Robert K Ernst

Summary

Affiliation: University of Washington
Country: USA

Publications

  1. pmc Unique lipid a modifications in Pseudomonas aeruginosa isolated from the airways of patients with cystic fibrosis
    Robert K Ernst
    Department of Medicine, University of Washington, Seattle, WA 98195, USA
    J Infect Dis 196:1088-92. 2007
  2. pmc The Pseudomonas aeruginosa lipid A deacylase: selection for expression and loss within the cystic fibrosis airway
    Robert K Ernst
    Department of Medicine, University of Washington, HSB T 293, Box 357710, 1959 Pacific Street N E, Seattle, WA 98195, USA
    J Bacteriol 188:191-201. 2006
  3. ncbi request reprint Pseudomonas aeruginosa lipid A diversity and its recognition by Toll-like receptor 4
    Robert K Ernst
    Department of Medicine, HSB K 155, Box 357710, University of Washington, Seattle, WA 98195, USA
    J Endotoxin Res 9:395-400. 2003
  4. pmc Inhibition of Salmonella enterica serovar Typhimurium lipopolysaccharide deacylation by aminoarabinose membrane modification
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Health Sciences Building, K140, Box 357710, 1959 Pacific St N E, Seattle, WA 98195, USA
    J Bacteriol 187:2448-57. 2005
  5. pmc Humanized TLR4/MD-2 mice reveal LPS recognition differentially impacts susceptibility to Yersinia pestis and Salmonella enterica
    Adeline M Hajjar
    Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
    PLoS Pathog 8:e1002963. 2012
  6. ncbi request reprint Deacylation and palmitoylation of lipid A by Salmonellae outer membrane enzymes modulate host signaling through Toll-like receptor 4
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
    J Endotoxin Res 10:439-44. 2004
  7. pmc Human Toll-like receptor 4 responses to P. gingivalis are regulated by lipid A 1- and 4'-phosphatase activities
    Stephen R Coats
    Department of Periodontics, School of Dentistry, University of Washington, 1959 NE Pacific St, Seattle, WA 98195 7444, USA
    Cell Microbiol 11:1587-99. 2009
  8. ncbi request reprint Purification and characterization of deacylated and/or palmitoylated lipid A species unique to Salmonella enterica serovar Typhimurium
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Seattle, Washington, USA
    J Endotoxin Res 11:57-61. 2005
  9. pmc Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients
    David A D'Argenio
    Department of Microbiology, University of Washington, Seattle, WA, USA
    Mol Microbiol 64:512-33. 2007
  10. pmc Structural heterogeneity and environmentally regulated remodeling of Francisella tularensis subspecies novicida lipid A characterized by tandem mass spectrometry
    Scott A Shaffer
    Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, USA
    J Am Soc Mass Spectrom 18:1080-92. 2007

Collaborators

Detail Information

Publications40

  1. pmc Unique lipid a modifications in Pseudomonas aeruginosa isolated from the airways of patients with cystic fibrosis
    Robert K Ernst
    Department of Medicine, University of Washington, Seattle, WA 98195, USA
    J Infect Dis 196:1088-92. 2007
    ..None of the isolates from the environment or from patients with other conditions displayed these modifications. These results indicate that unique lipid A modifications occur in clinical P. aeruginosa CF isolates...
  2. pmc The Pseudomonas aeruginosa lipid A deacylase: selection for expression and loss within the cystic fibrosis airway
    Robert K Ernst
    Department of Medicine, University of Washington, HSB T 293, Box 357710, 1959 Pacific Street N E, Seattle, WA 98195, USA
    J Bacteriol 188:191-201. 2006
    ..Finally, deacylated lipid A species were not observed in some clinical P. aeruginosa isolates from patients with severe pulmonary disease, suggesting that loss of PagL function can occur during long-term adaptation to the CF airway...
  3. ncbi request reprint Pseudomonas aeruginosa lipid A diversity and its recognition by Toll-like receptor 4
    Robert K Ernst
    Department of Medicine, HSB K 155, Box 357710, University of Washington, Seattle, WA 98195, USA
    J Endotoxin Res 9:395-400. 2003
    ..P. aeruginosa adaptation to the human airway may, therefore, play a fundamental role in the progressive lung damage associated with cystic fibrosis...
  4. pmc Inhibition of Salmonella enterica serovar Typhimurium lipopolysaccharide deacylation by aminoarabinose membrane modification
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Health Sciences Building, K140, Box 357710, 1959 Pacific St N E, Seattle, WA 98195, USA
    J Bacteriol 187:2448-57. 2005
    ..Taken together, these results suggest that PagL enzymatic deacylation is posttranslationally inhibited by membrane environments, which either sequester PagL from its substrate or alter its conformation...
  5. pmc Humanized TLR4/MD-2 mice reveal LPS recognition differentially impacts susceptibility to Yersinia pestis and Salmonella enterica
    Adeline M Hajjar
    Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
    PLoS Pathog 8:e1002963. 2012
    ..Thus, Y. pestis exploits temperature-dependent shifts in LPS acylation to selectively evade recognition by human TLR4/MD-2 uncovered with "humanized" TLR4/MD-2 transgenic mice...
  6. ncbi request reprint Deacylation and palmitoylation of lipid A by Salmonellae outer membrane enzymes modulate host signaling through Toll-like receptor 4
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
    J Endotoxin Res 10:439-44. 2004
    ..Compared with unmodified lipid A, the modified lipid A species are 10-100-fold less active. These results suggest that PagL and PagP modify lipid A to reduce TLR4-signaling as part of Salmonellae adaptation to the host environment...
  7. pmc Human Toll-like receptor 4 responses to P. gingivalis are regulated by lipid A 1- and 4'-phosphatase activities
    Stephen R Coats
    Department of Periodontics, School of Dentistry, University of Washington, 1959 NE Pacific St, Seattle, WA 98195 7444, USA
    Cell Microbiol 11:1587-99. 2009
    ..gingivalis lipid A activity from TLR4 evasive to TLR4 suppressive, potentially altering critical interactions between this bacterium, the local microbial community and the host innate immune system...
  8. ncbi request reprint Purification and characterization of deacylated and/or palmitoylated lipid A species unique to Salmonella enterica serovar Typhimurium
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Seattle, Washington, USA
    J Endotoxin Res 11:57-61. 2005
    ..The modified lipid A species showed reduced ability to induce cellular signaling through Toll-like receptor 4, suggesting a specific function of the lipid A modifications in the pathogenesis of salmonellae infection...
  9. pmc Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients
    David A D'Argenio
    Department of Microbiology, University of Washington, Seattle, WA, USA
    Mol Microbiol 64:512-33. 2007
    ..Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression...
  10. pmc Structural heterogeneity and environmentally regulated remodeling of Francisella tularensis subspecies novicida lipid A characterized by tandem mass spectrometry
    Scott A Shaffer
    Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, USA
    J Am Soc Mass Spectrom 18:1080-92. 2007
    ....
  11. pmc A Francisella mutant in lipid A carbohydrate modification elicits protective immunity
    Duangjit Kanistanon
    Department of Medicine, University of Washington, Seattle, Washington, United States of America
    PLoS Pathog 4:e24. 2008
    ....
  12. doi request reprint Comprehensive structure characterization of lipid A extracted from Yersinia pestis for determination of its phosphorylation configuration
    Jace W Jones
    Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
    J Am Soc Mass Spectrom 21:785-99. 2010
    ..The prevalent aminoarabinose modification was determined to be exclusively attached to the lipid A disaccharide via a phospho-diester linkage at either or both the C-1 and C-4' positions...
  13. pmc Activation of Toll-like receptors by Burkholderia pseudomallei
    T Eoin West
    Department of Medicine, University of Washington, Seattle, Washington, USA
    BMC Immunol 9:46. 2008
    ..We examined TLR signaling induced by B. pseudomallei, B. pseudomallei LPS, and B. pseudomallei lipid A using gain-of-function transfection assays of NF-kappaB activation and studies of TLR-deficient macrophages...
  14. ncbi request reprint Human Toll-like receptor 4 recognizes host-specific LPS modifications
    Adeline M Hajjar
    Department of Immunology, University of Washington, Seattle, WA 98195, USA
    Nat Immunol 3:354-9. 2002
    ..Thus, in contrast to mice, humans use TLR4 to recognize a molecular signature of bacterial-host adaptation to modulate the innate immune response...
  15. doi request reprint Automated lipid A structure assignment from hierarchical tandem mass spectrometry data
    Ying S Ting
    Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195 7610, USA
    J Am Soc Mass Spectrom 22:856-66. 2011
    ..Additionally, HiTMS correctly assigned 85% of the structures in a smaller library of lipid A species from Yersinia pestis demonstrating that it may be used across species...
  16. ncbi request reprint 3-O-deacylation of lipid A by PagL, a PhoP/PhoQ-regulated deacylase of Salmonella typhimurium, modulates signaling through Toll-like receptor 4
    Kiyoshi Kawasaki
    Department of Microbiology, University of Washington, Seattle, WA 98195, USA
    J Biol Chem 279:20044-8. 2004
    ..These results suggest that the lipid A modifications reduce TLR4-signaling as part of Salmonellae adaptation to host environments...
  17. pmc PmrAB, a two-component regulatory system of Pseudomonas aeruginosa that modulates resistance to cationic antimicrobial peptides and addition of aminoarabinose to lipid A
    Samuel M Moskowitz
    Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington 98195, USA
    J Bacteriol 186:575-9. 2004
    ..Thus, P. aeruginosa possesses a mechanism that induces resistance to cationic antimicrobial peptides in response to environmental conditions...
  18. ncbi request reprint LPS, TLR4 and infectious disease diversity
    Samuel I Miller
    Department of Medicine, University of Washington Medical School, Seattle, Washington 98195, USA
    Nat Rev Microbiol 3:36-46. 2005
    ..This review will examine the hypothesis that the variability of bacterial ligands such as LPS and their innate immune receptors is an important factor in determining the outcome of infectious disease...
  19. pmc Lack of in vitro and in vivo recognition of Francisella tularensis subspecies lipopolysaccharide by Toll-like receptors
    Adeline M Hajjar
    Department of Medicine, University of Washington, Health Sciences Building, Box 357710, 1959 NE Pacific Street, Seattle, WA 98195, USA
    Infect Immun 74:6730-8. 2006
    ..These results suggest that poor innate recognition of F. tularensis allows the bacterium to evade early recognition by the host innate immune system to promote its pathogenesis for mammals...
  20. pmc Acyl chain specificity of the acyltransferases LpxA and LpxD and substrate availability contribute to lipid A fatty acid heterogeneity in Porphyromonas gingivalis
    Brian W Bainbridge
    Department of Periodontics and Oral Biology and Medicine, University of Washington, D 652 Health Sciences Building, 1959 NE Pacific St, Seattle, Washington 98195 7444, USA
    J Bacteriol 190:4549-58. 2008
    ..gingivalis lipid A acyltransferases and the substrate availability account for the lipid A structural clusters that differ by 14 mass units observed in P. gingivalis lipopolysaccharide preparations...
  21. pmc Determination of pyrophosphorylated forms of lipid A in Gram-negative bacteria using a multivaried mass spectrometric approach
    Jace W Jones
    Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA 981915 1700, USA
    Proc Natl Acad Sci U S A 105:12742-7. 2008
    ..This indicated that pyrophosphate groups are present in diphosphorylated lipid A from a variety of Gram-negative bacteria...
  22. pmc The structurally similar, penta-acylated lipopolysaccharides of Porphyromonas gingivalis and Bacteroides elicit strikingly different innate immune responses
    Alex B Berezow
    Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
    Microb Pathog 47:68-77. 2009
    ..Further, we show the difference in potency between Bacteroides and P. gingivalis LPS is TLR4-dependent. Altogether, the data suggest subtle changes in lipid A structure may profoundly impact the host's innate immune response...
  23. ncbi request reprint Proteomic analysis of Pseudomonas aeruginosa grown under magnesium limitation
    Tina Guina
    Department of Pediatrics, Division of Infectious Diseases, University of Washington, Seattle, Washington 98195, USA
    J Am Soc Mass Spectrom 14:742-51. 2003
    ..aeruginosa outer membrane proteins. This study shows that large-scale quantitative proteomic technology can be successfully applied to the analysis of whole bacteria and to the discovery of functionally relevant biologic phenotypes...
  24. ncbi request reprint Respiratory epithelial cells regulate lung inflammation in response to inhaled endotoxin
    Shawn J Skerrett
    Department of Medicine, University of Washington School of Medicine, Seattle, 98104, USA
    Am J Physiol Lung Cell Mol Physiol 287:L143-52. 2004
    ..These data provide causal evidence that distal airway epithelial cells and the signals they transduce play a physiological role in lung inflammation in vivo...
  25. pmc Comparison of Francisella tularensis genomes reveals evolutionary events associated with the emergence of human pathogenic strains
    Laurence Rohmer
    Department of Genome Sciences, University of Washington, Campus Box 357710, 1705 NE Pacific Street Seattle, Washington 98195, USA
    Genome Biol 8:R102. 2007
    ....
  26. ncbi request reprint Genome mosaicism is conserved but not unique in Pseudomonas aeruginosa isolates from the airways of young children with cystic fibrosis
    Robert K Ernst
    Department of Microbiology, University of Washington, Health Sciences Building, K 140, Box 357710, Seattle, WA 98195, USA
    Environ Microbiol 5:1341-9. 2003
    ..Further characterization of P. aeruginosa diversity within the airways of individual CF patients may reveal common adaptations, perhaps mediated by gene loss, that suggest new opportunities for therapy...
  27. pmc A sensitive liquid chromatography/mass spectrometry-based assay for quantitation of amino-containing moieties in lipid A
    Thomas F Kalhorn
    Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
    Rapid Commun Mass Spectrom 23:433-42. 2009
    ..The described assay produces excellent repeatability and reproducibility for the detection of amino-containing moieties in lipid A from a variety of bacterial sources...
  28. doi request reprint Surface acoustic wave nebulization facilitating lipid mass spectrometric analysis
    Sung Hwan Yoon
    Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195 7610, USA
    Anal Chem 84:6530-7. 2012
    ..The ease of generating SAWN-MS(n) data combined with HiTMS interpretation offers the potential for high throughput lipid A structure analysis...
  29. pmc Pseudomonas aeruginosa activates caspase 1 through Ipaf
    Edward A Miao
    Institute for Systems Biology, Seattle, WA 98103, USA
    Proc Natl Acad Sci U S A 105:2562-7. 2008
    ..Thus, Ipaf-dependent detection of cytosolic flagellin is a conserved mechanism by which macrophages detect the presence of pathogens that use T3SS...
  30. pmc mig-14 is a Salmonella gene that plays a role in bacterial resistance to antimicrobial peptides
    Igor E Brodsky
    Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
    J Bacteriol 184:3203-13. 2002
    ..Therefore, mig-14 contributes to Salmonella resistance to antimicrobial peptides by a mechanism that is not yet fully understood...
  31. pmc Immunostimulatory properties of the emerging pathogen Stenotrophomonas maltophilia
    Valerie J Waters
    College of Physicians and Surgeons, Columbia University, 650 W 168th Street, BB 4 416, New York, NY 10032, USA
    Infect Immun 75:1698-703. 2007
    ..Despite the lack of invasiveness of S. maltophilia, the immunostimulatory properties of this organism and its induction of TNF-alpha expression specifically indicate that it is likely to contribute significantly to airway inflammation...
  32. ncbi request reprint Variation in lipid A structure in the pathogenic yersiniae
    Roberto Rebeil
    Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 S 4th St, Hamilton, MT 59840, USA
    Mol Microbiol 52:1363-73. 2004
    ....
  33. pmc Identification of an orphan response regulator required for the virulence of Francisella spp. and transcription of pathogenicity island genes
    Nrusingh P Mohapatra
    Center for Microbial Interface Biology, Department of Molecular Biology, Immunology and Medical Genetics, The Ohio State University, 460 W 12th Avenue, Columbus, OH 43210 1214, USA
    Infect Immun 75:3305-14. 2007
    ..Thus, the orphan response regulator PmrA is an important factor in controlling virulence in F. novicida, and a pmrA mutant strain is an effective vaccine against homologous challenge...
  34. pmc pmrA(Con) confers pmrHFIJKL-dependent EGTA and polymyxin resistance on msbB Salmonella by decorating lipid A with phosphoethanolamine
    Sean R Murray
    Department of Biology, Yale University, New Haven, Connecticut, USA
    J Bacteriol 189:5161-9. 2007
    ....
  35. pmc Mouse paneth cell secretory responses to cell surface glycolipids of virulent and attenuated pathogenic bacteria
    Hiroki Tanabe
    Department of Pathology, School of Medicine, College of Health Sciences, University of California, Irvine, CA 92697 4800, USA
    Infect Immun 73:2312-20. 2005
    ..Thus, mouse Paneth cells respond equivalently to purified bacterial cell envelope glycolipids, regardless of functional Tlr4, the structural properties of glycolipid acyl chains, or their association with virulence in humans...
  36. pmc Characterization of late acyltransferase genes of Yersinia pestis and their role in temperature-dependent lipid A variation
    Roberto Rebeil
    Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 S 4th St, Hamilton, Montana 59840, USA
    J Bacteriol 188:1381-8. 2006
    ..This mutant was able to infect and block fleas as well as the parental wild-type strain, indicating that the low-temperature-dependent change to hexa-acylated lipid A synthesis is not required for survival in the flea gut...
  37. pmc Differentiation and distribution of colistin- and sodium dodecyl sulfate-tolerant cells in Pseudomonas aeruginosa biofilms
    Janus A J Haagensen
    Center for Biomedical Microbiology, BioCentrum DTU, Building 301, The Technical University of Denmark, DK 2800 Lyngby, Denmark
    J Bacteriol 189:28-37. 2007
    ..These results suggest that increased antibiotic tolerance in biofilms may be a consequence of differentiation into distinct subpopulations with different phenotypic properties...
  38. pmc The structure and function of Francisella lipopolysaccharide
    John S Gunn
    The Center for Microbial Interface Biology, The Ohio State University, Biomedical Research Tower, Rm 1006, 460 W 12th Ave, Columbus, OH 43210 1214, USA
    Ann N Y Acad Sci 1105:202-18. 2007
    ..tularensis pathogenesis, and the inability of the LPS to alarm the immune system coupled with its frequent modification/alteration likely aid the success of this pathogen during human infection...
  39. ncbi request reprint Factors affecting the escape of Francisella tularensis from the phagolysosome
    Helena Lindgren
    Department of Clinical Microbiology, Clinical Bacteriology, Umea University, Umea, Sweden
    J Med Microbiol 53:953-8. 2004
    ..An even more profound effect on this escape is related to expression of IglC by F. tularensis. Its absence rendered the mutant bacteria incapable of escaping from the phagosome and of multiplying intracellularly...
  40. ncbi request reprint Exopolysaccharides from Burkholderia cenocepacia inhibit neutrophil chemotaxis and scavenge reactive oxygen species
    Johan Bylund
    Department of Pediatrics, University of British Columbia, Child and Family Research Institute, Vancouver, British Columbia V5Z 4H4, Canada
    J Biol Chem 281:2526-32. 2006
    ..These properties could explain why the two bacterial species resist clearance from the infected cystic fibrosis lung...