突变体完全丧失致病性。此外，对编码与 Gcn5 相关的 N-乙酰转移酶家族组蛋白乙酰转移酶的 MoSAS3 和 MoGCN5 的遗传分析表明，组蛋白乙酰化的两个保守成分以不同的方式整合到酵母和丝状真菌中的表观遗传调控机制中。ΔMosas3 的 RNA-seq 分析显示出两种总体趋势：许多 DNA 修复和 DNA 损伤反应基因上调，而碳和氮代谢基因下调。我们的工作证明了 MYST 家族组蛋白乙酰转移酶作为发育调节剂的重要性，并阐明了不同真菌物种中保守催化亚基的功能变化程度。
