title: Endocytosis-like protein uptake in the bacterium Gemmata obscuriglobus.
abstract: Endocytosis is a process by which extracellular material such as macromolecules can be incorporated into cells via a membrane-trafficking system. Although universal among eukaryotes, endocytosis has not been identified in Bacteria or Archaea. However, intracellular membranes are known to compartmentalize cells of bacteria in the phylum Planctomycetes, suggesting the potential for endocytosis and membrane trafficking in members of this phylum. Here we show that cells of the planctomycete Gemmata obscuriglobus have the ability to uptake proteins present in the external milieu in an energy-dependent process analogous to eukaryotic endocytosis, and that internalized proteins are associated with vesicle membranes. Occurrence of such ability in a bacterium is consistent with autogenous evolution of endocytosis and the endomembrane system in an ancestral noneukaryote cell.
authors.affiliation: School of Chemistry and Molecular Biosciences, Australian Research Council Centre of Excellence for Integrative Legume Research, University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Thierry G A
authors.initials: TG
authors.lastname: Lonhienne
authors.forename: Evgeny
authors.initials: E
authors.lastname: Sagulenko
authors.forename: Richard I
authors.initials: RI
authors.lastname: Webb
authors.forename: Kuo-Chang
authors.initials: KC
authors.lastname: Lee
authors.forename: Josef
authors.initials: J
authors.lastname: Franke
authors.forename: Damien P
authors.initials: DP
authors.lastname: Devos
authors.forename: Amanda
authors.initials: A
authors.lastname: Nouwens
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Carroll
authors.forename: John A
authors.initials: JA
authors.lastname: Fuerst
mesh_terms: D001419:Bacteria / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000378:metabolism*; D005075:Biological Evolution; D002451:Cell Compartmentation; D004269:DNA, Bacterial / Q000378:metabolism; D004705:Endocytosis; D004734:Energy Metabolism; D049452:Green Fluorescent Proteins; D011499:Protein Processing, Post-Translational; D022161:Transport Vesicles / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D049452:Green Fluorescent Proteins