John Michael Koomey

• Hadjineophytou, Chris; Loh, Edmund; Koomey, Michael & Scott, Nichollas E. (2024). Combining FAIMS based glycoproteomics and DIA proteomics reveals widespread proteome alterations in response to glycosylation occupancy changes in Neisseria gonorrhoeae. Proteomics. ISSN 1615-9853. doi: 10.1002/pmic.202300496.
• Corwin, Linn Merete B.; Ingebretsen, André; Campbell, Patricia; Alfsnes, Kristian; Müller, Fredrik & Mauder, Norman [Vis alle 8 forfattere av denne artikkelen] (2023). Fourier transform infrared spectroscopy; can it be used as a rapid typing method of Neisseria gonorrhoeae? Journal of Microbiological Methods. ISSN 0167-7012. 205, s. 1–9. doi: 10.1016/j.mimet.2023.106675. Fulltekst i vitenarkiv
• Hadjineophytou, Chris; Anonsen, Jan Haug; Svingerud, Tina; Mortimer, Tatum D.; Grad, Yonatan H. & Nichollas, Sscott E. [Vis alle 7 forfattere av denne artikkelen] (2022). Sculpting the Bacterial O-Glycoproteome: Functional Analyses of Orthologous Oligosaccharyltransferases with Diverse Targeting Specificities. mBio. ISSN 2161-2129. 13(3). doi: 10.1128/mbio.03797-21. Fulltekst i vitenarkiv Vis sammendrag

  Protein glycosylation systems are widely recognized in bacteria, including members of the genus Neisseria. In most bacterial species, the molecular mechanisms and evolutionary contexts underpinning target protein selection and the glycan repertoire remain poorly understood. Broad-spectrum O-linked protein glycosylation occurs in all human-associated species groups within the genus Neisseria, but knowledge of their individual glycoprotein repertoires is limited. Interestingly, PilE, the pilin subunit of the type IV pilus (Tfp) colonization factor, is glycosylated in Neisseria gonorrhoeae and Neisseria meningitidis but not in the deeply branching species N. elongata subsp. glycolytica. To examine this in more detail, we assessed PilE glycosylation status across the genus and found that PilEs of commensal clade species are not modified by the gonococcal PglO oligosaccharyltransferase. Experiments using PglO oligosaccharyltransferases from across the genus expressed in N. gonorrhoeae showed that although all were capable of broad-spectrum protein glycosylation, those from a deep-branching group of commensals were unable to support resident PilE glycosylation. Further glycoproteomic analyses of these strains using immunoblotting and mass spectrometry revealed other proteins differentially targeted by otherwise remarkably similar oligosaccharyltransferases. Finally, we generated pglO allelic chimeras that begin to localize PglO protein domains associated with unique substrate targeting activities. These findings reveal previously unappreciated differences within the protein glycosylation systems of highly related bacterial species. We propose that the natural diversity manifest in the neisserial protein substrates and oligosaccharyltransferases has significant potential to inform the structure-function relationships operating in these and related bacterial protein glycosylation systems.

• Coggan, Kimberly A.; Higgs, Matthew G.; Brutinel, Evan D.; Marden, Jeremiah N.; Intile, Peter J. & Winther-Larsen, Hanne Cecilie [Vis alle 9 forfattere av denne artikkelen] (2022). Global Regulatory Pathways Converge To Control Expression of Pseudomonas aeruginosa Type IV Pili. mBio. ISSN 2161-2129. 13(1). doi: 10.1128/MBIO.03696-21.
• Wang, Nelson; Anonsen, Jan Haug; Hadjineophytou, Chris; Reinar, William Brynildsen; Børud, Bente & Vik, Åshild [Vis alle 7 forfattere av denne artikkelen] (2020). Allelic polymorphisms in a glycosyltransferase gene shape glycan repertoire in the O-linked protein glycosylation system of Neisseria. Glycobiology. ISSN 0959-6658. doi: 10.1093/glycob/cwaa073. Fulltekst i vitenarkiv
• Vorkapic, Dina; Mitterer, Fabian; Pressler, Katharina; Leitner, Deborah R.; Anonsen, Jan Haug & Liesinger, Laura [Vis alle 16 forfattere av denne artikkelen] (2019). A Broad Spectrum Protein Glycosylation System Influences Type II Protein Secretion and Associated Phenotypes in Vibrio cholerae. Frontiers in Microbiology. ISSN 1664-302X. 10, s. 1–19. doi: 10.3389/fmicb.2019.02780. Fulltekst i vitenarkiv
• Hadjineophytou, Chris; Anonsen, Jan Haug; Wang, Nelson; Ma, Kevin; Viburiene, Raimonda & Vik, Åshild [Vis alle 10 forfattere av denne artikkelen] (2019). Genetic determinants of genus-level glycan diversity in a bacterial protein glycosylation system. PLoS Genetics. ISSN 1553-7390. 15(12), s. 1–24. doi: 10.1371/journal.pgen.1008532. Fulltekst i vitenarkiv Vis sammendrag

  The human pathogens N. gonorrhoeae and N. meningitidis display robust intra- and interstrain glycan diversity associated with their O-linked protein glycosylation (pgl) systems. In an effort to better understand the evolution and function of protein glycosylation operating there, we aimed to determine if other human-restricted, Neisseria species similarly glycosylate proteins and if so, to assess the levels of glycoform diversity. Comparative genomics revealed the conservation of a subset of genes minimally required for O-linked protein glycosylation glycan and established those pgl genes as core genome constituents of the genus. In conjunction with mass spectrometric–based glycan phenotyping, we found that extant glycoform repertoires in N. gonorrhoeae, N. meningitidis and the closely related species N. polysaccharea and N. lactamica reflect the functional replacement of a progenitor glycan biosynthetic pathway. This replacement involved loss of pgl gene components of the primordial pathway coincident with the acquisition of two exogenous glycosyltransferase genes. Critical to this discovery was the identification of a ubiquitous but previously unrecognized glycosyltransferase gene (pglP) that has uniquely undergone parallel but independent pseudogenization in N. gonorrhoeae and N. meningitidis. We suggest that the pseudogenization events are driven by processes of compositional epistasis leading to gene decay. Additionally, we documented instances where inter-species recombination influences pgl gene status and creates discordant genetic interactions due ostensibly to the multi-locus nature of pgl gene networks. In summary, these findings provide a novel perspective on the evolution of protein glycosylation systems and identify phylogenetically informative, genetic differences associated with Neisseria species.

• Zollner, Robert; Cronenberg, Tom; Kouzel, Nadzeya; Welker, Anton; Koomey, Michael & Maier, Berenike (2019). Type IV Pilin Post-Translational Modifications Modulate Material Properties of Bacterial Colonies. Biophysical Journal. ISSN 0006-3495. 116(5), s. 938–947. doi: 10.1016/j.bpj.2019.01.020.
• Berry, Jamie-Lee; Gurung, Ishwori; Anonsen, Jan Haug; Spielman, Ingrid; Harper, Elliot & Hall, Alexander M. J. [Vis alle 12 forfattere av denne artikkelen] (2019). Global biochemical and structural analysis of the type IV pilus from the Gram-positive bacterium Streptococcus sanguinis. Journal of Biological Chemistry. ISSN 0021-9258. 294(17), s. 6796–6808. doi: 10.1074/jbc.RA118.006917. Fulltekst i vitenarkiv
• Koomey, Michael (2019). O-linked protein glycosylation in bacteria: snapshots and current perspectives. Current Opinion in Structural Biology. ISSN 0959-440X. 56, s. 198–203. doi: 10.1016/j.sbi.2019.03.020.
• Wang, Nelson; Anonsen, Jan Haug; Viburiene, Raimonda; Lam, Joseph S; Vik, Åshild & Koomey, Michael (2019). Disrupted synthesis of a di-N-acetylated sugar perturbs mature glycoform structure and microheterogeneity in the O-linked protein glycosylation system of Neisseria elongata subsp. glycolytica. Journal of Bacteriology. ISSN 0021-9193. 201(1). doi: 10.1128/JB.00522-18.
• Eichler, Jerry & Koomey, Michael (2017). Sweet New Roles for Protein Glycosylation in Prokaryotes. Trends in Microbiology. ISSN 0966-842X. 25(8), s. 662–672. doi: 10.1016/j.tim.2017.03.001.
• Anonsen, Jan Haug; Børud, Bente; Vik, Åshild; Viburiene, Raimonda & Koomey, Michael (2017). Structural and genetic analyses of glycan O-acetylation in a bacterial protein glycosylation system: evidence for differential effects on glycan chain length. Glycobiology. ISSN 0959-6658. 27(9), s. 888–899. doi: 10.1093/glycob/cwx032. Fulltekst i vitenarkiv
• Anonsen, Jan Haug; Vik, Åshild; Børud, Bente; Viburiene, Raimonda; Aas, Finn Erik & Kidd, Shani Wilhelmina Aarek [Vis alle 8 forfattere av denne artikkelen] (2016). Characterization of a unique tetrasaccharide and distinct glycoproteome in the O-linked protein glycosylation system of Neisseria elongata subsp. glycolytica. Journal of Bacteriology. ISSN 0021-9193. 198(2), s. 256–267. doi: 10.1128/JB.00620-15.
• Aas, Finn Erik; Li, Xi; Edwards, James; Solbakken, Monica Hongrø; Deeudom, Manu & Vik, Åshild [Vis alle 9 forfattere av denne artikkelen] (2015). Cytochrome c-based domain modularity governs genus-level diversification of electron transfer to dissimilatory nitrite reduction. Environmental Microbiology. ISSN 1462-2912. 17(6), s. 2114–2132. doi: 10.1111/1462-2920.12661.
• Børud, Bente; Anonsen, Jan Haug; Viburiene, Raimonda; Cohen, Ellen Hanne; Samuelsen, Anne Berit C. & Koomey, Michael (2014). Extended glycan diversity in a bacterial protein glycosylation system linked to allelic polymorphisms and minimal genetic alterations in a glycosyltransferase gene. Molecular Microbiology. ISSN 0950-382X. Volume 94(3), s. 688–699. doi: 10.1111/mmi.12789. Vis sammendrag

  Glycans manifest in conjunction with the broad spectrum O-linked protein glycosylation in species within the genus Neisseria display intra- and interstrain diversity. Variability in glycan structure and antigenicity are attributable to differences in the content and expression status of glycan synthesis genes. Given the high degree of standing allelic polymorphisms in these genes, the level of glycan diversity may exceed that currently defined. Here, we identify unique protein-associated disaccharide glycoforms that carry N-acetylglucosamine (GlcNAc) at their non-reducing end. This altered structure was correlated with allelic variants of pglH whose product was previously demonstrated to be responsible for the expression of glucose (Glc)-containing disaccharides. Allele comparisons and site-specific mutagenesis showed that the presence of a single residue, alanine at position 303 in place of a glutamine, was sufficient for GlcNAc versus Glc incorporation. Phylogenetic analyses revealed that GlcNAc-containing disaccharides may be widely distributed within the pgl systems of Neisseria particularly in strains of N. meningitidis. Although analogous minimal structural alterations in glycosyltransferases have been documented in association with lipopolysaccharide and capsular polysaccharide variability, this appears to be the first example in which such changes have been implicated in glycan diversification within a bacterial protein glycosylation system.

• Gangel, Heike; Hepp, Christof; Müller, Stephanie; Oldewurtel, Enno R.; Aas, Finn Erik & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2014). Concerted Spatio-Temporal Dynamics of Imported DNA and ComE DNA Uptake Protein during Gonococcal Transformation. PLoS Pathogens. ISSN 1553-7366. 10(4). doi: 10.1371/journal.ppat.1004043. Fulltekst i vitenarkiv
• Vik, Åshild; Anonsen, Jan Haug; Aas, Finn Erik; Hegge, Finn Terje; Roos, Norbert & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2014). Type IV pilus assembly proficiency and dynamics influence pilin subunit phospho-form macro- and microheterogeneity in Neisseria gonorrhoeae. PLOS ONE. ISSN 1932-6203. 9(5). doi: 10.1371/journal.pone.0096419. Fulltekst i vitenarkiv
• Viburiene, Raimonda; Vik, Åshild; Børud, Bente & Koomey, Michael (2013). Allelic Variation in a Simple Sequence Repeat Element of Neisserial pglB2 and Its Consequences for Protein Expression and Protein Glycosylation. Journal of Bacteriology. ISSN 0021-9193. 195(15), s. 3476–3485. doi: 10.1128/JB.00276-13.
• Gebhart, Carol; Lelmini, Maria Veronica; Reiz, Bela; Price, Nancy L; Aas, Finn Erik & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2012). Characterization of exogenous bacterial oligosaccharyltransferases in Escherichia coli reveals the potential for O-linked protein glycosylation in Vibrio cholerae and Burkholderia thailandensis. Glycobiology. ISSN 0959-6658. 22(7), s. 962–974. doi: 10.1093/glycob/cws059.
• Vik, Åshild; Aspholm, Marina; Anonsen, Jan Haug; Børud, Bente; Roos, Norbert & Koomey, Michael (2012). Insights into type IV pilus biogenesis and dynamics from genetic analysis of a C-terminally tagged pilin: a role for O-linked glycosylation. Molecular Microbiology. ISSN 0950-382X. 85(6), s. 1166–1178. doi: 10.1111/j.1365-2958.2012.08166.x.
• Johannessen, Camilla; Koomey, Michael & Børud, Bente (2012). Hypomorphic glycosyltransferase alleles and recoding at contingency Loci influence glycan microheterogeneity in the protein glycosylation system of Neisseria species. Journal of Bacteriology. ISSN 0021-9193. 194(18), s. 5034–5043. doi: 10.1128/JB.00950-12.
• Anonsen, Jan Haug; Jacobsen, Wolfgang Mathias; Aas, Finn Erik; Børud, Bente; Koomey, Michael & Vik, Åshild (2012). Novel protein substrates of the phospho-form modification system in neisseria gonorrhoeae and their connection to O-linked protein glycosylation. Infection and Immunity. ISSN 0019-9567. 80(1), s. 22–30. doi: 10.1128/IAI.05920-11.
• Anonsen, Jan Haug; Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2012). An Extended Spectrum of Target Proteins and Modification Sites in the General O-Linked Protein Glycosylation System in Neisseria gonorrhoeae. Journal of Proteome Research. ISSN 1535-3893. 11(12), s. 5781–5793. doi: 10.1021/pr300584x.
• Jacobsen, Wolfgang Mathias; Salomonsson, Emelie; Aas, Finn Erik; Forslund, Anna-Lena; Winther-Larsen, Hanne Cecilie & Maier, Josef [Vis alle 14 forfattere av denne artikkelen] (2011). O-Linked Glycosylation of the PilA Pilin Protein of Francisella tularensis: Identification of the Endogenous Protein-Targeting Oligosaccharyltransferase and Characterization of the Native Oligosaccharide. Journal of Bacteriology. ISSN 0021-9193. 193(19), s. 5487–5497. doi: 10.1128/JB.00383-11.
• Tønjum, Tone & Koomey, Michael (2011). Kiss and run - phosphoglycerol modifications of N. meningitidis pili mediate detachment. Frontiers in Microbiology. ISSN 1664-302X. 2. doi: 10.3389/fmicb.2011.00082.
• Hartley, Meredith D; Morrison, MJ; Aas, Finn Erik; Børud, Bente; Koomey, Michael & Imperiali, Barbara (2011). Biochemical Characterization of the O-Linked Glycosylation Pathway in Neisseria gonorrhoeae Responsible for Biosynthesis of Protein Glycans Containing N,N '-Diacetylbacillosamine. Biochemistry. ISSN 0006-2960. 50(22), s. 4936–4948. doi: 10.1021/bi2003372.
• Børud, Bente; Viburiene, Raimonda; Hartley, Meredith D; Paulsen, Berit Smestad; Jacobsen, Wolfgang Mathias & Imperiali, Barbara [Vis alle 7 forfattere av denne artikkelen] (2011). Genetic and molecular analyses reveal an evolutionary trajectory for glycan synthesis in a bacterial protein glycosylation system. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 108(23), s. 9643–9648. doi: 10.1073/pnas.1103321108.
• Børud, Bente; Aas, Finn Erik; Vik, Åshild; Winther-Larsen, Hanne Cecilie; Jacobsen, Wolfgang Mathias & Koomey, Michael (2010). Genetic, Structural, and Antigenic Analyses of Glycan Diversity in the O-Linked Protein Glycosylation Systems of Human Neisseria Species. Journal of Bacteriology. ISSN 0021-9193. 192(11), s. 2816–2829. doi: 10.1128/JB.00101-10.
• Aspholm, Marina; Aas, Finn Erik; Harrison, OB; Quinn, D; Vik, Åshild & Viburiene, Raimonda [Vis alle 10 forfattere av denne artikkelen] (2010). Structural Alterations in a Component of Cytochrome c Oxidase and Molecular Evolution of Pathogenic Neisseria in Humans. PLoS Pathogens. ISSN 1553-7366. 6(8). doi: 10.1371/journal.ppat.1001055.
• Heiniger, Ryan W; Winther-Larsen, Hanne Cecilie; Raymond, Pickles; Koomey, Michael & Wolfgang, Matthew (2010). Infection of human mucosal tissue by Pseudomonas aeruginosa requires sequential and mutually dependent virulence factors and a novel pilus-associated adhesin. Cellular Microbiology. ISSN 1462-5814. 12(8), s. 1158–1173. doi: 10.1111/j.1462-5822.2010.01461.x.
• Holz, C; Opitz, Dirk; Greune, Lilo; Kurre, Rainer; Koomey, Michael & Schmidt, M. Alexander [Vis alle 7 forfattere av denne artikkelen] (2010). Multiple Pilus Motors Cooperate for Persistent Bacterial Movement in Two Dimensions. Physical Review Letters. ISSN 0031-9007. 104(17). doi: 10.1103/PhysRevLett.104.178104.
• Koomey, Michael (2009). Type IV Pilus Biogenesis, Structure and Function: Lessons from Type IVa Pilin Systems. I Jarrell, Ken (Red.), Pili and Flagella: Current Research and Future Trends. Caister Academic Press. ISSN 978-1-904455-48-6. s. 19–40.
• Vik, Åshild; Aas, Finn Erik; Anonsen, Jan Haug; Bilsborough, Shaun; Schneider, Andrea & Jacobsen, Wolfgang Mathias [Vis alle 7 forfattere av denne artikkelen] (2009). Broad spectrum O-linked protein glycosylation in the human pathogen Neisseria gonorrhoeae. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 106(11), s. 4447–4452. doi: 10.1073/pnas.0809504106.
• Salomonsson, Emelie; Forsberg, A; Roos, Norbert; Holz, C; Maier, B & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2009). Functional analyses of pilin-like proteins from Francisella tularensis: complementation of type IV pilus phenotypes in Neisseria gonorrhoeae. Microbiology (Reading). ISSN 1350-0872. 155, s. 2546–2559. doi: 10.1099/mic.0.028183-0.
• Clausen, Martin; Koomey, Michael & Maier, Berenike (2009). Dynamics of Type IV Pili Is Controlled by Switching Between Multiple States. Biophysical Journal. ISSN 0006-3495. 96(3), s. 1169–1177. doi: 10.1016/j.bpj.2008.10.017.
• Næssan, Cecilia L; Jacobsen, Wolfgang Mathias; Heiniger, Ryan W; Wolfgang, Matthew; Aas, Finn Erik & Røhr, Åsmund Kjendseth [Vis alle 8 forfattere av denne artikkelen] (2008). Genetic and functional analyses of PptA, a phospho-form transferase targeting type IV pili in Neisseria gonorrhoeae. Journal of Bacteriology. ISSN 0021-9193. 190(1), s. 387–400. doi: 10.1128/JB.00765-07.
• Deeudom, M; Koomey, Michael & Moir, JWB (2008). Roles of c-type cytochromes in respiration in Neisseria meningitidis. Microbiology (Reading). ISSN 1350-0872. 154, s. 2857–2864. doi: 10.1099/mic.0.2008/020339-0.
• Davidsen, Tonje; Koomey, Michael & Tønjum, Tone (2007). Microbial genome dynamics in CNS pathogenesis. Neuroscience. ISSN 0306-4522. 145. doi: 10.1016/j.neuroscience.2007.01.059.
• Aas, Finn Erik; Winther-Larsen, Hanne C; Wolfgang, Matthew; Frye, Stephan; Løvold, Cecilia & Roos, Norbert [Vis alle 8 forfattere av denne artikkelen] (2007). Substitutions in the N-terminal alpha helical spine of Neisseria gonorrhoeae pilin affect type IV pilus assembly, dynamics and associated functions. Molecular Microbiology. ISSN 0950-382X. 63, s. 69–85. doi: 10.1111/j.1365-2958.2006.05482.x.
• Winther-Larsen, Hanne C; Wolfgang, Matthew; van Putten, JPM; Roos, Norbert; Aas, Finn Erik & Jacobsen, Wolfgang Mathias [Vis alle 8 forfattere av denne artikkelen] (2007). Pseudomonas aeruginosa type IV pilus expression in Neisseria gonorrhoeae: Effects of pilin subunit composition on function and organelle dynamics. Journal of Bacteriology. ISSN 0021-9193. 189(18), s. 6676–6685. doi: 10.1128/JB.00407-07.
• Aas, Finn Erik; Vik, Åshild; Vedde, John Øivind; Koomey, Michael & Jacobsen, Wolfgang Mathias (2007). Neisseria gonorrhoeae O-linked pilin glycosylation: functional analyses define both the biosynthetic pathway and glycan structure. Molecular Microbiology. ISSN 0950-382X. 65. doi: 10.1111/j.1365-2958.2007.05806.x.
• Aas, Finn Erik; Jacobsen, Wolfgang Mathias; Winther-Larsen, Hanne C; Løvold, Cecilia; Hitchen, Paul G. & Dell, Ann [Vis alle 7 forfattere av denne artikkelen] (2006). Neisseria gonorrhoeae type IV pili undergo multisite, hierarchical modifications with phosphoethanolamine and phosphocholine requiring an enzyme structurally related to lipopolysaccharide phosphoethanolamine transferases. Journal of Biological Chemistry. ISSN 0021-9258. 281(38), s. 27712–27723.
• Aas, Finn Erik; Winther-Larsen, Hanne C; Wolfgang, Matthew; Frye, Stephan Alfons; Løvold, Cecilia & Roos, Norbert [Vis alle 8 forfattere av denne artikkelen] (2006). Substitutions in the N-terminal alpha helical spine of Neisseria gonorrhoeae pilin affects Type IV pilus assembly, dynamics and associated functions. Molecular Microbiology. ISSN 0950-382X. 63(1), s. 69–85.
• Winther-Larsen, Hanne C; Wolfgang, M; Dunham, S; van Putten, JPM; Dorward, D & Løvold, Cecilia [Vis alle 8 forfattere av denne artikkelen] (2005). A conserved set of pilin-like molecules controls type IV pilus dynamics and organelle-associated functions in Neisseria gonorrhoeae. Molecular Microbiology. ISSN 0950-382X. 56(4), s. 903–917. doi: 10.1111/j.1365-2958.2005.04591.
• Gill, DA; Spitzer, D; Koomey, Michael; Heuser, JE & Atkinson, JP (2005). Release of host-derived membrane vesicles following pilus-mediated adhesion of Neisseria gonorrhoeae. Cellular Microbiology. ISSN 1462-5814. 7, s. 1672–1683.

Se alle arbeider i Cristin

• Hadjineophytou, Chris; Anonsen, Jan Haug & Koomey, Michael (2019). Genus-wide assessment of pilus glycosylation in the genus Neisseria.
• Hadjineophytou, Chris & Koomey, Michael (2018). A genus-wide assessment of neisserial Tfp pilin subunit glycosylation: a systems level approach reveals distribution and governing co-factors.
• Wang, Nelson; Anonsen, Jan Haug; Vik, Åshild & Koomey, Michael (2018). Functional analyses of a glycosyltransferase reveal a genus-wide trajectory for glycan evolution in a bacterial protein glycosylation system.
• Hadjineophytou, Chris; Anonsen, Jan Haug & Koomey, Michael (2018). A genus-wide assessment of neisserial Tfp pilin subunit glycosylation: a systems level approach reveals distribution and governing co-factors.
• Wang, Nelson; Anonsen, Jan Haug; Viburiene, Raimonda; Lam, Joseph S; Vik, Åshild & Koomey, Michael (2016). Identification and analyses of pgl genes required for tetrasaccharide biosynthesis in Neisseria elongata subsp. glycolytica reveals patterns of protein glycosylation evolution at the genus level.
• Koomey, Michael (2015). Glycan diversification in a bacterial protein glycosylation system: a perspective from within the genus Neisseria.
• Viburiene, Raimonda; Børud, Bente; Anonsen, Jan Haug; Vik, Åshild & Koomey, Michael (2014). Status and strategies for vaccine prevention of gonorrhoea.
• Viburiene, Raimonda; Børud, Bente; Vik, Åshild; Anonsen, Jan Haug & Koomey, Michael (2014). Genetic, structural, and phylogenetic studies of the general O-linked protein glycosylation system in Neisseria.
• Viburiene, Raimonda; Børud, Bente; Vik, Åshild; Anonsen, Jan Haug & Koomey, Michael (2014). Genetic, structural, and phylogenetic studies of the general O-linked protein glycosylation system in Neisseria.
• Vik, Åshild; Anonsen, Jan Haug; Aas, Finn Erik; Hegge, Finn Terje; Roos, Norbert & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2014). Type IV pilus assembly proficiency and dynamics influence pilin subunit phospho-form marcro- and microheterogeneity in Neisseria gonorrhoeae.
• Viburiene, Raimonda; Anonsen, Jan Haug; Vik, Åshild; Koomey, Michael & Børud, Bente (2014). Identification and functional characterization of a split ORF variants of the bifunctional PglB and PglB2 glycosylation proteins in Neisseria.
• Eriksson, Jens; Caugant, Dominique A; Koomey, Michael & Tonjum, Tone (2013). Genetically engineered Neisseria lactamica as a vaccine delivery agent. Vis sammendrag

  Objective Carriers of Neisseria lactamica (Nla) develop mucosal and systemic humoral immunity to Nla together with cross-reacting systemic opsonophagocytic, but not bactericidal, antibodies to N. meningitidis (Mc). Modification of Nla to express an optimal profile of Mc antigens, relevant for vaccine purposes, is dependent on efficient in vitro genetic manipulation of Nla strains. A major obstacle to using Nla in antigen delivery is its recalcitrance to genetic manipulation in vitro. Therefore, we investigated both the cause, and means to circumvent, the resistance to genetic manipulation in strains of Nla. Methods Genome sequences of Nla were investigated for unique Restriction-modification systems (RM). A synthetic antibiotic resistance marker, designed to avoid DNA motifs recognized by Nla-specific RM, was constructed. Standard transformation assays were employed to measure transformation efficiencies in a representative library of MLST sequenced Nla strains. Results Resistance to genetic manipulation in Nla is caused by the presence of RM. By disrupting a unique restriction endonuclease gene with the synthetic antibiotic resistance marker, we managed to reduce the gene-flow barrier in Nla and, for the first time, unlock the natural competence of this organism for genetic manipulation. This includes exogenous DNA from other species, such as N. meningitidis. Conclusions Our study indicates that it is indeed possible to engineer N. lactamica to express defined N. meningitidis, as well as any other, vaccine antigens.

• Aas, Finn Erik; Vik, Åshild; Anonsen, Jan Haug; Koomey, Michael & Aspholm, Marina (2013). Characterization of a novel c-type cytochrome in Neisseria; structure function and evolution.
• Anonsen, Jan Haug; Børud, Bente & Koomey, Michael (2013). Mass spectrometry based investigation of post-translational modification systems in Neisseria.
• Anonsen, Jan Haug; Vik, Åshild; Børud, Bente; Aas, Finn Erik; Viburiene, Raimonda & Moen, Anders [Vis alle 7 forfattere av denne artikkelen] (2013). Mass spectrometry based investigation of post-translational modification systems in Neisseria.
• Anonsen, Jan Haug; Børud, Bente & Koomey, Michael (2013). Mass spectrometry based investigation of post-translational modification systems in Neisseria.
• Koomey, Michael (2012). Bacterial protein glycosylation systems and links to membrane transporters.
• Koomey, Michael (2012). Type IV pilus adherence mechanisms: an update.
• Koomey, Michael (2012). Evolution and function of O-linked protein glycosylation in the genus Neisseria.
• Koomey, Michael (2012). Genome Dynamics Governing Glycan Diversification in a Bacterial Model System.
• Anonsen, Jan Haug; Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2012). General protein glycosylation and the connection with protein phosphoform modification in Neisseria gonorrhoeae.
• Aspholm, Marina; Aas, Finn Erik; Vik, Åshild & Koomey, Michael (2012). Characterization of a novel C-type cytochrome in Neisseria; structure, function and evolution.
• Børud, Bente; Viburiene, Raimonda; Johannessen, Camilla & Koomey, Michael (2012). Intrinsic genetic interactions and their role in the evolution ofglycan repertoire and microheterogeneity.
• Anonsen, Jan Haug; Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2012). An extended spectrum of target proteins and modification sites in the general O-linked protein glycosylation system in N. gonorrhoeae.
• Anonsen, Jan Haug; Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2011). Post translational modification of proteins in Neisseria gonorrhoeae.
• Anonsen, Jan Haug; Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2011). Post translational modification of proteins in Neisseria gonorrhoeae.
• Børud, Bente; Viburiene, Raimonda; Hartley, Meredith D; Paulsen, Berit Smestad; Egge-Jacobsen, Wolfgang & Imperiali, Barbara [Vis alle 7 forfattere av denne artikkelen] (2011). Genetic and molecular analyses reveal an evolutionary trajectory for glycan synthesis in a bacterial protein glycosylation system.
• Børud, Bente; Viburiene, Raimonda; Aas, Finn Erik; Vik, Åshild; Hartley, Meredith D & Egge-Jacobsen, Wolfgang [Vis alle 8 forfattere av denne artikkelen] (2011). Neisseria species as a model system for bacterial O-linked protein glycosylation.
• Koomey, Michael; Viburiene, Raimonda; Aas, Finn Erik; Vik, Åshild; Anonsen, Jan Haug & Egge-Jacobsen, Wolfgang [Vis alle 7 forfattere av denne artikkelen] (2011). Bacterial O-linked protein glycosylation: the perspective from within the genus Neisseria.
• Anonsen, Jan Haug; Jacobsen, Wolfgang Mathias; Aas, Finn Erik; Børud, Bente; Koomey, Michael & Vik, Åshild (2011). New targets of the phospho-form modification system in N. gonorrhoeae and a connection to O-linked protein glycosylation.
• Vik, Åshild; Aspholm, Marina & Koomey, Michael (2010). Probing the functions of O-linked protein glycosylation in Neisseria gonorrhoeae.
• Vik, Åshild; Aspholm, Marina & Koomey, Michael (2010). Probing the functions of O‐linked protein glycosylation in Neisseria gonorrhoeae.
• Vik, Åshild; Aspholm, Marina & Koomey, Michael (2010). Probing the functions of O‐linked protein glycosylation in Neisseria gonorrhoeae.
• Vik, Åshild; Jacobsen, Wolfgang Mathias & Koomey, Michael (2009). Gonore, en søt bakterie. [Avis]. Uniforum.
• Anonsen, Jan Haug; Jacobsen, Wolfgang Mathias; Koomey, Michael & Vik, Åshild (2009). Phospho-form modification of bacterial glycoproteins.
• Salomonsson, Emelie; Forsberg, A; Roos, Norbert; Holz, C; Maier, B. & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2009). Heterologous expression of Francisella tularensis type IV pili genes in Neisseria gonorrhoeae confirms that PilA can form functional pili.
• Anonsen, Jan Haug; Vik, Åshild; Koomey, Michael & Jacobsen, Wolfgang Mathias (2009). Studying post-tranlational modifications in the model organism Neisseria gonorrhoeae. Profiling of phosphoform modifications and protein O-linked glycosylation using a LTQ Orbitrap hybrid mass spectrometer.
• Anonsen, Jan Haug; Jacobsen, Wolfgang Mathias; Koomey, Michael & Vik, Åshild (2009). Covalent modification of periplasmic proteins with phosphoethanolamine and phosphocholine and its association with protein glycosylation.
• Børud, Bente; Aas, Finn Erik; Vik, Åshild; Egge-Jacobsen, Wolfgang & Koomey, Michael (2009). Glycomic and genetic strategies define glycoprotein carbohydrate diversity in Neisseria gonorrhoeae and related species.
• Salomonsson, Emelie; Winther-Larsen, Hanne Cecilie; Holz, Claudia; Maier, Berenike; Koomey, Michael & Forsberg, Åke (2008). Expressing Type IV pilin-like genes from Francisella tularensis in Neisseria gonorrhoeae.
• Aas, Finn Erik; Vik, Åshild; Jacobsen, Wolfgang Mathias; Anonsen, Jan Haug & Koomey, Michael (2008). Functional reconstitution of the O-linked protein glycosylation system of Neisseria gonorrhoeae in E. coli.
• Salomonsson, Emelie; Koomey, Michael; Roos, Norbert; Forsberg, Åke & Winther-Larsen, Hanne C (2007). Exploring the role of virulence-associated pilin proteins from Francisella tularensis using heterologous expression in Neisseria.
• Salomonsson, Emelie; Koomey, Michael; Roos, Norbert; Forsberg, Åke & Winther-Larsen, Hanne C (2007). Knowledge about the bioterrorism class A agent Francisella tularensis by utilizing Neisseria gonorrhoeae.
• Vik, Åshild; Aas, Finn Erik; Jacobsen, Wolfgang Mathias & Koomey, Michael (2006). A generalized O-linked glycosylation system in Neisseria gonorrhoeae.
• Winther-Larsen, Hanne C; Løvold, Cecilia; Wolfgang, Matthew; van Putten, JPM; Roos, Norbert & Aas, Finn Erik [Vis alle 10 forfattere av denne artikkelen] (2006). Microbial hair-extention.
• Winther-Larsen, Hanne C; Heiniger, Ryan W; Roos, Norbert; Egge-Jacobsen, Wolfgang; van Putten, JPM & Koomey, Michael [Vis alle 7 forfattere av denne artikkelen] (2006). Dynamics of Type IV pili Biogenesis in Pseudomonas aeruginosa.
• Salomonsson, Emelie; Forsberg, Åke; Koomey, Michael & Winther-Larsen, Hanne C (2006). Heterologous expression of Francisella pilin genes in Neisseria gonorrhoeae. Vis sammendrag

  Analysis of the genome sequence of F. tularensis subsp. tularensis strain SCHU S4 has identified gene clusters encoding proteins postulated to be involved in protein secretion or in type IV pili (Tfp) expression. SCHU S4 encodes at least six putative pilin genes. We have recently verified that one of these genes, denoted pilA, is essential for full virulence in a mouse infection model. However, so far we have been unable to verify that F. tularensis expresses Tfp.or secreton related organelles To establish if any of the six pilin genes could form a pilus we expressed them, and in addition the pilA gene of subsp. novicida, in N. gonorrhoeae Western blot analysis verified that all pilins except one were expressed in this background. Expression of pilin filaments was analysed by immunofluorescence and electron microscopy and only PilA of F. novicida and SCHU S4 produced Tfp-like filaments. In support of PilA from F. novicida to form pilus-like multimers was that its expression also resulted in restored competence for DNA uptake in N. gonorrhoeae. However, at this point we cannot exclude that additional pilins are part of or can also form Tfp or a protein secretion related pseudopilus.

• Winther-Larsen, Hanne C; Heiniger, Ryan; Roos, Norbert; van Putten, JPM; Koomey, Michael & Wolfgang, Matthew (2006). Dynamics of Type IV pilus biogenesis in Pseudomonas aeruginosa.
• Koomey, Michael (2005). "Linking organelle to function: pilins and minor pilins in the Neisseria gonorrhoeae type IV pilus system".
• Koomey, Michael (2005). "DNA uptake in Neisseria gonorrhoeae".
• Koomey, Michael (2005). "Cell signaling in Neisseria gonorrhoeae".
• Koomey, Michael (2005). "Biogenesis and structure of Neisseria gonorrhoeae Type IV pili: implications for organelle dynamics and function".
• Løvold, Cecilia; Aas, Finn Erik; Winther-Larsen, Hanne C; Egge-Jacobsen, Wolfgang; Hegge, Finn Terje & Roos, Norbert [Vis alle 8 forfattere av denne artikkelen] (2005). Mutant analysis of dca: a gene encoding a putative transferase that mediates phosphoethanolamine and phosphocholine modifications of the Type IV pili in Neisseria gonorrhoeae.
• Winther-Larsen, Hanne C; Løvold, Cecilia; Wolfgang, Matthew; van Putten, JPM; Roos, Norbert & Aas, Finn Erik [Vis alle 10 forfattere av denne artikkelen] (2005). Pseudomonas aeruginosa PAK Type IV pili expression in Neisseria gonorrhoeae complements Tfp associated functions.

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