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Tax G, Guay KP, Pantalone L, Ceci M, Soldà T, Hitchman CJ, Hill JC, Vasiljević S, Lia A, Modenutti CP, Straatman KR, Santino A, Molinari M, Zitzmann N, Hebert DN, Roversi P, Trerotola M. Rescue of secretion of rare-disease-associated misfolded mutant glycoproteins in UGGT1 knock-out mammalian cells. Traffic 2024; 25:e12927. [PMID: 38272446 PMCID: PMC10832616 DOI: 10.1111/tra.12927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 11/02/2023] [Accepted: 12/05/2023] [Indexed: 01/27/2024]
Abstract
Endoplasmic reticulum (ER) retention of misfolded glycoproteins is mediated by the ER-localized eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognizes a misfolded glycoprotein and flags it for ER retention by re-glucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease, even if the mutant glycoprotein retains activity ("responsive mutant"). Using confocal laser scanning microscopy, we investigated here the subcellular localization of the human Trop-2-Q118E, E227K and L186P mutants, which cause gelatinous drop-like corneal dystrophy (GDLD). Compared with the wild-type Trop-2, which is correctly localized at the plasma membrane, these Trop-2 mutants are retained in the ER. We studied fluorescent chimeras of the Trop-2 Q118E, E227K and L186P mutants in mammalian cells harboring CRISPR/Cas9-mediated inhibition of the UGGT1 and/or UGGT2 genes. The membrane localization of the Trop-2 Q118E, E227K and L186P mutants was successfully rescued in UGGT1-/- cells. UGGT1 also efficiently reglucosylated Trop-2-Q118E-EYFP in cellula. The study supports the hypothesis that UGGT1 modulation would constitute a novel therapeutic strategy for the treatment of pathological conditions associated to misfolded membrane glycoproteins (whenever the mutation impairs but does not abrogate function), and it encourages the testing of modulators of ER glycoprotein folding quality control as broad-spectrum rescue-of-secretion drugs in rare diseases caused by responsive secreted glycoprotein mutants.
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Affiliation(s)
- Gabor Tax
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
| | - Kevin P. Guay
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, United States
| | - Ludovica Pantalone
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Italy; Laboratory of Cancer Pathology, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
| | - Martina Ceci
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Italy; Laboratory of Cancer Pathology, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
| | - Tatiana Soldà
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, UniversitàdellaSvizzeraItaliana (USI), Bellinzona, Switzerland
| | - Charlie J. Hitchman
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
| | - Johan C. Hill
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Snežana Vasiljević
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Andrea Lia
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
- Institute of Sciences of Food Production, ISPA-CNR Unit of Lecce, via Monteroni, I-73100 Lecce, Italy
| | - Carlos P. Modenutti
- Departamento de QuímicaBiológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de QuímicaBiológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellón 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Kees R. Straatman
- Core Biotechnology Services, University of Leicester, University Road, Leicester LE1 7RH, England, United Kingdom
| | - Angelo Santino
- Institute of Sciences of Food Production, ISPA-CNR Unit of Lecce, via Monteroni, I-73100 Lecce, Italy
| | - Maurizio Molinari
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicole Zitzmann
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Daniel N. Hebert
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, United States
| | - Pietro Roversi
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
- Institute of AgriculturalBiology and Biotecnology, IBBA-CNR Unit of Milano, via Bassini 15, I-20133 Milano, Italy
| | - Marco Trerotola
- Department of Medical, Oral and Biotechnological Sciences, "G. d'Annunzio" University of Chieti-Pescara, Italy; Laboratory of Cancer Pathology, Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Italy
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Guay KP, Ibba R, Kiappes J, Vasiljević S, Bonì F, De Benedictis M, Zeni I, Le Cornu JD, Hensen M, Chandran AV, Kantsadi AL, Caputo AT, Blanco Capurro JI, Bayo Y, Hill JC, Hudson K, Lia A, Brun J, Withers SG, Martí M, Biasini E, Santino A, De Rosa M, Milani M, Modenutti CP, Hebert DN, Zitzmann N, Roversi P. A quinolin-8-ol sub-millimolar inhibitor of UGGT, the ER glycoprotein folding quality control checkpoint. iScience 2023; 26:107919. [PMID: 37822503 PMCID: PMC10562782 DOI: 10.1016/j.isci.2023.107919] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 07/05/2023] [Accepted: 09/12/2023] [Indexed: 10/13/2023] Open
Abstract
Misfolded glycoprotein recognition and endoplasmic reticulum (ER) retention are mediated by the ER glycoprotein folding quality control (ERQC) checkpoint enzyme, UDP-glucose glycoprotein glucosyltransferase (UGGT). UGGT modulation is a promising strategy for broad-spectrum antivirals, rescue-of-secretion therapy in rare disease caused by responsive mutations in glycoprotein genes, and many cancers, but to date no selective UGGT inhibitors are known. The small molecule 5-[(morpholin-4-yl)methyl]quinolin-8-ol (5M-8OH-Q) binds a CtUGGTGT24 "WY" conserved surface motif conserved across UGGTs but not present in other GT24 family glycosyltransferases. 5M-8OH-Q has a 47 μM binding affinity for CtUGGTGT24in vitro as measured by ligand-enhanced fluorescence. In cellula, 5M-8OH-Q inhibits both human UGGT isoforms at concentrations higher than 750 μM. 5M-8OH-Q binding to CtUGGTGT24 appears to be mutually exclusive to M5-9 glycan binding in an in vitro competition experiment. A medicinal program based on 5M-8OH-Q will yield the next generation of UGGT inhibitors.
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Affiliation(s)
- Kevin P. Guay
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Roberta Ibba
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
- Department of Medicine, Surgery and Pharmacy, University of Sassari, Via Muroni 23A, 07100 Sassari, Italy
| | - J.L. Kiappes
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Snežana Vasiljević
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Francesco Bonì
- Institute of Biophysics, IBF-CNR Unit of Milano, via Celoria 26, 20133 Milano, Italy
| | - Maria De Benedictis
- Institute of Sciences of Food Production, C.N.R. Unit of Lecce, via Monteroni, 73100 Lecce, Italy
| | - Ilaria Zeni
- Department of Cellular, Computational and Integrative Biology, University of Trento, Povo, 38123 Trento, Italy
| | - James D. Le Cornu
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Mario Hensen
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Anu V. Chandran
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Anastassia L. Kantsadi
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Alessandro T. Caputo
- Biomedical Manufacturing, Commonwealth Scientific and Industrial Research Organisation, 343 Royal Parade, Parkville, VIC 3052, Australia
| | - Juan I. Blanco Capurro
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
| | - Yusupha Bayo
- Department of Biosciences, University of Milano, via Celoria 26, 20133 Milano, Italy
| | - Johan C. Hill
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Kieran Hudson
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Andrea Lia
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
- Institute of Biophysics, IBF-CNR Unit of Milano, via Celoria 26, 20133 Milano, Italy
| | - Juliane Brun
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Stephen G. Withers
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Marcelo Martí
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
| | - Emiliano Biasini
- Department of Cellular, Computational and Integrative Biology, University of Trento, Povo, 38123 Trento, Italy
- Dulbecco Telethon Institute, University of Trento, Povo, 38123 Trento, Italy
| | - Angelo Santino
- Institute of Sciences of Food Production, C.N.R. Unit of Lecce, via Monteroni, 73100 Lecce, Italy
| | - Matteo De Rosa
- Institute of Biophysics, IBF-CNR Unit of Milano, via Celoria 26, 20133 Milano, Italy
| | - Mario Milani
- Institute of Biophysics, IBF-CNR Unit of Milano, via Celoria 26, 20133 Milano, Italy
| | - Carlos P. Modenutti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Ciudad Universitaria, Pab. II (CE1428EHA), Buenos Aires, Argentina
| | - Daniel N. Hebert
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Nicole Zitzmann
- Oxford Glycobiology Institute, Department of Biochemistry and Kavli Institute for Nanoscience Discovery, South Parks Road, Oxford OX1 3QU, UK
| | - Pietro Roversi
- Institute of Agricultural Biology and Biotechnology, IBBA-CNR Unit of Milano, via Bassini 15, 20133 Milano, Italy
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, LE1 7HR Leicester, UK
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Tax G, Guay KP, Soldà T, Hitchman CJ, Hill JC, Vasiljević S, Lia A, Modenutti CP, Straatman KR, Santino A, Molinari M, Zitzmann N, Hebert DN, Roversi P, Trerotola M. Rescue of secretion of a rare-disease associated mis-folded mutant glycoprotein in UGGT1 knock-out mammalian cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542711. [PMID: 37398215 PMCID: PMC10312515 DOI: 10.1101/2023.05.30.542711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Endoplasmic reticulum (ER) retention of mis-folded glycoproteins is mediated by the ERlocalised eukaryotic glycoprotein secretion checkpoint, UDP-glucose glycoprotein glucosyl-transferase (UGGT). The enzyme recognises a mis-folded glycoprotein and flags it for ER retention by reglucosylating one of its N-linked glycans. In the background of a congenital mutation in a secreted glycoprotein gene, UGGT-mediated ER retention can cause rare disease even if the mutant glycoprotein retains activity ("responsive mutant"). Here, we investigated the subcellular localisation of the human Trop-2 Q118E variant, which causes gelatinous droplike corneal dystrophy (GDLD). Compared with the wild type Trop-2, which is correctly localised at the plasma membrane, the Trop-2-Q118E variant is found to be heavily retained in the ER. Using Trop-2-Q118E, we tested UGGT modulation as a rescue-of-secretion therapeutic strategy for congenital rare disease caused by responsive mutations in genes encoding secreted glycoproteins. We investigated secretion of a EYFP-fusion of Trop-2-Q118E by confocal laser scanning microscopy. As a limiting case of UGGT inhibition, mammalian cells harbouring CRISPR/Cas9-mediated inhibition of the UGGT1 and/or UGGT2 gene expressions were used. The membrane localisation of the Trop-2-Q118E-EYFP mutant was successfully rescued in UGGT1-/- and UGGT1/2-/- cells. UGGT1 also efficiently reglucosylated Trop-2-Q118E-EYFP in cellula. The study supports the hypothesis that UGGT1 modulation constitutes a novel therapeutic strategy for the treatment of Trop-2-Q118E associated GDLD, and it encourages the testing of modulators of ER glycoprotein folding Quality Control (ERQC) as broad-spectrum rescueof-secretion drugs in rare diseases caused by responsive secreted glycoprotein mutants.
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Affiliation(s)
- Gábor Tax
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
| | - Kevin P. Guay
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, United States
| | - Tatiana Soldà
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera Italiana (USI), Bellinzona, Switzerland
| | - Charlie J. Hitchman
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
| | - Johan C. Hill
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Snežana Vasiljević
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Andrea Lia
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
- Institute of Sciences of Food Production, ISPA-CNR Unit of Lecce, via Monteroni, I-73100 Lecce, Italy
| | - Carlos P. Modenutti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (FCEyN-UBA) e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) CONICET, Pabellón 2 de Ciudad Universitaria, Ciudad de Buenos Aires C1428EHA, Argentina
| | - Kees R. Straatman
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
- Core Biotechnology Services, University of Leicester, University Road, Leicester LE1 7RH, England, United Kingdom
| | - Angelo Santino
- Institute of Sciences of Food Production, ISPA-CNR Unit of Lecce, via Monteroni, I-73100 Lecce, Italy
| | - Maurizio Molinari
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicole Zitzmann
- Institute of Glycobiology, Department of Biochemistry, South Parks Road, Oxford OX1 3RQ, United Kingdom
| | - Daniel N. Hebert
- Department of Biochemistry and Molecular Biology, and Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, United States
| | - Pietro Roversi
- Leicester Institute of Chemical and Structural Biology and Department of Molecular and Cell Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HR, England, United Kingdom
- Institute of Agricultural Biology and Biotecnology, IBBACNR Unit of Milano, via Bassini 15, I-20133 Milano, Italy
| | - Marco Trerotola
- Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University of Chieti-Pescara, Italy; Laboratory of Cancer Pathology, Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, Italy
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Abe J, Takeda Y, Kikuma T, Kizuka Y, Kajiura H, Kajihara Y, Ito Y. Squaryl group-modified UDP analogs as inhibitors of the endoplasmic reticulum-resident folding sensor enzyme UGGT. Chem Commun (Camb) 2023; 59:2803-2806. [PMID: 36790024 DOI: 10.1039/d2cc06634c] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
UDP-Glc:glycoprotein glucosyltransferase (UGGT) has a central role to retain quality control of correctly folded N-glycoprotein in the endoplasmic reticulum (ER). A selective and potent inhibitor against UGGT could lead to elucidation of UGGT-related events, but such a molecule has not been identified so far. Examples of small molecules with UGGT inhibitory activity are scarce. Here, we report squaryl group-modified UDP analogs as a promising UGGT inhibitor. Among these, the compound possessing a 2'-amino group of the uridine moiety and hydroxyethyl-substituted squaramide exhibited the highest potency, suggesting its relevance as a molecule for further optimization.
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Affiliation(s)
- Junpei Abe
- Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan
| | - Yoichi Takeda
- College of Life Sciences, Ritsumeikan University, Kusastu, 525-8577, Japan
| | - Takashi Kikuma
- College of Life Sciences, Ritsumeikan University, Kusastu, 525-8577, Japan
| | - Yasuhiko Kizuka
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu 501-1193, Japan
| | - Hiroyuki Kajiura
- International Center for Biotechnology, Osaka University, Suita, 565-0871, Japan
| | - Yasuhiro Kajihara
- Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan
| | - Yukishige Ito
- Graduate School of Science, Osaka University, Toyonaka, 560-0043, Japan.,RIKEN Cluster for Pioneering Research, Wako, 351-0198, Japan
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Nitta K, Kuribara T, Totani K. Synthetic trisaccharides reveal discrimination of endo-glycosidic linkages by exo-acting α-1,2-mannosidases in the endoplasmic reticulum. Org Biomol Chem 2021; 19:4137-4145. [PMID: 33876795 DOI: 10.1039/d1ob00428j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A tri-antennary Man9GlcNAc2 glycan on the surface of endoplasmic reticulum (ER) glycoproteins functions as a glycoprotein secretion or degradation signal after regioselective cleavage of the terminal α-1,2-mannose residue of each branch. Four α-1,2-mannosidases-ER mannosidase I, ER degradation-enhancing α-mannosidase-like protein 1 (EDEM1), EDEM2, and EDEM3-are involved in the production of these signal glycans. Although selective production of signal glycans is important in determining the fate of glycoproteins, the branch-discrimination abilities of the α-1,2-mannosidases are not well understood. A structural feature of the Man9GlcNAc2 glycan is that all terminal glycosidic linkages of the three branches are of the α-1,2 type, while the adjacent inner glycosidic linkages are different. In this study, we examined whether the α-1,2-mannosidases showed branch specificity by discriminating between different inner glycosides. Four trisaccharides with different glycosidic linkages [Manα1-2Manα1-2Man (natural A-branch), Manα1-2Manα1-3Man (natural B-branch), Manα1-2Manα1-6Man (natural C-branch), and Manα1-2Manα1-4Man (unnatural D-branch)] were synthesized and used to evaluate the hypothesis. When synthesizing these oligosaccharides, highly stereoselective glycosylation was achieved with a high yield in each case by adding a weak base or tuning the polarity of the mixed solvent. Enzymatic hydrolysis of the synthetic trisaccharides by a mouse liver ER fraction containing the target enzymes showed that the ER α-1,2-mannosidases had clear specificity for the trisaccharides in the order of A-branch > B-branch > C-branch ≈ D-branch. Various competitive experiments have revealed for the first time that α-1,2-mannosidase with inner glycoside specificity is present in the ER. Our findings suggest that exo-acting ER α-1,2-mannosidases can discriminate between endo-glycosidic linkages.
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Affiliation(s)
- Kyohei Nitta
- Department of Materials and Life Science, Seikei University, Musashino-shi, Tokyo, 180-8633, Japan.
| | - Taiki Kuribara
- Department of Materials and Life Science, Seikei University, Musashino-shi, Tokyo, 180-8633, Japan.
| | - Kiichiro Totani
- Department of Materials and Life Science, Seikei University, Musashino-shi, Tokyo, 180-8633, Japan.
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Ito Y, Kajihara Y, Takeda Y. Chemical‐Synthesis‐Based Approach to Glycoprotein Functions in the Endoplasmic Reticulum. Chemistry 2020; 26:15461-15470. [DOI: 10.1002/chem.202004158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Yukishige Ito
- Project Research Center for Fundamental Sciences Graduate School of Science Osaka University Toyonaka Osaka 5600043 Japan
- RIKEN Cluster for Pioneering Research Wako Saitama 3510198 Japan
| | - Yasuhiro Kajihara
- Project Research Center for Fundamental Sciences Graduate School of Science Osaka University Toyonaka Osaka 5600043 Japan
- Department of Chemistry Graduate School of Science Osaka University Toyonaka Osaka 5600043 Japan
| | - Yoichi Takeda
- Department of Biotechnology Ritsumeikan University Kusatsu Shiga 5258577 Japan
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7
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Hirano M, Adachi Y, Ito Y, Totani K. Calreticulin discriminates the proximal region at the N-glycosylation site of Glc1Man9GlcNAc2 ligand. Biochem Biophys Res Commun 2015; 466:350-5. [DOI: 10.1016/j.bbrc.2015.09.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 09/05/2015] [Indexed: 12/30/2022]
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