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.
Full-textDOI: · Available from: John Fuerst, Jul 27, 2015
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- "Prokaryotes made many a start. There are examples of bacteria or archaea with nucleus-like structures (Lindsay et al. 2001), recombination (Smith et al. 1993), linear chromosomes (Bentley et al. 2002), internal membranes (Pinevich 1997), multiple replicons (Robinson and Bell 2007), giant size (Schulz and Jorgensen 2001), extreme polyploidy (Mendell et al. 2008), a dynamic cytoskeleton (Vats and Rothfield 2009), predation (Davidov and Jurkevitch 2009), parasitism (Moran 2007), introns and exons (Simon and Zimmerly 2008), intercellular signaling (Waters and Bassler 2005), endocytosis-like processes (Lonhienne et al. 2010), and even endosymbionts (Wujek 1979; von Dohlen et al. 2001). Yet, for each of these traits, bacteria and archaea stopped well short of the baroque complexity of eukaryotes. "
ABSTRACT: All morphologically complex life on Earth, beyond the level of cyanobacteria, is eukaryotic. All eukaryotes share a common ancestor that was already a complex cell. Despite their biochemical virtuosity, prokaryotes show little tendency to evolve eukaryotic traits or large genomes. Here I argue that prokaryotes are constrained by their membrane bioenergetics, for fundamental reasons relating to the origin of life. Eukaryotes arose in a rare endosymbiosis between two prokaryotes, which broke the energetic constraints on prokaryotes and gave rise to mitochondria. Loss of almost all mitochondrial genes produced an extreme genomic asymmetry, in which tiny mitochondrial genomes support, energetically, a massive nuclear genome, giving eukaryotes three to five orders of magnitude more energy per gene than prokaryotes. The requirement for endosymbiosis radically altered selection on eukaryotes, potentially explaining the evolution of unique traits, including the nucleus, sex, two sexes, speciation, and aging.Cold Spring Harbor perspectives in biology 05/2014; 6(5). DOI:10.1101/cshperspect.a015982 · 8.23 Impact Factor
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- "In the last decade, special importance has been given to this group in the field of evolutionary biology because of the unusual presence of characteristics that are usually features mainly found in eukaryotic cells (Devos and Reynaud 2010; Fuerst and Sagulenko 2012). These include the presence of membrane-bounded cell compartments (Lindsay et al. 1997, 2001), the absence of the common bacterial tubulin like protein FtsZ (Pilhofer et al. 2008; Bernander and Ettema 2010), that is also absent in eukaryotes and the archaeal group Crenachaeota (Vaughan et al. 2004), the ability to perform endocytosis (Lonhienne et al. 2010), that was never found in Bacteria or Archaea and the presence of genes homologous to membrane coat protein genes (Santarella-Mellwig et al. 2010) that are essential in the eukaryotic endocytosis. Other unusual features in this group are the budding reproduction of many of their members, the presence of crateriform structures on the cell surface, whose function is still unknown and the presence of a proteinaceous cell wall that lacks the characteristic bacterial peptidoglycan with consequent ability to resist to b-lactam antibiotics. "
ABSTRACT: Knowledge of the interesting phylum of Planctomycetes has increased in the last decades both due to cultural and molecular methods. Although a restricted number of species have been described to date, this group presents a much larger diversity that has been mainly revealed by molecular ecology studies. Isolation experiments allowed us to get a number of new Planctomycetes taxa that extend the already described ones. In this work we present the ultrastructural morphological characterization of these new taxa as well as we give new details of Aquisphaera giovannonii ultrastructure. Furthermore, our interpretation on Planctomycetes cell envelope is provided.Antonie van Leeuwenhoek 07/2013; 104(4). DOI:10.1007/s10482-013-9969-2 · 2.14 Impact Factor
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- "(a) Green fluorescent protein with Arabidopsis roots (Paungfoo-Lonhienne et al. 2008) (the copyright notice), (b) fluorescent-labelled DNA with Arabidopsis roots (Paungfoo- Lonhienne et al. 2010a) (www.plantphysiol.org, Copyright American Society of Plant Biologists, accessed 9 January 2013) and (c) yeast cells expressing GFP in roots of tomato (Paungfoo-Lonhienne et al. 2010b) (the copyright notice). (d) EGFP-tagged Pseudomonas putida PICP2 colonised olive root hairs (Mercado-Blanco and Prieto 2012) (reprinted from Plant and Soil, Vol. "
ABSTRACT: Plants typically have photosynthetically competent green shoots. To complement resources derived from the atmospheric environment, plants also acquire essential elements from soil. Inorganic ions and molecules are generally considered to be the sources of soil-derived nutrients, and plants tested in this respect can grow with only inorganic nutrients and so can live as autotrophs. However, mycorrhizal symbionts are known to access nutrients from organic matter. Furthermore, specialist lineages of terrestrial photosynthetically competent plants are mixotrophic, including species that obtain organic nutrition from animal prey (carnivores), fungal partners (mycoheterotrophs) or plant hosts (hemi-parasites). Although mixotrophy is deemed the exception in terrestrial plants, it is a common mode of nutrition in aquatic algae. There is mounting evidence that non-specialist plants acquire organic compounds as sources of nutrients, taking up and metabolising a range of organic monomers, oligomers, polymers and even microbes as sources of nitrogen and phosphorus. Plasma-membrane located transporter proteins facilitate the uptake of low-molecular mass organic compounds, endo- and phagocytosis may enable the acquisition of larger compounds, although this has not been confirmed. Identifying the mechanisms involved in the acquisition of organic nutrients will provide understanding of the ecological significance of mixotrophy. Here, we discuss mixotrophy in the context of nitrogen and phosphorus nutrition drawing parallels between algae and plants.Functional Plant Biology 01/2013; 40(5):-. DOI:10.1071/FP13061 · 2.57 Impact Factor