1
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Gan Q, Fan C. Orthogonal Translation for Site-Specific Installation of Post-translational Modifications. Chem Rev 2024; 124:2805-2838. [PMID: 38373737 PMCID: PMC11230630 DOI: 10.1021/acs.chemrev.3c00850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Post-translational modifications (PTMs) endow proteins with new properties to respond to environmental changes or growth needs. With the development of advanced proteomics techniques, hundreds of distinct types of PTMs have been observed in a wide range of proteins from bacteria, archaea, and eukarya. To identify the roles of these PTMs, scientists have applied various approaches. However, high dynamics, low stoichiometry, and crosstalk between PTMs make it almost impossible to obtain homogeneously modified proteins for characterization of the site-specific effect of individual PTM on target proteins. To solve this problem, the genetic code expansion (GCE) strategy has been introduced into the field of PTM studies. Instead of modifying proteins after translation, GCE incorporates modified amino acids into proteins during translation, thus generating site-specifically modified proteins at target positions. In this review, we summarize the development of GCE systems for orthogonal translation for site-specific installation of PTMs.
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Affiliation(s)
- Qinglei Gan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Chenguang Fan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, United States
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, Arkansas 72701, United States
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2
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Rahman SMT, Zhou W, Deiters A, Haugh JM. Dissection of MKK6 and p38 Signaling Using Light-Activated Protein Kinases. Chembiochem 2024; 25:e202300551. [PMID: 37856284 DOI: 10.1002/cbic.202300551] [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: 08/04/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 10/21/2023]
Abstract
Stress-activated signaling pathways orchestrate cellular behaviors and fates. Studying the precise role(s) of stress-activated protein kinases is challenging, because stress conditions induce adaptation and impose selection pressure. To meet this challenge, we have applied an optogenetic system with a single plasmid to express light-activated p38α or its upstream activator, MKK6, in conjunction with live-cell fluorescence microscopy. In starved cells, decaging of constitutively active p38α or MKK6 by brief exposure to UV light elicits rapid p38-mediated signaling, release of cytochrome c from mitochondria, and apoptosis with different kinetics. In parallel, light activation of p38α also suppresses autophagosome formation, similarly to stimulation with growth factors that activate PI3K/Akt/mTORC1 signaling. Active MKK6 negatively regulates serum-induced ERK activity, which is p38-independent as previously reported. Here, we reproduce that result with the one plasmid system and show that although decaging active p38α does not reduce basal ERK activity in our cells, it can block growth factor-stimulated ERK signaling in serum-starved cells. These results clarify the roles of MKK6 and p38α in dynamic signaling programs, which act in concert to actuate apoptotic death while suppressing cell survival mechanisms.
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Affiliation(s)
- Shah Md Toufiqur Rahman
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Campus Box 7905, 911 Partners Way, Raleigh, NC, 27695, USA
| | - Wenyuan Zhou
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Jason M Haugh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Campus Box 7905, 911 Partners Way, Raleigh, NC, 27695, USA
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3
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Wu F, Muskat NH, Dvilansky I, Koren O, Shahar A, Gazit R, Elia N, Arbely E. Acetylation-dependent coupling between G6PD activity and apoptotic signaling. Nat Commun 2023; 14:6208. [PMID: 37798264 PMCID: PMC10556143 DOI: 10.1038/s41467-023-41895-2] [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: 03/27/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023] Open
Abstract
Lysine acetylation has been discovered in thousands of non-histone human proteins, including most metabolic enzymes. Deciphering the functions of acetylation is key to understanding how metabolic cues mediate metabolic enzyme regulation and cellular signaling. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway, is acetylated on multiple lysine residues. Using site-specifically acetylated G6PD, we show that acetylation can activate (AcK89) and inhibit (AcK403) G6PD. Acetylation-dependent inactivation is explained by structural studies showing distortion of the dimeric structure and active site of G6PD. We provide evidence for acetylation-dependent K95/97 ubiquitylation of G6PD and Y503 phosphorylation, as well as interaction with p53 and induction of early apoptotic events. Notably, we found that the acetylation of a single lysine residue coordinates diverse acetylation-dependent processes. Our data provide an example of the complex roles of acetylation as a posttranslational modification that orchestrates the regulation of enzymatic activity, posttranslational modifications, and apoptotic signaling.
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Affiliation(s)
- Fang Wu
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Natali H Muskat
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Inbar Dvilansky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Omri Koren
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Anat Shahar
- Macromolecular Crystallography Research Center (MCRC), Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Roi Gazit
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Eyal Arbely
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
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4
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Direct Capsid Labeling of Infectious HIV-1 by Genetic Code Expansion Allows Detection of Largely Complete Nuclear Capsids and Suggests Nuclear Entry of HIV-1 Complexes via Common Routes. mBio 2022; 13:e0195922. [PMID: 35972146 PMCID: PMC9600849 DOI: 10.1128/mbio.01959-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The cone-shaped mature HIV-1 capsid is the main orchestrator of early viral replication. After cytosolic entry, it transports the viral replication complex along microtubules toward the nucleus. While it was initially believed that the reverse transcribed genome is released from the capsid in the cytosol, recent observations indicate that a high amount of capsid protein (CA) remains associated with subviral complexes during import through the nuclear pore complex (NPC). Observation of postentry events via microscopic detection of HIV-1 CA is challenging, since epitope shielding limits immunodetection and the genetic fragility of CA hampers direct labeling approaches. Here, we present a minimally invasive strategy based on genetic code expansion and click chemistry that allows for site-directed fluorescent labeling of HIV-1 CA, while retaining virus morphology and infectivity. Thereby, we could directly visualize virions and subviral complexes using advanced microscopy, including nanoscopy and correlative imaging. Quantification of signal intensities of subviral complexes revealed an amount of CA associated with nuclear complexes in HeLa-derived cells and primary T cells consistent with a complete capsid and showed that treatment with the small molecule inhibitor PF74 did not result in capsid dissociation from nuclear complexes. Cone-shaped objects detected in the nucleus by electron tomography were clearly identified as capsid-derived structures by correlative microscopy. High-resolution imaging revealed dose-dependent clustering of nuclear capsids, suggesting that incoming particles may follow common entry routes.
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5
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Schloßhauer JL, Cavak N, Zemella A, Thoring L, Kubick S. Cell Engineering and Cultivation of Chinese Hamster Ovary Cells for the Development of Orthogonal Eukaryotic Cell-free Translation Systems. Front Mol Biosci 2022; 9:832379. [PMID: 35586195 PMCID: PMC9109823 DOI: 10.3389/fmolb.2022.832379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/15/2022] [Indexed: 12/03/2022] Open
Abstract
The investigation of protein structures, functions and interactions often requires modifications to adapt protein properties to the specific application. Among many possible methods to equip proteins with new chemical groups, the utilization of orthogonal aminoacyl-tRNA synthetase/tRNA pairs enables the site-specific incorporation of non-canonical amino acids at defined positions in the protein. The open nature of cell-free protein synthesis reactions provides an optimal environment, as the orthogonal components do not need to be transported across the cell membrane and the impact on cell viability is negligible. In the present work, it was shown that the expression of orthogonal aminoacyl-tRNA synthetases in CHO cells prior to cell disruption enhanced the modification of the pharmaceutically relevant adenosine A2a receptor. For this purpose, in complement to transient transfection of CHO cells, an approach based on CRISPR/Cas9 technology was selected to generate a translationally active cell lysate harboring endogenous orthogonal aminoacyl-tRNA synthetase.
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Affiliation(s)
- Jeffrey L. Schloßhauer
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Niño Cavak
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Anne Zemella
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Lena Thoring
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
| | - Stefan Kubick
- Branch Bioanalytics and Bioprocesses (IZI-BB), Fraunhofer Institute for Cell Therapy and Immunology (IZI), Potsdam, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus –Senftenberg, The Brandenburg Medical School Theodor Fontane and the University of Potsdam, Potsdam, Germany
- *Correspondence: Stefan Kubick,
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6
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Stieglitz JT, Potts KA, Van Deventer JA. Broadening the Toolkit for Quantitatively Evaluating Noncanonical Amino Acid Incorporation in Yeast. ACS Synth Biol 2021; 10:3094-3104. [PMID: 34730946 DOI: 10.1021/acssynbio.1c00370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Genetic code expansion is a powerful approach for advancing critical fields such as biological therapeutic discovery. However, the machinery for genetically encoding noncanonical amino acids (ncAAs) is only available in limited plasmid formats, constraining potential applications. In extreme cases, the introduction of two separate plasmids, one containing an orthogonal translation system (OTS) to facilitate ncAA incorporation and a second for expressing a ncAA-containing protein of interest, is not possible due to a lack of the available selection markers. One strategy to circumvent this challenge is to express the OTS and protein of interest from a single vector. For what we believe is the first time in yeast, we describe here several sets of single plasmid systems (SPSs) for performing genetic code manipulation and compare the ncAA incorporation capabilities of these plasmids against the capabilities of previously described dual plasmid systems (DPSs). For both dual fluorescent protein reporters and yeast display reporters tested with multiple OTSs and ncAAs, measured ncAA incorporation efficiencies with SPSs were determined to be equal to efficiencies determined with DPSs. Click chemistry on yeast cells displaying ncAA-containing proteins was also shown to be feasible in both formats, although differences in reactivity between formats suggest the need for caution when using such approaches. Additionally, we investigated whether these reporters would support the separation of yeast strains known to exhibit distinct ncAA incorporation efficiencies. Model sorts conducted with mixtures of two strains transformed with the same SPS or DPS both led to the enrichment of a strain known to support a higher efficiency ncAA incorporation, suggesting that these reporters will be suitable for conducting screens for strains exhibiting enhanced ncAA incorporation efficiencies. Overall, our results confirm that SPSs are well behaved in yeast and provide a convenient alternative to DPSs. SPSs are expected to be invaluable for conducting high-throughput investigations of the effects of genetic or genomic changes on ncAA incorporation efficiency and, more fundamentally, the eukaryotic translation apparatus.
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Affiliation(s)
- Jessica T. Stieglitz
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
| | - Kelly A. Potts
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
| | - James A. Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
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7
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Bartoschek MD, Ugur E, Nguyen TA, Rodschinka G, Wierer M, Lang K, Bultmann S. Identification of permissive amber suppression sites for efficient non-canonical amino acid incorporation in mammalian cells. Nucleic Acids Res 2021; 49:e62. [PMID: 33684219 PMCID: PMC8216290 DOI: 10.1093/nar/gkab132] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/20/2022] Open
Abstract
The genetic code of mammalian cells can be expanded to allow the incorporation of non-canonical amino acids (ncAAs) by suppressing in-frame amber stop codons (UAG) with an orthogonal pyrrolysyl-tRNA synthetase (PylRS)/tRNAPylCUA (PylT) pair. However, the feasibility of this approach is substantially hampered by unpredictable variations in incorporation efficiencies at different stop codon positions within target proteins. Here, we apply a proteomics-based approach to quantify ncAA incorporation rates at hundreds of endogenous amber stop codons in mammalian cells. With these data, we compute iPASS (Identification of Permissive Amber Sites for Suppression; available at www.bultmannlab.eu/tools/iPASS), a linear regression model to predict relative ncAA incorporation efficiencies depending on the surrounding sequence context. To verify iPASS, we develop a dual-fluorescence reporter for high-throughput flow-cytometry analysis that reproducibly yields context-specific ncAA incorporation efficiencies. We show that nucleotides up- and downstream of UAG synergistically influence ncAA incorporation efficiency independent of cell line and ncAA identity. Additionally, we demonstrate iPASS-guided optimization of ncAA incorporation rates by synonymous exchange of codons flanking the amber stop codon. This combination of in silico analysis followed by validation in living mammalian cells substantially simplifies identification as well as adaptation of sites within a target protein to confer high ncAA incorporation rates.
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Affiliation(s)
- Michael D Bartoschek
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Enes Ugur
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany.,Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Tuan-Anh Nguyen
- Department of Chemistry, Synthetic Biochemistry, Technical University of Munich, Garching 85748, Germany
| | - Geraldine Rodschinka
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
| | - Michael Wierer
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Kathrin Lang
- Department of Chemistry, Synthetic Biochemistry, Technical University of Munich, Garching 85748, Germany
| | - Sebastian Bultmann
- Department of Biology II and Center for Molecular Biosystems (BioSysM), Human Biology and BioImaging, Ludwig-Maximilians-Universität München, Munich 81377, Germany
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8
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Genetic code expansion in mammalian cells: A plasmid system comparison. Bioorg Med Chem 2020; 28:115772. [PMID: 33069552 DOI: 10.1016/j.bmc.2020.115772] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/22/2022]
Abstract
Genetic code expansion with unnatural amino acids (UAAs) has significantly broadened the chemical repertoire of proteins. Applications of this method in mammalian cells include probing of molecular interactions, conditional control of biological processes, and new strategies for therapeutics and vaccines. A number of methods have been developed for transient UAA mutagenesis in mammalian cells, each with unique features and advantages. All have in common a need to deliver genes encoding additional protein biosynthetic machinery (an orthogonal tRNA/tRNA synthetase pair) and a gene for the protein of interest. In this study, we present a comparative evaluation of select plasmid-based genetic code expansion systems and a detailed analysis of suppression efficiency with different UAAs and in different cell lines.
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9
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Kadunc L, Svetličič M, Forstnerič V, Hafner Bratkovič I, Jerala R. Increased gene translation stringency in mammalian cells by nonsense suppression at multiple permissive sites with a single noncanonical amino acid. FEBS Lett 2020; 594:2452-2461. [PMID: 32401336 DOI: 10.1002/1873-3468.13810] [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: 03/02/2020] [Revised: 04/15/2020] [Accepted: 04/27/2020] [Indexed: 11/10/2022]
Abstract
The considerable potential of engineered cells compels the development of strategies for the stringent control of gene expression. A promising approach is the introduction of a premature stop codon (PTC) into a selected gene that is expressed only in the presence of noncanonical amino acids through nonsense suppression. Here, different strategies of amber PTC readthrough in mammalian cells were tested. The use of a tRNA synthetase together with a TAG codon-specific tRNA achieved PTC readthrough depending on the addition of a noncanonical amino acid (4-benzoyl-L-phenylalanine; Bpa). While single TAG codon incorporation exhibited detectable expression of the reporter protein even in the absence of Bpa, the use of a double PTC enabled virtually leakage-free functional gene translation. The introduction of an additional 5'-PTC, therefore, represents a generally applicable strategy to increase stringency in gene translation.
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Affiliation(s)
- Lucija Kadunc
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,Graduate School of Biomedicine, University of Ljubljana, Ljubljana, Slovenia
| | - Maja Svetličič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Vida Forstnerič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Iva Hafner Bratkovič
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Ljubljana, Slovenia
| | - Roman Jerala
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, Slovenia.,EN-FIST Centre of Excellence, Ljubljana, Slovenia
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10
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Cohen S, Kramarski L, Levi S, Deshe N, Ben David O, Arbely E. Nonsense mutation-dependent reinitiation of translation in mammalian cells. Nucleic Acids Res 2020; 47:6330-6338. [PMID: 31045216 PMCID: PMC6614817 DOI: 10.1093/nar/gkz319] [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: 09/17/2018] [Revised: 04/16/2019] [Accepted: 04/22/2019] [Indexed: 11/14/2022] Open
Abstract
In-frame stop codons mark the termination of translation. However, post-termination ribosomes can reinitiate translation at downstream AUG codons. In mammals, reinitiation is most efficient when the termination codon is positioned close to the 5′-proximal initiation site and around 78 bases upstream of the reinitiation site. The phenomenon was studied mainly in the context of open reading frames (ORFs) found within the 5′-untranslated region, or polycicstronic viral mRNA. We hypothesized that reinitiation of translation following nonsense mutations within the main ORF of p53 can promote the expression of N-truncated p53 isoforms such as Δ40, Δ133 and Δ160p53. Here, we report that expression of all known N-truncated p53 isoforms by reinitiation is mechanistically feasible, including expression of the previously unidentified variant Δ66p53. Moreover, we found that significant reinitiation of translation can be promoted by nonsense mutations located even 126 codons downstream of the 5′-proximal initiation site, and observed when the reinitiation site is positioned between 6 and 243 bases downstream of the nonsense mutation. We also demonstrate that reinitiation can stabilise p53 mRNA transcripts with a premature termination codon, by allowing such transcripts to evade the nonsense mediated decay pathway. Our data suggest that the expression of N-truncated proteins from alleles carrying a premature termination codon is more prevalent than previously thought.
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Affiliation(s)
- Sarit Cohen
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Lior Kramarski
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Shahar Levi
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Noa Deshe
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Oshrit Ben David
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Eyal Arbely
- Department of Chemistry and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.,Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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11
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König AI, Sorkin R, Alon A, Nachmias D, Dhara K, Brand G, Yifrach O, Arbely E, Roichman Y, Elia N. Live cell single molecule tracking and localization microscopy of bioorthogonally labeled plasma membrane proteins. NANOSCALE 2020; 12:3236-3248. [PMID: 31970355 DOI: 10.1039/c9nr08594g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tracking the localization and mobility of individual proteins in live cells is key for understanding how they mediate their function. Such information can be obtained from single molecule imaging techniques including as Single Particle Tracking (SPT) and Single Molecule Localization Microscopy (SMLM). Genetic code expansion (GCE) combined with bioorthogonal chemistry offers an elegant approach for direct labeling of proteins with fluorescent dyes, holding great potential for improving protein labeling in single molecule applications. Here we calibrated conditions for performing SPT and live-SMLM of bioorthogonally labeled plasma membrane proteins in live mammalian cells. Using SPT, the diffusion of bioorthogonally labeled EGF receptor and the prototypical Shaker voltage-activated potassium channel (Kv) was measured and characterized. Applying live-SMLM to bioorthogonally labeled Shaker Kv channels enabled visualizing the plasma membrane distribution of the channel over time with ∼30 nm accuracy. Finally, by competitive labeling with two Fl-dyes, SPT and live-SMLM were performed in a single cell and both the density and dynamics of the EGF receptor were measured at single molecule resolution in subregions of the cell. We conclude that GCE and bioorthogonal chemistry is a highly suitable, flexible approach for protein labeling in quantitative single molecule applications that outperforms current protein live-cell labeling approaches.
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Affiliation(s)
- Andres I König
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.
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12
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Segal I, Nachmias D, Konig A, Alon A, Arbely E, Elia N. A straightforward approach for bioorthogonal labeling of proteins and organelles in live mammalian cells, using a short peptide tag. BMC Biol 2020; 18:5. [PMID: 31937312 PMCID: PMC6961407 DOI: 10.1186/s12915-019-0708-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 10/15/2019] [Indexed: 11/29/2022] Open
Abstract
Background In the high-resolution microscopy era, genetic code expansion (GCE)-based bioorthogonal labeling offers an elegant way for direct labeling of proteins in live cells with fluorescent dyes. This labeling approach is currently not broadly used in live-cell applications, partly because it needs to be adjusted to the specific protein under study. Results We present a generic, 14-residue long, N-terminal tag for GCE-based labeling of proteins in live mammalian cells. Using this tag, we generated a library of GCE-based organelle markers, demonstrating the applicability of the tag for labeling a plethora of proteins and organelles. Finally, we show that the HA epitope, used as a backbone in our tag, may be substituted with other epitopes and, in some cases, can be completely removed, reducing the tag length to 5 residues. Conclusions The GCE-tag presented here offers a powerful, easy-to-implement tool for live-cell labeling of cellular proteins with small and bright probes.
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Affiliation(s)
- Inbar Segal
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.,National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Dikla Nachmias
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.,National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Andres Konig
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.,National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Ariel Alon
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.,National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Eyal Arbely
- National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.,Department of Chemistry, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel. .,National Institute for Biotechnology in the Negev (NIBN), Ben-Gurion University of the Negev, 84105, Beer Sheva, Israel.
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13
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Nödling AR, Spear LA, Williams TL, Luk LYP, Tsai YH. Using genetically incorporated unnatural amino acids to control protein functions in mammalian cells. Essays Biochem 2019; 63:237-266. [PMID: 31092687 PMCID: PMC6610526 DOI: 10.1042/ebc20180042] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 02/07/2023]
Abstract
Genetic code expansion allows unnatural (non-canonical) amino acid incorporation into proteins of interest by repurposing the cellular translation machinery. The development of this technique has enabled site-specific incorporation of many structurally and chemically diverse amino acids, facilitating a plethora of applications, including protein imaging, engineering, mechanistic and structural investigations, and functional regulation. Particularly, genetic code expansion provides great tools to study mammalian proteins, of which dysregulations often have important implications in health. In recent years, a series of methods has been developed to modulate protein function through genetically incorporated unnatural amino acids. In this review, we will first discuss the basic concept of genetic code expansion and give an up-to-date list of amino acids that can be incorporated into proteins in mammalian cells. We then focus on the use of unnatural amino acids to activate, inhibit, or reversibly modulate protein function by translational, optical or chemical control. The features of each approach will also be highlighted.
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Affiliation(s)
| | - Luke A Spear
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Thomas L Williams
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Louis Y P Luk
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Yu-Hsuan Tsai
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
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14
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Aloush N, Schvartz T, König AI, Cohen S, Brozgol E, Tam B, Nachmias D, Ben-David O, Garini Y, Elia N, Arbely E. Live Cell Imaging of Bioorthogonally Labelled Proteins Generated With a Single Pyrrolysine tRNA Gene. Sci Rep 2018; 8:14527. [PMID: 30267004 PMCID: PMC6162220 DOI: 10.1038/s41598-018-32824-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/19/2018] [Indexed: 11/08/2022] Open
Abstract
Genetic code expansion enables the incorporation of non-canonical amino acids (ncAAs) into expressed proteins. ncAAs are usually encoded by a stop codon that is decoded by an exogenous orthogonal aminoacyl tRNA synthetase and its cognate suppressor tRNA, such as the pyrrolysine [Formula: see text] pair. In such systems, stop codon suppression is dependent on the intracellular levels of the exogenous tRNA. Therefore, multiple copies of the tRNAPyl gene (PylT) are encoded to improve ncAA incorporation. However, certain applications in mammalian cells, such as live-cell imaging applications, where labelled tRNAs contribute to background fluorescence, can benefit from the use of less invasive minimal expression systems. Accordingly, we studied the effect of tRNAPyl on live-cell fluorescence imaging of bioorthogonally-labelled intracellular proteins. We found that in COS7 cells, a decrease in PylT copy numbers had no measurable effect on protein expression levels. Importantly, reducing PylT copy numbers improved the quality of live-cell images by enhancing the signal-to-noise ratio and reducing an immobile tRNAPyl population. This enabled us to improve live cell imaging of bioorthogonally labelled intracellular proteins, and to simultaneously label two different proteins in a cell. Our results indicate that the number of introduced PylT genes can be minimized according to the transfected cell line, incorporated ncAA, and application.
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Affiliation(s)
- Noa Aloush
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Tomer Schvartz
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Andres I König
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Sarit Cohen
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Eugene Brozgol
- Physics Department and Institute for Nanotechnology, Bar Ilan University, Ramat Gan, 5290002, Israel
| | - Benjamin Tam
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Dikla Nachmias
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Oshrit Ben-David
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Yuval Garini
- Physics Department and Institute for Nanotechnology, Bar Ilan University, Ramat Gan, 5290002, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel
| | - Eyal Arbely
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel.
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel.
- National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 8410501, Israel.
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15
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Chen H, Venkat S, McGuire P, Gan Q, Fan C. Recent Development of Genetic Code Expansion for Posttranslational Modification Studies. Molecules 2018; 23:E1662. [PMID: 29986538 PMCID: PMC6100177 DOI: 10.3390/molecules23071662] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 12/29/2022] Open
Abstract
Nowadays advanced mass spectrometry techniques make the identification of protein posttranslational modifications (PTMs) much easier than ever before. A series of proteomic studies have demonstrated that large numbers of proteins in cells are modified by phosphorylation, acetylation and many other types of PTMs. However, only limited studies have been performed to validate or characterize those identified modification targets, mostly because PTMs are very dynamic, undergoing large changes in different growth stages or conditions. To overcome this issue, the genetic code expansion strategy has been introduced into PTM studies to genetically incorporate modified amino acids directly into desired positions of target proteins. Without using modifying enzymes, the genetic code expansion strategy could generate homogeneously modified proteins, thus providing powerful tools for PTM studies. In this review, we summarized recent development of genetic code expansion in PTM studies for research groups in this field.
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Affiliation(s)
- Hao Chen
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Sumana Venkat
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Paige McGuire
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Qinglei Gan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
| | - Chenguang Fan
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701, USA.
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
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16
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Abstract
Exciting new technological developments have pushed the boundaries of structural biology, and have enabled studies of biological macromolecules and assemblies that would have been unthinkable not long ago. Yet, the enhanced capabilities of structural biologists to pry into the complex molecular world have also placed new demands on the abilities of protein engineers to reproduce this complexity into the test tube. With this challenge in mind, we review the contents of the modern molecular engineering toolbox that allow the manipulation of proteins in a site-specific and chemically well-defined fashion. Thus, we cover concepts related to the modification of cysteines and other natural amino acids, native chemical ligation, intein and sortase-based approaches, amber suppression, as well as chemical and enzymatic bio-conjugation strategies. We also describe how these tools can be used to aid methodology development in X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy and in the studies of dynamic interactions. It is our hope that this monograph will inspire structural biologists and protein engineers alike to apply these tools to novel systems, and to enhance and broaden their scope to meet the outstanding challenges in understanding the molecular basis of cellular processes and disease.
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17
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Brabham R, Fascione MA. Pyrrolysine Amber Stop-Codon Suppression: Development and Applications. Chembiochem 2017; 18:1973-1983. [DOI: 10.1002/cbic.201700148] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/28/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Robin Brabham
- York Structural Biology Laboratory; Department of Chemistry; University of York; Heslington Road York YO10 5DD UK
| | - Martin A. Fascione
- York Structural Biology Laboratory; Department of Chemistry; University of York; Heslington Road York YO10 5DD UK
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18
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Schvartz T, Aloush N, Goliand I, Segal I, Nachmias D, Arbely E, Elia N. Direct fluorescent-dye labeling of α-tubulin in mammalian cells for live cell and superresolution imaging. Mol Biol Cell 2017; 28:2747-2756. [PMID: 28835375 PMCID: PMC5638579 DOI: 10.1091/mbc.e17-03-0161] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 12/28/2022] Open
Abstract
This work describes an elegant approach for direct, site-specific labeling of proteins with fluorescent-dyes for live cell imaging. By integrating a noncanonical amino acid that is capable of binding a fluorescent dye into tubulin, we directly and specifically labeled tubulin with a fluorescent-dye and imaged microtubules in live mammlian cells. Genetic code expansion and bioorthogonal labeling provide for the first time a way for direct, site-specific labeling of proteins with fluorescent-dyes in live cells. Although the small size and superb photophysical parameters of fluorescent-dyes offer unique advantages for high-resolution microscopy, this approach has yet to be embraced as a tool in live cell imaging. Here we evaluated the feasibility of this approach by applying it for α-tubulin labeling. After a series of calibrations, we site-specifically labeled α-tubulin with silicon rhodamine (SiR) in live mammalian cells in an efficient and robust manner. SiR-labeled tubulin successfully incorporated into endogenous microtubules at high density, enabling video recording of microtubule dynamics in interphase and mitotic cells. Applying this labeling approach to structured illumination microscopy resulted in an increase in resolution, highlighting the advantages in using a smaller, brighter tag. Therefore, using our optimized assay, genetic code expansion provides an attractive tool for labeling proteins with a minimal, bright tag in quantitative high-resolution imaging.
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Affiliation(s)
- Tomer Schvartz
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel
| | - Noa Aloush
- The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel.,Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Inna Goliand
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel
| | - Inbar Segal
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel
| | - Dikla Nachmias
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel
| | - Eyal Arbely
- The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel.,Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel .,The National Institute for Biotechnology in the Negev, Beer Sheva 84105, Israel
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19
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Expanding the genetic code of mammalian cells. Biochem Soc Trans 2017; 45:555-562. [PMID: 28408495 DOI: 10.1042/bst20160336] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/22/2017] [Accepted: 02/24/2017] [Indexed: 12/27/2022]
Abstract
In the last two decades, unnatural amino acid (UAA) mutagenesis has emerged as a powerful new method to probe and engineer protein structure and function. This technology enables precise incorporation of a rapidly expanding repertoire of UAAs into predefined sites of a target protein expressed in living cells. Owing to the small footprint of these genetically encoded UAAs and the large variety of enabling functionalities they offer, this technology has tremendous potential for deciphering the delicate and complex biology of the mammalian cells. Over the last few years, exciting progress has been made toward expanding the toolbox of genetically encoded UAAs in mammalian cells, improving the efficiency of their incorporation and developing innovative applications. Here, we provide our perspective on these recent developments and highlight the current challenges that must be overcome to realize the full potential of this technology.
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20
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Sakin V, Hanne J, Dunder J, Anders-Össwein M, Laketa V, Nikić I, Kräusslich HG, Lemke EA, Müller B. A Versatile Tool for Live-Cell Imaging and Super-Resolution Nanoscopy Studies of HIV-1 Env Distribution and Mobility. Cell Chem Biol 2017; 24:635-645.e5. [PMID: 28457706 DOI: 10.1016/j.chembiol.2017.04.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/12/2017] [Accepted: 04/06/2017] [Indexed: 12/27/2022]
Abstract
The envelope glycoproteins (Env) of HIV-1 mediate cell entry through fusion of the viral envelope with a target cell membrane. Intramembrane mobility and clustering of Env trimers at the viral budding site are essential for its function. Previous live-cell and super-resolution microscopy studies were limited by lack of a functional fluorescent Env derivative, requiring antibody labeling for detection. Introduction of a bio-orthogonal amino acid by genetic code expansion, combined with click chemistry, offers novel possibilities for site-specific, minimally invasive labeling. Using this approach, we established efficient incorporation of non-canonical amino acids within HIV-1 Env in mammalian cells. The engineered protein retained plasma membrane localization, glycosylation, virion incorporation, and fusogenic activity, and could be rapidly and specifically labeled with synthetic dyes. This strategy allowed us to revisit Env dynamics and nanoscale distribution at the plasma membrane close to its native state, applying fluorescence recovery after photo bleaching and STED nanoscopy, respectively.
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Affiliation(s)
- Volkan Sakin
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Janina Hanne
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Optical Nanoscopy Division, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Jessica Dunder
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Maria Anders-Össwein
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Vibor Laketa
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; German Center for Infection Research, Partner Site Heidelberg, 69120 Heidelberg, Germany
| | - Ivana Nikić
- Structural and Computational Biology Unit, Cell Biology and Biophysics Unit, EMBL, 69117 Heidelberg, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; German Center for Infection Research, Partner Site Heidelberg, 69120 Heidelberg, Germany
| | - Edward A Lemke
- Structural and Computational Biology Unit, Cell Biology and Biophysics Unit, EMBL, 69117 Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany.
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