Peres da Silva Roberta, Martins Sharon de Toledo, Rizzo Juliana, Dos Reis Flavia C G, Joffe Luna S, Vainstein Marilene, Kmetzsch Livia, Oliveira Débora L, Puccia Rosana, Goldenberg Samuel, Rodrigues Marcio L, Alves Lysangela R
Departamento de Microbiologia, Imunologia e Parasitologia da Escola Paulista de Medicina-UNIFESP, São Paulo, SP 04023-062, Brazil.
School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
Genes (Basel). 2018 Aug 8;9(8):400. doi: 10.3390/genes9080400.
Golgi reassembly and stacking protein (GRASP) is required for polysaccharide secretion and virulence in . In fungal species, extracellular vesicles (EVs) participate in the export of polysaccharides, proteins and RNA. In the present work, we investigated if EV-mediated RNA export is functionally connected with GRASP in using a Δ mutant. Since GRASP-mediated unconventional secretion involves autophagosome formation in yeast, we included the Δ mutant with defective autophagic mechanisms in our analysis. All fungal strains exported EVs but deletion of or profoundly affected vesicular dimensions. The mRNA content of the Δ EVs differed substantially from that of the other two strains. The transcripts associated to the endoplasmic reticulum were highly abundant transcripts in Δ EVs. Among non-coding RNAs (ncRNAs), tRNA fragments were the most abundant in both mutant EVs but Δ EVs alone concentrated 22 exclusive sequences. In general, our results showed that the EV RNA content from Δ and WT were more related than the RNA content of Δ, suggesting that GRASP, but not the autophagy regulator Atg7, is involved in the EV export of RNA. This is a previously unknown function for a key regulator of unconventional secretion in eukaryotic cells.
高尔基体重新组装和堆叠蛋白（GRASP）对于[具体物种]中的多糖分泌和毒力是必需的。在真菌物种中，细胞外囊泡（EVs）参与多糖、蛋白质和RNA的输出。在本研究中，我们使用Δ突变体研究了EV介导的RNA输出在[具体物种]中是否与GRASP在功能上相关联。由于GRASP介导的非常规分泌在酵母中涉及自噬体形成，我们在分析中纳入了自噬机制有缺陷的Δ突变体。所有真菌菌株都能输出EVs，但缺失[具体基因]或[具体基因]会严重影响囊泡大小。Δ EVs的mRNA含量与其他两个菌株的有很大差异。与内质网相关的转录本是Δ EVs中高度丰富的转录本。在非编码RNA（ncRNAs）中，tRNA片段在两种突变体EVs中都是最丰富的，但仅Δ EVs富集了22个独特序列。总体而言，我们的结果表明，来自Δ和野生型（WT）的EV RNA含量比Δ的RNA含量更相关，这表明GRASP而非自噬调节因子Atg7参与了RNA的EV输出。这是真核细胞中非常规分泌关键调节因子的一个此前未知的功能。
