1
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McMillan IO, Liang L, Su G, Song X, Drago K, Yang H, Alvarez C, Sood A, Gibson J, Woods RJ, Wang C, Liu J, Zhang F, Brett TJ, Wang L. TREM2 on microglia cell surface binds to and forms functional binary complexes with heparan sulfate modified with 6-O-sulfation and iduronic acid. J Biol Chem 2024:107691. [PMID: 39159814 DOI: 10.1016/j.jbc.2024.107691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 08/07/2024] [Accepted: 08/08/2024] [Indexed: 08/21/2024] Open
Abstract
The Triggering Receptor Expressed on Myeloid Cells-2 (TREM2), a pivotal innate immune receptor, orchestrates functions such as inflammatory responses, phagocytosis, cell survival, and neuroprotection. TREM2 variants R47H and R62H have been associated with Alzheimer's disease, yet the underlying mechanisms remain elusive. Our previous research established that TREM2 binds to heparan sulfate (HS) and variants R47H and R62H exhibit reduced affinity for HS. Building upon this groundwork, our current study delves into the interplay between TREM2 and HS and its impact on microglial function. We confirm TREM2's binding to cell surface HS and demonstrate that TREM2 interacts with HS, forming HS-TREM2 binary complexes on microglia cell surfaces. Employing various biochemical techniques, including Surface Plasmon Resonance, low molecular weight HS microarray screening, and serial HS mutant cell surface binding assays, we demonstrate TREM2's robust affinity for HS, and the effective binding requires a minimum HS size of approximately 10 saccharide units. Notably, TREM2 selectively binds specific HS structures, with 6-O-sulfation and, to a lesser extent, the iduronic acid residue playing crucial roles. N-sulfation and 2-O-sulfation are dispensable for this interaction. Furthermore, we reveal that 6-O-sulfation is essential for HS-TREM2 ternary complex formation on the microglial cell surface, and HS and its 6-O-sulfation are necessary for TREM2-mediated ApoE3 uptake in microglia. By delineating the interaction between HS and TREM2 on the microglial cell surface and demonstrating its role in facilitating TREM2-mediated ApoE uptake by microglia, our findings provide valuable insights that can inform targeted interventions for modulating microglial functions in Alzheimer's disease.
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Affiliation(s)
- Ilayda Ozsan McMillan
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Li Liang
- Center for Biotechnology and Interdisciplinary Studies, Departments of Chemistry and Chemical Biology, Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Guowei Su
- Glycan Therapeutics, Raleigh, NC 27606, USA
| | - Xuehong Song
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Kelly Drago
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Hua Yang
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Claudia Alvarez
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Amika Sood
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, 30602, USA
| | - James Gibson
- Center for Biotechnology and Interdisciplinary Studies, Departments of Chemistry and Chemical Biology, Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Robert J Woods
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, 30602, USA
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Departments of Chemistry and Chemical Biology, Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Jian Liu
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC 27599, USA
| | - Fuming Zhang
- Center for Biotechnology and Interdisciplinary Studies, Departments of Chemistry and Chemical Biology, Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Tom J Brett
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, USA
| | - Lianchun Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, Tampa, FL, USA.
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2
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Greitens C, Leroux JC, Burger M. The intracellular visualization of exogenous DNA in fluorescence microscopy. Drug Deliv Transl Res 2024; 14:2242-2261. [PMID: 38526634 PMCID: PMC11208204 DOI: 10.1007/s13346-024-01563-4] [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] [Accepted: 02/28/2024] [Indexed: 03/27/2024]
Abstract
In the development of non-viral gene delivery vectors, it is essential to reliably localize and quantify transfected DNA inside the cell. To track DNA, fluorescence microscopy methods are commonly applied. These mostly rely on fluorescently labeled DNA, DNA binding proteins fused to a fluorescent protein, or fluorescence in situ hybridization (FISH). In addition, co-stainings are often used to determine the colocalization of the DNA in specific cellular compartments, such as the endolysosomes or the nucleus. We provide an overview of these DNA tracking methods, advice on how they should be combined, and indicate which co-stainings or additional methods are required to draw precise conclusions from a DNA tracking experiment. Some emphasis is given to the localization of exogenous DNA inside the nucleus, which is the last step of DNA delivery. We argue that suitable tools which allow for the nuclear detection of faint signals are still missing, hampering the rational development of more efficient non-viral transfection systems.
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Affiliation(s)
- Christina Greitens
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland
| | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
| | - Michael Burger
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093, Zurich, Switzerland.
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3
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Fagbadebo FO, Rothbauer U. Peptide-Tag Specific Nanobodies for Studying Proteins in Live Cells. Methods Mol Biol 2022; 2446:555-579. [PMID: 35157294 DOI: 10.1007/978-1-0716-2075-5_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Single-domain antibodies such as nanobodies (Nbs) have substantially expanded the possibilities of advanced cellular imaging. In comparison to conventional antibodies, Nbs are characterized by small size, high stability, and solubility in many environments, including the cytoplasm. Nbs can be efficiently functionalized or modified according to the needs of the imaging approach. Target-specific Nbs can be easily converted into genetically encoded fluorescently labeled intrabodies, also known as chromobodies (CBs), which represent powerful tools to study the dynamics of different proteins of interest within living cells. In this context, CBs specific for a short peptide epitope provide a versatile alternative to bypass the limitations observed with larger fluorescent protein fusions and can be readily used to visualize and monitor peptide-tagged proteins for which specific Nbs are not available. Here, we present our novel detection system comprising a 15 amino acid peptide-tag (PepTag) in combination with a peptide-tag specific CB (PepCB). We provide protocols for adding the PepTag to different proteins of interest, reformatting the peptide-specific Nb (PepNb) into a CB for expression in mammalian cells, and establishment of stable cell lines expressing the PepCB for protein interaction assays and compound screenings.
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Affiliation(s)
- Funmilayo O Fagbadebo
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tuebingen, Tuebingen, Germany.
- Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany.
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4
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Rashid FZM, Mahlandt E, van der Vaart M, Boer DEC, Varela Alvarez M, Henneman B, Brocken DJW, Voskamp P, Blok A, Shimizu T, Meijer A, Luijsterburg M, Goedhart J, Crémazy FGE, Dame R. HI-NESS: a family of genetically encoded DNA labels based on a bacterial nucleoid-associated protein. Nucleic Acids Res 2021; 50:e10. [PMID: 34734265 PMCID: PMC8789088 DOI: 10.1093/nar/gkab993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 02/02/2023] Open
Abstract
The interplay between three-dimensional chromosome organisation and genomic processes such as replication and transcription necessitates in vivo studies of chromosome dynamics. Fluorescent organic dyes are often used for chromosome labelling in vivo. The mode of binding of these dyes to DNA cause its distortion, elongation, and partial unwinding. The structural changes induce DNA damage and interfere with the binding dynamics of chromatin-associated proteins, consequently perturbing gene expression, genome replication, and cell cycle progression. We have developed a minimally-perturbing, genetically encoded fluorescent DNA label consisting of a (photo-switchable) fluorescent protein fused to the DNA-binding domain of H-NS — a bacterial nucleoid-associated protein. We show that this DNA label, abbreviated as HI-NESS (H-NS-based indicator for nucleic acid stainings), is minimally-perturbing to genomic processes and labels chromosomes in eukaryotic cells in culture, and in zebrafish embryos with preferential binding to AT-rich chromatin.
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Affiliation(s)
- Fatema-Zahra M Rashid
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Eike Mahlandt
- Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 1098XH, The Netherlands
| | - Michiel van der Vaart
- Animal Sciences, Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Daphne E C Boer
- Department of Human Genetics, Leiden University Medical Center, Leiden 2333ZC, The Netherlands
| | - Monica Varela Alvarez
- Animal Sciences, Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Bram Henneman
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
| | - Daan J W Brocken
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
| | - Patrick Voskamp
- Biophysical Structural Chemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
| | - Anneloes J Blok
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
| | - Thomas S Shimizu
- Systems Biology, AMOLF Institute, Amsterdam 1098XG, The Netherlands
| | - Annemarie H Meijer
- Animal Sciences, Institute of Biology Leiden, Leiden University, Leiden 2333CC, The Netherlands
| | - Martijn S Luijsterburg
- Department of Human Genetics, Leiden University Medical Center, Leiden 2333ZC, The Netherlands
| | - Joachim Goedhart
- Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam 1098XH, The Netherlands
| | - Frédéric G E Crémazy
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Leiden 2333CC, The Netherlands
| | - Remus T Dame
- To whom correspondence should be addressed. Tel: +31 71 527 5605;
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5
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Yue J, Jin W, Yang H, Faulkner J, Song X, Qiu H, Teng M, Azadi P, Zhang F, Linhardt RJ, Wang L. Heparan Sulfate Facilitates Spike Protein-Mediated SARS-CoV-2 Host Cell Invasion and Contributes to Increased Infection of SARS-CoV-2 G614 Mutant and in Lung Cancer. Front Mol Biosci 2021; 8:649575. [PMID: 34179075 PMCID: PMC8231436 DOI: 10.3389/fmolb.2021.649575] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022] Open
Abstract
The severe acute respiratory syndrome (SARS)-like coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has been a serious threat to global public health with limited treatment. Cellular heparan sulfate (HS) has been found to bind SARS-CoV-2 spike protein (SV2-S) and co-operate with cell surface receptor angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 infection of host cells. In this study, we determined that host cell surface SV2-S binding depends on and correlates with host cell surface HS expression. This binding is required for SARS-Cov-2 virus to infect host cells and can be blocked by heparin lyase, HS antagonist surfen, heparin, and heparin derivatives. The binding of heparin/HS to SV2-S is mainly determined by its overall sulfation with potential, minor contribution of specific SV2-S binding motifs. The higher binding affinity of SV2-S G614 mutant to heparin and upregulated HS expression may be one of the mechanisms underlying the higher infectivity of the SARS-CoV-2 G614 variant and the high vulnerability of lung cancer patients to SARS-CoV-2 infection, respectively. The higher host cell infection by SARS-CoV-2 G614 variant pseudovirus and the increased infection caused by upregulated HS expression both can be effectively blocked by heparin lyase and heparin, and possibly surfen and heparin derivatives too. Our findings support blocking HS-SV2-S interaction may provide one addition to achieve effective prevention and/treatment of COVID-19.
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Affiliation(s)
- Jingwen Yue
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Weihua Jin
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Hua Yang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
| | - John Faulkner
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
| | - Xuehong Song
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
| | - Hong Qiu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Michael Teng
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Fuming Zhang
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Robert J. Linhardt
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Lianchun Wang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida Health, Tampa, FL, United States
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6
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The Long Linker Region of Telomere-Binding Protein TRF2 Is Responsible for Interactions with Lamins. Int J Mol Sci 2021; 22:ijms22073293. [PMID: 33804854 PMCID: PMC8036907 DOI: 10.3390/ijms22073293] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/15/2022] Open
Abstract
Telomere-binding factor 2 (TRF2) is part of the shelterin protein complex found at chromosome ends. Lamin A/C interacts with TRF2 and influences telomere position. TRF2 has an intrinsically disordered region between the ordered dimerization and DNA-binding domains. This domain is referred to as the long linker region of TRF2, or udTRF2. We suggest that udTRF2 might be involved in the interaction between TRF2 and lamins. The recombinant protein corresponding to the udTRF2 region along with polyclonal antibodies against this region were used in co-immunoprecipitation with purified lamina and nuclear extracts. Co-immunoprecipitation followed by Western blots and mass spectrometry indicated that udTRF2 interacts with lamins, preferably lamins A/C. The interaction did not involve any lamin-associated proteins, was not dependent on the post-translation modification of lamins, nor did it require their higher-order assembly. Besides lamins, a number of other udTRF2-interacting proteins were identified by mass spectrometry, including several heterogeneous nuclear ribonucleoproteins (hnRNP A2/B1, hnRNPA1, hnRNP A3, hnRNP K, hnRNP L, hnRNP M), splicing factors (SFPQ, NONO, SRSF1, and others), helicases (DDX5, DHX9, and Eif4a3l1), topoisomerase I, and heat shock protein 71, amongst others. Some of the identified interactors are known to be involved in telomere biology; the roles of the others remain to be investigated. Thus, the long linker region of TRF2 (udTRF2) is a regulatory domain responsible for the association between TRF2 and lamins and is involved in interactions with other proteins.
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7
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Montecinos-Franjola F, Bauer BL, Mears JA, Ramachandran R. GFP fluorescence tagging alters dynamin-related protein 1 oligomerization dynamics and creates disassembly-refractory puncta to mediate mitochondrial fission. Sci Rep 2020; 10:14777. [PMID: 32901052 PMCID: PMC7479153 DOI: 10.1038/s41598-020-71655-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/19/2020] [Indexed: 01/22/2023] Open
Abstract
Green fluorescent protein (GFP)-tagging is the prevalent strategy to monitor protein dynamics in living cells. However, the consequences of appending the bulky GFP moiety to the protein of interest are rarely investigated. Here, using a powerful combination of quantitative fluorescence spectroscopic and imaging techniques, we have examined the oligomerization dynamics of the GFP-tagged mitochondrial fission GTPase dynamin-related protein 1 (Drp1) both in vitro and in vivo. We find that GFP-tagged Drp1 exhibits impaired oligomerization equilibria in solution that corresponds to a greatly diminished cooperative GTPase activity in comparison to native Drp1. Consequently, GFP-tagged Drp1 constitutes aberrantly stable, GTP-resistant supramolecular assemblies both in vitro and in vivo, neither of which reflects a more dynamic native Drp1 oligomerization state. Indeed, GFP-tagged Drp1 is detected more frequently per unit length over mitochondria in Drp1-null mouse embryonic fibroblasts (MEFs) compared to wild-type (wt) MEFs, indicating that the drastically reduced GTP turnover restricts oligomer disassembly from the mitochondrial surface relative to mixed oligomers comprising native and GFP-tagged Drp1. Yet, GFP-tagged Drp1 retains the capacity to mediate membrane constriction in vitro and mitochondrial division in vivo. These findings suggest that instead of robust assembly-disassembly dynamics, persistent Drp1 higher-order oligomerization over membranes is sufficient for mitochondrial fission.
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Affiliation(s)
- Felipe Montecinos-Franjola
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Brianna L Bauer
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Jason A Mears
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Center for Mitochondrial Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Rajesh Ramachandran
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA. .,Cleveland Center for Membrane and Structural Biology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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8
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Zhao Y, Yang JY, Thieker DF, Xu Y, Zong C, Boons GJ, Liu J, Woods RJ, Moremen KW, Amster IJ. A Traveling Wave Ion Mobility Spectrometry (TWIMS) Study of the Robo1-Heparan Sulfate Interaction. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1153-1165. [PMID: 29520710 PMCID: PMC6004239 DOI: 10.1007/s13361-018-1903-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/14/2018] [Accepted: 01/14/2018] [Indexed: 06/10/2023]
Abstract
Roundabout 1 (Robo1) interacts with its receptor Slit to regulate axon guidance, axon branching, and dendritic development in the nervous system and to regulate morphogenesis and many cell functions in the nonneuronal tissues. This interaction is known to be critically regulated by heparan sulfate (HS). Previous studies suggest that HS is required to promote the binding of Robo1 to Slit to form the minimal signaling complex, but the molecular details and the structural requirements of HS for this interaction are still unclear. Here, we describe the application of traveling wave ion mobility spectrometry (TWIMS) to study the conformational details of the Robo1-HS interaction. The results suggest that Robo1 exists in two conformations that differ by their compactness and capability to interact with HS. The results also suggest that the highly flexible interdomain hinge region connecting the Ig1 and Ig2 domains of Robo1 plays an important functional role in promoting the Robo1-Slit interaction. Moreover, variations in the sulfation pattern and size of HS were found to affect its binding affinity and selectivity to interact with different conformations of Robo1. Both MS measurements and CIU experiments show that the Robo1-HS interaction requires the presence of a specific size and pattern of modification of HS. Furthermore, the effect of N-glycosylation on the conformation of Robo1 and its binding modes with HS is reported. Graphical Abstract ᅟ.
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Affiliation(s)
- Yuejie Zhao
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA
| | - Jeong Yeh Yang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - David F Thieker
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Yongmei Xu
- Eshelman School of Pharmacy, Division of Chemical Biology & Medicinal Chemistry, University of North Carolina, Chapel Hill, NC, USA
| | - Chengli Zong
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Jian Liu
- Eshelman School of Pharmacy, Division of Chemical Biology & Medicinal Chemistry, University of North Carolina, Chapel Hill, NC, USA
| | - Robert J Woods
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - I Jonathan Amster
- Department of Chemistry, University of Georgia, Athens, GA, 30602, USA.
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9
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Abstract
Streptomyces are of great biological and industrial significance due to their complex morphological development and ability to produce numerous secondary metabolites. However, the intrinsic biochemical mechanisms underlying morphogenesis and secondary metabolism are rarely revealed, partially because of the limited availability of the biochemical tools in Streptomyces. Here we provided series of integrative vectors with various affinity tags, including single tags 3×FLAG, 3×HA, 3×Strep-tag II, 18×His, 13×Myc, and dual tags, all of which were driven from a strong constitutive promoter ermEp*. Using a sigma factor SigT from S. coelicolor as a model, we successfully expressed and immuno-detected SigT fused with all tags. Moreover, after SigT was N-terminally tagged with 3×FLAG and C-terminally tagged with 18×His, we isolated SigT-interactive proteins from the S. coelicolor lysate based on the tandem affinity purification (TAP). Particularly, among the proteins purified, the SigT cognate anti-sigma factor RstA ranked the top with the most total independent spectra. These data suggested the feasibility of these affinity tags in Streptomyces, which will be widely employed to explore the biochemical mechanisms to further understand the dynamic and elaborate regulation in this genus.
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10
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Zong C, Huang R, Condac E, Chiu Y, Xiao W, Li X, Lu W, Ishihara M, Wang S, Ramiah A, Stickney M, Azadi P, Amster IJ, Moremen KW, Wang L, Sharp JS, Boons GJ. Integrated Approach to Identify Heparan Sulfate Ligand Requirements of Robo1. J Am Chem Soc 2016; 138:13059-13067. [PMID: 27611601 PMCID: PMC5068570 DOI: 10.1021/jacs.6b08161] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An integrated methodology is described to establish ligand requirements for heparan sulfate (HS) binding proteins based on a workflow in which HS octasaccharides are produced by partial enzymatic degradation of natural HS followed by size exclusion purification, affinity enrichment using an immobilized HS-binding protein of interest, putative structure determination of isolated compounds by a hydrophilic interaction chromatography-high-resolution mass spectrometry platform, and chemical synthesis of well-defined HS oligosaccharides for structure-activity relationship studies. The methodology was used to establish the ligand requirements of human Roundabout receptor 1 (Robo1), which is involved in a number of developmental processes. Mass spectrometric analysis of the starting octasaccharide mixture and the Robo1-bound fraction indicated that Robo1 has a preference for a specific set of structures. Further analysis was performed by sequential permethylation, desulfation, and pertrideuteroacetylation followed by online separation and structural analysis by MS/MS. Sequences of tetrasaccharides could be deduced from the data, and by combining the compositional and sequence data, a putative octasaccharide ligand could be proposed (GlA-GlcNS6S-IdoA-GlcNS-IdoA2S-GlcNS6S-IdoA-GlcNAc6S). A modular synthetic approach was employed to prepare the target compound, and binding studies by surface plasmon resonance (SPR) confirmed it to be a high affinity ligand for Robo1. Further studies with a number of tetrasaccharides confirmed that sulfate esters at C-6 are critical for binding, whereas such functionalities at C-2 substantially reduce binding. High affinity ligands were able to reverse a reduction in endothelial cell migration induced by Slit2-Robo1 signaling.
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Affiliation(s)
- Chengli Zong
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Rongrong Huang
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Eduard Condac
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Yulun Chiu
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Institute of Bioinformatics, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Wenyuan Xiao
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Xiuru Li
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Weigang Lu
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Mayumi Ishihara
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Shuo Wang
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Annapoorani Ramiah
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Morgan Stickney
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - I. Jonathan Amster
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Kelley W. Moremen
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Lianchun Wang
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Joshua S. Sharp
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, Georgia 30602, United States
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, and Bijvoet Center for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
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