Characterization of Yeast Extracellular Vesicles: Evidence for the Participation of Different Pathways of Cellular Traffic in Vesicle Biogenesis
Open Access
- 13 June 2010
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 5 (6), e11113
- https://doi.org/10.1371/journal.pone.0011113
Abstract
Background: Extracellular vesicles in yeast cells are involved in the molecular traffic across the cell wall. In yeast pathogens, these vesicles have been implicated in the transport of proteins, lipids, polysaccharide and pigments to the extracellular space. Cellular pathways required for the biogenesis of yeast extracellular vesicles are largely unknown. Methodology/Principal Findings: We characterized extracellular vesicle production in wild type (WT) and mutant strains of the model yeast Saccharomyces cerevisiae using transmission electron microscopy in combination with light scattering analysis, lipid extraction and proteomics. WT cells and mutants with defective expression of Sec4p, a secretory vesicle-associated Rab GTPase essential for Golgi-derived exocytosis, or Snf7p, which is involved in multivesicular body (MVB) formation, were analyzed in parallel. Bilayered vesicles with diameters at the 100-300 nm range were found in extracellular fractions from yeast cultures. Proteomic analysis of vesicular fractions from the cells aforementioned and additional mutants with defects in conventional secretion pathways (sec1-1, fusion of Golgi-derived exocytic vesicles with the plasma membrane; bos1-1, vesicle targeting to the Golgi complex) or MVB functionality (vps23, late endosomal trafficking) revealed a complex and interrelated protein collection. Semi-quantitative analysis of protein abundance revealed that mutations in both MVB- and Golgi-derived pathways affected the composition of yeast extracellular vesicles, but none abrogated vesicle production. Lipid analysis revealed that mutants with defects in Golgi-related components of the secretory pathway had slower vesicle release kinetics, as inferred from intracellular accumulation of sterols and reduced detection of these lipids in vesicle fractions in comparison with WT cells. Conclusions/Significance: Our results suggest that both conventional and unconventional pathways of secretion are required for biogenesis of extracellular vesicles, which demonstrate the complexity of this process in the biology of yeast cells.Keywords
This publication has 73 references indexed in Scilit:
- Unconventional secretion of Acb1 is mediated by autophagosomesThe Journal of cell biology, 2010
- Cryptococcus neoformans cryoultramicrotomy and vesicle fractionation reveals an intimate association between membrane lipids and glucuronoxylomannanFungal Genetics and Biology, 2009
- An atlas of chaperone–protein interactions in Saccharomyces cerevisiae : implications to protein folding pathways in the cellMolecular Systems Biology, 2009
- GPIomics: global analysis of glycosylphosphatidylinositol‐anchored molecules of Trypanosoma cruziMolecular Systems Biology, 2009
- Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cellsNature, 2007
- A Eukaryotic Capsular Polysaccharide Is Synthesized Intracellularly and Secreted via ExocytosisMolecular Biology of the Cell, 2006
- Rtn1p Is Involved in Structuring the Cortical Endoplasmic ReticulumMolecular Biology of the Cell, 2006
- Global landscape of protein complexes in the yeast Saccharomyces cerevisiaeNature, 2006
- Exploration of the Function and Organization of the Yeast Early Secretory Pathway through an Epistatic Miniarray ProfileCell, 2005
- An approach to correlate tandem mass spectral data of peptides with amino acid sequences in a protein databaseJournal of the American Society for Mass Spectrometry, 1994