Fungal S-adenosylmethionine synthetase and the control of development and secondary metabolism in Aspergillus nidulans
Fungal S-adenosylmethionine synthetase and the control of development and secondary metabolism in Aspergillus nidulans
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DOI：
10.1016/j.fgb.2012.04.003
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发表时间：
2012-06-01
影响因子：
3
通讯作者：
Braus, Gerhard H.
中科院分区：
文献类型：
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作者：
Gerke, Jennifer;Bayram, Oezguer;Braus, Gerhard H.
丝状真菌Nidulans只携带一个S-腺苷甲硫氨酸(SAM)合成酶基因，而许多其他生物则具有多个SAM合成酶。保守的酶催化蛋氨酸和三磷酸腺苷与普遍存在的甲基供体SAM的反应。SAM是甲基转移酶的主要甲基供体，用于修饰DNA、RNA、蛋白质、代谢物或磷脂靶标底物。我们在这里证明了编码单链霉菌SAM合成酶基因saA是必需的。过度表达SAA，编码一种主要是细胞质的蛋白质，导致发育受损，包括只有小的不育的子实体，子实体被异常着色的辅助外壳细胞包围。壳细胞是唯一不含大量SASA的真菌细胞类型。当Sasa过表达时，杂色曲霉毒素的产生会发生变化，这表明发育和次生代谢的协调存在缺陷。SASA与多种代谢蛋白相互作用，包括蛋氨酸或线粒体代谢酶，以及参与真菌形态发生的蛋白。SAA与组蛋白-2B的相互作用可能反映了表观遗传学与基因表达的关系。我们的数据表明SASA在协调真菌次生代谢和发育方面发挥着独特的作用。(C)2012 Elsevier Inc.保留所有权利。
The filamentous fungus Aspergillus nidulans carries a single gene for the S-adenosylmethionine (SAM) synthetase SasA, whereas many other organisms possess multiple SAM synthetases. The conserved enzyme catalyzes the reaction of methionine and ATP to the ubiquitous methyl group donor SAM. SAM is the main methyl group donor for methyltransferases to modify DNA, RNA, protein, metabolites, or phospholipid target substrates. We show here that the single A. nidulans SAM synthetase encoding gene sasA is essential. Overexpression of sasA, encoding a predominantly cytoplasmic protein, led to impaired development including only small sterile fruiting bodies which are surrounded by unusually pigmented auxiliary Hulle cells. Hulle cells are the only fungal cell type which does not contain significant amounts of SasA. Sterigmatocystin production is altered when sasA is overexpressed, suggesting defects in coordination of development and secondary metabolism. SasA interacts with various metabolic proteins including methionine or mitochondrial metabolic enzymes as well as proteins involved in fungal morphogenesis. SasA interaction to histone-2B might reflect a putative epigenetic link to gene expression. Our data suggest a distinct role of SasA in coordinating fungal secondary metabolism and development. (C) 2012 Elsevier Inc. All rights reserved.