State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, China.
College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.
Toxicon. 2020 Aug;183:61-68. doi: 10.1016/j.toxicon.2020.05.015. Epub 2020 May 29.
Amanita fuligineoides, a lethal mushroom discovered in China, contains abundant cyclic peptide toxins that can cause fatal poisoning. However, the MSDIN gene family encoding for these cyclic peptides in A. fuligineoides has not been systematically studied. In this research, the transcriptome sequencing of A. fuligineoides was performed and its MSDIN family members were analyzed. A total of 4.41 Gb data containing 30833 unigenes was obtained; sequence alignments throughout several databases were done to obtain their functional annotations. Based on these annotations, MSDIN genes were found and verified by RT-PCR. A total of 29 different core peptides were obtained: 3 toxin genes, encoding β-amanitin (β-AMA), phalloidin (PHD), and phallacidin (PCD), and 26 genes encoding unknown cyclic peptides, 20 of which are reported for the first time and may encode for novel cyclic peptides. Analysis of the predicted precursor peptides indicated that octocyclic peptides were the main MSDIN peptides synthesized by A. fuligineoides, accounting for the 45%. A phylogenetic analysis suggested that studied precursor peptides could be clustered into 7 clades, which might represent different functionalities. Results suggested that A. fuligineoides might have a strong capacity to synthesize cyclopeptides, laying the foundation for their excavation and utilization.
中国发现的致命毒蘑菇灰花纹鹅膏含有丰富的环状肽毒素，可导致致命中毒。然而，灰花纹鹅膏中编码这些环状肽的 MSDIN 基因家族尚未得到系统研究。本研究对灰花纹鹅膏进行了转录组测序，并对其 MSDIN 家族成员进行了分析。共获得 44.1G 数据，包含 30833 个 unigenes；通过与多个数据库的序列比对，获得了它们的功能注释。基于这些注释，通过 RT-PCR 找到了并验证了 MSDIN 基因。共获得 29 种不同的核心肽：3 个毒素基因，编码β-鹅膏蕈碱（β-AMA）、鹅膏蕈氨酸（PHD）和鹅膏蕈氨酸（PCD），以及 26 个编码未知环状肽的基因，其中 20 个是首次报道的，可能编码新的环状肽。对预测的前体肽进行分析表明，八环肽是灰花纹鹅膏主要合成的 MSDIN 肽，占 45%。系统发育分析表明，研究的前体肽可以聚类为 7 个分支，可能代表不同的功能。结果表明，灰花纹鹅膏可能具有很强的合成环肽能力，为其挖掘和利用奠定了基础。
