1
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Peng W, Garcia N, Servage KA, Kohler JJ, Ready JM, Tomchick DR, Fernandez J, Orth K. Pseudomonas effector AvrB is a glycosyltransferase that rhamnosylates plant guardee protein RIN4. Sci Adv 2024; 10:eadd5108. [PMID: 38354245 PMCID: PMC10866546 DOI: 10.1126/sciadv.add5108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
The plant pathogen Pseudomonas syringae encodes a type III secretion system avirulence effector protein, AvrB, that induces a form of programmed cell death called the hypersensitive response in plants as a defense mechanism against systemic infection. Despite the well-documented catalytic activities observed in other Fido (Fic, Doc, and AvrB) proteins, the enzymatic activity and target substrates of AvrB have remained elusive. Here, we show that AvrB is an unprecedented glycosyltransferase that transfers rhamnose from UDP-rhamnose to a threonine residue of the Arabidopsis guardee protein RIN4. We report structures of various enzymatic states of the AvrB-catalyzed rhamnosylation reaction of RIN4, which reveal the structural and mechanistic basis for rhamnosylation by a Fido protein. Collectively, our results uncover an unexpected reaction performed by a prototypical member of the Fido superfamily while providing important insights into the plant hypersensitive response pathway and foreshadowing more diverse chemistry used by Fido proteins and their substrates.
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Affiliation(s)
- Wei Peng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nalleli Garcia
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Kelly A. Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joseph M. Ready
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Diana R. Tomchick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jessie Fernandez
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
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2
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Peng J, Yu L, Huang L, Paschoal VA, Chu H, de Souza CO, Varre JV, Oh DY, Kohler JJ, Xiao X, Xu L, Holland WL, Shaul PW, Mineo C. Hepatic sialic acid synthesis modulates glucose homeostasis in both liver and skeletal muscle. Mol Metab 2023; 78:101812. [PMID: 37777009 PMCID: PMC10583174 DOI: 10.1016/j.molmet.2023.101812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/02/2023] Open
Abstract
OBJECTIVE Sialic acid is a terminal monosaccharide of glycans in glycoproteins and glycolipids, and its derivation from glucose is regulated by the rate-limiting enzyme UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE). Although the glycans on key endogenous hepatic proteins governing glucose metabolism are sialylated, how sialic acid synthesis and sialylation in the liver influence glucose homeostasis is unknown. Studies were designed to fill this knowledge gap. METHODS To decrease the production of sialic acid and sialylation in hepatocytes, a hepatocyte-specific GNE knockdown mouse model was generated, and systemic glucose metabolism, hepatic insulin signaling and glucagon signaling were evaluated in vivo or in primary hepatocytes. Peripheral insulin sensitivity was also assessed. Furthermore, the mechanisms by which sialylation in the liver influences hepatic insulin signaling and glucagon signaling and peripheral insulin sensitivity were identified. RESULTS Liver GNE deletion in mice caused an impairment of insulin suppression of hepatic glucose production. This was due to a decrease in the sialylation of hepatic insulin receptors (IR) and a decline in IR abundance due to exaggerated degradation through the Eph receptor B4. Hepatic GNE deficiency also caused a blunting of hepatic glucagon receptor (GCGR) function which was related to a decline in its sialylation and affinity for glucagon. An accompanying upregulation of hepatic FGF21 production caused an enhancement of skeletal muscle glucose disposal that led to an overall increase in glucose tolerance and insulin sensitivity. CONCLUSION These collective observations reveal that hepatic sialic acid synthesis and sialylation modulate glucose homeostasis in both the liver and skeletal muscle. By interrogating how hepatic sialic acid synthesis influences glucose control mechanisms in the liver, a new metabolic cycle has been identified in which a key constituent of glycans generated from glucose modulates the systemic control of its precursor.
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Affiliation(s)
- Jun Peng
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
| | - Liming Yu
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Linzhang Huang
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Vivian A Paschoal
- Dept. of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Haiyan Chu
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Camila O de Souza
- Dept. of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Joseph V Varre
- Dept. of Nutrition & Integrative Physiology, University of Utah College of Health, 250 1850 E, Salt Lake City, UT, 84112, USA
| | - Da Young Oh
- Dept. of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Jennifer J Kohler
- Dept. of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Xue Xiao
- Peter O'Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - Lin Xu
- Peter O'Donnell Jr. School of Public Health, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA
| | - William L Holland
- Dept. of Nutrition & Integrative Physiology, University of Utah College of Health, 250 1850 E, Salt Lake City, UT, 84112, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Dept. of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA; Dept. of Cell Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390, USA.
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3
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Burns MWN, Kohler JJ. O-GlcNAc regulates YTHDF1 and YTHDF3 activity. Nat Cell Biol 2023; 25:1570-1572. [PMID: 37945828 DOI: 10.1038/s41556-023-01275-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Affiliation(s)
- Mary W N Burns
- Department of Biochemistry, UT Southwestern, Dallas, TX, USA
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4
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Singla A, Boucher A, Wallom KL, Lebens M, Kohler JJ, Platt FM, Yrlid U. Cholera intoxication of human enteroids reveals interplay between decoy and functional glycoconjugate ligands. Glycobiology 2023; 33:801-816. [PMID: 37622990 PMCID: PMC10629719 DOI: 10.1093/glycob/cwad069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 07/31/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023] Open
Abstract
Prior research on cholera toxin (CT) binding and intoxication has relied on human colonic cancer derived epithelial cells. While these transformed cell lines have been beneficial, they neither derive from small intestine where intoxication occurs, nor represent the diversity of small intestinal epithelial cells (SI-ECs) and variation in glycoconjugate expression among individuals. Here, we used human enteroids, derived from jejunal biopsies of multipledonors to study CT binding and intoxication of human non-transformed SI-ECs. We modulated surface expression of glycosphingolipids, glycoproteins and specific glycans to distinguish the role of each glycan/glycoconjugate. Cholera-toxin-subunit-B (CTB) mutants were generated to decipher the preference of each glycoconjugate to different binding sites and the correlation between CT binding and intoxication. Human enteroids contain trace amounts of GM1, but other glycosphingolipids may be contributing to CT intoxication. We discovered that inhibition of either fucosylation or O-glycosylation sensitize enteroids to CT-intoxication. This can either be a consequence of the removal of fucosylated "decoy-like-ligands" binding to CTB's non-canonical site and/or increase in the availability of Gal/GalNAc-terminating glycoconjugates binding to the canonical site. Furthermore, simultaneous inhibition of fucosylation and O-glycosylation increased the availability of additional Gal/GalNAc-terminating glycoconjugates but counteracted the sensitization in CT intoxication caused by inhibiting O-glycosylation because of reduction in fucose. This implies a dual role of fucose as a functional glycan and a decoy, the interplay of which influences CT binding and intoxication. Finally, while the results were similar for enteroids from different donors, they were not identical, pointing to a role for human genetic variation in determining sensitivity to CT.
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Affiliation(s)
- Akshi Singla
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Medicinaregatan 1G, 41390 Gothenburg, Sweden
- Department of Medical Chemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Medicinaregatan 1G, 41390 Gothenburg, Sweden
| | - Andrew Boucher
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Medicinaregatan 1G, 41390 Gothenburg, Sweden
| | - Kerri-Lee Wallom
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Michael Lebens
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Medicinaregatan 1G, 41390 Gothenburg, Sweden
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9185, United States
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Medicinaregatan 1G, 41390 Gothenburg, Sweden
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5
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Holborough-Kerkvliet MD, Mucignato G, Moons SJ, Psomiadou V, Konada RSR, Pedowitz NJ, Pratt MR, Kissel T, Koeleman CAM, Tjokrodirijo RTN, van Veelen PA, Huizinga T, van Schie KAJ, Wuhrer M, Kohler JJ, Bonger KM, Boltje TJ, Toes REM. A photoaffinity glycan-labeling approach to investigate immunoglobulin glycan-binding partners. Glycobiology 2023; 33:732-744. [PMID: 37498177 PMCID: PMC10627247 DOI: 10.1093/glycob/cwad055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/13/2023] [Accepted: 06/30/2023] [Indexed: 07/28/2023] Open
Abstract
Glycans play a pivotal role in biology. However, because of the low-affinity of glycan-protein interactions, many interaction pairs remain unknown. Two important glycoproteins involved in B-cell biology are the B-cell receptor and its secreted counterpart, antibodies. It has been indicated that glycans expressed by these B-cell-specific molecules can modulate immune activation via glycan-binding proteins. In several autoimmune diseases, an increased prevalence of variable domain glycosylation of IgG autoantibodies has been observed. Especially, the hallmarking autoantibodies in rheumatoid arthritis, anti-citrullinated protein antibodies, carry a substantial amount of variable domain glycans. The variable domain glycans expressed by these autoantibodies are N-linked, complex-type, and α2-6 sialylated, and B-cell receptors carrying variable domain glycans have been hypothesized to promote selection of autoreactive B cells via interactions with glycan-binding proteins. Here, we use the anti-citrullinated protein antibody response as a prototype to study potential in solution and in situ B-cell receptor-variable domain glycan interactors. We employed SiaDAz, a UV-activatable sialic acid analog carrying a diazirine moiety that can form covalent bonds with proximal glycan-binding proteins. We show, using oligosaccharide engineering, that SiaDAz can be readily incorporated into variable domain glycans of both antibodies and B-cell receptors. Our data show that antibody variable domain glycans are able to interact with inhibitory receptor, CD22. Interestingly, although we did not detect this interaction on the cell surface, we captured CD79 β glycan-B-cell receptor interactions. These results show the utility of combining photoaffinity labeling and oligosaccharide engineering for identifying antibody and B-cell receptor interactions and indicate that variable domain glycans appear not to be lectin cis ligands in our tested conditions.
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Affiliation(s)
| | - Greta Mucignato
- Department of Rheumatology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Sam J Moons
- Department of Synthetic Organic Chemistry, Radboud University, Toernooiveld 1, Mercator III, 6525 ED, Nijmegen, The Netherlands
| | - Venetia Psomiadou
- Department of Synthetic Organic Chemistry, Radboud University, Toernooiveld 1, Mercator III, 6525 ED, Nijmegen, The Netherlands
| | - Rohit S R Konada
- Department of Biochemistry, University of Texas Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390-09185, United States
| | - Nichole J Pedowitz
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States
| | - Matthew R Pratt
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States
| | - Theresa Kissel
- Department of Rheumatology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Carolien A M Koeleman
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Rayman T N Tjokrodirijo
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Petrus A van Veelen
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Thomas Huizinga
- Department of Rheumatology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Karin A J van Schie
- Department of Rheumatology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern, 5323 Harry Hines Boulevard, Dallas, TX 75390-09185, United States
| | - Kimberly M Bonger
- Department of Synthetic Organic Chemistry, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Thomas J Boltje
- Department of Synthetic Organic Chemistry, Radboud University, Toernooiveld 1, Mercator III, 6525 ED, Nijmegen, The Netherlands
| | - Reinaldus E M Toes
- Department of Rheumatology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
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6
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Ghorashi AC, Boucher A, Archer-Hartmann SA, Murray NB, Konada RSR, Zhang X, Xing C, Azadi P, Yrlid U, Kohler JJ. Fucosylated glycoproteins and fucosylated glycolipids play opposing roles in cholera intoxication. bioRxiv 2023:2023.08.02.551727. [PMID: 37577488 PMCID: PMC10418270 DOI: 10.1101/2023.08.02.551727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Cholera toxin (CT) is the etiological agent of cholera. Here we report that multiple classes of fucosylated glycoconjugates function in CT binding and intoxication of intestinal epithelial cells. In Colo205 cells, knockout of B3GNT5, the enzyme required for synthesis of lacto- and neolacto-series glycosphingolipids (GSLs), reduces CT binding but sensitizes cells to intoxication. Overexpressing B3GNT5 to generate more fucosylated GSLs confers protection against intoxication, indicating that fucosylated GSLs act as decoy receptors for CT. Knockout (KO) of B3GALT5 causes increased production of fucosylated O-linked and N-linked glycoproteins, and leads to increased CT binding and intoxication. Knockout of B3GNT5 in B3GALT5 KO cells eliminates production of fucosylated GSLs but increases intoxication, identifying fucosylated glycoproteins as functional receptors for CT. These findings provide insight into molecular determinants regulating CT sensitivity of host cells.
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Affiliation(s)
- Atossa C. Ghorashi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas TX 75390 USA
| | - Andrew Boucher
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | | | - Nathan B. Murray
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | | | - Xunzhi Zhang
- McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas TX 75390 USA
| | - Chao Xing
- McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas TX 75390 USA
- Department of Bioinformatics, UT Southwestern Medical Center, Dallas TX 75390 USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Jennifer J. Kohler
- Department of Biochemistry, UT Southwestern Medical Center, Dallas TX 75390 USA
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7
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Boyce M, Malaker SA, Riley NM, Kohler JJ. The 2022 Nobel prize in chemistry - sweet! Glycobiology 2023; 33:178-181. [PMID: 36892406 DOI: 10.1093/glycob/cwad016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/13/2023] [Accepted: 02/05/2023] [Indexed: 03/10/2023] Open
Affiliation(s)
- Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Stacy A Malaker
- Department of Chemistry, Yale University, 275 Prospect St, New Haven, CT 06511, United States
| | - Nicholas M Riley
- Department of Chemistry, Sarafan ChEM-H, Stanford University, Stanford, California, USA
| | - Jennifer J Kohler
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75930, USA
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8
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Burns MWN, Kohler JJ. Engineering Glyco‐Enzymes for Substrate Identification and Targeting. Isr J Chem 2022. [DOI: 10.1002/ijch.202200093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mary W. N. Burns
- Department of Biochemistry UT Southwestern Medical Center Dallas TX 75390 USA
| | - Jennifer J. Kohler
- Department of Biochemistry UT Southwestern Medical Center Dallas TX 75390 USA
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9
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Yarravarapu N, Konada RSR, Darabedian N, Pedowitz NJ, Krishnamurthy SN, Pratt MR, Kohler JJ. Exo-Enzymatic Addition of Diazirine-Modified Sialic Acid to Cell Surfaces Enables Photocrosslinking of Glycoproteins. Bioconjug Chem 2022; 33:781-787. [PMID: 35437982 DOI: 10.1021/acs.bioconjchem.2c00037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glycan binding often mediates extracellular macromolecular recognition events. Accurate characterization of these binding interactions can be difficult because of dissociation and scrambling that occur during purification and analysis steps. Use of photocrosslinking methods has been pursued to covalently capture glycan-dependent interactions in situ; however, use of metabolic glycan engineering methods to incorporate photocrosslinking sugar analogs is limited to certain cell types. Here, we report an exo-enzymatic labeling method to add a diazirine-modified sialic acid (SiaDAz) to cell surface glycoconjugates. The method involves the chemoenzymatic synthesis of diazirine-modified CMP-sialic acid (CMP-SiaDAz), followed by sialyltransferase-catalyzed addition of SiaDAz to desialylated cell surfaces. Cell surface SiaDAzylation is compatible with multiple cell types and is facilitated by endogenous extracellular sialyltransferase activity present in Daudi B cells. This method for extracellular addition of α2-6-linked SiaDAz enables UV-induced crosslinking of CD22, demonstrating the utility for covalent capture of glycan-mediated binding interactions.
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Affiliation(s)
| | | | | | | | | | | | - Jennifer J Kohler
- Department of Biochemistry, UT Southwestern, Dallas, Texas 75390, United States
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10
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Carroll DJ, Burns MWN, Mottram L, Propheter DC, Boucher A, Lessen GM, Kumar A, Malaker SA, Xing C, Hooper LV, Yrlid U, Kohler JJ. Interleukin-22 regulates B3GNT7 expression to induce fucosylation of glycoproteins in intestinal epithelial cells. J Biol Chem 2022; 298:101463. [PMID: 34864058 PMCID: PMC8808068 DOI: 10.1016/j.jbc.2021.101463] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/24/2021] [Accepted: 11/27/2021] [Indexed: 12/13/2022] Open
Abstract
Interleukin (IL)-22 is a cytokine that plays a critical role in intestinal epithelial homeostasis. Its downstream functions are mediated through interaction with the heterodimeric IL-22 receptor and subsequent activation of signal transducer and activator of transcription 3 (STAT3). IL-22 signaling can induce transcription of genes necessary for intestinal epithelial cell proliferation, tissue regeneration, tight junction fortification, and antimicrobial production. Recent studies have also implicated IL-22 signaling in the regulation of intestinal epithelial fucosylation in mice. However, whether IL-22 regulates intestinal fucosylation in human intestinal epithelial cells and the molecular mechanisms that govern this process are unknown. Here, in experiments performed in human cell lines and human-derived enteroids, we show that IL-22 signaling regulates expression of the B3GNT7 transcript, which encodes a β1-3-N-acetylglucosaminyltransferase that can participate in the synthesis of poly-N-acetyllactosamine (polyLacNAc) chains. Additionally, we find that IL-22 signaling regulates levels of the α1-3-fucosylated Lewis X (Lex) blood group antigen, and that this glycan epitope is primarily displayed on O-glycosylated intestinal epithelial glycoproteins. Moreover, we show that increased expression of B3GNT7 alone is sufficient to promote increased display of Lex-decorated carbohydrate glycan structures primarily on O-glycosylated intestinal epithelial glycoproteins. Together, these data identify B3GNT7 as an intermediary in IL-22-dependent induction of fucosylation of glycoproteins and uncover a novel role for B3GNT7 in intestinal glycosylation.
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Affiliation(s)
- Daniela J Carroll
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mary W N Burns
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lynda Mottram
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Daniel C Propheter
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Andrew Boucher
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Gabrielle M Lessen
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ashwani Kumar
- Eugene McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Stacy A Malaker
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Bioinformatics, The University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Population and Data Sciences, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lora V Hooper
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA; Howard Hughes Medical Institute, Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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11
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Jackson EG, Cutolo G, Yang B, Yarravarapu N, Burns MWN, Bineva-Todd G, Roustan C, Thoden JB, Lin-Jones HM, van Kuppevelt TH, Holden HM, Schumann B, Kohler JJ, Woo CM, Pratt MR. 4-Deoxy-4-fluoro-GalNAz (4FGalNAz) Is a Metabolic Chemical Reporter of O-GlcNAc Modifications, Highlighting the Notable Substrate Flexibility of O-GlcNAc Transferase. ACS Chem Biol 2022; 17:159-170. [PMID: 34931806 PMCID: PMC8787749 DOI: 10.1021/acschembio.1c00818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Bio-orthogonal chemistries
have revolutionized many fields. For
example, metabolic chemical reporters (MCRs) of glycosylation are
analogues of monosaccharides that contain a bio-orthogonal functionality,
such as azides or alkynes. MCRs are metabolically incorporated into
glycoproteins by living systems, and bio-orthogonal reactions can
be subsequently employed to install visualization and enrichment tags.
Unfortunately, most MCRs are not selective for one class of glycosylation
(e.g., N-linked vs O-linked), complicating the types of information
that can be gleaned. We and others have successfully created MCRs
that are selective for intracellular O-GlcNAc modification by altering
the structure of the MCR and thus biasing it to certain metabolic
pathways and/or O-GlcNAc transferase (OGT). Here, we attempt to do
the same for the core GalNAc residue of mucin O-linked glycosylation.
The most widely applied MCR for mucin O-linked glycosylation, GalNAz,
can be enzymatically epimerized at the 4-hydroxyl to give GlcNAz.
This results in a mixture of cell-surface and O-GlcNAc labeling. We
reasoned that replacing the 4-hydroxyl of GalNAz with a fluorine would
lock the stereochemistry of this position in place, causing the MCR
to be more selective. After synthesis, we found that 4FGalNAz labels
a variety of proteins in mammalian cells and does not perturb endogenous
glycosylation pathways unlike 4FGalNAc. However, through subsequent
proteomic and biochemical characterization, we found that 4FGalNAz
does not widely label cell-surface glycoproteins but instead is primarily
a substrate for OGT. Although these results are somewhat unexpected,
they once again highlight the large substrate flexibility of OGT,
with interesting and important implications for intracellular protein
modification by a potential range of abiotic and native monosaccharides.
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Affiliation(s)
- Emma G. Jackson
- Departments of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Giuliano Cutolo
- Departments of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Bo Yang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Nageswari Yarravarapu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Mary W. N. Burns
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Ganka Bineva-Todd
- Chemical Glycobiology Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - Chloë Roustan
- Structural Biology Science Technology Platform, The Francis Crick Institute, NW1 1AT London, United Kingdom
| | - James B. Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Halley M. Lin-Jones
- Departments of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Toin H. van Kuppevelt
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6500 HB Nijmegen The Netherlands
| | - Hazel M. Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Benjamin Schumann
- Chemical Glycobiology Laboratory, The Francis Crick Institute, NW1 1AT London, United Kingdom
- Department of Chemistry, Imperial College London, W120BZ London, United Kingdom
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Christina M. Woo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Matthew R. Pratt
- Departments of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Biological Sciences, University of Southern California, Los Angeles, California 90089, United States
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12
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Wu H, Shajahan A, Yang JY, Capota E, Wands AM, Arthur CM, Stowell SR, Moremen KW, Azadi P, Kohler JJ. A photo-cross-linking GlcNAc analog enables covalent capture of N-linked glycoprotein-binding partners on the cell surface. Cell Chem Biol 2022; 29:84-97.e8. [PMID: 34331854 PMCID: PMC8792112 DOI: 10.1016/j.chembiol.2021.07.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/11/2021] [Accepted: 07/08/2021] [Indexed: 02/07/2023]
Abstract
N-glycans are displayed on cell-surface proteins and can engage in direct binding interactions with membrane-bound and secreted glycan-binding proteins (GBPs). Biochemical identification and characterization of glycan-mediated interactions is often made difficult by low binding affinities. Here we describe the metabolic introduction of a diazirine photo-cross-linker onto N-acetylglucosamine (GlcNAc) residues of N-linked glycoproteins on cell surfaces. We characterize sites at which diazirine-modified GlcNAc is incorporated, as well as modest perturbations to glycan structure. We show that diazirine-modified GlcNAc can be used to covalently cross-link two extracellular GBPs, galectin-1 and cholera toxin subunit B, to cell-surface N-linked glycoproteins. The extent of cross-linking correlates with display of the preferred glycan ligands for the GBPs. In addition, covalently cross-linked complexes could be isolated, and protein components of cross-linked N-linked glycoproteins were identified by proteomics analysis. This method may be useful in the discovery and characterization of binding interactions that depend on N-glycans.
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Affiliation(s)
- Han Wu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Asif Shajahan
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Jeong-Yeh Yang
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA,current affiliation: Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia 30605
| | - Emanuela Capota
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Amberlyn M. Wands
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA
| | - Connie M. Arthur
- Joint Program in Transfusion Medicine, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, Harvard Glycomics Center, Harvard Medical School, Boston, MA USA
| | - Sean R. Stowell
- Joint Program in Transfusion Medicine, Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, Harvard Glycomics Center, Harvard Medical School, Boston, MA USA
| | - Kelley W. Moremen
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 USA,Lead Contact:
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13
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Pedowitz NJ, Jackson EG, Overhulse JM, McKenna CE, Kohler JJ, Pratt MR. Anomeric Fatty Acid Functionalization Prevents Nonenzymatic S-Glycosylation by Monosaccharide Metabolic Chemical Reporters. ACS Chem Biol 2021; 16:1924-1929. [PMID: 34282887 DOI: 10.1021/acschembio.1c00470] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Metabolic chemical reports have fundamentally changed the way researchers study glycosylation. However, when administered as per-O-acetylated sugars, reporter molecules can participate in nonspecific chemical labeling of cysteine residues termed S-glycosylation. Without detailed proteomic analyses, these labeling events can be indistinguishable from bona fide enzymatic labeling convoluting experimental results. Here, we report a solution in the synthesis and characterization of two reporter molecules functionalized at the anomeric position with hexanoic acid: 1-Hex-GlcNAlk and 1-Hex-6AzGlcNAc. Both reporters exhibit robust labeling over background with negligible amounts of nonspecific chemical labeling in cell lysates. This strategy serves as a template for the design of future reporter molecules allowing for more reliable interpretation of results.
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Affiliation(s)
- Nichole J. Pedowitz
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Emma G. Jackson
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Justin M. Overhulse
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Matthew R. Pratt
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, California 90089, United States
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14
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Kakde BN, Capota E, Kohler JJ, Tambar UK. Synthesis of Cell-Permeable N-Acetylhexosamine 1-Phosphates. J Org Chem 2021; 86:18257-18264. [PMID: 34618463 DOI: 10.1021/acs.joc.1c01781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We recently reported the incorporation of diazirine photo-cross-linkers onto the O-GlcNAc posttranslational modification in mammalian cells, enabling the identification of binding partners of O-GlcNAcylated proteins. Unfortunately, the syntheses of the diazirine-functionalized substrates have exhibited inconsistent yields. We report a robust and stereoselective synthesis of cell-permeable GlcNAc-1-phosphate esters based on the use of commercially available bis(diisopropylamino)chlorophosphine. We demonstrate this approach for two diazirine-containing GlcNAc analogues, and we report the cellular incorporation of these compounds into glycoconjugates to support photo-cross-linking applications.
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Affiliation(s)
- Badrinath N Kakde
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Emanuela Capota
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Jennifer J Kohler
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
| | - Uttam K Tambar
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States
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15
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Abstract
This protocol enables identification of the interaction partners of O-GlcNAcylated proteins. The method involves the introduction of the diazirine photocrosslinker onto the O-GlcNAc modification within living cells. The photocrosslinker is activated by UV light to yield covalent crosslinking between O-GlcNAcylated proteins and neighboring molecules. The binding partners can be further characterized by immunoblot or proteomics mass spectrometry methods. The benefits of using the photocrosslinker include the capacity to trap low-affinity binding interactions and the ability to selectively target the interaction partners of the O-GlcNAcylated form of the protein of interest. © 2021 Wiley Periodicals LLC. Basic Protocol 1: In-cell production and crosslinking of O-GlcNDAzylated proteins Basic Protocol 2: Immunoblot analysis to assess O-GlcNDAz crosslinking Support Protocol: Detection of UDP-GlcNDAz from cell lysates.
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Affiliation(s)
- Emanuela Capota
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas
| | - Han Wu
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas
| | - Jennifer J Kohler
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas
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16
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Kohler JJ. What sugar does to your pores. J Cell Biol 2021; 220:212387. [PMID: 34132758 PMCID: PMC8212696 DOI: 10.1083/jcb.202105163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
FG-repeat nucleoporins at the center of the nuclear pore complex (NPC) are highly modified with O-GlcNAc. In this issue, Yoo and Mitchison (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202010141) use optogenetic probes to show that O-GlcNAc enhances permeability of the NPC, accelerating transport in both directions.
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Affiliation(s)
- Jennifer J Kohler
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX
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17
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Shajahan A, Supekar NT, Wu H, Wands AM, Bhat G, Kalimurthy A, Matsubara M, Ranzinger R, Kohler JJ, Azadi P. Mass Spectrometric Method for the Unambiguous Profiling of Cellular Dynamic Glycosylation. ACS Chem Biol 2020; 15:2692-2701. [PMID: 32809798 DOI: 10.1021/acschembio.0c00453] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Various biological processes at the cellular level are regulated by glycosylation which is a highly microheterogeneous post-translational modification (PTM) on proteins and lipids. The dynamic nature of glycosylation can be studied through metabolic incorporation of non-natural sugars into glycan epitopes and their detection using bio-orthogonal probes. However, this approach possesses a significant drawback due to nonspecific background reactions and ambiguity of non-natural sugar metabolism. Here, we report a probe-free strategy for their direct detection by glycoproteomics and glycomics using mass spectrometry (MS). The method dramatically simplifies the detection of non-natural functional group bearing monosaccharides installed through promiscuous sialic acid, N-acetyl-d-galactosamine (GalNAc) and N-acetyl-d-glucosamine (GlcNAc) biosynthetic pathways. Multistage enrichment of glycoproteins by cellular fractionation, subsequent ZIC-HILIC (zwitterionic-hydrophilic interaction chromatography) based glycopeptide enrichment, and a spectral enrichment algorithm for the MS data processing enabled direct detection of non-natural monosaccharides that are incorporated at low abundance on the N/O-glycopeptides along with their natural counterparts. Our approach allowed the detection of both natural and non-natural sugar bearing glycopeptides, N- and O-glycopeptides, differentiation of non-natural monosaccharide types on the glycans and also their incorporation efficiency through quantitation. Through this, we could deduce interconversion of monosaccharides during their processing through glycan salvage pathway and subsequent incorporation into glycan chains. The study of glycosylation dynamics through this method can be conducted in high throughput, as few sample processing steps are involved, enabling understanding of glycosylation dynamics under various external stimuli and thereby could bolster the use of metabolic glycan engineering in glycosylation functional studies.
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Affiliation(s)
- Asif Shajahan
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Nitin T. Supekar
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Han Wu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Amberlyn M. Wands
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Ganapati Bhat
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Aravind Kalimurthy
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Masaaki Matsubara
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Rene Ranzinger
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, The University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
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18
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Broussard A, Florwick A, Desbiens C, Nischan N, Robertson C, Guan Z, Kohler JJ, Wells L, Boyce M. Human UDP-galactose 4′-epimerase (GALE) is required for cell-surface glycome structure and function. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49882-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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19
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Broussard A, Florwick A, Desbiens C, Nischan N, Robertson C, Guan Z, Kohler JJ, Wells L, Boyce M. Human UDP-galactose 4'-epimerase (GALE) is required for cell-surface glycome structure and function. J Biol Chem 2019; 295:1225-1239. [PMID: 31819007 DOI: 10.1074/jbc.ra119.009271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 11/23/2019] [Indexed: 12/27/2022] Open
Abstract
Glycan biosynthesis relies on nucleotide sugars (NSs), abundant metabolites that serve as monosaccharide donors for glycosyltransferases. In vivo, signal-dependent fluctuations in NS levels are required to maintain normal cell physiology and are dysregulated in disease. However, how mammalian cells regulate NS levels and pathway flux remains largely uncharacterized. To address this knowledge gap, here we examined UDP-galactose 4'-epimerase (GALE), which interconverts two pairs of essential NSs. Using immunoblotting, flow cytometry, and LC-MS-based glycolipid and glycan profiling, we found that CRISPR/Cas9-mediated GALE deletion in human cells triggers major imbalances in NSs and dramatic changes in glycolipids and glycoproteins, including a subset of integrins and the cell-surface death receptor FS-7-associated surface antigen. In particular, we observed substantial decreases in total sialic acid, galactose, and GalNAc levels in glycans. These changes also directly impacted cell signaling, as GALE -/- cells exhibited FS-7-associated surface antigen ligand-induced apoptosis. Our results reveal a role of GALE-mediated NS regulation in death receptor signaling and may have implications for the molecular etiology of illnesses characterized by NS imbalances, including galactosemia and metabolic syndrome.
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Affiliation(s)
- Alex Broussard
- Department of Biochemistry, Duke University, Durham, North Carolina 27710
| | - Alyssa Florwick
- Department of Biochemistry, Duke University, Durham, North Carolina 27710
| | - Chelsea Desbiens
- Department of Chemistry, University of Georgia, Athens, Georgia 30602
| | - Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Corrina Robertson
- Department of Biochemistry, Duke University, Durham, North Carolina 27710
| | - Ziqiang Guan
- Department of Biochemistry, Duke University, Durham, North Carolina 27710
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Lance Wells
- Department of Chemistry, University of Georgia, Athens, Georgia 30602.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | - Michael Boyce
- Department of Biochemistry, Duke University, Durham, North Carolina 27710
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20
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Affiliation(s)
- Atossa C Ghorashi
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Jennifer J Kohler
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas 75390, United States
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21
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Sethi A, Wands AM, Mettlen M, Krishnamurthy S, Wu H, Kohler JJ. Cell type and receptor identity regulate cholera toxin subunit B (CTB) internalization. Interface Focus 2019; 9:20180076. [PMID: 30842875 PMCID: PMC6388018 DOI: 10.1098/rsfs.2018.0076] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2019] [Indexed: 12/21/2022] Open
Abstract
Cholera toxin (CT) is a secreted bacterial toxin that binds to glycoconjugate receptors on the surface of mammalian cells, enters mammalian cells through endocytic mechanisms and intoxicates mammalian cells by activating cytosolic adenylate cyclase. CT recognizes cell surface receptors through its B subunit (CTB). While the ganglioside GM1 has been historically described as the sole receptor, CTB is also capable of binding to fucosylated glycoconjugates, and fucosylated molecules have been shown to play a functional role in host cell intoxication by CT. Here, we use colonic epithelial and respiratory epithelial cell lines to examine how two types of CT receptors-gangliosides and fucosylated glycoconjugates-contribute to CTB internalization. We show that fucosylated glycoconjugates contribute to CTB binding to and internalization into host cells, even when the ganglioside GM1 is present. The contributions of the two classes of receptors to CTB internalization depend on cell type. Additionally, in a cell line that harbours both classes of receptors, gangliosides dictate the efficiency of CTB internalization. Together, the results lend support to the idea that fucosylated glycoconjugates play a functional role in CTB internalization, and suggest that CT internalization depends on both receptor identity and cell type.
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Affiliation(s)
- Anirudh Sethi
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Amberlyn M Wands
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marcel Mettlen
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Soumya Krishnamurthy
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Han Wu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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22
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Wands AM, Cervin J, Huang H, Zhang Y, Youn G, Brautigam CA, Matson Dzebo M, Björklund P, Wallenius V, Bright DK, Bennett CS, Wittung-Stafshede P, Sampson NS, Yrlid U, Kohler JJ. Fucosylated Molecules Competitively Interfere with Cholera Toxin Binding to Host Cells. ACS Infect Dis 2018; 4:758-770. [PMID: 29411974 DOI: 10.1021/acsinfecdis.7b00085] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cholera toxin (CT) enters host intestinal epithelia cells, and its retrograde transport to the cytosol results in the massive loss of fluids and electrolytes associated with severe dehydration. To initiate this intoxication process, the B subunit of CT (CTB) first binds to a cell surface receptor displayed on the apical surface of the intestinal epithelia. While the monosialoganglioside GM1 is widely accepted to be the sole receptor for CT, intestinal epithelial cell lines also utilize fucosylated glycan epitopes on glycoproteins to facilitate cell surface binding and endocytic uptake of the toxin. Further, l-fucose can competively inhibit CTB binding to intestinal epithelia cells. Here, we use competition binding assays with l-fucose analogs to decipher the molecular determinants for l-fucose inhibition of cholera toxin subunit B (CTB) binding. Additionally, we find that mono- and difucosylated oligosaccharides are more potent inhibitors than l-fucose alone, with the LeY tetrasaccharide emerging as the most potent inhibitor of CTB binding to two colonic epithelial cell lines (T84 and Colo205). Finally, a non-natural fucose-containing polymer inhibits CTB binding two orders of magnitude more potently than the LeY glycan when tested against Colo205 cells. This same polymer also inhibits CTB binding to T84 cells and primary human jejunal epithelial cells in a dose-dependent manner. These findings suggest the possibility that polymeric display of fucose might be exploited as a prophylactic or therapeutic approach to block the action of CT toward the human intestinal epithelium.
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Affiliation(s)
| | - Jakob Cervin
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden
| | - He Huang
- Department of Chemistry, Stony Brook University, 100 Toll Road, Stony Brook, New York 11790-3400, United States
| | - Ye Zhang
- Department of Chemistry, Stony Brook University, 100 Toll Road, Stony Brook, New York 11790-3400, United States
| | - Gyusaang Youn
- Department of Chemistry, Stony Brook University, 100 Toll Road, Stony Brook, New York 11790-3400, United States
| | | | - Maria Matson Dzebo
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Per Björklund
- Department of Gastrosurgical Research and Education, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra, SE-41345 Gothenburg, Sweden
| | - Ville Wallenius
- Department of Gastrosurgical Research and Education, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital/Östra, SE-41345 Gothenburg, Sweden
| | - Danielle K. Bright
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Clay S. Bennett
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden
| | - Nicole S. Sampson
- Department of Chemistry, Stony Brook University, 100 Toll Road, Stony Brook, New York 11790-3400, United States
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden
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23
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Park SK, Zhou X, Pendleton KE, Hunter OV, Kohler JJ, O'Donnell KA, Conrad NK. A Conserved Splicing Silencer Dynamically Regulates O-GlcNAc Transferase Intron Retention and O-GlcNAc Homeostasis. Cell Rep 2018; 20:1088-1099. [PMID: 28768194 PMCID: PMC5588854 DOI: 10.1016/j.celrep.2017.07.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/11/2017] [Accepted: 07/10/2017] [Indexed: 11/05/2022] Open
Abstract
Modification of nucleocytoplasmic proteins with O-GlcNAc regulates a wide variety of cellular processes and has been linked to human diseases. The enzymes O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) add and remove O-GlcNAc, but the mechanisms regulating their expression remain unclear. Here, we demonstrate that retention of the fourth intron of OGT is regulated in response to O-GlcNAc levels. We further define a conserved intronic splicing silencer (ISS) that is necessary for OGT intron retention. Deletion of the ISS in colon cancer cells leads to increases in OGT, but O-GlcNAc homeostasis is maintained by concomitant increases in OGA protein. However, the ISS-deleted cells are hypersensitive to OGA inhibition in culture and in soft agar. Moreover, growth of xenograft tumors from ISS-deleted cells is compromised in mice treated with an OGA inhibitor. Thus, ISS-mediated regulation of OGT intron retention is a key component in OGT expression and maintaining O-GlcNAc homeostasis.
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Affiliation(s)
- Sung-Kyun Park
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiaorong Zhou
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kathryn E Pendleton
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Olga V Hunter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kathryn A O'Donnell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nicholas K Conrad
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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24
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Cervin J, Wands AM, Casselbrant A, Wu H, Krishnamurthy S, Cvjetkovic A, Estelius J, Dedic B, Sethi A, Wallom KL, Riise R, Bäckström M, Wallenius V, Platt FM, Lebens M, Teneberg S, Fändriks L, Kohler JJ, Yrlid U. GM1 ganglioside-independent intoxication by Cholera toxin. PLoS Pathog 2018; 14:e1006862. [PMID: 29432456 PMCID: PMC5825173 DOI: 10.1371/journal.ppat.1006862] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 02/23/2018] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors via its B subunit (CTB). We have recently shown that in addition to the previously described binding partner ganglioside GM1, CTB binds to fucosylated proteins. Using flow cytometric analysis of primary human jejunal epithelial cells and granulocytes, we now show that CTB binding correlates with expression of the fucosylated Lewis X (LeX) glycan. This binding is competitively blocked by fucosylated oligosaccharides and fucose-binding lectins. CTB binds the LeX glycan in vitro when this moiety is linked to proteins but not to ceramides, and this binding can be blocked by mAb to LeX. Inhibition of glycosphingolipid synthesis or sialylation in GM1-deficient C6 rat glioma cells results in sensitization to CT-mediated intoxication. Finally, CT gavage produces an intact diarrheal response in knockout mice lacking GM1 even after additional reduction of glycosphingolipids. Hence our results show that CT can induce toxicity in the absence of GM1 and support a role for host glycoproteins in CT intoxication. These findings open up new avenues for therapies to block CT action and for design of detoxified enterotoxin-based adjuvants.
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Affiliation(s)
- Jakob Cervin
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Amberlyn M. Wands
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Anna Casselbrant
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Han Wu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Soumya Krishnamurthy
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Aleksander Cvjetkovic
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Johanna Estelius
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Benjamin Dedic
- Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anirudh Sethi
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Kerri-Lee Wallom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Rebecca Riise
- Sahlgrenska Cancer Center, University of Gothenburg, Gothenburg, Sweden
| | - Malin Bäckström
- Mammalian Protein Expression Core Facility, University of Gothenburg, Gothenburg, Sweden
| | - Ville Wallenius
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Frances M. Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Michael Lebens
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Susann Teneberg
- Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lars Fändriks
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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25
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Tanigaki K, Sacharidou A, Peng J, Chambliss KL, Yuhanna IS, Ghosh D, Ahmed M, Szalai AJ, Vongpatanasin W, Mattrey RF, Chen Q, Azadi P, Lingvay I, Botto M, Holland WL, Kohler JJ, Sirsi SR, Hoyt K, Shaul PW, Mineo C. Hyposialylated IgG activates endothelial IgG receptor FcγRIIB to promote obesity-induced insulin resistance. J Clin Invest 2017; 128:309-322. [PMID: 29202472 DOI: 10.1172/jci89333] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/17/2017] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a common complication of obesity. Here, we have shown that activation of the IgG receptor FcγRIIB in endothelium by hyposialylated IgG plays an important role in obesity-induced insulin resistance. Despite becoming obese on a high-fat diet (HFD), mice lacking FcγRIIB globally or selectively in endothelium were protected from insulin resistance as a result of the preservation of insulin delivery to skeletal muscle and resulting maintenance of muscle glucose disposal. IgG transfer in IgG-deficient mice implicated IgG as the pathogenetic ligand for endothelial FcγRIIB in obesity-induced insulin resistance. Moreover, IgG transferred from patients with T2DM but not from metabolically healthy subjects caused insulin resistance in IgG-deficient mice via FcγRIIB, indicating that similar processes may be operative in T2DM in humans. Mechanistically, the activation of FcγRIIB by IgG from obese mice impaired endothelial cell insulin transcytosis in culture and in vivo. These effects were attributed to hyposialylation of the Fc glycan, and IgG from T2DM patients was also hyposialylated. In HFD-fed mice, supplementation with the sialic acid precursor N-acetyl-D-mannosamine restored IgG sialylation and preserved insulin sensitivity without affecting weight gain. Thus, IgG sialylation and endothelial FcγRIIB may represent promising therapeutic targets to sever the link between obesity and T2DM.
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Affiliation(s)
- Keiji Tanigaki
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Anastasia Sacharidou
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jun Peng
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ken L Chambliss
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ivan S Yuhanna
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Debabrata Ghosh
- Department of Bioengineering, University of Texas at Dallas, Richardson Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mohamed Ahmed
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Alexander J Szalai
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wanpen Vongpatanasin
- Hypertension Section, Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Robert F Mattrey
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Qiushi Chen
- The Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Parastoo Azadi
- The Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Ildiko Lingvay
- Division of Endocrinology, Diabetes, and Metabolism and Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Marina Botto
- Centre for Complement and Inflammation Research, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London, United Kingdom
| | | | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Shashank R Sirsi
- Department of Bioengineering, University of Texas at Dallas, Richardson Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kenneth Hoyt
- Department of Bioengineering, University of Texas at Dallas, Richardson Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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26
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Andres LM, Blong IW, Evans AC, Rumachik NG, Yamaguchi T, Pham ND, Thompson P, Kohler JJ, Bertozzi CR. Chemical Modulation of Protein O-GlcNAcylation via OGT Inhibition Promotes Human Neural Cell Differentiation. ACS Chem Biol 2017; 12:2030-2039. [PMID: 28541657 DOI: 10.1021/acschembio.7b00232] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The enzymes that determine protein O-GlcNAcylation, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), act on key transcriptional and epigenetic regulators, and both are abundantly expressed in the brain. However, little is known about how alterations in O-GlcNAc cycling affect human embryonic stem cell (hESC) neural differentiation. Here, we studied the effects of perturbing O-GlcNAcylation during neural induction of hESCs using the metabolic inhibitor of OGT, peracetylated 5-thio-N-acetylglucosamine (Ac4-5SGlcNAc). Treatment of hESCs with Ac4-5SGlcNAc during induction limited protein O-GlcNAcylation and also caused a dramatic decrease in global levels of UDP-GlcNAc. Concomitantly, a subpopulation of neural progenitor cells (NPCs) acquired an immature neuronal morphology and expressed early neuronal markers such as β-III tubulin (TUJ1) and microtubule associated protein 2 (MAP2), phenotypes that took longer to manifest in the absence of OGT inhibition. These data suggest that chemical inhibition of OGT and perturbation of protein O-GlcNAcylation accelerate the differentiation of hESCs along the neuronal lineage, thus providing further insight into the dynamic molecular mechanisms involved in neuronal development.
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Affiliation(s)
- Lissette M. Andres
- Department
of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Ian W. Blong
- Department
of Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California 94305, United States
| | - Angela C. Evans
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Neil G. Rumachik
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Teppei Yamaguchi
- Department
of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States
| | - Nam D. Pham
- Department
of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Pamela Thompson
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Jennifer J. Kohler
- Department
of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Carolyn R. Bertozzi
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States
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28
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Wright JD, An SW, Xie J, Yoon J, Nischan N, Kohler JJ, Oliver N, Lim C, Huang CL. Modeled structural basis for the recognition of α2-3-sialyllactose by soluble Klotho. FASEB J 2017; 31:3574-3586. [PMID: 28442546 DOI: 10.1096/fj.201700043r] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/11/2017] [Indexed: 01/09/2023]
Abstract
Soluble Klotho (sKlotho) is the shed ectodomain of antiaging membrane Klotho that contains 2 extracellular domains KL1 and KL2, each of which shares sequence homology to glycosyl hydrolases. sKlotho elicits pleiotropic cellular responses with a poorly understood mechanism of action. Notably, in injury settings, sKlotho confers cardiac and renal protection by down-regulating calcium-permeable transient receptor potential canonical type isoform 6 (TRPC6) channels in cardiomyocytes and glomerular podocytes. Inhibition of PI3K-dependent exocytosis of TRPC6 is thought to be the underlying mechanism, and recent studies showed that sKlotho interacts with α2-3-sialyllactose-containing gangliosides enriched in lipid rafts to inhibit raft-dependent PI3K signaling. However, the structural basis for binding and recognition of α2-3-sialyllactose by sKlotho is unknown. Using homology modeling followed by docking, we identified key protein residues in the KL1 domain that are likely involved in binding sialyllactose. Functional experiments based on the ability of Klotho to down-regulate TRPC6 channel activity confirm the importance of these residues. Furthermore, KL1 domain binds α2-3-sialyllactose, down-regulates TRPC6 channels, and exerts protection against stress-induced cardiac hypertrophy in mice. Our results support the notion that sialogangliosides and lipid rafts are membrane receptors for sKlotho and that the KL1 domain is sufficient for the tested biologic activities. These findings can help guide the design of a simpler Klotho mimetic.-Wright, J. D., An, S.-W., Xie, J., Yoon, J., Nischan, N., Kohler, J. J., Oliver, N., Lim, C., Huang, C.-L. Modeled structural basis for the recognition of α2-3-sialyllactose by soluble Klotho.
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Affiliation(s)
- Jon D Wright
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Sung-Wan An
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Texas, USA
| | - Jian Xie
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Texas, USA
| | - Joonho Yoon
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Texas, USA
| | - Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Noelynn Oliver
- Cardiometabolic Disease Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut, USA
| | - Carmay Lim
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; .,Department of Chemistry, National Tsing Hua University, HsinChu, Taiwan
| | - Chou-Long Huang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Texas, USA;
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29
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Pham ND, Pang PC, Krishnamurthy S, Wands AM, Grassi P, Dell A, Haslam SM, Kohler JJ. Effects of altered sialic acid biosynthesis on N-linked glycan branching and cell surface interactions. J Biol Chem 2017; 292:9637-9651. [PMID: 28424265 PMCID: PMC5465488 DOI: 10.1074/jbc.m116.764597] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 04/17/2017] [Indexed: 12/22/2022] Open
Abstract
GNE (UDP-GlcNAc 2-epimerase/ManNAc kinase) myopathy is a rare muscle disorder associated with aging and is related to sporadic inclusion body myositis, the most common acquired muscle disease of aging. Although the cause of sporadic inclusion body myositis is unknown, GNE myopathy is associated with mutations in GNE. GNE harbors two enzymatic activities required for biosynthesis of sialic acid in mammalian cells. Mutations to both GNE domains are linked to GNE myopathy. However, correlation between mutation-associated reductions in sialic acid production and disease severity is imperfect. To investigate other potential effects of GNE mutations, we compared sialic acid production in cell lines expressing wild type or mutant forms of GNE. Although we did not detect any differences attributable to disease-associated mutations, lectin binding and mass spectrometry analysis revealed that GNE deficiency is associated with unanticipated effects on the structure of cell-surface glycans. In addition to exhibiting low levels of sialylation, GNE-deficient cells produced distinct N-linked glycan structures with increased branching and extended poly-N-acetyllactosamine. GNE deficiency may affect levels of UDP-GlcNAc, a key metabolite in the nutrient-sensing hexosamine biosynthetic pathway, but this modest effect did not fully account for the change in N-linked glycan structure. Furthermore, GNE deficiency and glucose supplementation acted independently and additively to increase N-linked glycan branching. Notably, N-linked glycans produced by GNE-deficient cells displayed enhanced binding to galectin-1, indicating that changes in GNE activity can alter affinity of cell-surface glycoproteins for the galectin lattice. These findings suggest an unanticipated mechanism by which GNE activity might affect signaling through cell-surface receptors.
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Affiliation(s)
- Nam D Pham
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038 and
| | - Poh-Choo Pang
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Soumya Krishnamurthy
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038 and
| | - Amberlyn M Wands
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038 and
| | - Paola Grassi
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Anne Dell
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Stuart M Haslam
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Jennifer J Kohler
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038 and
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30
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Leija C, Rijo-Ferreira F, Kinch LN, Grishin NV, Nischan N, Kohler JJ, Hu Z, Phillips MA. Pyrimidine Salvage Enzymes Are Essential for De Novo Biosynthesis of Deoxypyrimidine Nucleotides in Trypanosoma brucei. PLoS Pathog 2016; 12:e1006010. [PMID: 27820863 PMCID: PMC5098729 DOI: 10.1371/journal.ppat.1006010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/18/2016] [Indexed: 01/17/2023] Open
Abstract
The human pathogenic parasite Trypanosoma brucei possess both de novo and salvage routes for the biosynthesis of pyrimidine nucleotides. Consequently, they do not require salvageable pyrimidines for growth. Thymidine kinase (TK) catalyzes the formation of dTMP and dUMP and is one of several salvage enzymes that appear redundant to the de novo pathway. Surprisingly, we show through analysis of TK conditional null and RNAi cells that TK is essential for growth and for infectivity in a mouse model, and that a catalytically active enzyme is required for its function. Unlike humans, T. brucei and all other kinetoplastids lack dCMP deaminase (DCTD), which provides an alternative route to dUMP formation. Ectopic expression of human DCTD resulted in full rescue of the RNAi growth phenotype and allowed for selection of viable TK null cells. Metabolite profiling by LC-MS/MS revealed a buildup of deoxypyrimidine nucleosides in TK depleted cells. Knockout of cytidine deaminase (CDA), which converts deoxycytidine to deoxyuridine led to thymidine/deoxyuridine auxotrophy. These unexpected results suggested that T. brucei encodes an unidentified 5'-nucleotidase that converts deoxypyrimidine nucleotides to their corresponding nucleosides, leading to their dead-end buildup in TK depleted cells at the expense of dTTP pools. Bioinformatics analysis identified several potential candidate genes that could encode 5'-nucleotidase activity including an HD-domain protein that we show catalyzes dephosphorylation of deoxyribonucleotide 5'-monophosphates. We conclude that TK is essential for synthesis of thymine nucleotides regardless of whether the nucleoside precursors originate from the de novo pathway or through salvage. Reliance on TK in the absence of DCTD may be a shared vulnerability among trypanosomatids and may provide a unique opportunity to selectively target a diverse group of pathogenic single-celled eukaryotes with a single drug.
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Affiliation(s)
- Christopher Leija
- Department of Pharmacology University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Filipa Rijo-Ferreira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Department of Neuroscience, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Lisa N. Kinch
- Department of Biophysics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Nick V. Grishin
- Department of Biophysics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Zeping Hu
- Children’s Medical Center Research Institute, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Margaret A. Phillips
- Department of Pharmacology University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
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31
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McCombs JE, Diaz JP, Luebke KJ, Kohler JJ. Glycan specificity of neuraminidases determined in microarray format. Carbohydr Res 2016; 428:31-40. [PMID: 27131125 PMCID: PMC4885666 DOI: 10.1016/j.carres.2016.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/31/2016] [Accepted: 04/05/2016] [Indexed: 11/27/2022]
Abstract
Neuraminidases hydrolytically remove sialic acids from glycoconjugates. Neuraminidases are produced by both humans and their pathogens, and function in normal physiology and in pathological events. Identification of neuraminidase substrates is needed to reveal their mechanism of action, but high-throughput methods to determine glycan specificity of neuraminidases are limited. Here we use two glycan labeling reactions to monitor neuraminidase activity toward glycan substrates. While both periodate oxidation and aniline-catalyzed oxime ligation (PAL) and galactose oxidase and aniline-catalyzed oxime ligation (GAL) can be used to monitor neuraminidase activity toward glycans in microtiter plates, only GAL accurately measured neuraminidase activity toward glycans displayed on a commercial glass slide microarray. Using GAL, we confirm known linkage specificities of three pneumococcal neuraminidases and obtain new information about underlying glycan specificity.
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Affiliation(s)
- Janet E McCombs
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jason P Diaz
- Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin J Luebke
- Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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32
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Nischan N, Kohler JJ. Advances in cell surface glycoengineering reveal biological function. Glycobiology 2016; 26:789-96. [PMID: 27066802 DOI: 10.1093/glycob/cww045] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 04/04/2016] [Indexed: 12/31/2022] Open
Abstract
Cell surface glycans are critical mediators of cell-cell, cell-ligand, and cell-pathogen interactions. By controlling the set of glycans displayed on the surface of a cell, it is possible to gain insight into the biological functions of glycans. Moreover, control of glycan expression can be used to direct cellular behavior. While genetic approaches to manipulate glycosyltransferase gene expression are available, their utility in glycan engineering has limitations due to the combinatorial nature of glycan biosynthesis and the functional redundancy of glycosyltransferase genes. Biochemical and chemical strategies offer valuable complements to these genetic approaches, notably by enabling introduction of unnatural functionalities, such as fluorophores, into cell surface glycans. Here, we describe some of the most recent developments in glycoengineering of cell surfaces, with an emphasis on strategies that employ novel chemical reagents. We highlight key examples of how these advances in cell surface glycan engineering enable study of cell surface glycans and their function. Exciting new technologies include synthetic lipid-glycans, new chemical reporters for metabolic oligosaccharide engineering to allow tandem and in vivo labeling of glycans, improved chemical and enzymatic methods for glycoproteomics, and metabolic glycosyltransferase inhibitors. Many chemical and biochemical reagents for glycan engineering are commercially available, facilitating their adoption by the biological community.
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Affiliation(s)
- Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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Abstract
Neuraminidases (sialidases) are enzymes that hydrolytically remove sialic acid from sialylated proteins and lipids. Neuraminidases are encoded by a range of human pathogens, including bacteria, viruses, fungi, and protozoa. Many pathogen neuraminidases are virulence factors, indicating that desialylation of host glycoconjugates can be a critical step in infection. Specifically, desialylation of host cell surface glycoproteins can enable these molecules to function as pathogen receptors or can alter signaling through the plasma membrane. Despite these critical effects, no unbiased approaches exist to identify glycoprotein substrates of neuraminidases. Here, we combine previously reported glycoproteomics methods with quantitative proteomics analysis to identify glycoproteins whose sialylation changes in response to neuraminidase treatment. The two glycoproteomics methods-periodate oxidation and aniline-catalyzed oxime ligation (PAL) and galactose oxidase and aniline-catalyzed oxime ligation (GAL)-rely on chemoselective labeling of sialylated and nonsialylated glycoproteins, respectively. We demonstrated the utility of the combined approaches by identifying substrates of two pneumococcal neuraminidases in a human cell line that models the blood-brain barrier. The methods deliver complementary lists of neuraminidase substrates, with GAL identifying a larger number of substrates than PAL (77 versus 17). Putative neuraminidase substrates were confirmed by other methods, establishing the validity of the approach. Among the identified substrates were host glycoproteins known to function in bacteria adherence and infection. Functional assays suggest that multiple desialylated cell surface glycoproteins may act together as pneumococcus receptors. Overall, this method will provide a powerful approach to identify glycoproteins that are desialylated by both purified neuraminidases and intact pathogens.
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Affiliation(s)
- Janet E McCombs
- Department of Biochemistry, The University of Texas Southwestern Medical Center , Dallas, Texas 75390-9038, United States
| | - Jennifer J Kohler
- Department of Biochemistry, The University of Texas Southwestern Medical Center , Dallas, Texas 75390-9038, United States
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34
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McCombs JE, Zou C, Parker RB, Cairo CW, Kohler JJ. Enhanced Cross-Linking of Diazirine-Modified Sialylated Glycoproteins Enabled through Profiling of Sialidase Specificities. ACS Chem Biol 2016; 11:185-92. [PMID: 26541974 DOI: 10.1021/acschembio.5b00775] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sialic-acid-mediated interactions play critical roles on the cell surface, providing an impetus for the development of methods to study this important monosaccharide. In particular, photo-cross-linking sialic acids incorporated onto cell surfaces have allowed covalent capture of transient interactions between sialic acids and sialic-acid-recognizing proteins via cross-linking. However, natural sialic acids also present on the cell surface compete with photo-cross-linking sialic acids in binding events, limiting cross-linking yields. In order to improve the utility of one such photo-cross-linking sialic acid, SiaDAz, we examined a number of sialidases, enzymes that remove sialic acids from glycoconjugates, to find one that would cleave natural sialic acids but remain inactive toward SiaDAz. Using this sialidase, we improved SiaDAz-mediated cross-linking of an antisialyl Lewis X antibody and of endoglin. This protocol can be applied generally to sialic-acid-mediated interactions and will facilitate identification of sialic acid binding partners.
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Affiliation(s)
- Janet E. McCombs
- Department
of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
| | - Chunxia Zou
- Alberta
Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Randy B. Parker
- Department
of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
| | - Christopher W. Cairo
- Alberta
Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Jennifer J. Kohler
- Department
of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038, United States
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35
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Wands AM, Fujita A, McCombs JE, Cervin J, Dedic B, Rodriguez AC, Nischan N, Bond MR, Mettlen M, Trudgian DC, Lemoff A, Quiding-Järbrink M, Gustavsson B, Steentoft C, Clausen H, Mirzaei H, Teneberg S, Yrlid U, Kohler JJ. Fucosylation and protein glycosylation create functional receptors for cholera toxin. eLife 2015; 4:e09545. [PMID: 26512888 PMCID: PMC4686427 DOI: 10.7554/elife.09545] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/26/2015] [Indexed: 12/14/2022] Open
Abstract
Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we report that CTB binds cell surface glycoproteins. Relative contributions of gangliosides and glycoproteins to CTB binding depend on cell type, and CTB binds primarily to glycoproteins in colonic epithelial cell lines. Using a metabolically incorporated photocrosslinking sugar, we identified one CTB-binding glycoprotein and demonstrated that the glycan portion of the molecule, not the protein, provides the CTB interaction motif. We further show that fucosylated structures promote CTB entry into a colonic epithelial cell line and subsequent host cell intoxication. CTB-binding fucosylated glycoproteins are present in normal human intestinal epithelia and could play a role in cholera. DOI:http://dx.doi.org/10.7554/eLife.09545.001 Cholera is a serious diarrheal disease that can be deadly if left untreated. It is caused by eating food, or drinking water, contaminated by the bacterium Vibrio cholerae. This bacterium can survive passage through the acidic conditions of the stomach. Inside the small intestine, V. cholerae attaches to the intestinal wall and starts producing cholera toxin. The toxin enters intestinal cells, causing them to release water and ions, including sodium and chloride ions. The salt-water environment created inside the intestine can, by osmosis, draw up to a further six liters of water into the intestine each day. This results in the copious production of watery diarrhea and severe dehydration. Cholera toxin is composed of six protein subunits, including five copies of cholera toxin subunit B (CTB). CTB subunits help the uptake of the toxin by intestinal cells, and it has long been reported that CTB subunits attach to intestinal cells by binding to a cell surface molecule called GM1. CTB subunits have a high affinity for GM1, yet recent work suggests CTB may not bind exclusively to GM1; one or more additional cell surface molecules may be directly involved in cholera toxin uptake. Wands et al. now reveal that numerous cell surface molecules are recognized by CTB, and that these molecules can assist cholera toxin uptake by host cells. Glycoproteins, proteins that are marked with sugar molecules, were shown to be the primary CTB binding sites on human colon cells, and it was the glycoprotein’s sugar component, not the protein itself, that interacted with CTB. Wands et al. discovered that in particular glycoproteins containing a sugar called fucose were largely responsible for CTB binding and toxin uptake. Together these findings reveal a previously unrecognized mechanism for cholera toxin entry into host cells, and suggest that fucose-containing or fucose-mimicking molecules could be developed as new treatments for cholera. DOI:http://dx.doi.org/10.7554/eLife.09545.002
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Affiliation(s)
- Amberlyn M Wands
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Akiko Fujita
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Janet E McCombs
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jakob Cervin
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Benjamin Dedic
- Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Andrea C Rodriguez
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Michelle R Bond
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marcel Mettlen
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - David C Trudgian
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Andrew Lemoff
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Marianne Quiding-Järbrink
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Bengt Gustavsson
- Department of Surgery, University of Gothenburg, Gothenburg, Sweden
| | - Catharina Steentoft
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.,School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.,School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hamid Mirzaei
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Susann Teneberg
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ulf Yrlid
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
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Rodriguez AC, Yu SH, Li B, Zegzouti H, Kohler JJ. Enhanced transfer of a photocross-linking N-acetylglucosamine (GlcNAc) analog by an O-GlcNAc transferase mutant with converted substrate specificity. J Biol Chem 2015; 290:22638-48. [PMID: 26240142 DOI: 10.1074/jbc.m115.667006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 12/23/2022] Open
Abstract
O-Linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational modification of proteins in multicellular organisms. O-GlcNAc modification is catalyzed by the O-GlcNAc transferase (OGT), which transfers N-acetylglucosamine (GlcNAc) from the nucleotide sugar donor UDP-GlcNAc to serine or threonine residues of protein substrates. Recently, we reported a novel metabolic labeling method to introduce the diazirine photocross-linking functional group onto O-GlcNAc residues in mammalian cells. In this method, cells are engineered to produce diazirine-modified UDP-GlcNAc (UDP-GlcNDAz), and the diazirine-modified GlcNAc analog (GlcNDAz) is transferred to substrate proteins by endogenous OGT, producing O-GlcNDAz. O-GlcNDAz-modified proteins can be covalently cross-linked to their binding partners, providing information about O-GlcNAc-dependent interactions. The utility of the method was demonstrated by cross-linking highly O-GlcNAc-modified nucleoporins to proteins involved in nuclear transport. For practical application of this method to a broader range of O-GlcNAc-modified proteins, efficient O-GlcNDAz production is critical. Here we examined the ability of OGT to transfer GlcNDAz and found that the wild-type enzyme (wtOGT) prefers the natural substrate, UDP-GlcNAc, over the unnatural UDP-GlcNDAz. This competition limits O-GlcNDAz production in cells and the extent of O-GlcNDAz-dependent cross-linking. Here we identified an OGT mutant, OGT(C917A), that efficiently transfers GlcNDAz and, surprisingly, has altered substrate specificity, preferring to transfer GlcNDAz rather than GlcNAc to protein substrates. We confirmed the reversed substrate preference by determining the Michaelis-Menten parameters describing the activity of wtOGT and OGT(C917A) with both UDP-GlcNAc and UDP-GlcNDAz. Use of OGT(C917A) enhances O-GlcNDAz production, yielding improved cross-linking of O-GlcNDAz-modified molecules both in vitro and in cells.
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Affiliation(s)
- Andrea C Rodriguez
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390 and
| | - Seok-Ho Yu
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390 and
| | - Bin Li
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390 and
| | | | - Jennifer J Kohler
- From the Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390 and
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37
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Pham ND, Fermaintt CS, Rodriguez AC, McCombs JE, Nischan N, Kohler JJ. Cellular metabolism of unnatural sialic acid precursors. Glycoconj J 2015; 32:515-29. [PMID: 25957566 DOI: 10.1007/s10719-015-9593-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/10/2015] [Accepted: 04/23/2015] [Indexed: 10/23/2022]
Abstract
Carbohydrates, in addition to their metabolic functions, serve important roles as receptors, ligands, and structural molecules for diverse biological processes. Insight into carbohydrate biology and mechanisms has been aided by metabolic oligosaccharide engineering (MOE). In MOE, unnatural carbohydrate analogs with novel functional groups are incorporated into cellular glycoconjugates and used to probe biological systems. While MOE has expanded knowledge of carbohydrate biology, limited metabolism of unnatural carbohydrate analogs restricts its use. Here we assess metabolism of SiaDAz, a diazirine-modified analog of sialic acid, and its cell-permeable precursor, Ac4ManNDAz. We show that the efficiency of Ac4ManNDAz and SiaDAz metabolism depends on cell type. Our results indicate that different cell lines can have different metabolic roadblocks in the synthesis of cell surface SiaDAz. These findings point to roles for promiscuous intracellular esterases, kinases, and phosphatases during unnatural sugar metabolism and provide guidance for ways to improve MOE.
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Affiliation(s)
- Nam D Pham
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Charles S Fermaintt
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Andrea C Rodriguez
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Janet E McCombs
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Nicole Nischan
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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38
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Affiliation(s)
- Akiko Fujita
- Department of Biochemistry, University of Texas Southwestern Medical Center
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center
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39
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Affiliation(s)
- Akiko Fujita
- Department of Biochemistry, University of Texas Southwestern Medical Center
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center
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40
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Abstract
The O-linked β-N-acetylglucosamine (O-GlcNAc) posttranslational modification was first discovered 30 years ago and is highly concentrated in the nuclear pore. In the years since the discovery of this single sugar modification, substantial progress has been made in understanding the biochemistry of O-GlcNAc and its regulation. Nonetheless, O-GlcNAc modification of proteins continues to be overlooked, due in large part to the lack of reliable methods available for its detection. Recently, a new crop of immunological and chemical detection reagents has changed the research landscape. Using these tools, approximately 1000 O-GlcNAc-modified proteins have been identified. While other forms of glycosylation are typically associated with extracellular proteins, O-GlcNAc is abundant on nuclear and cytoplasmic proteins. In particular, phenylalanine-glycine nucleoporins are heavily O-GlcNAc-modified. Recent experiments are beginning to provide insight into the functional implications of O-GlcNAc modification on certain proteins, but its role in the nuclear pore has remained enigmatic. However, tantalizing new results suggest that O-GlcNAc may play roles in regulating nucleocytoplasmic transport.
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Affiliation(s)
- Bin Li
- Department of Biochemistry, University of Texas Southwestern Medical Centre, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
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41
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Abstract
The mammalian O-GlcNAc hydrolase (OGA) removes O-GlcNAc from serine and threonine residues on intracellular glycoproteins. OGA activity is sensitive to N-acyl substitutions to O-GlcNAc, with alkyl diazirine-modified O-GlcNAc (O-GlcNDAz) being completely resistant to removal by OGA. Using homology modeling, we identified OGA residues proximal to the N-acyl position of O-GlcNAc substrate. Mutation of one of these residues, C215, results in mutant enzymes that are able to hydrolytically remove O-GlcNDAz from a model compound. Further, the C215A mutant is capable of removing O-GlcNDAz from a peptide substrate. These results can be used to improve metabolism of O-GlcNAc analogs in cells. In addition, the enzyme specificity studies reported here provide new insight into the active site of OGA, an important drug target.
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Affiliation(s)
- Andrea C Rodriguez
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
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42
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Abstract
Glycosylation is increasingly recognized as a common and biologically significant post-translational modification of proteins. Modern mass spectrometry methods offer the best ways to characterize the glycosylation state of proteins. Both glycobiology and mass spectrometry rely on specialized nomenclature, techniques, and knowledge, which pose a barrier to entry by the nonspecialist. This introductory chapter provides an overview of the fundamentals of glycobiology, mass spectrometry methods, and the intersection of the two fields. Foundational material included in this chapter includes a description of the biological process of glycosylation, an overview of typical glycoproteomics workflows, a description of mass spectrometry ionization methods and instrumentation, and an introduction to bioinformatics resources. In addition to providing an orientation to the contents of the other chapters of this volume, this chapter cites other important works of potential interest to the practitioner. This overview, combined with the state-of-the-art protocols contained within this volume, provides a foundation for both glycobiologists and mass spectrometrists seeking to bridge the two fields.
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Affiliation(s)
- Steven M Patrie
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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43
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Abstract
Sialidases hydrolytically remove sialic acids from sialylated glycoproteins and glycolipids. Sialidases are widely distributed in nature and sialidase-mediated desialylation is implicated in normal and pathological processes. However, mechanisms by which sialidases exert their biological effects remain obscure, in part because sialidase substrate preferences are poorly defined. Here we report the design and implementation of a sialidase substrate specificity assay based on chemoselective labeling of sialosides. We show that this assay identifies components of glycosylated substrates that contribute to sialidase specificity. We demonstrate that specificity of sialidases can depend on structure of the underlying glycan, a characteristic difficult to discern using typical sialidase assays. Moreover, we discovered that Streptococcus pneumoniae sialidase NanC strongly prefers sialosides containing the Neu5Ac form of sialic acid versus those that contain Neu5Gc. We propose using this approach to evaluate sialidase preferences for diverse potential substrates.
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Affiliation(s)
- Randy B. Parker
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas
75390-9185, United States
| | - Janet E. McCombs
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas
75390-9185, United States
| | - Jennifer J. Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas
75390-9185, United States
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44
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Abstract
Carbohydrates and carbohydrate-containing biomolecules engage in binding events that underlie many essential biological processes. Yet these carbohydrate-mediated interactions are often poorly characterized, due to their low affinities and heterogenous natures. The use of photocrosslinking functional groups offers a way to photochemically capture carbohydrate-containing complexes, which can be isolated for further analysis. Here we survey progress in the synthesis and use of carbohydrate-based photoprobes, reagents that incorporate carbohydrates or their analogs, photocrosslinking moieties, and affinity purification handles. Carbohydrate photoprobes, used in combination with modern mass spectrometry methods, can provide important new insights into the cellular roles of carbohydrates and glycosylated molecules.
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Affiliation(s)
- Seok-Ho Yu
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
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45
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Bond MR, Zhang H, Kim J, Yu SH, Yang F, Patrie SM, Kohler JJ. Metabolism of diazirine-modified N-acetylmannosamine analogues to photo-cross-linking sialosides. Bioconjug Chem 2011; 22:1811-23. [PMID: 21838313 DOI: 10.1021/bc2002117] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Terminal sialic acid residues often mediate the interactions of cell surface glycoconjugates. Sialic acid-dependent interactions typically exhibit rapid dissociation rates, precluding the use of traditional biological techniques for complex isolation. To stabilize these transient interactions, we employ a targeted photo-cross-linking approach in which a diazirine photo-cross-linker is incorporated into cell surface sialylated glycoconjugates through the use of metabolic oligosaccharide engineering. We describe three diazirine-modified N-acetylmannosamine (ManNAc) analogues in which the length of the linker between the pyranose ring and the diazirine was varied. These analogues were each metabolized to their respective sialic acid counterparts, which were added to both glycoproteins and glycolipids. Diazirine-modified sialic acid analogues could be incorporated into both α2-3 and α2-6 linkages. Upon exposure to UV irradiation, diazirine-modified glycoconjugates were covalently cross-linked to their interaction partners. We demonstrate that all three diazirine-modified analogues were capable of competing with endogeneous sialic acid, albeit to varying degrees. We found that larger analogues were less efficiently metabolized, yet could still function as effective cross-linkers. Notably, the addition of the diazirine substituent interferes with metabolism of ManNAc analogues to glycans other than sialosides, providing fidelity to selectively incorporate the cross-linker into sialylated molecules. These compounds are nontoxic and display only minimal growth inhibition at the concentrations required for cross-linking studies. This report provides essential information for the deployment of photo-cross-linking analogues to capture and study ephemeral, yet essential, sialic acid-mediated interactions.
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Affiliation(s)
- Michelle R Bond
- Department of Chemistry, Stanford University , Stanford, CA 94305, United States
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46
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Whitman CM, Yang F, Kohler JJ. Modified GM3 gangliosides produced by metabolic oligosaccharide engineering. Bioorg Med Chem Lett 2011; 21:5006-10. [PMID: 21620696 DOI: 10.1016/j.bmcl.2011.04.128] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 04/25/2011] [Accepted: 04/27/2011] [Indexed: 10/18/2022]
Abstract
Metabolic oligosaccharide engineering is powerful approach to altering the structure of cellular sialosides. This method relies on culturing cells with N-acetylmannosamine (ManNAc) analogs that are metabolized to their sialic acid counterparts and added to glycoproteins and glycolipids. Here we employed two cell lines that are deficient in ManNAc biosynthesis and examined their relative abilities to metabolize a panel of ManNAc analogs to sialosides. In addition to measuring global sialoside production, we also examined biosynthesis of the sialic acid-containing glycolipid, GM3. We discovered that the two cell lines differ in their ability to discriminate among the variant forms of ManNAc. Further, our data suggest that modified forms of sialic acid may be preferentially incorporated into certain sialosides and excluded from others. Taken together, our results demonstrate that global analysis of sialoside production can obscure sialoside-specific differences. These findings have implications for downstream applications of metabolic oligosaccharide engineering, including imaging and proteomics.
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Affiliation(s)
- Chad M Whitman
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9185, United States
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47
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Dube DH, Li B, Greenblatt EJ, Nimer S, Raymond AK, Kohler JJ. A two-hybrid assay to study protein interactions within the secretory pathway. PLoS One 2010; 5:e15648. [PMID: 21209940 PMCID: PMC3011011 DOI: 10.1371/journal.pone.0015648] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/18/2010] [Indexed: 11/18/2022] Open
Abstract
Interactions of transcriptional activators are difficult to study using transcription-based two-hybrid assays due to potent activation resulting in false positives. Here we report the development of the Golgi two-hybrid (G2H), a method that interrogates protein interactions within the Golgi, where transcriptional activators can be assayed with negligible background. The G2H relies on cell surface glycosylation to report extracellularly on protein-protein interactions occurring within the secretory pathway. In the G2H, protein pairs are fused to modular domains of the reporter glycosyltransferase, Och1p, and proper cell wall formation due to Och1p activity is observed only when a pair of proteins interacts. Cells containing interacting protein pairs are identified by selectable phenotypes associated with Och1p activity and proper cell wall formation: cells that have interacting proteins grow under selective conditions and display weak wheat germ agglutinin (WGA) binding by flow cytometry, whereas cells that lack interacting proteins display stunted growth and strong WGA binding. Using this assay, we detected the interaction between transcription factor MyoD and its binding partner Id2. Interfering mutations along the MyoD:Id2 interaction interface ablated signal in the G2H assay. Furthermore, we used the G2H to detect interactions of the activation domain of Gal4p with a variety of binding partners. Finally, selective conditions were used to enrich for cells encoding interacting partners. The G2H detects protein-protein interactions that cannot be identified via traditional two-hybrid methods and should be broadly useful for probing previously inaccessible subsets of the interactome, including transcriptional activators and proteins that traffic through the secretory pathway.
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Affiliation(s)
- Danielle H. Dube
- Department of Chemistry and Biochemistry, Bowdoin College, Brunswick, Maine, United States of America
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Bin Li
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Ethan J. Greenblatt
- Department of Chemistry, Stanford University, Stanford, California, United States of America
- Biophysics Program, Stanford University, Stanford, California, United States of America
| | - Sadeieh Nimer
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Amanda K. Raymond
- Department of Chemistry, Stanford University, Stanford, California, United States of America
| | - Jennifer J. Kohler
- Department of Chemistry, Stanford University, Stanford, California, United States of America
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail:
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48
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Bond MR, Whitman CM, Kohler JJ. Metabolically incorporated photocrosslinking sialic acid covalently captures a ganglioside-protein complex. Mol Biosyst 2010; 6:1796-9. [PMID: 20625600 DOI: 10.1039/c0mb00069h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
When photoirradiated, an unnatural sialic acid analog can covalently capture the complex formed by ganglioside GM1 and cholera toxin subunit B.
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Affiliation(s)
- Michelle R Bond
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9185, USA.
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49
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Abstract
The plasma membrane of eukaryotic cells is coated with carbohydrates. By virtue of their extracellular position and recognizable chemical features, cell surface glycans mediate many receptor-ligand interactions. Recently, mammalian extracellular hydrolytic enzymes have been shown to modify the structure of cell surface glycans and consequently alter their binding properties. These cell surface glycan remodeling events can cause rapid changes in critical signal transduction phenomena. This Review highlights recent studies on the roles of eukaryotic extracellular sialidases, sulfatases, and a deacetylase in regulation of intracellular signaling. We also describe possible therapies that target extracellular glycan remodeling processes and discuss the potential for new discoveries in this area.
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Affiliation(s)
- Randy B. Parker
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9185
| | - Jennifer J. Kohler
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9185
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50
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Abstract
Protein-carbohydrate interactions play essential roles in a variety of biological processes. This class of interactions is particularly important in development, immunology, infection, and carcinogenesis. However, the transient nature of glycan-dependent interactions hampers efforts to detect and characterize these complexes. Photocrosslinking is emerging as a powerful tool to discover and study glycan-dependent complexes. Through the use of photocrosslinking groups, UV irradiation can be employed to introduce a covalent bond between two transiently interacting molecules. Here we describe the use of metabolic oligosaccharide engineering to incorporate a photocrosslinkable sugar into cellular glycoconjugates and the use of this photocrosslinker to covalently capture glycan-mediated interactions.
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Affiliation(s)
- Seok-Ho Yu
- Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, USA
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