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Lee JM, Kim JH, Kim JY, Oh MK, Kim BG. Enhancing the soluble expression of α-1,2-fucosyltransferase in E. coli using high-throughput flow cytometry screening coupled with a split-GFP. J Biotechnol 2024; 387:49-57. [PMID: 38556215 DOI: 10.1016/j.jbiotec.2024.03.014] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/14/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
2'-Fucosyllactose (2'-FL), one of the major human milk oligosaccharides, was produced in several engineered microorganisms. However, the low solubility of α-1,2-fucosyltransferase (α1,2-FucT) often becomes a bottleneck to produce maximum amount of 2'-FL in the microorganisms. To overcome this solubility issue, the following studies were conducted to improve the soluble expression of α1,2-FucT. Initially, hydrophobic amino acids in the hydrophilic region of the 6 α-helices were mutated, adhering to the α-helix rule. Subsequently, gfp11 was fused to the C-terminal of futC gene encoding α1,2-FucT (FutC), enabling selection of high-fluorescence mutants through split-GFP. Each mutant library was screened via fluorescence activated cell sorting (FACS) to separate soluble mutants for high-throughput screening. As a result, L80C single mutant and A121D/P124A/L125R triple mutant were found, and a combined quadruple mutant was created. Furthermore, we combined mutations of conserved sequences (Q150H/C151R/Q239S) of FutC, which showed positive effects in the previous studies from our lab, with the above quadruple mutants (L80C/A121D/P124A/L125R). The resulting strain produced approximately 3.4-fold higher 2'-FL titer than that of the wild-type, suggesting that the conserved sequence mutations are an independent subset of the mutations that further improve the solubility of the target protein acquired by random mutagenesis using split-GFP.
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Affiliation(s)
- Jun-Min Lee
- Department of Chemical & Biological Engineering, Korea University, Seoul 136-763, South Korea
| | - Jung Hwa Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, South Korea; Interdisciplinary Program for Biochemical Engineering and Biotechnology, Seoul National University, Seoul, South Korea
| | - Jin Young Kim
- Interdisciplinary Program for Biochemical Engineering and Biotechnology, Seoul National University, Seoul, South Korea
| | - Min-Kyu Oh
- Department of Chemical & Biological Engineering, Korea University, Seoul 136-763, South Korea.
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering, Seoul National University, Seoul, South Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea; Interdisciplinary Program for Biochemical Engineering and Biotechnology, Seoul National University, Seoul, South Korea; Bio-MAX/N-Bio Institute, Seoul National University, Seoul, South Korea; Institute for Sustainable Development (ISD), Seoul National University, Seoul, South Korea.
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2
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Conde JN, Himmler GE, Mladinich MC, Setoh YX, Amarilla AA, Schutt WR, Saladino N, Gorbunova EE, Salamango DJ, Benach J, Kim HK, Mackow ER. Establishment of a CPER reverse genetics system for Powassan virus defines attenuating NS1 glycosylation sites and an infectious NS1-GFP11 reporter virus. mBio 2023; 14:e0138823. [PMID: 37489888 PMCID: PMC10470542 DOI: 10.1128/mbio.01388-23] [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: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 07/26/2023] Open
Abstract
Powassan virus (POWV) is an emerging tick-borne Flavivirus that causes lethal encephalitis and long-term neurologic damage. Currently, there are no POWV therapeutics, licensed vaccines, or reverse genetics systems for producing infectious POWVs from recombinant DNA. Using a circular polymerase extension reaction (CPER), we generated recombinant LI9 (recLI9) POWVs with attenuating NS1 protein mutations and a recLI9-split-eGFP reporter virus. NS1 proteins are highly conserved glycoproteins that regulate replication, spread, and neurovirulence. POWV NS1 contains three putative N-linked glycosylation sites that we modified individually in infectious recLI9 mutants (N85Q, N208Q, and N224Q). NS1 glycosylation site mutations reduced replication kinetics and were attenuated, with 1-2 log decreases in titer. Severely attenuated recLI9-N224Q exhibited a 2- to 3-day delay in focal cell-to-cell spread and reduced NS1 secretion but was lethal when intracranially inoculated into suckling mice. However, footpad inoculation of recLI9-N224Q resulted in the survival of 80% of mice and demonstrated that NS1-N224Q mutations reduce POWV neuroinvasion in vivo. To monitor NS1 trafficking, we CPER fused a split GFP11-tag to the NS1 C-terminus and generated an infectious reporter virus, recLI9-NS1-GFP11. Cells infected with recLI9-NS1-GFP11 revealed NS1 trafficking in live cells and the novel formation of large NS1-lined intracellular vesicles. An infectious recLI9-NS1-GFP11 reporter virus permits real-time analysis of NS1 functions in POWV replication, assembly, and secretion and provides a platform for evaluating antiviral compounds. Collectively, our robust POWV reverse genetics system permits analysis of viral spread and neurovirulence determinants in vitro and in vivo and enables the rational genetic design of live attenuated POWV vaccines. IMPORTANCE Our findings newly establish a mechanism for genetically modifying Powassan viruses (POWVs), systematically defining pathogenic determinants and rationally designing live attenuated POWV vaccines. This initial study demonstrates that mutating POWV NS1 glycosylation sites attenuates POWV spread and neurovirulence in vitro and in vivo. Our findings validate a robust circular polymerase extension reaction approach as a mechanism for developing, and evaluating, attenuated genetically modified POWVs. We further designed an infectious GFP-tagged reporter POWV that permits us to monitor secretory trafficking of POWV in live cells, which can be applied to screen potential POWV replication inhibitors. This robust system for modifying POWVs provides the ability to define attenuating POWV mutations and create genetically attenuated recPOWV vaccines.
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Affiliation(s)
- Jonas N. Conde
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Grace E. Himmler
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
- Molecular and Cell Biology Program, Stony Brook University, Stony Brook, New York, USA
| | - Megan C. Mladinich
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - Yin Xiang Setoh
- Microbiology and Molecular Epidemiology Division, Environmental Health Institute, National Environmental Agency, Singapore, Singapore
| | - Alberto A. Amarilla
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, Australia
| | - William R. Schutt
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Nicholas Saladino
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Elena E. Gorbunova
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Daniel J. Salamango
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Jorge Benach
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Hwan Keun Kim
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cell Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Erich R. Mackow
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cell Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
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3
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Jost A, Knitsch R, Völkner K, Pfeifer F. Effect of Mutations in GvpJ and GvpM on Gas Vesicle Formation of Halobacterium salinarum. Front Microbiol 2022; 12:794240. [PMID: 34975818 PMCID: PMC8716928 DOI: 10.3389/fmicb.2021.794240] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 10/13/2021] [Accepted: 11/17/2021] [Indexed: 12/02/2022] Open
Abstract
The two haloarchaeal proteins, GvpM and GvpJ, are homologous to GvpA, the major gas vesicle structural protein. All three are hydrophobic and essential for gas vesicle formation. The effect of mutations in GvpJ and GvpM was studied in Haloferax volcanii transformants by complementing the respective mutated gene with the remaining gvp genes and inspecting the cells for the presence of gas vesicles (Vac+). In case of GvpJ, 56 of 66 substitutions analyzed yielded Vac– ΔJ + Jmut transformants, indicating that GvpJ is very sensitive to alterations, whereas ten of the 38 GvpM variants resulted in Vac– ΔM + Mmut transformants. The variants were also tested by split-GFP for their ability to interact with their partner protein GvpL. Some of the alterations leading to a Vac– phenotype affected the J/L or M/L interaction. Also, the interactions J/A and J/M were studied using fragments to exclude an unspecific aggregation of these hydrophobic proteins. Both fragments of GvpJ interacted with the M1–25 and M60–84 fragments of GvpM, and fragment J1–56 of GvpJ interacted with the N-terminal fragment A1–22 of GvpA. A comparison of the results on the three homologous proteins indicates that despite their relatedness, GvpA, GvpJ, and GvpM have unique features and cannot substitute each other.
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Affiliation(s)
- Alisa Jost
- Microbiology and Archaea, Department of Biology, Technical University Darmstadt, Darmstadt, Germany
| | - Regine Knitsch
- Microbiology and Archaea, Department of Biology, Technical University Darmstadt, Darmstadt, Germany
| | - Kerstin Völkner
- Microbiology and Archaea, Department of Biology, Technical University Darmstadt, Darmstadt, Germany
| | - Felicitas Pfeifer
- Microbiology and Archaea, Department of Biology, Technical University Darmstadt, Darmstadt, Germany
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Völkner K, Jost A, Pfeifer F. Accessory Gvp Proteins Form a Complex During Gas Vesicle Formation of Haloarchaea. Front Microbiol 2020; 11:610179. [PMID: 33281806 PMCID: PMC7688916 DOI: 10.3389/fmicb.2020.610179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 09/28/2020] [Accepted: 10/23/2020] [Indexed: 11/13/2022] Open
Abstract
Halobacterium salinarum forms gas vesicles consisting of a protein wall surrounding a gas-filled space. The hydrophobic 8-kDa protein GvpA is the major constituent of the ribbed wall, stabilized by GvpC at the exterior surface. In addition, eight accessory Gvp proteins are involved, encoded by gvpFGHIJKLM that are co-transcribed in early stages of growth. Most of these proteins are essential, but their functions are not yet clear. Here we investigate whether GvpF through GvpM interact. Pull-down experiments performed in Haloferax volcanii with the cellulose-binding-domain as tag suggested many interactions, and most of these were supported by the split-GFP analyses. The latter study indicated that GvpL attracted all other accessory Gvp, and the related GvpF bound besides GvpL also GvpG, GvpH and GvpI. A strong interaction was found between GvpH and GvpI. GvpG showed affinity to GvpF and GvpL, whereas GvpJ, GvpK and GvpM bound GvpL only. Using GvpA for similar analyses yielded GvpF as the only interaction partner. The contact site of GvpF was confined to the N-terminal half of GvpA and subsequently mapped to certain amino acids. Taken together, our results support the idea that the accessory Gvp form a complex early in gas-vesicle assembly attracting GvpA via GvpF.
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Affiliation(s)
- Kerstin Völkner
- Microbiology and Archaea, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Alisa Jost
- Microbiology and Archaea, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
| | - Felicitas Pfeifer
- Microbiology and Archaea, Department of Biology, Technical University of Darmstadt, Darmstadt, Germany
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5
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Kesari AS, Aryal UK, LaCount DJ. A Novel Proximity Biotinylation Assay Based on the Self-Associating Split GFP1-10/11. Proteomes 2020; 8:37. [PMID: 33276494 DOI: 10.3390/proteomes8040037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/26/2020] [Accepted: 11/29/2020] [Indexed: 01/08/2023] Open
Abstract
Proximity biotinylation was developed to detect physiologically relevant protein–protein interactions in living cells. In this method, the protein of interest is tagged with a promiscuous biotin ligase, such as BioID or BioID2, which produces activated biotin that reacts with nearby proteins; these proteins can subsequently be purified and identified by mass spectrometry. Here we report a novel modification of this technique by combining it with a self-associating split-GFP system in which we exploit the high-affinity interaction between GFP1–10 and GFP11 to recruit BioID2 to the protein of interest. As a test case, we fused GFP11 to clathrin light chain (CLTB) and BioID2 to GFP1–10. Co-expression of GFP11-CLTB and BioID2-GFP1–10 yielded a green fluorescent complex that co-localized with clathrin heavy chain. To facilitate removal of non-specifically biotinylated proteins, we generated an inducible cell line expressing BioID2-GFP1–10. Proximity biotinylation in this cell line with GFP11-CLTB yielded a higher percentage of biologically relevant interactions than direct fusion of BioID2 to CLTB. Thus, this system can be used to monitor expression and localization of BioID bait proteins and to identify protein–protein interactions.
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Giamogante F, Barazzuol L, Brini M, Calì T. ER-Mitochondria Contact Sites Reporters: Strengths and Weaknesses of the Available Approaches. Int J Mol Sci 2020; 21:E8157. [PMID: 33142798 DOI: 10.3390/ijms21218157] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 12/12/2022] Open
Abstract
Organelle intercommunication represents a wide area of interest. Over the last few decades, increasing evidence has highlighted the importance of organelle contact sites in many biological processes including Ca2+ signaling, lipid biosynthesis, apoptosis, and autophagy but also their involvement in pathological conditions. ER–mitochondria tethering is one of the most investigated inter-organelle communications and it is differently modulated in response to several cellular conditions including, but not limited to, starvation, Endoplasmic Reticulum (ER) stress, and mitochondrial shape modifications. Despite many studies aiming to understand their functions and how they are perturbed under different conditions, approaches to assess organelle proximity are still limited. Indeed, better visualization and characterization of contact sites remain a fascinating challenge. The aim of this review is to summarize strengths and weaknesses of the available methods to detect and quantify contact sites, with a main focus on ER–mitochondria tethering.
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Laplagne C, Meddour S, Figarol S, Michelas M, Calvayrac O, Favre G, Laurent C, Fournié JJ, Cabantous S, Poupot M. Vγ9Vδ2 T Cells Activation Through Phosphoantigens Can Be Impaired by a RHOB Rerouting in Lung Cancer. Front Immunol 2020; 11:1396. [PMID: 32733462 PMCID: PMC7358576 DOI: 10.3389/fimmu.2020.01396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 04/01/2020] [Accepted: 06/01/2020] [Indexed: 11/25/2022] Open
Abstract
Vγ9Vδ2 T cells are known to be efficient anti-tumor effectors activated through phosphoantigens (PAg) that are naturally expressed by tumor cells or induced by amino bisphosphonates treatment. This PAg-activation which is TCR and butyrophilin BTN3A dependent can be modulated by NKG2D ligands, immune checkpoint ligands, adhesion molecules, and costimulatory molecules. This could explain the immune-resistance observed in certain clinical trials based on Vγ9Vδ2 T cells therapies. In NSCLC, encouraging responses were obtained with zoledronate administrations for 50% of patients. According to the in vivo results, we showed that the in vitro Vγ9Vδ2 T cell reactivity depends on the NSCLC cell line considered. If the PAg-pretreated KRAS mutated A549 is highly recognized and killed by Vγ9Vδ2 T cells, the EGFR mutated PC9 remains resistant to these killers despite a pre-treatment either with zoledronate or with exogenous BrHPP. The immune resistance of PC9 was shown not to be due to immune checkpoint ligands able to counterbalance NKG2D ligands or adhesion molecules such as ICAM-1 highly expressed by PC9. RHOB has been shown to be involved in the Vγ9Vδ2 TCR signaling against these NSCLC cell lines, in this study we therefore focused on its intracellular behavior. In comparison to a uniform distribution of RHOB in endosomes and at the plasma membrane in A549, the presence of large endosomal clusters of RHOB was visualized by a split-GFP system, suggesting that RHOB rerouting in the PC9 tumor cell could impair the reactivity of the immune response.
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Affiliation(s)
- Chloé Laplagne
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Sarah Meddour
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Sarah Figarol
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Marie Michelas
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Olivier Calvayrac
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Gilles Favre
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France.,IUCT-O, Toulouse, France
| | - Camille Laurent
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France.,IUCT-O, Toulouse, France
| | - Jean-Jacques Fournié
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Stéphanie Cabantous
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
| | - Mary Poupot
- Centre de Recherches en Cancérologie de Toulouse, Inserm UMR1037, Toulouse, France.,Université Toulouse III Paul-Sabatier, Toulouse, France.,ERL 5294 CNRS, Toulouse, France
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Pedelacq JD, Cabantous S. Development and Applications of Superfolder and Split Fluorescent Protein Detection Systems in Biology. Int J Mol Sci 2019; 20:ijms20143479. [PMID: 31311175 PMCID: PMC6678664 DOI: 10.3390/ijms20143479] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 01/08/2023] Open
Abstract
Molecular engineering of the green fluorescent protein (GFP) into a robust and stable variant named Superfolder GFP (sfGFP) has revolutionized the field of biosensor development and the use of fluorescent markers in diverse area of biology. sfGFP-based self-associating bipartite split-FP systems have been widely exploited to monitor soluble expression in vitro, localization, and trafficking of proteins in cellulo. A more recent class of split-FP variants, named « tripartite » split-FP, that rely on the self-assembly of three GFP fragments, is particularly well suited for the detection of protein–protein interactions. In this review, we describe the different steps and evolutions that have led to the diversification of superfolder and split-FP reporter systems, and we report an update of their applications in various areas of biology, from structural biology to cell biology.
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Affiliation(s)
- Jean-Denis Pedelacq
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France.
| | - Stéphanie Cabantous
- Centre de Recherche en Cancérologie de Toulouse (CRCT), Inserm, Université Paul Sabatier-Toulouse III, CNRS, 31037 Toulouse, France.
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Smoyer CJ, Smith SE, Gardner JM, McCroskey S, Unruh JR, Jaspersen SL. Distribution of Proteins at the Inner Nuclear Membrane Is Regulated by the Asi1 E3 Ligase in Saccharomyces cerevisiae. Genetics 2019; 211:1269-82. [PMID: 30709848 DOI: 10.1534/genetics.119.301911] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 01/30/2019] [Indexed: 12/11/2022] Open
Abstract
Inner nuclear membrane (INM) protein composition regulates nuclear function, affecting processes such as gene expression, chromosome organization, nuclear shape, and stability. Mechanisms that drive changes in the INM proteome are poorly understood, in part because it is difficult to definitively assay INM composition rigorously and systematically. Using a split-GFP complementation system to detect INM access, we examined the distribution of all C-terminally tagged Saccharomyces cerevisiae membrane proteins in wild-type cells and in mutants affecting protein quality control pathways, such as INM-associated degradation (INMAD), ER-associated degradation, and vacuolar proteolysis. Deletion of the E3 ligase Asi1 had the most specific effect on the INM compared to mutants in vacuolar or ER-associated degradation pathways, consistent with a role for Asi1 in the INMAD pathway. Our data suggest that Asi1 not only removes mistargeted proteins at the INM, but also controls the levels and distribution of native INM components, such as the membrane nucleoporin Pom33. Interestingly, loss of Asi1 does not affect Pom33 protein levels but instead alters Pom33 distribution in the nuclear envelope through Pom33 ubiquitination, which drives INM redistribution. Taken together, our data demonstrate that the Asi1 E3 ligase has a novel function in INM protein regulation in addition to protein turnover.
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Mo HM, Xu Y, Yu XW. Improved Soluble Expression and Catalytic Activity of a Thermostable Esterase Using a High-Throughput Screening System Based on a Split-GFP Assembly. J Agric Food Chem 2018; 66:12756-12764. [PMID: 30411620 DOI: 10.1021/acs.jafc.8b04646] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The thermostable esterase Aaeo1 displays a low expression level and forms a great amount of inclusion bodies in E. coli. Herein, a split-GFP system was established in which the fluorescence intensity exhibited a good linear correlation with the soluble protein expression level and the esterase activity. In the primary high-throughput screening, the mutant library was screened by flow cytometry via detection of a split-GFP reporter. Then, through a secondary screening against esterase activity, two mutants with improved soluble expression and catalytic activity were obtained. The soluble expression of the mutant enzymes in E. coli was improved by 2-fold. The kcat/ Km values of the mutant enzymes were 2-fold higher than that of the parent. We explored the relationship between the amino acid mutations in the two mutants and the enzyme activity. The enzyme activity of mutant I51V-E170D was 4.5 times higher than that of the parent.
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Affiliation(s)
- Hong-Mei Mo
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
| | - Xiao-Wei Yu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology , Jiangnan University , Wuxi 214122 , PR China
- Suqian Industrial Technology Research Institute of Jiangnan University , Suqian 223814 , PR China
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Abstract
Several extremely halophilic archaea produce proteinaceous gas vesicles consisting of a gas-permeable protein wall constituted mainly by the gas vesicle proteins GvpA and GvpC. Eight additional accessory Gvp are involved in gas vesicle formation and might assist the assembly of this structure. Investigating interactions of halophilic proteins in vivo requires a method functioning at 2.5–5 M salt, and the split-GFP method was tested for this application. The two fragments NGFP and CGFP do not assemble a fluorescent GFP protein when produced in trans, but they assemble a fluorescent GFP when fused to interacting proteins. To adapt the method to high salt, we used the genes encoding two fragments of the salt-stable mGFP2 to construct four vector plasmids that allow an N- or C-terminal fusion to the two proteins of interest. To avoid a hindrance in the assembly of mGFP2, the fusion included a linker of 15 or 19 amino acids. The small gas vesicle accessory protein GvpM and its interaction partners GvpH, GvpJ, and GvpL were investigated by split-GFP. Eight different combinations were studied in each case, and fluorescent transformants indicative of an interaction were observed. We also determined that GvpF interacts with GvpM and uncovered the location of the interaction site of each of these proteins in GvpM. GvpL mainly interacted with the N-terminal 25-amino acid fragment of GvpM, whereas the other three proteins bound predominately to the C-terminal portion. Overall, the split-GFP method is suitable to investigate the interaction of two proteins in haloarchaeal cells. In future experiments, we will study the interactions of the remaining Gvps and determine whether some or all of these accessory Gvp proteins form (a) protein complex(es) during early stages of the assembly of the gas vesicle wall.
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Affiliation(s)
- Kerstin Winter
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Johannes Born
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Felicitas Pfeifer
- Microbiology and Archaea, Department of Biology, Technische Universität Darmstadt, Darmstadt, Germany
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Polge C, Cabantous S, Deval C, Claustre A, Hauvette A, Bouchenot C, Aniort J, Béchet D, Combaret L, Attaix D, Taillandier D. A muscle-specific MuRF1-E2 network requires stabilization of MuRF1-E2 complexes by telethonin, a newly identified substrate. J Cachexia Sarcopenia Muscle 2018; 9:129-145. [PMID: 29271608 PMCID: PMC5803617 DOI: 10.1002/jcsm.12249] [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] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/21/2017] [Accepted: 09/05/2017] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Muscle wasting is observed in the course of many diseases and also during physiological conditions (disuse, ageing). Skeletal muscle mass is largely controlled by the ubiquitin-proteasome system and thus by the ubiquitinating enzymes (E2s and E3s) that target substrates for subsequent degradation. MuRF1 is the only E3 ubiquitin ligase known to target contractile proteins (α-actin, myosins) during catabolic situations. However, MuRF1 depends on E2 ubiquitin-conjugating enzymes for ubiquitin chain formation on the substrates. MuRF1-E2 couples are therefore putative targets for preventing muscle wasting. METHODS We focused on 14 E2 enzymes that are either expressed in skeletal muscle or up-regulated during atrophying conditions. In this work, we demonstrated that only highly sensitive and complementary interactomic approaches (surface plasmon resonance, yeast three-hybrid, and split green fluorescent protein) allowed the identification of MuRF1 E2 partners. RESULTS Five E2 enzymes physically interacted with MuRF1, namely, E2E1, E2G1, E2J1, E2J2, and E2L3. Moreover, we demonstrated that MuRF1-E2E1 and MuRF1-E2J1 interactions are facilitated by telethonin, a newly identified MuRF1 substrate. We next showed that the five identified E2s functionally interacted with MuRF1 since, in contrast to the non-interacting E2D2, their co-expression in HEK293T cells with MuRF1 led to increased telethonin degradation. Finally, we showed that telethonin governed the affinity between MuRF1 and E2E1 or E2J1. CONCLUSIONS We report here the first MuRF1-E2s network, which may prove valuable for deciphering the precise mechanisms involved in the atrophying muscle programme and for proposing new therapeutical approaches.
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Affiliation(s)
- Cécile Polge
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Stéphanie Cabantous
- Cancer Research Center of Toulouse, INSERM UMR 1037F‐31037ToulouseFrance
- Université de ToulouseF‐31062ToulouseFrance
| | - Christiane Deval
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Agnès Claustre
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Antoine Hauvette
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Catherine Bouchenot
- Cancer Research Center of Toulouse, INSERM UMR 1037F‐31037ToulouseFrance
- Université de ToulouseF‐31062ToulouseFrance
| | - Julien Aniort
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
- Service de Néphrologie Réanimation Médicale, Pôle Respiratoire, Endocrinologie‐Diabétologie, Urologie, Néphrologie‐Dialyse, Nutrition Clinique, InfectiologieRéanimation Médicale, Hygiène Hospitalière (REUNNIRH)F‐63000Clermont‐FerrandFrance
| | - Daniel Béchet
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Lydie Combaret
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Didier Attaix
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
| | - Daniel Taillandier
- Université Clermont Auvergne, INRA, UNH, Unité de Nutrition HumaineCRNH AuvergneF‐63000Clermont‐FerrandFrance
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Young AM, Minson M, McQuate SE, Palmer AE. Optimized Fluorescence Complementation Platform for Visualizing Salmonella Effector Proteins Reveals Distinctly Different Intracellular Niches in Different Cell Types. ACS Infect Dis 2017; 3:575-584. [PMID: 28551989 PMCID: PMC5720895 DOI: 10.1021/acsinfecdis.7b00052] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [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] [Indexed: 01/24/2023]
Abstract
The bacterial pathogen Salmonella uses sophisticated type III secretion systems (T3SS) to translocate and deliver bacterial effector proteins into host cells to establish infection. Monitoring these important virulence determinants in the context of live infections is a key step in defining the dynamic interface between the host and pathogen. Here, we provide a modular labeling platform based on fluorescence complementation with split-GFP that permits facile tagging of new Salmonella effector proteins. We demonstrate enhancement of split-GFP complementation signals by manipulating the promoter or by multimerizing the fluorescent tag and visualize three effector proteins, SseF, SseG, and SlrP, that have never before been visualized over time during infection of live cells. Using this platform, we developed a methodology for visualizing effector proteins in primary macrophage cells for the first time and reveal distinct differences in the effector-defined intracellular niche between primary macrophage and commonly used HeLa and RAW cell lines.
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Affiliation(s)
- Alexandra M. Young
- Department of Chemistry and Biochemistry, BioFrontiers Institute, UCB 596, 3415 Colorado Ave, University of Colorado, Boulder, CO 80303
| | - Michael Minson
- Department of Chemistry and Biochemistry, BioFrontiers Institute, UCB 596, 3415 Colorado Ave, University of Colorado, Boulder, CO 80303
| | - Sarah E. McQuate
- Department of Chemistry and Biochemistry, BioFrontiers Institute, UCB 596, 3415 Colorado Ave, University of Colorado, Boulder, CO 80303
| | - Amy E. Palmer
- Department of Chemistry and Biochemistry, BioFrontiers Institute, UCB 596, 3415 Colorado Ave, University of Colorado, Boulder, CO 80303
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Gruet A, Dosnon M, Blocquel D, Brunel J, Gerlier D, Das RK, Bonetti D, Gianni S, Fuxreiter M, Longhi S, Bignon C. Fuzzy regions in an intrinsically disordered protein impair protein-protein interactions. FEBS J 2016; 283:576-94. [PMID: 26684000 DOI: 10.1111/febs.13631] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [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: 08/08/2015] [Revised: 11/22/2015] [Accepted: 12/15/2015] [Indexed: 12/13/2022]
Abstract
Despite the partial disorder-to-order transition that intrinsically disordered proteins often undergo upon binding to their partners, a considerable amount of residual disorder may be retained in the bound form, resulting in a fuzzy complex. Fuzzy regions flanking molecular recognition elements may enable partner fishing through non-specific, transient contacts, thereby facilitating binding, but may also disfavor binding through various mechanisms. So far, few computational or experimental studies have addressed the effect of fuzzy appendages on partner recognition by intrinsically disordered proteins. In order to shed light onto this issue, we used the interaction between the intrinsically disordered C-terminal domain of the measles virus (MeV) nucleoprotein (NTAIL ) and the X domain (XD) of the viral phosphoprotein as model system. After binding to XD, the N-terminal region of NTAIL remains conspicuously disordered, with α-helical folding taking place only within a short molecular recognition element. To study the effect of the N-terminal fuzzy region on NTAIL /XD binding, we generated N-terminal truncation variants of NTAIL , and assessed their binding abilities towards XD. The results revealed that binding increases with shortening of the N-terminal fuzzy region, with this also being observed with hsp70 (another MeV NTAIL binding partner), and for the homologous NTAIL /XD pairs from the Nipah and Hendra viruses. Finally, similar results were obtained when the MeV NTAIL fuzzy region was replaced with a highly dissimilar artificial disordered sequence, supporting a sequence-independent inhibitory effect of the fuzzy region.
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Affiliation(s)
- Antoine Gruet
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France.,Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France
| | - Marion Dosnon
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France.,Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France
| | - David Blocquel
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France.,Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France
| | - Joanna Brunel
- Centre International de Recherche en Infectiologie, INSERM U1111, Centre National de la Recherche Scientifique, UMR 5308, Université Lyon 1, Lyon, France
| | - Denis Gerlier
- Centre International de Recherche en Infectiologie, INSERM U1111, Centre National de la Recherche Scientifique, UMR 5308, Université Lyon 1, Lyon, France
| | - Rahul K Das
- Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St Louis, MO, USA
| | - Daniela Bonetti
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli' and Istituto di Biologia e Patologia Molecolari del Consiglio Nazionale delle Ricerche, Sapienza Università di Roma, Rome, Italy
| | - Stefano Gianni
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'A. Rossi Fanelli' and Istituto di Biologia e Patologia Molecolari del Consiglio Nazionale delle Ricerche, Sapienza Università di Roma, Rome, Italy.,Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Monika Fuxreiter
- Hungarian Academy of Sciences, Momentum Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, University of Debrecen, Hungary
| | - Sonia Longhi
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France.,Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France
| | - Christophe Bignon
- Aix-Marseille Université, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France.,Centre National de la Recherche Scientifique, Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 7257, Marseille, France
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Tsetsenis T, Boucard AA, Araç D, Brunger AT, Südhof TC. Direct visualization of trans-synaptic neurexin-neuroligin interactions during synapse formation. J Neurosci 2014; 34:15083-96. [PMID: 25378172 DOI: 10.1523/JNEUROSCI.0348-14.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neurexins and neuroligins are synaptic cell-adhesion molecules that are essential for normal synapse specification and function and are thought to bind to each other trans-synaptically, but such interactions have not been demonstrated directly. Here, we generated neurexin-1β and neuroligin-1 and neuroligin-2 fusion proteins containing complementary "split" GFP fragments positioned such that binding of neurexin-1β to neuroligin-1 or neuroligin-2 allowed GFP reconstitution without dramatically changing their binding affinities. GFP fluorescence was only reconstituted from split-GFP-modified neurexin-1β and neuroligin-1 if and after neurexin-1β bound to its neuroligin partner; reassociation of the split-GFP components with each other did not mediate binding. Using trans-cellular reconstitution of GFP fluorescence from split-GFP-modified neurexin-1β and neuroligins as an assay, we demonstrate that trans-synaptic neurexin/neuroligin binding indeed occurred when mouse hippocampal neurons formed synapses onto non-neuronal COS-7 cells expressing neuroligins or when mouse hippocampal neurons formed synapses with each other. This visualization of synapses by neurexin/neuroligin binding prompted us to refer to this approach as "SynView." Our data demonstrate that neurexin-1β forms a trans-synaptic complex with neuroligin-1 and neuroligin-2 and that this interaction can be used to label synapses in a specific fashion in vivo.
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