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Yutin N, Wolf MY, Wolf YI, Koonin EV. The origins of phagocytosis and eukaryogenesis. Biol Direct 2009; 4:9. [PMID: 19245710 PMCID: PMC2651865 DOI: 10.1186/1745-6150-4-9] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 02/26/2009] [Indexed: 11/10/2022] Open
Abstract
Background Phagocytosis, that is, engulfment of large particles by eukaryotic cells, is found in diverse organisms and is often thought to be central to the very origin of the eukaryotic cell, in particular, for the acquisition of bacterial endosymbionts including the ancestor of the mitochondrion. Results Comparisons of the sets of proteins implicated in phagocytosis in different eukaryotes reveal extreme diversity, with very few highly conserved components that typically do not possess readily identifiable prokaryotic homologs. Nevertheless, phylogenetic analysis of those proteins for which such homologs do exist yields clues to the possible origin of phagocytosis. The central finding is that a subset of archaea encode actins that are not only monophyletic with eukaryotic actins but also share unique structural features with actin-related proteins (Arp) 2 and 3. All phagocytic processes are strictly dependent on remodeling of the actin cytoskeleton and the formation of branched filaments for which Arp2/3 are responsible. The presence of common structural features in Arp2/3 and the archaeal actins suggests that the common ancestors of the archaeal and eukaryotic actins were capable of forming branched filaments, like modern Arp2/3. The Rho family GTPases that are ubiquitous regulators of phagocytosis in eukaryotes appear to be of bacterial origin, so assuming that the host of the mitochondrial endosymbiont was an archaeon, the genes for these GTPases come via horizontal gene transfer from the endosymbiont or in an earlier event. Conclusion The present findings suggest a hypothetical scenario of eukaryogenesis under which the archaeal ancestor of eukaryotes had no cell wall (like modern Thermoplasma) but had an actin-based cytoskeleton including branched actin filaments that allowed this organism to produce actin-supported membrane protrusions. These protrusions would facilitate accidental, occasional engulfment of bacteria, one of which eventually became the mitochondrion. The acquisition of the endosymbiont triggered eukaryogenesis, in particular, the emergence of the endomembrane system that eventually led to the evolution of modern-type phagocytosis, independently in several eukaryotic lineages. Reviewers This article was reviewed by Simonetta Gribaldo, Gaspar Jekely, and Pierre Pontarotti. For the full reviews, please go to the Reviewers' Reports section.
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Affiliation(s)
- Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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Mao YS, Yamaga M, Zhu X, Wei Y, Sun HQ, Wang J, Yun M, Wang Y, Di Paolo G, Bennett M, Mellman I, Abrams CS, De Camilli P, Lu CY, Yin HL. Essential and unique roles of PIP5K-gamma and -alpha in Fcgamma receptor-mediated phagocytosis. ACTA ACUST UNITED AC 2009; 184:281-96. [PMID: 19153220 PMCID: PMC2654300 DOI: 10.1083/jcb.200806121] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The actin cytoskeleton is dynamically remodeled during Fcγ receptor (FcγR)-mediated phagocytosis in a phosphatidylinositol (4,5)-bisphosphate (PIP2)-dependent manner. We investigated the role of type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K) γ and α isoforms, which synthesize PIP2, during phagocytosis. PIP5K-γ−/− bone marrow–derived macrophages (BMM) have a highly polymerized actin cytoskeleton and are defective in attachment to IgG-opsonized particles and FcγR clustering. Delivery of exogenous PIP2 rescued these defects. PIP5K-γ knockout BMM also have more RhoA and less Rac1 activation, and pharmacological manipulations establish that they contribute to the abnormal phenotype. Likewise, depletion of PIP5K-γ by RNA interference inhibits particle attachment. In contrast, PIP5K-α knockout or silencing has no effect on attachment but inhibits ingestion by decreasing Wiskott-Aldrich syndrome protein activation, and hence actin polymerization, in the nascent phagocytic cup. In addition, PIP5K-γ but not PIP5K-α is transiently activated by spleen tyrosine kinase–mediated phosphorylation. We propose that PIP5K-γ acts upstream of Rac/Rho and that the differential regulation of PIP5K-γ and -α allows them to work in tandem to modulate the actin cytoskeleton during the attachment and ingestion phases of phagocytosis.
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Affiliation(s)
- Yuntao S Mao
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Malyukova I, Murray KF, Zhu C, Boedeker E, Kane A, Patterson K, Peterson JR, Donowitz M, Kovbasnjuk O. Macropinocytosis in Shiga toxin 1 uptake by human intestinal epithelial cells and transcellular transcytosis. Am J Physiol Gastrointest Liver Physiol 2009; 296:G78-92. [PMID: 18974311 PMCID: PMC2636932 DOI: 10.1152/ajpgi.90347.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Shiga toxin 1 and 2 production is a cardinal virulence trait of enterohemorrhagic Escherichia coli infection that causes a spectrum of intestinal and systemic pathology. However, intestinal sites of enterohemorrhagic E. coli colonization during the human infection and how the Shiga toxins are taken up and cross the globotriaosylceramide (Gb3) receptor-negative intestinal epithelial cells remain largely uncharacterized. We used samples of human intestinal tissue from patients with E. coli O157:H7 infection to detect the intestinal sites of bacterial colonization and characterize the distribution of Shiga toxins. We further used a model of largely Gb3-negative T84 intestinal epithelial monolayers treated with B-subunit of Shiga toxin 1 to determine the mechanisms of non-receptor-mediated toxin uptake. We now report that E. coli O157:H7 were found at the apical surface of epithelial cells only in the ileocecal valve area and that both toxins were present in large amounts inside surface and crypt epithelial cells in all tested intestinal samples. Our in vitro data suggest that macropinocytosis mediated through Src activation significantly increases toxin endocytosis by intestinal epithelial cells and also stimulates toxin transcellular transcytosis. We conclude that Shiga toxin is taken up by human intestinal epithelial cells during E. coli O157:H7 infection regardless of the presence of bacterial colonies. Macropinocytosis might be responsible for toxin uptake by Gb3-free intestinal epithelial cells and transcytosis. These observations provide new insights into the understanding of Shiga toxin contribution to enterohemorrhagic E. coli-related intestinal and systemic diseases.
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Affiliation(s)
- Irina Malyukova
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Karen F. Murray
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Chengru Zhu
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Edgar Boedeker
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Anne Kane
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Kathleen Patterson
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Jeffrey R. Peterson
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Olga Kovbasnjuk
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
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