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Mark A. Lehrman - One of the best experts on this subject based on the ideXlab platform.
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analysis of glycosylation in cdg ia fibroblasts by fluorophore assisted carbohydrate electrophoresis implications for extracellular glucose and intracellular mannose 6 phosphate
Journal of Biological Chemistry, 2005Co-Authors: Jie Shang, Mark A. LehrmanAbstract:Abstract Phosphomannomutase (PMM) deficiency causes congenital disorder of glycosylation (CDG)-Ia, a broad spectrum disorder with developmental and neurological abnormalities. PMM converts mannose 6-phosphate (M6P) to mannose-1-phosphate, a precursor of GDP-mannose used to make Glc3Man9GlcNAc2-P-P-dolichol (lipid-linked oligosaccharide; LLO). LLO, in turn, is the donor substrate of Oligosaccharyltransferase for protein N-linked glycosylation. Hepatically produced N-linked glycoproteins in CDG-Ia blood are hypoglycosylated. Upon labeling with [3H]mannose, CDG-Ia fibroblasts have been widely reported to accumulate [3H]LLO intermediates. Since these are thought to be poor Oligosaccharyltransferase substrates, LLO intermediate accumulation has been the prevailing explanation for hypoglycosylation in patients. However, this is discordant with sporadic reports of specific glycoproteins (detected with antibodies) from CDG-Ia fibroblasts being fully glycosylated. Here, fluorophore-assisted carbohydrate electrophoresis (FACE, a nonradioactive technique) was used to analyze steady-state LLO compositions in CDG-Ia fibroblasts. FACE revealed that low glucose conditions accounted for previous observations of accumulated [3H]LLO intermediates. Additional FACE experiments demonstrated abundant Glc3Man9GlcNAc2-P-P-dolichol, without hypoglycosylation, CDG-Ia fibroblasts grown with physiological glucose. This suggested a “missing link” to explain hypoglycosylation in CDG-Ia patients. Because of the possibility of its accumulation, the effects of M6P on glycosylation were explored in vitro. Surprisingly, M6P was a specific activator for cleavage of Glc3Man9GlcNAc2-P-P-dolichol. This led to futile cycling the LLO pathway, exacerbated by GDP-mannose/PMM deficiency. The possibilities that M6P may accumulate in hepatocytes and that M6P-stimulated LLO cleavage may account for both hypoglycosylation and the clinical failure of dietary mannose therapy with CDG-Ia patients are discussed.
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Analysis of glycosylation in CDG-Ia fibroblasts by fluorophore-assisted carbohydrate electrophoresis: implications for extracellular glucose and intracellular mannose 6-phosphate.
The Journal of biological chemistry, 2005Co-Authors: Ningguo Gao, Jie Shang, Mark A. LehrmanAbstract:Abstract Phosphomannomutase (PMM) deficiency causes congenital disorder of glycosylation (CDG)-Ia, a broad spectrum disorder with developmental and neurological abnormalities. PMM converts mannose 6-phosphate (M6P) to mannose-1-phosphate, a precursor of GDP-mannose used to make Glc3Man9GlcNAc2-P-P-dolichol (lipid-linked oligosaccharide; LLO). LLO, in turn, is the donor substrate of Oligosaccharyltransferase for protein N-linked glycosylation. Hepatically produced N-linked glycoproteins in CDG-Ia blood are hypoglycosylated. Upon labeling with [3H]mannose, CDG-Ia fibroblasts have been widely reported to accumulate [3H]LLO intermediates. Since these are thought to be poor Oligosaccharyltransferase substrates, LLO intermediate accumulation has been the prevailing explanation for hypoglycosylation in patients. However, this is discordant with sporadic reports of specific glycoproteins (detected with antibodies) from CDG-Ia fibroblasts being fully glycosylated. Here, fluorophore-assisted carbohydrate electrophoresis (FACE, a nonradioactive technique) was used to analyze steady-state LLO compositions in CDG-Ia fibroblasts. FACE revealed that low glucose conditions accounted for previous observations of accumulated [3H]LLO intermediates. Additional FACE experiments demonstrated abundant Glc3Man9GlcNAc2-P-P-dolichol, without hypoglycosylation, CDG-Ia fibroblasts grown with physiological glucose. This suggested a “missing link” to explain hypoglycosylation in CDG-Ia patients. Because of the possibility of its accumulation, the effects of M6P on glycosylation were explored in vitro. Surprisingly, M6P was a specific activator for cleavage of Glc3Man9GlcNAc2-P-P-dolichol. This led to futile cycling the LLO pathway, exacerbated by GDP-mannose/PMM deficiency. The possibilities that M6P may accumulate in hepatocytes and that M6P-stimulated LLO cleavage may account for both hypoglycosylation and the clinical failure of dietary mannose therapy with CDG-Ia patients are discussed.
B Schulz - One of the best experts on this subject based on the ideXlab platform.
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intramembrane protease rhbdl4 cleaves subunits of the Oligosaccharyltransferase complex to target them for er associated degradation
bioRxiv, 2020Co-Authors: Julia D Knopf, Nathalie Kuhnle, Nina Landscheidt, Cassandra L Pegg, B Schulz, Chaowei Chao, Simon Huck, Marius K LembergAbstract:The Endoplasmic Reticulum (ER)-resident intramembrane rhomboid protease RHBDL4 generates metastable protein fragments and together with the ER-associated degradation (ERAD) machinery provides a clearance mechanism for aberrant and surplus proteins. However, the endogenous substrate spectrum and with that the role of RHBDL4 in physiological ERAD is mainly unknown. Here, we use a substrate trapping approach in combination with quantitative proteomics to identify physiological RHBDL4 substrates. This revealed oligosacharyltransferase (OST) complex subunits such as the catalytic active subunit STT3A as substrates for the RHBDL4-dependent ERAD pathway. RHBDL4-catalyzed cleavage inactivates OST subunits by triggering dislocation into the cytoplasm and subsequent proteasomal degradation. Thereby, RHBDL4 controls the abundance and activity of OST, suggesting a novel link between the ERAD machinery and glycosylation tuning.
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intramembrane protease rhbdl4 cleaves Oligosaccharyltransferase subunits to target them for er associated degradation
Journal of Cell Science, 2020Co-Authors: Julia D Knopf, Nathalie Kuhnle, Nina Landscheidt, Cassandra L Pegg, B Schulz, Chaowei Chao, Simon Huck, Marius K LembergAbstract:The Endoplasmic Reticulum (ER)-resident intramembrane rhomboid protease RHBDL4 generates metastable protein fragments and together with the ER-associated degradation (ERAD) machinery provides a clearance mechanism for aberrant and surplus proteins. However, the endogenous substrate spectrum and with that the role of RHBDL4 in physiological ERAD is mainly unknown. Here, we use a substrate trapping approach in combination with quantitative proteomics to identify physiological RHBDL4 substrates. This revealed oligosacharyltransferase (OST) complex subunits such as the catalytic active subunit STT3A as substrates for the RHBDL4-dependent ERAD pathway. RHBDL4-catalyzed cleavage inactivates OST subunits by triggering dislocation into the cytoplasm and subsequent proteasomal degradation. Thereby, RHBDL4 controls the abundance and activity of OST, suggesting a novel link between the ERAD machinery and glycosylation tuning.
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intramembrane protease rhbdl4 induces er associated degradation of the Oligosaccharyltransferase complex
bioRxiv, 2019Co-Authors: Julia D Knopf, Nathalie Kuhnle, Nina Landscheidt, Cassandra L Pegg, B Schulz, Chaowei Chao, Simon Huck, Marius K LembergAbstract:The Endoplasmic Reticulum (ER)-resident intramembrane rhomboid protease RHBDL4 generates metastable protein fragments and together with the ER-associated degradation (ERAD) machinery provides a clearance mechanism for aberrant and surplus proteins. However, the endogenous substrate spectrum and with that the role of RHBDL4 in physiological ERAD is mainly unknown. Here, we use quantitative proteomics to identify physiological RHBDL4 substrates. This revealed oligosacharyltransferase (OST) complex subunits such as the catalytic active subunit STT3A as substrates for the RHBDL4-dependent ERAD pathway. RHBDL4-catalyzed cleavage inactivates OST subunits by triggering dislocation into the cytoplasm and subsequent proteasomal degradation. RHBDL4-catalyzed cleavage is enhanced by positive charged transmembrane residues, which are recognized by a putative negative-charged docking site at the rhomboid active site gate. RHBDL4 controls the abundance and activity of OST, suggesting a novel link between the ERAD machinery and glycosylation tuning in the ER.
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the age receptor ost48 drives podocyte foot process effacement and basement membrane expansion in experimental diabetic kidney disease via promotion of endoplasmic reticulum stress
bioRxiv, 2019Co-Authors: Aowen Zhuang, B Schulz, D Mccarthy, Sally A Penfold, Karly C Sourris, Melinda T Coughlan, Josephine M ForbesAbstract:Abstract The accumulation of advanced glycation end products is implicated in the development and progression of diabetic kidney disease. No study has examined whether stimulating advanced glycation clearance via receptor manipulation is reno-protective in diabetes. Podocytes, which are early contributors to diabetic kidney disease and could be a target for reno-protection. To examine the effects of increased podocyte Oligosaccharyltransferase-48 on kidney function, glomerular sclerosis, tubulointerstitial fibrosis and proteome (PXD011434), we generated a mouse with increased Oligosaccharyltransferase-48kDa subunit abundance in podocytes driven by the podocin promoter. Despite increased urinary clearance of advanced glycation end products, we observed a decline in renal function, significant glomerular damage including glomerulosclerosis, collagen IV deposition, glomerular basement membrane thickening and foot process effacement and tubulointerstitial fibrosis. Analysis of isolated glomeruli identified enrichment in proteins associated with collagen deposition, endoplasmic reticulum stress and oxidative stress. Ultra-resolution microscopy of podocytes revealed denudation of foot processes where there was co-localization of Oligosaccharyltransferase-48kDa subunit and advanced glycation end-products. These studies indicate that increased podocyte expression of Oligosaccharyltransferase-48kDa subunit results in glomerular endoplasmic reticulum stress and a decline in kidney function.
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distinct donor and acceptor specificities of trypanosoma brucei Oligosaccharyltransferases
The EMBO Journal, 2009Co-Authors: Luis Izquierdo, Markus Aebi, B Schulz, Joao A Rodrigues, Maria Lucia S Guther, James B Procter, Geoffrey J Barton, Michael A J FergusonAbstract:Asparagine-linked glycosylation is catalysed by Oligosaccharyltransferase (OTase). In Trypanosoma brucei OTase activity is catalysed by single-subunit enzymes encoded by three paralogous genes of which TbSTT3B and TbSTT3C can complement a yeast Δstt3 mutant. The two enzymes have overlapping but distinct peptide acceptor specificities, with TbSTT3C displaying an enhanced ability to glycosylate sites flanked by acidic residues. TbSTT3A and TbSTT3B, but not TbSTT3C, are transcribed in the bloodstream and procyclic life cycle stages of T. brucei. Selective knockdown and analysis of parasite protein N-glycosylation showed that TbSTT3A selectively transfers biantennary Man5GlcNAc2 to specific glycosylation sites whereas TbSTT3B selectively transfers triantennary Man9GlcNAc2 to others. Analysis of T. brucei glycosylation site occupancy showed that TbSTT3A and TbSTT3B glycosylate sites in acidic to neutral and neutral to basic regions of polypeptide, respectively. This embodiment of distinct specificities in single-subunit OTases may have implications for recombinant glycoprotein engineering. TbSTT3A and TbSTT3B could be knocked down individually, but not collectively, in tissue culture. However, both were independently essential for parasite growth in mice, suggesting that inhibiting protein N-glycosylation could have therapeutic potential against trypanosomiasis.
Christian M. Harding - One of the best experts on this subject based on the ideXlab platform.
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A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host.
Nature Communications, 2019Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Guillaume Goyette-desjardins, Sthefany M. Chavez, Jeremy P. Huynh, Rachel L. Kinsella, Harald Nothaft, Nichollas E Scott, Anne E Mayer, Christine M SzymanskiAbstract:Chemical synthesis of conjugate vaccines, consisting of a polysaccharide linked to a protein, can be technically challenging, and in vivo bacterial conjugations (bioconjugations) have emerged as manufacturing alternatives. Bioconjugation relies upon an Oligosaccharyltransferase to attach polysaccharides to proteins, but currently employed enzymes are not suitable for the generation of conjugate vaccines when the polysaccharides contain glucose at the reducing end, which is the case for ~75% of Streptococcus pneumoniae capsules. Here, we use an O-linking Oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end. In addition, we show that different vaccine carrier proteins can be glycosylated using this system. Pneumococcal bioconjugates are immunogenic, protective and rapidly produced within E. coli using recombinant techniques. These proof-of-principle experiments establish a platform to overcome limitations of other conjugating enzymes enabling the development of bioconjugate vaccines for many important human and animal pathogens.
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A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host
Nature Publishing Group, 2019Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Guillaume Goyette-desjardins, Sthefany M. Chavez, Jeremy P. Huynh, Rachel L. Kinsella, Harald Nothaft, Nichollas E Scott, Anne E Mayer, Christine M SzymanskiAbstract:Bioconjugation is a promising process to manufacture conjugate vaccines, but currently employed enzymes cannot generate the full spectrum of bacterial glycoproteins. Here, the authors use an O-linking Oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end
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acinetobacter strains carry two functional Oligosaccharyltransferases one devoted exclusively to type iv pilin and the other one dedicated to o glycosylation of multiple proteins
Molecular Microbiology, 2015Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Rachel L. Kinsella, Nichollas E Scott, Leonard J Foster, Brent S Weber, Steve E Fiester, Luis A Actis, Erin N TracyAbstract:Summary Multiple species within the Acinetobacter genus are nosocomial opportunistic pathogens of increasing relevance worldwide. Among the virulence factors utilized by these bacteria are the type IV pili and a protein O-glycosylation system. Glycosylation is mediated by O-Oligosaccharyltransferases (O-OTases), enzymes that transfer the glycan from a lipid carrier to target proteins. O-Oligosaccharyltransferases are difficult to identify due to similarities with the WaaL ligases that catalyze the last step in lipopolysaccharide synthesis. A bioinformatics analysis revealed the presence of two genes encoding putative O-OTases or WaaL ligases in most of the strains within the genus Acinetobacter. Employing A. nosocomialis M2 and A. baylyi ADP1 as model systems, we show that these genes encode two O-OTases, one devoted uniquely to type IV pilin, and the other one responsible for glycosylation of multiple proteins. With the exception of ADP1, the pilin-specific OTases in Acinetobacter resemble the TfpO/PilO O-OTase from Pseudomonas aeruginosa. In ADP1 instead, the two O-OTases are closely related to PglL, the general O-OTase first discovered in Neisseria. However, one of them is exclusively dedicated to the glycosylation of the pilin-like protein ComP. Our data reveal an intricate and remarkable evolutionary pathway for bacterial O-OTases and provide novel tools for glycoengineering.
Jie Shang - One of the best experts on this subject based on the ideXlab platform.
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analysis of glycosylation in cdg ia fibroblasts by fluorophore assisted carbohydrate electrophoresis implications for extracellular glucose and intracellular mannose 6 phosphate
Journal of Biological Chemistry, 2005Co-Authors: Jie Shang, Mark A. LehrmanAbstract:Abstract Phosphomannomutase (PMM) deficiency causes congenital disorder of glycosylation (CDG)-Ia, a broad spectrum disorder with developmental and neurological abnormalities. PMM converts mannose 6-phosphate (M6P) to mannose-1-phosphate, a precursor of GDP-mannose used to make Glc3Man9GlcNAc2-P-P-dolichol (lipid-linked oligosaccharide; LLO). LLO, in turn, is the donor substrate of Oligosaccharyltransferase for protein N-linked glycosylation. Hepatically produced N-linked glycoproteins in CDG-Ia blood are hypoglycosylated. Upon labeling with [3H]mannose, CDG-Ia fibroblasts have been widely reported to accumulate [3H]LLO intermediates. Since these are thought to be poor Oligosaccharyltransferase substrates, LLO intermediate accumulation has been the prevailing explanation for hypoglycosylation in patients. However, this is discordant with sporadic reports of specific glycoproteins (detected with antibodies) from CDG-Ia fibroblasts being fully glycosylated. Here, fluorophore-assisted carbohydrate electrophoresis (FACE, a nonradioactive technique) was used to analyze steady-state LLO compositions in CDG-Ia fibroblasts. FACE revealed that low glucose conditions accounted for previous observations of accumulated [3H]LLO intermediates. Additional FACE experiments demonstrated abundant Glc3Man9GlcNAc2-P-P-dolichol, without hypoglycosylation, CDG-Ia fibroblasts grown with physiological glucose. This suggested a “missing link” to explain hypoglycosylation in CDG-Ia patients. Because of the possibility of its accumulation, the effects of M6P on glycosylation were explored in vitro. Surprisingly, M6P was a specific activator for cleavage of Glc3Man9GlcNAc2-P-P-dolichol. This led to futile cycling the LLO pathway, exacerbated by GDP-mannose/PMM deficiency. The possibilities that M6P may accumulate in hepatocytes and that M6P-stimulated LLO cleavage may account for both hypoglycosylation and the clinical failure of dietary mannose therapy with CDG-Ia patients are discussed.
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Analysis of glycosylation in CDG-Ia fibroblasts by fluorophore-assisted carbohydrate electrophoresis: implications for extracellular glucose and intracellular mannose 6-phosphate.
The Journal of biological chemistry, 2005Co-Authors: Ningguo Gao, Jie Shang, Mark A. LehrmanAbstract:Abstract Phosphomannomutase (PMM) deficiency causes congenital disorder of glycosylation (CDG)-Ia, a broad spectrum disorder with developmental and neurological abnormalities. PMM converts mannose 6-phosphate (M6P) to mannose-1-phosphate, a precursor of GDP-mannose used to make Glc3Man9GlcNAc2-P-P-dolichol (lipid-linked oligosaccharide; LLO). LLO, in turn, is the donor substrate of Oligosaccharyltransferase for protein N-linked glycosylation. Hepatically produced N-linked glycoproteins in CDG-Ia blood are hypoglycosylated. Upon labeling with [3H]mannose, CDG-Ia fibroblasts have been widely reported to accumulate [3H]LLO intermediates. Since these are thought to be poor Oligosaccharyltransferase substrates, LLO intermediate accumulation has been the prevailing explanation for hypoglycosylation in patients. However, this is discordant with sporadic reports of specific glycoproteins (detected with antibodies) from CDG-Ia fibroblasts being fully glycosylated. Here, fluorophore-assisted carbohydrate electrophoresis (FACE, a nonradioactive technique) was used to analyze steady-state LLO compositions in CDG-Ia fibroblasts. FACE revealed that low glucose conditions accounted for previous observations of accumulated [3H]LLO intermediates. Additional FACE experiments demonstrated abundant Glc3Man9GlcNAc2-P-P-dolichol, without hypoglycosylation, CDG-Ia fibroblasts grown with physiological glucose. This suggested a “missing link” to explain hypoglycosylation in CDG-Ia patients. Because of the possibility of its accumulation, the effects of M6P on glycosylation were explored in vitro. Surprisingly, M6P was a specific activator for cleavage of Glc3Man9GlcNAc2-P-P-dolichol. This led to futile cycling the LLO pathway, exacerbated by GDP-mannose/PMM deficiency. The possibilities that M6P may accumulate in hepatocytes and that M6P-stimulated LLO cleavage may account for both hypoglycosylation and the clinical failure of dietary mannose therapy with CDG-Ia patients are discussed.
Nichollas E Scott - One of the best experts on this subject based on the ideXlab platform.
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A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host.
Nature Communications, 2019Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Guillaume Goyette-desjardins, Sthefany M. Chavez, Jeremy P. Huynh, Rachel L. Kinsella, Harald Nothaft, Nichollas E Scott, Anne E Mayer, Christine M SzymanskiAbstract:Chemical synthesis of conjugate vaccines, consisting of a polysaccharide linked to a protein, can be technically challenging, and in vivo bacterial conjugations (bioconjugations) have emerged as manufacturing alternatives. Bioconjugation relies upon an Oligosaccharyltransferase to attach polysaccharides to proteins, but currently employed enzymes are not suitable for the generation of conjugate vaccines when the polysaccharides contain glucose at the reducing end, which is the case for ~75% of Streptococcus pneumoniae capsules. Here, we use an O-linking Oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end. In addition, we show that different vaccine carrier proteins can be glycosylated using this system. Pneumococcal bioconjugates are immunogenic, protective and rapidly produced within E. coli using recombinant techniques. These proof-of-principle experiments establish a platform to overcome limitations of other conjugating enzymes enabling the development of bioconjugate vaccines for many important human and animal pathogens.
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A platform for glycoengineering a polyvalent pneumococcal bioconjugate vaccine using E. coli as a host
Nature Publishing Group, 2019Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Guillaume Goyette-desjardins, Sthefany M. Chavez, Jeremy P. Huynh, Rachel L. Kinsella, Harald Nothaft, Nichollas E Scott, Anne E Mayer, Christine M SzymanskiAbstract:Bioconjugation is a promising process to manufacture conjugate vaccines, but currently employed enzymes cannot generate the full spectrum of bacterial glycoproteins. Here, the authors use an O-linking Oligosaccharyltransferase to generate a polyvalent pneumococcal bioconjugate vaccine with polysaccharides containing glucose at their reducing end
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acinetobacter strains carry two functional Oligosaccharyltransferases one devoted exclusively to type iv pilin and the other one dedicated to o glycosylation of multiple proteins
Molecular Microbiology, 2015Co-Authors: Christian M. Harding, Mohamed Adel Nasr, Rachel L. Kinsella, Nichollas E Scott, Leonard J Foster, Brent S Weber, Steve E Fiester, Luis A Actis, Erin N TracyAbstract:Summary Multiple species within the Acinetobacter genus are nosocomial opportunistic pathogens of increasing relevance worldwide. Among the virulence factors utilized by these bacteria are the type IV pili and a protein O-glycosylation system. Glycosylation is mediated by O-Oligosaccharyltransferases (O-OTases), enzymes that transfer the glycan from a lipid carrier to target proteins. O-Oligosaccharyltransferases are difficult to identify due to similarities with the WaaL ligases that catalyze the last step in lipopolysaccharide synthesis. A bioinformatics analysis revealed the presence of two genes encoding putative O-OTases or WaaL ligases in most of the strains within the genus Acinetobacter. Employing A. nosocomialis M2 and A. baylyi ADP1 as model systems, we show that these genes encode two O-OTases, one devoted uniquely to type IV pilin, and the other one responsible for glycosylation of multiple proteins. With the exception of ADP1, the pilin-specific OTases in Acinetobacter resemble the TfpO/PilO O-OTase from Pseudomonas aeruginosa. In ADP1 instead, the two O-OTases are closely related to PglL, the general O-OTase first discovered in Neisseria. However, one of them is exclusively dedicated to the glycosylation of the pilin-like protein ComP. Our data reveal an intricate and remarkable evolutionary pathway for bacterial O-OTases and provide novel tools for glycoengineering.
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comparative proteomics and glycoproteomics reveal increased n linked glycosylation and relaxed sequon specificity in campylobacter jejuni nctc11168 o
Journal of Proteome Research, 2014Co-Authors: Nichollas E Scott, Bishara N Marzook, Joel A Cain, Nestor Solis, Morten Thaysenandersen, Steven P Djordjevic, Nicolle H Packer, Martin R Larsen, Stuart J CordwellAbstract:Campylobacter jejuni is a major cause of bacterial gastroenteritis. C. jejuni encodes a protein glycosylation (Pgl) locus responsible for the N-glycosylation of membrane-associated proteins. We examined two variants of the genome sequenced strain NCTC11168: O, a representative of the original clinical isolate, and GS, a laboratory-adapted relative of O. Comparative proteomics by iTRAQ and two-dimensional liquid chromatography coupled to tandem mass spectrometry (2D-LC–MS/MS) allowed the confident identification of 1214 proteins (73.9% of the predicted C. jejuni proteome), of which 187 were present at statistically significant altered levels of abundance between variants. Proteins associated with the O variant included adhesins (CadF and FlpA), proteases, capsule biosynthesis, and cell shape determinants as well as six proteins encoded by the Pgl system, including the PglK flippase and PglB Oligosaccharyltransferase. Lectin blotting highlighted specific glycoproteins more abundant in NCTC11168 O, whereas o...
