The molecular and genetic basis of conidial pigmentation in Aspergillus niger
The molecular and genetic basis of conidial pigmentation in Aspergillus niger
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DOI：
10.1016/j.fgb.2011.01.005
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发表时间：
2011-05-01
影响因子：
3
通讯作者：
Ram, Arthur F. J.
中科院分区：
文献类型：
--
作者：
Jorgensen, Thomas R.;Park, Joohae;Ram, Arthur F. J.
黑曲霉的一个特征是形成黑色分生孢子。我们通过结合基因组和经典互补方法，确定了参与黑曲霉孢子色素沉着的四个基因座。首先，我们鉴定了一种新分离的颜色突变体 colA，它缺乏色素沉着，导致白色或无色分生孢子。 colA 突变体的色素沉着由编码推定的 4'磷酸泛酰基转移酶蛋白 (PptA) 的基因 (An12g03950) 恢复。聚酮合酶 (PKS) 和/或非核糖体肽合酶 (NRPS) 的激活需要 4' 磷酸酯酰基转移酶活性。通过互补来鉴定突变导致黄褐色、橄榄色和棕色表型的基因座。小鹿表型由PKS蛋白（FwnA，An09g05730）补充，ovlA突变体由An14g05350（OlvA）补充，brnA突变体由An14g05370（BrnA）补充，它们分别是烟曲霉中alb1/pksP、ayg1和abr1的同源物。 pptA、fwnA、olvA 和 brnA 基因的靶向破坏证实了互补结果。 pptA基因的破坏消除了所有聚酮化合物和非核糖体肽的合成，而聚酮化合物的萘并-γ-吡喃酮亚类特别依赖于fwnA，而富纳烯酮则依赖于fwnA、olvA和brnA。因此，颜色突变体的次级代谢物分析揭示了黑曲霉中聚酮化合物合成与分生孢子色素沉着之间的密切关系。 (C) 2011 Elsevier Inc. 保留所有权利。
A characteristic hallmark of Aspergillus niger is the formation of black conidiospores. We have identified four loci involved in spore pigmentation of A. niger by using a combined genomic and classical complementation approach. First, we characterized a newly isolated color mutant, colA, which lacked pigmentation resulting in white or colorless conidia. Pigmentation of the colA mutant was restored by a gene (An12g03950) which encodes a putative 4'phosphopantetheinyl transferase protein (PptA). 4'Phosphopantetheinyl transferase activity is required for the activation of Polyketide Synthases (PKSs) and/or Non-Ribosomal Peptide Synthases (NRPSs). The loci whose mutation resulted in fawn, olive, and brown color phenotypes were identified by complementation. The fawn phenotype was complemented by a PKS protein (FwnA, An09g05730), the ovlA mutant by An14g05350 (OlvA) and the brnA mutant by An14g05370 (BrnA), the respective homologs of alb1/pksP, ayg1 and abr1 in A fumigatus. Targeted disruption of the pptA, fwnA, olvA and brnA genes confirmed the complementation results. Disruption of the pptA gene abolished synthesis of all polyketides and non-ribosomal peptides, while the naphtho-gamma-pyrone subclass of polyketides were specifically dependent on fwnA, and funalenone on fwnA, olvA and brnA. Thus, secondary metabolite profiling of the color mutants revealed a close relationship between polyketide synthesis and conidial pigmentation in A. niger. (C) 2011 Elsevier Inc. All rights reserved.