Golgi Reassembly and Stacking Protein (GRASP) Participates in Vesicle-Mediated RNA Export in Cryptococcus Neoformans.

ABSTRACT: Golgi reassembly and stacking protein (GRASP) is required for polysaccharide secretion and virulence in Cryptococcus neoformans. 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 C. neoformans using a grasp? mutant. Since GRASP-mediated unconventional secretion involves autophagosome formation in yeast, we included the atg7? mutant with defective autophagic mechanisms in our analysis. All fungal strains exported EVs but deletion of GRASP or ATG7 profoundly affected vesicular dimensions. The mRNA content of the grasp? EVs differed substantially from that of the other two strains. The transcripts associated to the endoplasmic reticulum were highly abundant transcripts in grasp? EVs. Among non-coding RNAs (ncRNAs), tRNA fragments were the most abundant in both mutant EVs but grasp? EVs alone concentrated 22 exclusive sequences. In general, our results showed that the EV RNA content from atg7? and WT were more related than the RNA content of grasp?, 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.

SUBMITTER: Peres da Silva R 

PROVIDER: S-EPMC6115741 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature