title: Bacterial Vesicle Secretion and the Evolutionary Origin of the Eukaryotic Endomembrane System.
abstract: Eukaryotes possess an elaborate endomembrane system with endoplasmic reticulum, nucleus, Golgi, lysosomes, peroxisomes, autophagosomes, and dynamic vesicle traffic. Theories addressing the evolutionary origin of eukaryotic endomembranes have overlooked the outer membrane vesicles (OMVs) that bacteria, archaea, and mitochondria secrete into their surroundings. We propose that the eukaryotic endomembrane system originated from bacterial OMVs released by the mitochondrial ancestor within the cytosol of its archaeal host at eukaryote origin. Confined within the host's cytosol, OMVs accumulated naturally, fusing either with each other or with the host's plasma membrane. This matched the host's archaeal secretory pathway for cotranslational protein insertion with outward bound mitochondrial-derived vesicles consisting of bacterial lipids, forging a primordial, secretory endoplasmic reticulum as the cornerstone of the eukaryotic endomembrane system. VIDEO ABSTRACT.
authors.affiliation: Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany. Electronic address: gould@hhu.de.
authors.forename: Sven B
authors.initials: SB
authors.lastname: Gould
authors.affiliation: Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany.
authors.forename: Sriram G
authors.initials: SG
authors.lastname: Garg
authors.affiliation: Institute for Molecular Evolution, University of Düsseldorf, 40225 Düsseldorf, Germany. Electronic address: bill@hhu.de.
authors.forename: William F
authors.initials: WF
authors.lastname: Martin
mesh_terms: D001105:Archaea / Q000502:physiology; D001419:Bacteria; D005075:Biological Evolution; D004721:Endoplasmic Reticulum / Q000502:physiology*; D056890:Eukaryota / Q000502:physiology*; D005057:Eukaryotic Cells / Q000166:cytology; D006056:Golgi Apparatus / Q000502:physiology*; D008928:Mitochondria / Q000502:physiology; D051336:Mitochondrial Membranes / Q000502:physiology*; D057146:Multivesicular Bodies / Q000502:physiology*; D009685:Nuclear Envelope / Q000502:physiology
keywords: bacterial vesicle secretion; endomembrane system; endoplasmic reticulum; endosymbiosis; eukaryote origin; nucleus