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Zhang J, Xu X, Deng H, Liu L, Xiang Y, Feng J. Overcoming cancer drug-resistance calls for novel strategies targeting abnormal alternative splicing. Pharmacol Ther 2024; 261:108697. [PMID: 39025436 DOI: 10.1016/j.pharmthera.2024.108697] [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: 03/02/2024] [Revised: 05/12/2024] [Accepted: 07/15/2024] [Indexed: 07/20/2024]
Abstract
Abnormal gene alternative splicing (AS) events are strongly associated with cancer progression. Here, we summarize AS events that contribute to the development of drug resistance and classify them into three categories: alternative cis-splicing (ACS), alternative trans-splicing (ATS), and alternative back-splicing (ABS). The regulatory mechanisms underlying AS processes through cis-acting regulatory elements and trans-acting factors are comprehensively described, and the distinct functions of spliced variants, including linear spliced variants derived from ACS, chimeric spliced variants arising from ATS, and circRNAs generated through ABS, are discussed. The identification of dysregulated spliced variants, which contribute to drug resistance and hinder effective cancer treatment, suggests that abnormal AS processes may together serve as a precise regulatory mechanism enabling drug-resistant cancer cell survival or, alternatively, represent an evolutionary pathway for cancer cells to adapt to changes in the external environment. Moreover, this review summarizes recent advancements in treatment approaches targeting AS-associated drug resistance, focusing on cis-acting regulatory elements, trans-acting factors, and specific spliced variants. Collectively, gaining an in-depth understanding of the mechanisms underlying aberrant alternative splicing events and developing strategies to target this process hold great promise for overcoming cancer drug resistance.
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Affiliation(s)
- Ji Zhang
- Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China
| | - Xinyu Xu
- Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China
| | - Hongwei Deng
- Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China
| | - Li Liu
- Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China
| | - Yuancai Xiang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Southwest Medical University, Luzhou city, Sichuan 646000, China.
| | - Jianguo Feng
- Department of Anesthesiology, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan Province 646000, China; Nucleic Acid Medicine of Luzhou Key Laboratory, Southwest Medical University, Luzhou, Sichuan Province 646000, China.
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2
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Hume AJ, Deeney DJ, Smetana JS, Turcinovic J, Connor JH, Belfort M, Mühlberger E, Lennon CW. Improved protein splicing through viral passaging. mBio 2024; 15:e0098424. [PMID: 38780266 PMCID: PMC11237716 DOI: 10.1128/mbio.00984-24] [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: 04/01/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
Intervening proteins (inteins) are translated as subdomains within host proteins and removed through an intein-driven splicing reaction where the flanking sequences (exteins) are joined with a peptide bond. Previously, we developed a self-removing translation reporter for labeling Ebola virus (EBOV). In this reporter, an intein (RadA) containing the fluorescent protein ZsGreen (ZsG) is inserted within the EBOV protein VP30. Upon VP30-RadA-ZsG expression from the viral genome, RadA-ZsG is removed from VP30 through the protein splicing activity of RadA, generating functional, non-tagged VP30 and functional ZsGreen. While incorporation of our VP30-RadA-ZsG fusion reporter into recombinant EBOV (rEBOV-RadA-ZsG) resulted in an infectious virus that expresses ZsG upon infection of cells, this virus displayed a replication defect compared to wild-type EBOV, which might be the result of insufficient RadA splicing. Here, we demonstrate that the serial passaging of rEBOV-RadA-ZsG in human cells led to an increase in replication efficiency compared to unpassaged rEBOV-RadA-ZsG. Sequencing of passaged viruses revealed intein-specific mutations. These mutations improve intein activity in both prokaryotic and eukaryotic systems, as well as in multiple extein contexts. Taken together, our findings offer a novel means to select for inteins with enhanced catalytic properties that appear independent of extein context and expression system.IMPORTANCEIntervening proteins (inteins) are self-removing protein elements that have been utilized to develop a variety of innovative protein engineering technologies. Here, we report the isolation of inteins with improved catalytic activity through viral passaging. Specifically, we inserted a highly active intein within an essential protein of Ebola virus and serially passaged this recombinant virus, which led to intein-specific hyper-activity mutations. The identified mutations showed improved intein activity within both bacterial and eukaryotic expression systems and in multiple extein contexts. These results present a new strategy for developing inteins with improved splicing activity.
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Affiliation(s)
- Adam J Hume
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, Massachusetts, USA
| | - Dylan J Deeney
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - John S Smetana
- Department of Biological Sciences, Murray State University, Murray, Kentucky, USA
| | - Jacquelyn Turcinovic
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - John H Connor
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, Massachusetts, USA
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, New York, USA
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - Christopher W Lennon
- Department of Biological Sciences, Murray State University, Murray, Kentucky, USA
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3
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Schneider RF, Hallstrom K, DeMott C, McDonough KA. Conditional protein splicing of the Mycobacterium tuberculosis RecA intein in its native host. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589443. [PMID: 38659745 PMCID: PMC11042385 DOI: 10.1101/2024.04.15.589443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The recA gene, encoding Recombinase A (RecA) is one of three Mycobacterium tuberculosis (Mtb) genes encoding an in-frame intervening protein sequence (intein) that must splice out of precursor host protein to produce functional protein. Ongoing debate about whether inteins function solely as selfish genetic elements or benefit their host cells requires understanding of interplay between inteins and their hosts. We measured environmental effects on native RecA intein splicing within Mtb using a combination of western blots and promoter reporter assays. RecA splicing was stimulated in bacteria exposed to DNA damaging agents or by treatment with copper in hypoxic, but not normoxic, conditions. Spliced RecA was processed by the Mtb proteasome, while free intein was degraded efficiently by other unknown mechanisms. Unspliced precursor protein was not observed within Mtb despite its accumulation during ectopic expression of Mtb recA within E. coli. Surprisingly, Mtb produced free N-extein in some conditions, and ectopic expression of Mtb N-extein activated LexA in E. coli. These results demonstrate that the bacterial environment greatly impacts RecA splicing in Mtb, underscoring the importance of studying intein splicing in native host environments and raising the exciting possibility of intein splicing as a novel regulatory mechanism in Mtb.
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Affiliation(s)
- Ryan F. Schneider
- Biomedical Sciences Department, School of Public Health, State University of New York at Albany
| | | | | | - Kathleen A. McDonough
- Biomedical Sciences Department, School of Public Health, State University of New York at Albany
- Wadsworth Center, New York Department of Health
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Iwaï H, Beyer HM, Johansson JEM, Li M, Wlodawer A. The three-dimensional structure of the Vint domain from Tetrahymena thermophila suggests a ligand-regulated cleavage mechanism by the HINT fold. FEBS Lett 2024; 598:864-874. [PMID: 38351630 DOI: 10.1002/1873-3468.14817] [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: 11/12/2023] [Revised: 12/13/2023] [Accepted: 01/03/2024] [Indexed: 04/23/2024]
Abstract
Vint proteins have been identified in unicellular metazoans as a novel hedgehog-related gene family, merging the von Willebrand factor type A domain and the Hedgehog/INTein (HINT) domains. We present the first three-dimensional structure of the Vint domain from Tetrahymena thermophila corresponding to the auto-processing domain of hedgehog proteins, shedding light on the unique features, including an adduct recognition region (ARR). Our results suggest a potential binding between the ARR and sulfated glycosaminoglycans like heparin sulfate. Moreover, we uncover a possible regulatory role of the ARR in the auto-processing by Vint domains, expanding our understanding of the HINT domain evolution and their use in biotechnological applications. Vint domains might have played a crucial role in the transition from unicellular to multicellular organisms.
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Affiliation(s)
- Hideo Iwaï
- Institute of Biotechnology, University of Helsinki, Finland
| | - Hannes M Beyer
- Institute of Biotechnology, University of Helsinki, Finland
| | | | - Mi Li
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
- Basic Science Program, Frederick National Laboratory for Cancer Research, MD, USA
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
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Kolesnik VV, Nurtdinov RF, Oloruntimehin ES, Karabelsky AV, Malogolovkin AS. Optimization strategies and advances in the research and development of AAV-based gene therapy to deliver large transgenes. Clin Transl Med 2024; 14:e1607. [PMID: 38488469 PMCID: PMC10941601 DOI: 10.1002/ctm2.1607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 02/07/2024] [Accepted: 02/15/2024] [Indexed: 03/18/2024] Open
Abstract
Adeno-associated virus (AAV)-based therapies are recognized as one of the most potent next-generation treatments for inherited and genetic diseases. However, several biological and technological aspects of AAV vectors remain a critical issue for their widespread clinical application. Among them, the limited capacity of the AAV genome significantly hinders the development of AAV-based gene therapy. In this context, genetically modified transgenes compatible with AAV are opening up new opportunities for unlimited gene therapies for many genetic disorders. Recent advances in de novo protein design and remodelling are paving the way for new, more efficient and targeted gene therapeutics. Using computational and genetic tools, AAV expression cassette and transgenic DNA can be split, miniaturized, shuffled or created from scratch to mediate efficient gene transfer into targeted cells. In this review, we highlight recent advances in AAV-based gene therapy with a focus on its use in translational research. We summarize recent research and development in gene therapy, with an emphasis on large transgenes (>4.8 kb) and optimizing strategies applied by biomedical companies in the research pipeline. We critically discuss the prospects for AAV-based treatment and some emerging challenges. We anticipate that the continued development of novel computational tools will lead to rapid advances in basic gene therapy research and translational studies.
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Affiliation(s)
- Valeria V. Kolesnik
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | - Ruslan F. Nurtdinov
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | - Ezekiel Sola Oloruntimehin
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
| | | | - Alexander S. Malogolovkin
- Martsinovsky Institute of Medical ParasitologyTropical and Vector‐Borne Diseases, Sechenov UniversityMoscowRussia
- Center for Translational MedicineSirius University of Science and TechnologySochiRussia
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6
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McDonald A, Wijnholds J. Retinal Ciliopathies and Potential Gene Therapies: A Focus on Human iPSC-Derived Organoid Models. Int J Mol Sci 2024; 25:2887. [PMID: 38474133 DOI: 10.3390/ijms25052887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
The human photoreceptor function is dependent on a highly specialised cilium. Perturbation of cilial function can often lead to death of the photoreceptor and loss of vision. Retinal ciliopathies are a genetically diverse range of inherited retinal disorders affecting aspects of the photoreceptor cilium. Despite advances in the understanding of retinal ciliopathies utilising animal disease models, they can often lack the ability to accurately mimic the observed patient phenotype, possibly due to structural and functional deviations from the human retina. Human-induced pluripotent stem cells (hiPSCs) can be utilised to generate an alternative disease model, the 3D retinal organoid, which contains all major retinal cell types including photoreceptors complete with cilial structures. These retinal organoids facilitate the study of disease mechanisms and potential therapies in a human-derived system. Three-dimensional retinal organoids are still a developing technology, and despite impressive progress, several limitations remain. This review will discuss the state of hiPSC-derived retinal organoid technology for accurately modelling prominent retinal ciliopathies related to genes, including RPGR, CEP290, MYO7A, and USH2A. Additionally, we will discuss the development of novel gene therapy approaches targeting retinal ciliopathies, including the delivery of large genes and gene-editing techniques.
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Affiliation(s)
- Andrew McDonald
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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7
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Foo GW, Leichthammer CD, Saita IM, Lukas ND, Batko IZ, Heinrichs DE, Edgell DR. Intein-based thermoregulated meganucleases for containment of genetic material. Nucleic Acids Res 2024; 52:2066-2077. [PMID: 38180814 PMCID: PMC10899782 DOI: 10.1093/nar/gkad1247] [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] [Received: 08/23/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024] Open
Abstract
Limiting the spread of synthetic genetic information outside of the intended use is essential for applications where biocontainment is critical. In particular, biocontainment of engineered probiotics and plasmids that are excreted from the mammalian gastrointestinal tract is needed to prevent escape and acquisition of genetic material that could confer a selective advantage to microbial communities. Here, we built a simple and lightweight biocontainment system that post-translationally activates a site-specific DNA endonuclease to degrade DNA at 18°C and not at higher temperatures. We constructed an orthogonal set of temperature-sensitive meganucleases (TSMs) by inserting the yeast VMA1 L212P temperature-sensitive intein into the coding regions of LAGLIDADG homing endonucleases. We showed that the TSMs eliminated plasmids carrying the cognate TSM target site from laboratory strains of Escherichia coli at the permissive 18°C but not at higher restrictive temperatures. Plasmid elimination is dependent on both TSM endonuclease activity and intein splicing. TSMs eliminated plasmids from E. coli Nissle 1917 after passage through the mouse gut when fecal resuspensions were incubated at 18°C but not at 37°C. Collectively, our data demonstrates the potential of thermoregulated meganucleases as a means of restricting engineered plasmids and probiotics to the mammalian gut.
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Affiliation(s)
- Gary W Foo
- Department of Biochemistry, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
| | | | - Ibrahim M Saita
- Department of Biochemistry, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
| | - Nicholas D Lukas
- Department of Biochemistry, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
| | - Izabela Z Batko
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
| | - David E Heinrichs
- Department of Microbiology and Immunology, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
| | - David R Edgell
- Department of Biochemistry, Schulich School of Medicine and Dentistry, London, Ontario N6A 5C1, Canada
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8
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Knapp M, Kohl V, Best T, Rammo O, Ebert S. Chromatographic single-step purification of tagless proteins using gp41-1 split inteins. Front Bioeng Biotechnol 2024; 11:1319916. [PMID: 38390601 PMCID: PMC10882715 DOI: 10.3389/fbioe.2023.1319916] [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: 10/11/2023] [Accepted: 12/11/2023] [Indexed: 02/24/2024] Open
Abstract
The current trend in biopharmaceutical drug manufacturing is towards increasing potency and complexity of products such as peptide scaffolds, oligonucleotides and many more. Therefore, a universal affinity purification step is important in order to meet the requirements for cost and time efficient drug production. By using a self-splicing intein affinity tag, a purification template is generated that allows for a universal chromatographic affinity capture step to generate a tagless target protein without the use of proteases for further tag removal. This study describes the successful implementation of gp41-1-based split inteins in a chromatographic purification process for, e.g., E. coli-derived targets. The tagless target is generated in a single-step purification run. The on-column cleavage is induced by triggering a simple pH change in the buffer conditions without the need for additives such as Zn2+ or thiols. This system has proven to be reusable for at least ten purification cycles that use 150 mM H3PO4 as the cleaning agent.
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Affiliation(s)
- Michael Knapp
- Faculty of Natural Sciences, Ulm University, Ulm, Germany
- Institute of Applied Biotechnology, Biberach University of Applied Sciences, Biberach, Germany
- Merck-Life Science KGaA, Darmstadt, Germany
| | | | | | | | - Sybille Ebert
- Institute of Applied Biotechnology, Biberach University of Applied Sciences, Biberach, Germany
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Panda S, Rout M, Mishra S, Turuk J, Pati S, Dehury B. Molecular docking and MD simulations reveal protease inhibitors block the catalytic residues in Prp8 intein of Aspergillus fumigatus: a potential target for antimycotics. J Biomol Struct Dyn 2023:1-16. [PMID: 38149850 DOI: 10.1080/07391102.2023.2298735] [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: 10/03/2023] [Accepted: 12/18/2023] [Indexed: 12/28/2023]
Abstract
Resistance to azoles and amphotericin B especially in Aspergillus fumigatus is a growing concern towards the treatment of invasive fungal infection. At this critical juncture, intein splicing would be a productive, and innovative target to establish therapies against resistant strains. Intein splicing is the central event for the activation of host protein, essential for the growth and survival of various microorganisms including A. fumigatus. The splicing process is a four-step protease-like nucleophilic cascade. Thus, we hypothesise that protease inhibitors would successfully halt intein splicing and potentially restrict the growth of the aforementioned pathogen. Using Rosetta Fold and molecular dynamics simulations, we modelled Prp8 intein structure; resembling classic intein fold with horse shoe shaped splicing domain. To fully comprehend the active site of Afu Prp8 intein, C1, T62, H65, H818, N819 from intein sequences and S820, the first C-extein residue are selected. Molecular docking shows that two FDA-approved drugs, i.e. Lufotrelvir and Remdesivir triphosphate efficiently interact with Prp8 intein from the assortment of 212 protease inhibitors. MD simulation portrayed that Prp8 undergoes conformational change upon ligand binding, and inferred the molecular recognition and stability of the docked complexes. Per-residue decomposition analysis confirms the importance of F: block R802, V803, and Q807 binding pocket in intein splicing domain towards recognition of inhibitors, along with active site residues through strong hydrogen bonds and hydrophobic contacts. However, in vitro and in vivo assays are required to confirm the inhibitory action on Prp8 intein splicing; which may pave the way for the development of new antifungals for A. fumigatus.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sunita Panda
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Madhusmita Rout
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sarbani Mishra
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Jyotirmayee Turuk
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sanghamitra Pati
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Budheswar Dehury
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
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10
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Wood DW, Belfort M, Lennon CW. Inteins-mechanism of protein splicing, emerging regulatory roles, and applications in protein engineering. Front Microbiol 2023; 14:1305848. [PMID: 38029209 PMCID: PMC10663303 DOI: 10.3389/fmicb.2023.1305848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Protein splicing is a posttranslational process in which an intein segment excises itself from two flanking peptides, referred to as exteins. In the native context, protein splicing results in two separate protein products coupled to the activation of the intein-containing host protein. Inteins are generally described as either full-length inteins, mini-inteins or split inteins, which are differentiated by their genetic structure and features. Inteins can also be divided into three classes based on their splicing mechanisms, which differ in the location of conserved residues that mediate the splicing pathway. Although inteins were once thought to be selfish genetic elements, recent evidence suggests that inteins may confer a genetic advantage to their host cells through posttranslational regulation of their host proteins. Finally, the ability of modified inteins to splice and cleave their fused exteins has enabled many new applications in protein science and synthetic biology. In this review, we briefly cover the mechanisms of protein splicing, evidence for some inteins as environmental sensors, and intein-based applications in protein engineering.
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Affiliation(s)
- David W. Wood
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany, Albany, NY, United States
| | - Christopher W. Lennon
- Department of Biological Sciences, Murray State University, Murray, KY, United States
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11
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Ariagno TM, Smetana JS, Lennon CW. An artificially split class 3 intein. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000977. [PMID: 37811346 PMCID: PMC10559147 DOI: 10.17912/micropub.biology.000977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 10/10/2023]
Abstract
Inteins excise themselves from precursor polypeptides through protein splicing, joining N- and C-exteins with a peptide bond. Split inteins are expressed as separate polypeptides that undergo protein trans splicing (PTS). Here, we demonstrate PTS can be achieved using an artificially split class 3 intein. Because class 3 inteins use an internal initiating nucleophile near the C-extein junction, rather than the first residue of the intein, both catalytic nucleophiles are present on a single polypeptide. This results in a compact arrangement of catalytic nucleophiles for PTS compared to the standard arrangement for split class 1 inteins.
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Affiliation(s)
- Tia M. Ariagno
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
| | - John S. Smetana
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
| | - Christopher W. Lennon
- Department of Biological Sciences, Murray State University, Murray, Kentucky, United States
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12
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Schloßhauer JL, Zemella A, Dondapati SK, Thoring L, Meyer M, Kubick S. Enhancing the performance of a mutant pyrrolysyl-tRNA synthetase to create a highly versatile eukaryotic cell-free protein synthesis tool. Sci Rep 2023; 13:15236. [PMID: 37709815 PMCID: PMC10502014 DOI: 10.1038/s41598-023-42198-8] [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: 04/25/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023] Open
Abstract
Modification of proteins with a broad range of chemical functionalities enables the investigation of protein structure and activity by manipulating polypeptides at single amino acid resolution. Indeed, various functional groups including bulky non-canonical amino acids like strained cyclooctenes could be introduced by the unique features of the binding pocket of the double mutant pyrrolysyl-tRNA synthetase (Y306A, Y384F), but the instable nature of the enzyme limits its application in vivo. Here, we constructed a cell-free protein production system, which increased the overall enzyme stability by combining different reaction compartments. Moreover, a co-expression approach in a one-pot reaction allowed straightforward site-specific fluorescent labeling of the functional complex membrane protein cystic fibrosis transmembrane conductance regulator. Our work provides a versatile platform for introducing various non-canonical amino acids into difficult-to-express proteins for structural and fluorescence based investigation of proteins activity.
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Affiliation(s)
- Jeffrey L Schloßhauer
- Fraunhofer Project Group PZ-Syn of the Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Institute of Biotechnology,, Brandenburg University of Technology Cottbus-Senftenberg, Am Mühlenberg, Potsdam, Germany
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg, Potsdam, Germany
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany
| | - Anne Zemella
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg, Potsdam, Germany.
| | - Srujan K Dondapati
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg, Potsdam, Germany
| | - Lena Thoring
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg, Potsdam, Germany
| | - Manpreet Meyer
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany
| | - Stefan Kubick
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg, Potsdam, Germany
- Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus -Senftenberg, The Brandenburg Medical School Theodor Fontane, University of Potsdam, Potsdam, Germany
- Laboratory of Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany
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13
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Zhan Q, Shi C, Jiang Y, Gao X, Lin Y. Efficient splicing of the CPE intein derived from directed evolution of the Cryptococcus neoformans PRP8 intein. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1310-1318. [PMID: 37489009 PMCID: PMC10448054 DOI: 10.3724/abbs.2023135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/19/2023] [Indexed: 07/26/2023] Open
Abstract
Intein-mediated protein splicing has been widely used in protein engineering; however, the splicing efficiency and extein specificity usually limit its further application. Thus, there is a demand for more general inteins that can overcome these limitations. Here, we study the trans-splicing of CPE intein obtained from the directed evolution of Cne PRP8, which shows that its splicing rate is ~29- fold higher than that of the wild-type. When the +1 residue of C-extein is changed to cysteine, CPE also shows high splicing activity. Faster association and higher affinity may contribute to the high splicing rate compared with wild-type intein. These findings have important implications for the future engineering of inteins and provide clues for fundamental studies of protein structure and folding.
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Affiliation(s)
- Qin Zhan
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Changhua Shi
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Yu Jiang
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
| | - Xianling Gao
- Shandong Guoli Biotechnology Co.Ltd.Jinan250101China
| | - Ying Lin
- College of Biological Science and Medical EngineeringDonghua UniversityShanghai201620China
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14
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Wang Y, Shi Y, Hellinga HW, Beese LS. Thermally controlled intein splicing of engineered DNA polymerases provides a robust and generalizable solution for accurate and sensitive molecular diagnostics. Nucleic Acids Res 2023; 51:5883-5894. [PMID: 37166959 PMCID: PMC10287962 DOI: 10.1093/nar/gkad368] [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] [Received: 02/27/2023] [Revised: 04/18/2023] [Accepted: 05/09/2023] [Indexed: 05/12/2023] Open
Abstract
DNA polymerases are essential for nucleic acid synthesis, cloning, sequencing and molecular diagnostics technologies. Conditional intein splicing is a powerful tool for controlling enzyme reactions. We have engineered a thermal switch into thermostable DNA polymerases from two structurally distinct polymerase families by inserting a thermally activated intein domain into a surface loop that is integral to the polymerase active site, thereby blocking DNA or RNA template access. The fusion proteins are inactive, but retain their structures, such that the intein excises during a heat pulse delivered at 70-80°C to generate spliced, active polymerases. This straightforward thermal activation step provides a highly effective, one-component 'hot-start' control of PCR reactions that enables accurate target amplification by minimizing unwanted by-products generated by off-target reactions. In one engineered enzyme, derived from Thermus aquaticus DNA polymerase, both DNA polymerase and reverse transcriptase activities are controlled by the intein, enabling single-reagent amplification of DNA and RNA under hot-start conditions. This engineered polymerase provides high-sensitivity detection for molecular diagnostics applications, amplifying 5-6 copies of the tested DNA and RNA targets with >95% certainty. The design principles used to engineer the inteins can be readily applied to construct other conditionally activated nucleic acid processing enzymes.
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Affiliation(s)
- You Wang
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Yuqian Shi
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Homme W Hellinga
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Lorena S Beese
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
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15
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Lin T, Zhang S, Zhang D, Chen X, Ge Y, Hu Y, Fan J. Use of the redox-dependent intein system for enhancing production of the cyclic green fluorescent protein. Protein Expr Purif 2023; 207:106272. [PMID: 37062513 DOI: 10.1016/j.pep.2023.106272] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 04/18/2023]
Abstract
To expand the reported redox-dependent intein system application, in this work, we used the split intein variant with highly trans-splicing efficiency and minimal extein dependence to cyclize the green fluorescent protein variant reporter in vitro. The CPG residues were introduced adjacent to the intein's catalytic cysteine for reversible formation of a disulfide bond to retard the trans-splicing reaction under the oxidative environment. The cyclized reporter protein in Escherichia coli cells was easily prepared by organic extraction and identified by the exopeptidase digestion. The amounts of extracted cyclized protein reporter in BL21 (DE3) cells were higher than those in hyperoxic SHuffle T7 coexpression system for facilitating the disulfide bond formation. The double His6-tagged precursor was purified for in vitro cyclization of the protein for 3 h. Compared with the purified linear counterpart, the cyclic reporter showed about twofold increase in fluorescence intensity, exhibited thermal and hydrolytic stability, and displayed better folding efficiency in BL21 (DE3) cells at the elevated temperature. Taken together, the developed redox-dependent intein system will be used for producing other cyclic disulfide-free proteins. The cyclic reporter is a potential candidate applied in certain thermophilic aerobes.
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Affiliation(s)
- Tingting Lin
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Shuncheng Zhang
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Di Zhang
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Xiaofeng Chen
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Yuanyuan Ge
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Yafang Hu
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China
| | - Jun Fan
- School of Life Science, Anhui Agricultural University, Hefei, Anhui, 230036, PR China.
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16
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Abstract
The ability to manipulate the chemical composition of proteins and peptides has been central to the development of improved polypeptide-based therapeutics and has enabled researchers to address fundamental biological questions that would otherwise be out of reach. Protein ligation, in which two or more polypeptides are covalently linked, is a powerful strategy for generating semisynthetic products and for controlling polypeptide topology. However, specialized tools are required to efficiently forge a peptide bond in a chemoselective manner with fast kinetics and high yield. Fortunately, nature has addressed this challenge by evolving enzymatic mechanisms that can join polypeptides using a diverse set of chemical reactions. Here, we summarize how such nature-inspired protein ligation strategies have been repurposed as chemical biology tools that afford enhanced control over polypeptide composition.
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Affiliation(s)
- Rasmus Pihl
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Qingfei Zheng
- Department of Radiation Oncology, College of Medicine, The Ohio State University, Columbus, OH, USA.
- Center for Cancer Metabolism, James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA.
| | - Yael David
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.
- Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, New York, NY, USA.
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17
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Tang H, Wang H, Wang S, Hu SW, Lv J, Xun M, Gao K, Wang F, Chen Y, Wang D, Wang W, Li H, Shu Y. Hearing of Otof-deficient mice restored by trans-splicing of N- and C-terminal otoferlin. Hum Genet 2023; 142:289-304. [PMID: 36383253 DOI: 10.1007/s00439-022-02504-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022]
Abstract
Mutations to the OTOF gene are among the most common reasons for auditory neuropathy. Although cochlear implants are often effective in restoring sound transduction, there are currently no biological treatments for individuals with variants of OTOF. Previous studies have reported the rescue of hearing in DFNB9 mice using OTOF gene replacement although the efficacy needs improvement. Here, we developed a novel dual-AAV-mediated gene therapy system based on the principles of protein trans-splicing, and we show that this system can reverse bilateral deafness in Otof -/- mice after a single unilateral injection. The system effectively expressed exogenous mouse or human otoferlin after injection on postnatal day 0-2. Human otoferlin restored hearing to near wild-type levels for at least 6 months and restored the release of synaptic vesicles in inner hair cells. Our study not only provides a preferential clinical strategy for the treatment of OTOF-related auditory neuropathies, but also describes a route of development for other large-gene therapies and protein engineering techniques.
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Affiliation(s)
- Honghai Tang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Hui Wang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Shengyi Wang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Shao Wei Hu
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Jun Lv
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Mengzhao Xun
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Kaiyu Gao
- Shanghai Refreshgene Therapeutics Co., Ltd., Waigaoqiao Free Trade Zone, Room 2001, Building 7-5, Free Trade No.1 Park, 160 Basheng Road, Shanghai, 200131, China
| | - Fang Wang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Yuxin Chen
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Daqi Wang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China.,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China.,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China
| | - Wuqing Wang
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China. .,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China. .,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China.
| | - Huawei Li
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China. .,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China. .,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China.
| | - Yilai Shu
- ENT Institute and Department of Otorhinolaryngology, Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200031, China. .,Institute of Biomedical Science, Fudan University, Shanghai, 200032, China. .,NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, 200032, China.
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18
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Chung CZ, Söll D, Krahn N. Creating Selenocysteine-Specific Reporters Using Inteins. Methods Mol Biol 2023; 2676:69-86. [PMID: 37277625 DOI: 10.1007/978-1-0716-3251-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The selenium moiety in selenocysteine (Sec) imparts enhanced chemical properties to this amino acid and ultimately the protein in which it is inserted. These characteristics are attractive for designing highly active enzymes or extremely stable proteins and studying protein folding or electron transfer, to name a few. There are also 25 human selenoproteins, of which many are essential for our survival. The ability to create or study these selenoproteins is significantly hindered by the inability to easily produce them. Engineering translation has yielded simpler systems to facilitate site-specific insertion of Sec; however, Ser misincorporation remains problematic. Therefore, we have designed two Sec-specific reporters which promote high-throughput screening of Sec translation systems to overcome this barrier. This protocol outlines the workflow to engineer these Sec-specific reporters, with the application to any gene of interest and the ability to transfer this strategy to any organism.
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Affiliation(s)
- Christina Z Chung
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
| | - Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
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19
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Otaka A. Development of Naturally Inspired Peptide and Protein Chemistry. Chem Pharm Bull (Tokyo) 2022; 70:748-764. [DOI: 10.1248/cpb.c22-00623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Akira Otaka
- Institute of Biomedical Sciences and Graduate School of Pharmaceutical Sciences, Tokushima University
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20
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Heiden B, Mühlberger E, Lennon CW, Hume AJ. Labeling Ebola Virus with a Self-Splicing Fluorescent Reporter. Microorganisms 2022; 10:2110. [PMID: 36363701 PMCID: PMC9696229 DOI: 10.3390/microorganisms10112110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 07/21/2023] Open
Abstract
Inteins (intervening proteins) are polypeptides that interrupt the sequence of other proteins and remove themselves through protein splicing. In this intein-catalyzed reaction, the two peptide bonds surrounding the intein are rearranged to release the intein from the flanking protein sequences, termed N- and C-exteins, which are concurrently joined by a peptide bond. Because of this unique functionality, inteins have proven exceptionally useful in protein engineering. Previous work has demonstrated that heterologous proteins can be inserted within an intein, with both the intein and inserted protein retaining function, allowing for intein-containing genes to coexpress additional coding sequences. Here, we show that a fluorescent protein (ZsGreen) can be inserted within the Pyrococcus horikoshii RadA intein, with the hybrid protein (ZsG-Int) maintaining fluorescence and splicing capability. We used this system to create a recombinant Ebola virus expressing a fluorescent protein. We first tested multiple potential insertion sites for ZsG-Int within individual Ebola virus proteins, identifying a site within the VP30 gene that facilitated efficient intein splicing in mammalian cells while also preserving VP30 function. Next, we successfully rescued a virus containing the ZsG-Int-VP30 fusion protein, which displayed fluorescence in the infected cells. We thus report a new intein-based application for adding reporters to systems without the need to add additional genes. Further, this work highlights a novel reporter design, whereby the reporter is only made if the protein of interest is translated and does not remain fused to the protein of interest.
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Affiliation(s)
- Baylee Heiden
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | - Elke Mühlberger
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
| | | | - Adam J. Hume
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, MA 02118, USA
- Center for Emerging Infectious Diseases Policy & Research, Boston University, Boston, MA 02118, USA
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21
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Tharappel AM, Li Z, Zhu YC, Wu X, Chaturvedi S, Zhang QY, Li H. Calcimycin Inhibits Cryptococcus neoformans In Vitro and In Vivo by Targeting the Prp8 Intein Splicing. ACS Infect Dis 2022; 8:1851-1868. [PMID: 35948057 PMCID: PMC9464717 DOI: 10.1021/acsinfecdis.2c00137] [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] [Indexed: 01/29/2023]
Abstract
Drug resistance is a significant concern in the treatment of diseases, including cryptococcosis caused by Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga). Alternative drug targets are necessary to overcome drug resistance before it attains a critical stage. Splicing of inteins from pro-protein precursors is crucial for activities of essential proteins hosting intein elements in many organisms, including human pathogens such as Cne and Cga. Through a high-throughput screening, we identified calcimycin (CMN) as a potent Prp8 intein splicing inhibitor with a minimum inhibitory concentration (MIC) of 1.5 μg/mL against the wild-type Cne-H99 (Cne-WT or Cne). In contrast, CMN inhibited the intein-less mutant strain (Cne-Mut) with a 16-fold higher MIC. Interestingly, Aspergillus fumigatus and a few Candida species were resistant to CMN. Further studies indicated that CMN reduced virulence factors such as urease activity, melanin production, and biofilm formation in Cne. CMN also inhibited Cne intracellular infection in macrophages. In a target-specific split nanoluciferase assay, the IC50 of CMN was 4.6 μg/mL. Binding of CMN to recombinant Prp8 intein was demonstrated by thermal shift assay and microscale thermophoresis. Treating Cne cells with CMN reduced intein splicing. CMN was fungistatic and showed a synergistic effect with the known antifungal drug amphotericin B. Finally, CMN treatment at 20 mg/kg body weight led to 60% reduction in lung fungal load in a cryptococcal pulmonary infection mouse model. Overall, CMN represents a potent antifungal with a novel mechanism of action to treat Cne and possibly Cga infections.
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Affiliation(s)
- Anil Mathew Tharappel
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Zhong Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Yan Chun Zhu
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Xiangmeng Wu
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Sudha Chaturvedi
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Qing-Yu Zhang
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Hongmin Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
- The BIO5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
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22
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Machine learning/molecular dynamic protein structure prediction approach to investigate the protein conformational ensemble. Sci Rep 2022; 12:10018. [PMID: 35705565 PMCID: PMC9200820 DOI: 10.1038/s41598-022-13714-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 05/11/2022] [Indexed: 11/25/2022] Open
Abstract
Proteins exist in several different conformations. These structural changes are often associated with fluctuations at the residue level. Recent findings show that co-evolutionary analysis coupled with machine-learning techniques improves the precision by providing quantitative distance predictions between pairs of residues. The predicted statistical distance distribution from Multi Sequence Analysis reveals the presence of different local maxima suggesting the flexibility of key residue pairs. Here we investigate the ability of the residue-residue distance prediction to provide insights into the protein conformational ensemble. We combine deep learning approaches with mechanistic modeling to a set of proteins that experimentally showed conformational changes. The predicted protein models were filtered based on energy scores, RMSD clustering, and the centroids selected as the lowest energy structure per cluster. These models were compared to the experimental-Molecular Dynamics (MD) relaxed structure by analyzing the backbone residue torsional distribution and the sidechain orientations. Our pipeline allows to retrieve the experimental structural dynamics experimentally represented by different X-ray conformations for the same sequence as well the conformational space observed with the MD simulations. We show the potential correlation between the experimental structure dynamics and the predicted model ensemble demonstrating the susceptibility of the current state-of-the-art methods in protein folding and dynamics prediction and pointing out the areas of improvement.
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23
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Esposito F, Lyubenova H, Tornabene P, Auricchio S, Iuliano A, Nusco E, Merlin S, Olgasi C, Manni G, Gargaro M, Fallarino F, Follenzi A, Auricchio A. Liver gene therapy with intein-mediated F8 trans-splicing corrects mouse haemophilia A. EMBO Mol Med 2022; 14:e15199. [PMID: 35491676 PMCID: PMC9174883 DOI: 10.15252/emmm.202115199] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 04/01/2022] [Accepted: 04/11/2022] [Indexed: 11/09/2022] Open
Abstract
Liver gene therapy with adeno‐associated viral (AAV) vectors is under clinical investigation for haemophilia A (HemA), the most common inherited X‐linked bleeding disorder. Major limitations are the large size of the F8 transgene, which makes packaging in a single AAV vector a challenge, as well as the development of circulating anti‐F8 antibodies which neutralise F8 activity. Taking advantage of split‐intein‐mediated protein trans‐splicing, we divided the coding sequence of the large and highly secreted F8‐N6 variant in two separate AAV‐intein vectors whose co‐administration to HemA mice results in the expression of therapeutic levels of F8 over time. This occurred without eliciting circulating anti‐F8 antibodies unlike animals treated with the single oversized AAV‐F8 vector under clinical development. Therefore, liver gene therapy with AAV‐F8‐N6 intein should be considered as a potential therapeutic strategy for HemA.
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Affiliation(s)
- Federica Esposito
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | | | | | - Stefano Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Antonella Iuliano
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Edoardo Nusco
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Simone Merlin
- Department of Health Sciences, University of Piemonte Orientale "Amedeo Avogadro", Novara, Italy
| | - Cristina Olgasi
- Department of Health Sciences, University of Piemonte Orientale "Amedeo Avogadro", Novara, Italy
| | - Giorgia Manni
- Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Marco Gargaro
- Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | | | - Antonia Follenzi
- Department of Health Sciences, University of Piemonte Orientale "Amedeo Avogadro", Novara, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Medical Genetics, Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy
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24
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Kang C, Shrestha KL, Kwon S, Park S, Kim J, Kwon Y. Intein-Mediated Protein Engineering for Cell-Based Biosensors. BIOSENSORS 2022; 12:bios12050283. [PMID: 35624584 PMCID: PMC9138240 DOI: 10.3390/bios12050283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 11/21/2022]
Abstract
Cell-based sensors provide a flexible platform for screening biologically active targets and for monitoring their interactions in live cells. Their applicability extends across a vast array of biological research and clinical applications. Particularly, cell-based sensors are becoming a potent tool in drug discovery and cell-signaling studies by allowing function-based screening of targets in biologically relevant environments and enabling the in vivo visualization of cellular signals in real-time with an outstanding spatiotemporal resolution. In this review, we aim to provide a clear view of current cell-based sensor technologies, their limitations, and how the recent improvements were using intein-mediated protein engineering. We first discuss the characteristics of cell-based sensors and present several representative examples with a focus on their design strategies, which differentiate cell-based sensors from in vitro analytical biosensors. We then describe the application of intein-mediated protein engineering technology for cell-based sensor fabrication. Finally, we explain the characteristics of intein-mediated reactions and present examples of how the intein-mediated reactions are used to improve existing methods and develop new approaches in sensor cell fabrication to address the limitations of current technologies.
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25
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Prabhala SV, Gierach I, Wood DW. The Evolution of Intein-Based Affinity Methods as Reflected in 30 years of Patent History. Front Mol Biosci 2022; 9:857566. [PMID: 35463948 PMCID: PMC9033041 DOI: 10.3389/fmolb.2022.857566] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/04/2022] [Indexed: 11/18/2022] Open
Abstract
Self-cleaving affinity tags, based on engineered intein protein domains, have been touted as a universal single step purification platform for tagless non-mAb proteins. These approaches provide all of the power and flexibility of tag-based affinity methods, but deliver a tagless target protein suitable for clinical applications without complex process development. This combination of features might accelerate and de-risk biopharmaceutical development by bridging early discovery to full-scale manufacturing under a single platform. Despite this profound promise, intein-based technologies have yet to reach their full potential. This review examines the evolution of intein-based purification methods in the light of several significant intein patents filed over the last 3 decades. Illustrated with actual key figures from each of the relevant patents, key advances are described with a focus on applications in basic research and biopharmaceutical production. Suggestions for extending intein-based purification systems to emerging therapies and non-protein applications are presented as concluding remarks.
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Affiliation(s)
- Sai Vivek Prabhala
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States
| | | | - David W. Wood
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, United States,Protein Capture Science, Columbus, OH, United States,*Correspondence: David W. Wood,
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SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines. Biosci Rep 2022; 42:230724. [PMID: 35234249 PMCID: PMC8891592 DOI: 10.1042/bsr20212207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 01/11/2022] [Accepted: 01/27/2022] [Indexed: 11/24/2022] Open
Abstract
Inteins are auto-processing domains that implement a multistep biochemical reaction termed protein splicing, marked by cleavage and formation of peptide bonds. They excise from a precursor protein, generating a functional protein via covalent bonding of flanking exteins. We report the kinetic study of splicing and cleavage reaction in [Fe–S] cluster assembly protein SufB from Mycobacterium tuberculosis (Mtu). Although it follows a canonical intein splicing pathway, distinct features are added by extein residues present in the active site. Sequence analysis identified two conserved histidines in the N-extein region; His-5 and His-38. Kinetic analyses of His-5Ala and His-38Ala SufB mutants exhibited significant reductions in splicing and cleavage rates relative to the SufB wildtype (WT) precursor protein. Structural analysis and molecular dynamics (MD) simulations suggested that Mtu SufB displays a unique mechanism where two remote histidines work concurrently to facilitate N-terminal cleavage reaction. His-38 is stabilized by the solvent-exposed His-5, and can impact N–S acyl shift by direct interaction with the catalytic Cys1. Development of inteins as biotechnological tools or as pathogen-specific novel antimicrobial targets requires a more complete understanding of such unexpected roles of conserved extein residues in protein splicing.
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Wang H, Wang L, Zhong B, Dai Z. Protein Splicing of Inteins: A Powerful Tool in Synthetic Biology. Front Bioeng Biotechnol 2022; 10:810180. [PMID: 35265596 PMCID: PMC8899391 DOI: 10.3389/fbioe.2022.810180] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 01/25/2022] [Indexed: 12/21/2022] Open
Abstract
Inteins are protein segments that are capable of enabling the ligation of flanking extein into a new protein, a process known as protein splicing. Since its discovery, inteins have become powerful biotechnological tools for applications such as protein engineering. In the last 10 years, the development in synthetic biology has further endowed inteins with enhanced functions and diverse utilizations. Here we review these efforts and discuss the future directions.
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Affiliation(s)
- Hao Wang
- Materials Synthetic Biology Center, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Lin Wang
- Materials Synthetic Biology Center, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Baihua Zhong
- Materials Interfaces Center, Institute of Advanced Materials Science and Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhuojun Dai
- Materials Synthetic Biology Center, CAS Key Laboratory of Quantitative Engineering Biology, Guangdong Provincial Key Laboratory of Synthetic Genomics, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Yalala VR, Lynch AK, Mills KV. Conditional Alternative Protein Splicing Promoted by Inteins from Haloquadratum walsbyi. Biochemistry 2022; 61:294-302. [PMID: 35073064 PMCID: PMC8847336 DOI: 10.1021/acs.biochem.1c00788] [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] [Indexed: 11/28/2022]
Abstract
Protein splicing is a post-translational process by which an intervening protein, or an intein, catalyzes its own excision from flanking polypeptides, or exteins, coupled to extein ligation. Four inteins interrupt the MCM helicase of the halophile Haloquadratum walsbyi, two of which are mini-inteins that lack a homing endonuclease. Both inteins can be overexpressed in Escherichia coli and purified as unspliced precursors; splicing can be induced in vitro by incubation with salt. However, one intein can splice in 0.5 M NaCl in vitro, whereas the other splices efficiently only in buffer containing over 2 M NaCl; the organism also requires high salt to grow, with the standard growth media containing over 3 M NaCl and about 0.75 M magnesium salts. Consistent with this difference in salt-dependent activity, an intein-containing precursor protein with both inteins promotes conditional alternative protein splicing (CAPS) to yield different spliced products dependent on the salt concentration. Native Trp fluorescence of the inteins suggests that the difference in activity may be due to partial unfolding of the inteins at lower salt concentrations. This differential salt sensitivity of intein activity may provide a useful mechanism for halophiles to respond to environmental changes.
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Affiliation(s)
- Vaishnavi R Yalala
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
| | - Abigeal K Lynch
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, Massachusetts 01610, United States
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Tharappel AM, Li Z, Li H. Inteins as Drug Targets and Therapeutic Tools. Front Mol Biosci 2022; 9:821146. [PMID: 35211511 PMCID: PMC8861304 DOI: 10.3389/fmolb.2022.821146] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/10/2022] [Indexed: 12/12/2022] Open
Abstract
Multidrug-resistant pathogens are of significant concern in recent years. Hence new antifungal and anti-bacterial drug targets are urgently needed before the situation goes beyond control. Inteins are polypeptides that self-splice from exteins without the need for cofactors or external energy, resulting in joining of extein fragments. Inteins are present in many organisms, including human pathogens such as Mycobacterium tuberculosis, Cryptococcus neoformans, C. gattii, and Aspergillus fumigatus. Because intein elements are not present in human genes, they are attractive drug targets to develop antifungals and antibiotics. Thus far, a few inhibitors of intein splicing have been reported. Metal-ions such as Zn2+ and Cu2+, and platinum-containing compound cisplatin inhibit intein splicing in M. tuberculosis and C. neoformans by binding to the active site cysteines. A small-molecule inhibitor 6G-318S and its derivative 6G-319S are found to inhibit intein splicing in C. neoformans and C. gattii with a MIC in nanomolar concentrations. Inteins have also been used in many other applications. Intein can be used in activating a protein inside a cell using small molecules. Moreover, split intein can be used to deliver large genes in experimental gene therapy and to kill selected species in a mixed population of microbes by taking advantage of the toxin-antitoxin system. Furthermore, split inteins are used in synthesizing cyclic peptides and in developing cell culture model to study infectious viruses including SARS-CoV-2 in the biosafety level (BSL) 2 facility. This mini-review discusses the recent research developments of inteins in drug discovery and therapeutic research.
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Affiliation(s)
- Anil Mathew Tharappel
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ, United States
| | - Zhong Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ, United States
| | - Hongmin Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ, United States
- BIO5 Institute, The University of Arizona, Tucson, AZ, United States
- *Correspondence: Hongmin Li,
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Rehling D, Scaletti ER, Rozman Grinberg I, Lundin D, Sahlin M, Hofer A, Sjöberg BM, Stenmark P. Structural and Biochemical Investigation of Class I Ribonucleotide Reductase from the Hyperthermophile Aquifex aeolicus. Biochemistry 2021; 61:92-106. [PMID: 34941255 PMCID: PMC8772380 DOI: 10.1021/acs.biochem.1c00503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ribonucleotide reductase (RNR) is an essential enzyme with a complex mechanism of allosteric regulation found in nearly all living organisms. Class I RNRs are composed of two proteins, a large α-subunit (R1) and a smaller β-subunit (R2) that exist as homodimers, that combine to form an active heterotetramer. Aquifex aeolicus is a hyperthermophilic bacterium with an unusual RNR encoding a 346-residue intein in the DNA sequence encoding its R2 subunit. We present the first structures of the A. aeolicus R1 and R2 (AaR1 and AaR2, respectively) proteins as well as the biophysical and biochemical characterization of active and inactive A. aeolicus RNR. While the active oligomeric state and activity regulation of A. aeolicus RNR are similar to those of other characterized RNRs, the X-ray crystal structures also reveal distinct features and adaptations. Specifically, AaR1 contains a β-hairpin hook structure at the dimer interface, which has an interesting π-stacking interaction absent in other members of the NrdAh subclass, and its ATP cone houses two ATP molecules. We determined structures of two AaR2 proteins: one purified from a construct lacking the intein (AaR2) and a second purified from a construct including the intein sequence (AaR2_genomic). These structures in the context of metal content analysis and activity data indicate that AaR2_genomic displays much higher iron occupancy and activity compared to AaR2, suggesting that the intein is important for facilitating complete iron incorporation, particularly in the Fe2 site of the mature R2 protein, which may be important for the survival of A. aeolicus in low-oxygen environments.
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Affiliation(s)
- Daniel Rehling
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Emma Rose Scaletti
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Inna Rozman Grinberg
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Daniel Lundin
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Margareta Sahlin
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Anders Hofer
- Department of Biochemistry and Biophysics, Umeå University, SE-907 36 Umeå, Sweden
| | - Britt-Marie Sjöberg
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
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Nanda A, Nasker SS, Kushwaha AK, Ojha DK, Dearden AK, Nayak SK, Nayak S. Gold Nanoparticles Augment N-Terminal Cleavage and Splicing Reactions in Mycobacterium tuberculosis SufB. Front Bioeng Biotechnol 2021; 9:773303. [PMID: 35004641 PMCID: PMC8735848 DOI: 10.3389/fbioe.2021.773303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Protein splicing is a self-catalyzed event where the intervening sequence intein cleaves off, joining the flanking exteins together to generate a functional protein. Attempts have been made to regulate the splicing rate through variations in temperature, pH, and metals. Although metal-regulated protein splicing has been more captivating to researchers, metals were shown to only inhibit splicing reactions that confine their application. This is the first study to show the effect of nanoparticles (NPs) on protein splicing. We found that gold nanoparticles (AuNPs) of various sizes can increase the splicing efficiency by more than 50% and the N-terminal cleavage efficiency by more than 45% in Mycobacterium tuberculosis SufB precursor protein. This study provides an effective strategy for engineering splicing-enhanced intein platforms. UV-vis absorption spectroscopy, isothermal titration calorimetry (ITC), and transmission electron microscopy (TEM) confirmed AuNP interaction with the native protein. Quantum mechanics/molecular mechanics (QM/MM) analysis suggested a significant reduction in the energy barrier at the N-terminal cleavage site in the presence of gold atom, strengthening our experimental evidence on heightened the N-terminal cleavage reaction. The encouraging observation of enhanced N-terminal cleavage and splicing reaction can have potential implementations from developing a rapid drug delivery system to designing a contemporary protein purification system.
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Affiliation(s)
- Ananya Nanda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Sourya Subhra Nasker
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Anoop K. Kushwaha
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
| | - Deepak Kumar Ojha
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
| | - Albert K. Dearden
- Departments of Physics and Astronomy, College of Arts and Sciences, University of South Carolina, Columbia, SC, United States
| | - Saroj K. Nayak
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
| | - Sasmita Nayak
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, India
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Shubina-Oleinik O, Nist-Lund C, French C, Rockowitz S, Shearer AE, Holt JR. Dual-vector gene therapy restores cochlear amplification and auditory sensitivity in a mouse model of DFNB16 hearing loss. SCIENCE ADVANCES 2021; 7:eabi7629. [PMID: 34910522 PMCID: PMC8673757 DOI: 10.1126/sciadv.abi7629] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/28/2021] [Indexed: 05/27/2023]
Abstract
Hearing loss affects an estimated 466 million people worldwide, with a substantial fraction due to genetic causes. Approximately 16% of genetic hearing loss is caused by pathogenic mutations in STRC, a gene that encodes the protein stereocilin. To develop gene therapy strategies for patients with STRC hearing loss, we generated a mouse model with a targeted deletion in the Strc gene. We devised a novel dual-vector approach to circumvent the size limitation of AAV vectors and drive expression of full-length STRC protein. To target outer hair cells, which are difficult to transduce, we used synthetic AAV9-PHP.B vectors for efficient dual-vector transduction. We report robust recovery of exogenous STRC expression in outer hair cells of Strc-deficient mice, recovery of hair bundle morphology, substantially improved cochlear amplification, and enhanced auditory sensitivity. The data raise the prospect that our strategy could benefit ~2.3 million patients worldwide affected by STRC mutations.
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Affiliation(s)
- Olga Shubina-Oleinik
- Department of Otolaryngology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Carl Nist-Lund
- Department of Otolaryngology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Courtney French
- Children’s Rare Disease Cohort Initiative, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Shira Rockowitz
- Children’s Rare Disease Cohort Initiative, Boston Children’s Hospital, Boston, MA 02115, USA
| | - A. Eliot Shearer
- Department of Otolaryngology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Children’s Rare Disease Cohort Initiative, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Jeffrey R. Holt
- Department of Otolaryngology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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Oberhofer G, Ivy T, Hay BA. Gene drive that results in addiction to a temperature-sensitive version of an essential gene triggers population collapse in Drosophila. Proc Natl Acad Sci U S A 2021; 118:e2107413118. [PMID: 34845012 PMCID: PMC8670509 DOI: 10.1073/pnas.2107413118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2021] [Indexed: 12/15/2022] Open
Abstract
One strategy for population suppression seeks to use gene drive to spread genes that confer conditional lethality or sterility, providing a way of combining population modification with suppression. Stimuli of potential interest could be introduced by humans, such as an otherwise benign virus or chemical, or occur naturally on a seasonal basis, such as a change in temperature. Cleave and Rescue (ClvR) selfish genetic elements use Cas9 and guide RNAs (gRNAs) to disrupt endogenous versions of an essential gene while also including a Rescue version of the essential gene resistant to disruption. ClvR spreads by creating loss-of-function alleles of the essential gene that select against those lacking it, resulting in populations in which the Rescue provides the only source of essential gene function. As a consequence, if function of the Rescue, a kind of Trojan horse now omnipresent in a population, is condition dependent, so too will be the survival of that population. To test this idea, we created a ClvR in Drosophila in which Rescue activity of an essential gene, dribble, requires splicing of a temperature-sensitive intein (TS-ClvRdbe ). This element spreads to transgene fixation at 23 °C, but when populations now dependent on Ts-ClvRdbe are shifted to 29 °C, death and sterility result in a rapid population crash. These results show that conditional population elimination can be achieved. A similar logic, in which Rescue activity is conditional, could also be used in homing-based drive and to bring about suppression and/or killing of specific individuals in response to other stimuli.
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Affiliation(s)
- Georg Oberhofer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Tobin Ivy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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Alexander LT, Lepore R, Kryshtafovych A, Adamopoulos A, Alahuhta M, Arvin AM, Bomble YJ, Böttcher B, Breyton C, Chiarini V, Chinnam NB, Chiu W, Fidelis K, Grinter R, Gupta GD, Hartmann MD, Hayes CS, Heidebrecht T, Ilari A, Joachimiak A, Kim Y, Linares R, Lovering AL, Lunin VV, Lupas AN, Makbul C, Michalska K, Moult J, Mukherjee PK, Nutt W(S, Oliver SL, Perrakis A, Stols L, Tainer JA, Topf M, Tsutakawa SE, Valdivia‐Delgado M, Schwede T. Target highlights in CASP14: Analysis of models by structure providers. Proteins 2021; 89:1647-1672. [PMID: 34561912 PMCID: PMC8616854 DOI: 10.1002/prot.26247] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 12/11/2022]
Abstract
The biological and functional significance of selected Critical Assessment of Techniques for Protein Structure Prediction 14 (CASP14) targets are described by the authors of the structures. The authors highlight the most relevant features of the target proteins and discuss how well these features were reproduced in the respective submitted predictions. The overall ability to predict three-dimensional structures of proteins has improved remarkably in CASP14, and many difficult targets were modeled with impressive accuracy. For the first time in the history of CASP, the experimentalists not only highlighted that computational models can accurately reproduce the most critical structural features observed in their targets, but also envisaged that models could serve as a guidance for further studies of biologically-relevant properties of proteins.
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Affiliation(s)
- Leila T. Alexander
- Biozentrum, University of BaselBaselSwitzerland
- Computational Structural BiologySIB Swiss Institute of BioinformaticsBaselSwitzerland
| | | | | | - Athanassios Adamopoulos
- Oncode Institute and Division of BiochemistryNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Markus Alahuhta
- Bioscience Center, National Renewable Energy LaboratoryGoldenColoradoUSA
| | - Ann M. Arvin
- Department of PediatricsStanford University School of MedicineStanfordCaliforniaUSA
- Microbiology and ImmunologyStanford University School of MedicineStanfordCaliforniaUSA
| | - Yannick J. Bomble
- Bioscience Center, National Renewable Energy LaboratoryGoldenColoradoUSA
| | - Bettina Böttcher
- Biocenter and Rudolf Virchow Center, Julius‐Maximilians Universität WürzburgWürzburgGermany
| | - Cécile Breyton
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural BiologyGrenobleFrance
| | - Valerio Chiarini
- Program in Structural Biology and BiophysicsInstitute of Biotechnology, University of HelsinkiHelsinkiFinland
| | - Naga babu Chinnam
- Department of Molecular and Cellular OncologyThe University of Texas M.D. Anderson Cancer CenterHoustonTexasUSA
| | - Wah Chiu
- Microbiology and ImmunologyStanford University School of MedicineStanfordCaliforniaUSA
- BioengineeringStanford University School of MedicineStanfordCaliforniaUSA
- Division of Cryo‐EM and Bioimaging SSRLSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | | | - Rhys Grinter
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of MicrobiologyMonash UniversityClaytonAustralia
| | - Gagan D. Gupta
- Radiation Biology & Health Sciences DivisionBhabha Atomic Research CentreMumbaiIndia
| | - Marcus D. Hartmann
- Department of Protein EvolutionMax Planck Institute for Developmental BiologyTübingenGermany
| | - Christopher S. Hayes
- Department of Molecular, Cellular and Developmental BiologyUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
- Biomolecular Science and Engineering ProgramUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
| | - Tatjana Heidebrecht
- Oncode Institute and Division of BiochemistryNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Andrea Ilari
- Institute of Molecular Biology and Pathology of the National Research Council of Italy (CNR)RomeItaly
| | - Andrzej Joachimiak
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of ChicagoChicagoIllinoisUSA
- X‐ray Science DivisionArgonne National Laboratory, Structural Biology CenterArgonneIllinoisUSA
- Department of Biochemistry and Molecular BiologyUniversity of ChicagoChicagoIllinoisUSA
| | - Youngchang Kim
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of ChicagoChicagoIllinoisUSA
- X‐ray Science DivisionArgonne National Laboratory, Structural Biology CenterArgonneIllinoisUSA
| | - Romain Linares
- Univ. Grenoble Alpes, CNRS, CEA, Institute for Structural BiologyGrenobleFrance
| | | | - Vladimir V. Lunin
- Bioscience Center, National Renewable Energy LaboratoryGoldenColoradoUSA
| | - Andrei N. Lupas
- Department of Protein EvolutionMax Planck Institute for Developmental BiologyTübingenGermany
| | - Cihan Makbul
- Biocenter and Rudolf Virchow Center, Julius‐Maximilians Universität WürzburgWürzburgGermany
| | - Karolina Michalska
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of ChicagoChicagoIllinoisUSA
- X‐ray Science DivisionArgonne National Laboratory, Structural Biology CenterArgonneIllinoisUSA
| | - John Moult
- Department of Cell Biology and Molecular GeneticsInstitute for Bioscience and Biotechnology Research, University of MarylandRockvilleMarylandUSA
| | - Prasun K. Mukherjee
- Nuclear Agriculture & Biotechnology DivisionBhabha Atomic Research CentreMumbaiIndia
| | - William (Sam) Nutt
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of ChicagoChicagoIllinoisUSA
- X‐ray Science DivisionArgonne National Laboratory, Structural Biology CenterArgonneIllinoisUSA
| | - Stefan L. Oliver
- Department of PediatricsStanford University School of MedicineStanfordCaliforniaUSA
| | - Anastassis Perrakis
- Oncode Institute and Division of BiochemistryNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Lucy Stols
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of ChicagoChicagoIllinoisUSA
- X‐ray Science DivisionArgonne National Laboratory, Structural Biology CenterArgonneIllinoisUSA
| | - John A. Tainer
- Department of Molecular and Cellular OncologyThe University of Texas M.D. Anderson Cancer CenterHoustonTexasUSA
- Department of Cancer BiologyUniversity of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University College LondonLondonUK
- Centre for Structural Systems Biology, Leibniz‐Institut für Experimentelle VirologieHamburgGermany
| | - Susan E. Tsutakawa
- Molecular Biophysics and Integrated BioimagingLawrence Berkeley National LaboratoryBerkeleyCaliforniaUSA
| | | | - Torsten Schwede
- Biozentrum, University of BaselBaselSwitzerland
- Computational Structural BiologySIB Swiss Institute of BioinformaticsBaselSwitzerland
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Abstract
Intervening proteins, or inteins, are mobile genetic elements that are translated within host polypeptides and removed at the protein level by splicing. In protein splicing, a self-mediated reaction removes the intein, leaving a peptide bond in place. While protein splicing can proceed in the absence of external cofactors, several examples of conditional protein splicing (CPS) have emerged. In CPS, the rate and accuracy of splicing are highly dependent on environmental conditions. Because the activity of the intein-containing host protein is compromised prior to splicing and inteins are highly abundant in the microbial world, CPS represents an emerging form of posttranslational regulation that is potentially widespread in microbes. Reactive chlorine species (RCS) are highly potent oxidants encountered by bacteria in a variety of natural environments, including within cells of the mammalian innate immune system. Here, we demonstrate that two naturally occurring RCS, namely, hypochlorous acid (the active compound in bleach) and N-chlorotaurine, can reversibly block splicing of DnaB inteins from Mycobacterium leprae and Mycobacterium smegmatis in vitro. Further, using a reporter that monitors DnaB intein activity within M. smegmatis, we show that DnaB protein splicing is inhibited by RCS in the native host. DnaB, an essential replicative helicase, is the most common intein-housing protein in bacteria. These results add to the growing list of environmental conditions that are relevant to the survival of the intein-containing host and influence protein splicing, as well as suggesting a novel mycobacterial response to RCS. We propose a model in which DnaB splicing, and therefore replication, is paused when these mycobacteria encounter RCS. IMPORTANCE Inteins are both widespread and abundant in microbes, including within several bacterial and fungal pathogens. Inteins are domains translated within host proteins and removed at the protein level by splicing. Traditionally considered molecular parasites, some inteins have emerged in recent years as adaptive posttranslational regulatory elements. Several studies have demonstrated CPS, in which the rate and accuracy of protein splicing, and thus host protein functions, are responsive to environmental conditions relevant to the intein-containing organism. In this work, we demonstrate that two naturally occurring RCS, including the active compound in household bleach, reversibly inhibit protein splicing of Mycobacterium leprae and Mycobacterium smegmatis DnaB inteins. In addition to describing a new physiologically relevant condition that can temporarily inhibit protein splicing, this study suggests a novel stress response in Mycobacterium, a bacterial genus of tremendous importance to humans.
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Wall DA, Tarrant SP, Wang C, Mills KV, Lennon CW. Intein Inhibitors as Novel Antimicrobials: Protein Splicing in Human Pathogens, Screening Methods, and Off-Target Considerations. Front Mol Biosci 2021; 8:752824. [PMID: 34692773 PMCID: PMC8529194 DOI: 10.3389/fmolb.2021.752824] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/24/2021] [Indexed: 01/20/2023] Open
Abstract
Protein splicing is a post-translational process by which an intervening polypeptide, or intein, catalyzes its own removal from the flanking polypeptides, or exteins, concomitant with extein ligation. Although inteins are highly abundant in the microbial world, including within several human pathogens, they are absent in the genomes of metazoans. As protein splicing is required to permit function of essential proteins within pathogens, inteins represent attractive antimicrobial targets. Here we review key proteins interrupted by inteins in pathogenic mycobacteria and fungi, exciting discoveries that provide proof of concept that intein activity can be inhibited and that this inhibition has an effect on the host organism's fitness, and bioanalytical methods that have been used to screen for intein activity. We also consider potential off-target inhibition of hedgehog signaling, given the similarity in structure and function of inteins and hedgehog autoprocessing domains.
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Affiliation(s)
- Diana A Wall
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Seanan P Tarrant
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Chunyu Wang
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States.,Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Christopher W Lennon
- Department of Biological Sciences, Murray State University, Murray, KY, United States
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Kang C, Kim S, Lee E, Ryu J, Lee M, Kwon Y. Genetically Encoded Sensor Cells for the Screening of Glucocorticoid Receptor (GR) Effectors in Herbal Extracts. BIOSENSORS-BASEL 2021; 11:bios11090341. [PMID: 34562931 PMCID: PMC8465347 DOI: 10.3390/bios11090341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 01/13/2023]
Abstract
Although in vitro sensors provide facile low-cost ways to screen for biologically active targets, their results may not accurately represent the molecular interactions in biological systems. Cell-based sensors have emerged as promising platforms to screen targets in biologically relevant environments. However, there are few examples where cell-based sensors have been practically applied for drug screening. Here, we used engineered cortisol-detecting sensor cells to screen for natural mimetics of cortisol. The sensor cells were designed to report the presence of a target through signal peptide activation and subsequent fluorescence signal translocation. The developed sensor cells were able to detect known biological targets from human-derived analytes as well as natural product extracts, such as deer antlers and ginseng. The multi-use capability and versatility to screen in different cellular environments were also demonstrated. The sensor cells were used to identify novel GR effectors from medicinal plant extracts. Our results suggest that decursin from dongquai had the GR effector function as a selective GR agonist (SEGRA), making it a potent drug candidate with anti-inflammatory activity. We demonstrated the superiority of cell-based sensing technology over in vitro screening, proving its potential for practical drug screening applications that leads to the function-based discovery of target molecules.
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Affiliation(s)
- Chungwon Kang
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
| | - Soyoun Kim
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
| | - Euiyeon Lee
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, USA
| | - Jeahee Ryu
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
| | - Minhyeong Lee
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
| | - Youngeun Kwon
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Korea; (C.K.); (S.K.); (E.L.); (J.R.); (M.L.)
- Correspondence: ; Tel.: +82-31-961-5151
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Weinberger Ii J, Lennon CW. Monitoring Protein Splicing Using In-gel Fluorescence Immediately Following SDS-PAGE. Bio Protoc 2021; 11:e4121. [PMID: 34541040 DOI: 10.21769/bioprotoc.4121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 11/02/2022] Open
Abstract
Inteins garner significant interest from both basic and applied researchers due to their unique catalytic abilities. Herein, we describe a protocol for accurately monitoring protein splicing without purification using in-gel fluorescence immediately following Tris-Glycine SDS-PAGE. Following expression in Escherichia coli, cells are lysed by sonication, cell supernatants are separated using Tris-Glycine SDS-PAGE, and superfolder GFP (sfGFP) fluorescence is directly visualized within gels. This method is rapid, with sfGFP immediately imaged following SDS-PAGE without staining. Further, sfGFP can be specifically detected in complex samples such as E. coli cell supernatants, proteins run at expected masses, and all steps can be performed at ambient temperature. This strategy is broadly applicable beyond the study of protein splicing and can be used for sensitive and specific visualization of superfolder sfGFP-tagged proteins in-gel.
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Choi H, Eom S, Kim HU, Bae Y, Jung HS, Kang S. Load and Display: Engineering Encapsulin as a Modular Nanoplatform for Protein-Cargo Encapsulation and Protein-Ligand Decoration Using Split Intein and SpyTag/SpyCatcher. Biomacromolecules 2021; 22:3028-3039. [PMID: 34142815 DOI: 10.1021/acs.biomac.1c00481] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein cage nanoparticles have a unique spherical hollow structure that provides a modifiable interior space and an exterior surface. For full application, it is desirable to utilize both the interior space and the exterior surface simultaneously with two different functionalities in a well-combined way. Here, we genetically engineered encapsulin protein cage nanoparticles (Encap) as modular nanoplatforms by introducing a split-C-intein (IntC) fragment and SpyTag into the interior and exterior surfaces, respectively. A complementary split-N-intein (IntN) was fused to various protein cargoes, such as NanoLuc luciferase (Nluc), enhanced green fluorescent protein (eGFP), and Nluc-miniSOG, individually, which led to their successful encapsulation into Encaps to form Cargo@Encap through split intein-mediated protein ligation during protein coexpression and cage assembly in bacteria. Conversely, the SpyCatcher protein was fused to various protein ligands, such as a glutathione binder (GST-SC), dimerizing ligands (FKBP12-SC and FRB-SC), and a cancer-targeting affibody (SC-EGFRAfb); subsequently, they were displayed on Cargo@Encaps through SpyTag/SpyCatcher ligation to form Cargo@Encap/Ligands in a mix-and-match manner. Nluc@Encap/glutathione-S-transferase (GST) was effectively immobilized on glutathione (GSH)-coated solid supports exhibiting repetitive and long-term usage of the encapsulated luciferases. We also established luciferase-embedded layer-by-layer (LbL) nanostructures by alternately depositing Nluc@Encap/FKBP12 and Nluc@Encap/FRB in the presence of rapamycin and applied enhanced green fluorescent protein (eGFP)@Encap/EGFRAfb as a target-specific fluorescent imaging probe to visualize specific cancer cells selectively. Modular functionalization of the interior space and the exterior surface of a protein cage nanoparticle may offer the opportunity to develop new protein-based nanostructured devices and nanomedical tools.
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Affiliation(s)
- Hyukjun Choi
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Soomin Eom
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Han-Ul Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si 24341, Gangwon-do, Korea
| | - Yoonji Bae
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si 24341, Gangwon-do, Korea
| | - Sebyung Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
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Williams JE, Jaramillo MV, Li Z, Zhao J, Wang C, Li H, Mills KV. An alternative domain-swapped structure of the Pyrococcus horikoshii PolII mini-intein. Sci Rep 2021; 11:11680. [PMID: 34083592 PMCID: PMC8175363 DOI: 10.1038/s41598-021-91090-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/19/2021] [Indexed: 01/09/2023] Open
Abstract
Protein splicing is a post-translational process by which an intein catalyzes its own excision from flanking polypeptides, or exteins, concomitant with extein ligation. Many inteins have nested homing endonuclease domains that facilitate their propagation into intein-less alleles, whereas other inteins lack the homing endonuclease (HEN) and are called mini-inteins. The mini-intein that interrupts the DNA PolII of Pyrococcus horikoshii has a linker region in place of the HEN domain that is shorter than the linker in a closely related intein from Pyrococcus abyssi. The P. horikoshii PolII intein requires a higher temperature for catalytic activity and is more stable to digestion by the thermostable protease thermolysin, suggesting that it is more rigid than the P. abyssi intein. We solved a crystal structure of the intein precursor that revealed a domain-swapped dimer. Inteins found as domain swapped dimers have been shown to promote intein-mediated protein alternative splicing, but the solved P. horikoshii PolII intein structure has an active site unlikely to be catalytically competent.
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Affiliation(s)
- Jennie E Williams
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA
| | - Mario V Jaramillo
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA
| | - Zhong Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, 85721, USA
| | - Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
- China Agricultural University, Beijing, China
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Hongmin Li
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, 12208, USA
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ, 85721, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, 1 College Street, Worcester, MA, USA.
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Woods D, LeSassier DS, Egbunam I, Lennon CW. Construction and Quantitation of a Selectable Protein Splicing Sensor Using Gibson Assembly and Spot Titers. Curr Protoc 2021; 1:e82. [PMID: 33739627 DOI: 10.1002/cpz1.82] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Inteins (intervening proteins) are translated within host proteins and removed through protein splicing. Conditional protein splicing (CPS), where the rate and accuracy of splicing are highly dependent on environmental cues, has emerged as a novel form of post-translational regulation. While CPS has been demonstrated for several inteins in vitro, a comprehensive understanding of inteins requires tools to quantitatively monitor their activity within the cellular context. Here, we describe a method for construction of a splicing-dependent system that can be used to quantitatively assay for conditions that modulate protein splicing. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Construction of an intein-containing KanR2 library using Gibson assembly Basic Protocol 2: Phenotype determination using quantitative spot titers Support Protocol 1: Preparation of LB agar plates for spot titers Support Protocol 2: Preparation and transformation of competent M. smegmatis cells.
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Affiliation(s)
- Daniel Woods
- Wadsworth Center, New York State Department of Health, Albany, New York
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Panda S, Nanda A, Nasker SS, Sen D, Mehra A, Nayak S. Metal effect on intein splicing: A review. Biochimie 2021; 185:53-67. [PMID: 33727137 DOI: 10.1016/j.biochi.2021.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 02/08/2023]
Abstract
Inteins are intervening polypeptides that interrupt the functional domains of several important proteins across the three domains of life. Inteins excise themselves from the precursor protein, ligating concomitant extein residues in a process called protein splicing. Post-translational auto-removal of inteins remain critical for the generation of active proteins. The perspective of inteins in science is a robust field of research, however fundamental studies centralized upon splicing regulatory mechanism are imperative for addressing more intricate issues. Controlled engineering of intein splicing has many applications; intein inhibition can facilitate novel drug design, while activation of intein splicing is exploited in protein purification. This paper provides a comprehensive review of the past and recent advances in the splicing regulation via metal-intein interaction. We compare the behavior of different metal ions on diverse intein systems. Though metals such as Zn, Cu, Pt, Cd, Co, Ni exhibit intein inhibitory effect heterogeneously on different inteins, divalent metal ions such as Ca and Mg fail to do so. The observed diversity in the metal-intein interaction arises mostly due to intein polymorphism and variations in atomic structure of metals. A mechanistic understanding of intein regulation by metals in native as well as synthetically engineered intein systems may yield potent intein inhibitors via direct or indirect approach.
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Affiliation(s)
- Sunita Panda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ananya Nanda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sourya Subhra Nasker
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Debjani Sen
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ashwaria Mehra
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sasmita Nayak
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India.
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Abstract
Self-splicing proteins, called inteins, are present in many human pathogens, including the emerging fungal threats Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga), the causative agents of cryptococcosis. Inhibition of protein splicing in Cryptococcus sp. interferes with activity of the only intein-containing protein, Prp8, an essential intron splicing factor. Here, we screened a small-molecule library to find addititonal, potent inhibitors of the Cne Prp8 intein using a split-GFP splicing assay. This revealed the compound 6G-318S, with IC50 values in the low micromolar range in the split-GFP assay and in a complementary split-luciferase system. A fluoride derivative of the compound 6G-318S displayed improved cytotoxicity in human lung carcinoma cells, although there was a slight reduction in the inhibition of splicing. 6G-318S and its derivative inhibited splicing of the Cne Prp8 intein in vivo in Escherichia coli and in C. neoformans Moreover, the compounds repressed growth of WT C. neoformans and C. gattii In contrast, the inhibitors were less potent at inhibiting growth of the inteinless Candida albicans Drug resistance was observed when the Prp8 intein was overexpressed in C. neoformans, indicating specificity of this molecule toward the target. No off-target activity was observed, such as inhibition of serine/cysteine proteases. The inhibitors bound covalently to the Prp8 intein and binding was reduced when the active-site residue Cys1 was mutated. 6G-318S showed a synergistic effect with amphotericin B and additive to indifferent effects with a few other clinically used antimycotics. Overall, the identification of these small-molecule intein-splicing inhibitors opens up prospects for a new class of antifungals.
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Chiarini V, Fiorillo A, Camerini S, Crescenzi M, Nakamura S, Battista T, Guidoni L, Colotti G, Ilari A. Structural basis of ubiquitination mediated by protein splicing in early Eukarya. Biochim Biophys Acta Gen Subj 2021; 1865:129844. [PMID: 33444728 DOI: 10.1016/j.bbagen.2021.129844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/28/2020] [Accepted: 01/08/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Inteins are intervening proteins, which are known to perform protein splicing. The reaction results in the production of an intein domain and an inteinless protein, which shows no trace of the insertion. BIL2 is part of the polyubiquitin locus of Tetrahymena thermophila (BUBL), where two bacterial-intein-like (BIL) domains lacking the C + 1 nucleophile, are flanked by two independent ubiquitin-like domains (ubl4/ubl5). METHODS We solved the X-ray structures of BIL2 in both the inactive and unprecedented, zinc-induced active, forms. Then, we characterized by mass spectrometry the BUBL splicing products in the absence and in the presence of T.thRas-GTPase. Finally, we investigated the effect of ubiquitination on T.thRas-GTPase by molecular dynamics simulations. RESULTS The structural analysis demonstrated that zinc-induced conformational change activates protein splicing. Moreover, mass spectrometry characterization of the splicing products shed light on the possible function of BIL2, which operates as a "single-ubiquitin-dispensing-platform", allowing the conjugation, via isopeptide bond formation (K(εNH2)-C-ter), of ubl4 to either ubl5 or T.thRas-GTPase. Lastly, we demonstrated that T.thRas-GTPase ubiquitination occurs in proximity of the nucleotide binding pocket and stabilizes the protein active state. CONCLUSIONS We demonstrated that BIL2 is activated by zinc and that protein splicing induced by this intein does not take place through classical or aminolysis mechanisms but via formation of a covalent isopeptide bond, causing the ubiquitination of endogenous substrates such as T.thRas-GTPase. GENERAL SIGNIFICANCE In this "enzyme-free" ubiquitination mechanism the isopeptide formation, which canonically requires E1-E2-E3 enzymatic cascade and constitutes the alphabet of ubiquitin biology, is achieved in a single, concerted step without energy consumption.
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Affiliation(s)
- Valerio Chiarini
- Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, Viikinkaari 1, P.O. Box 65, FI-00014 Helsinki, Finland
| | - Annarita Fiorillo
- Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Serena Camerini
- Core Facilities, Italian National Institute of Health, viale Regina Elena 299, 00161 Rome, Italy
| | - Marco Crescenzi
- Core Facilities, Italian National Institute of Health, viale Regina Elena 299, 00161 Rome, Italy
| | - Shin Nakamura
- Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Theo Battista
- Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Leonardo Guidoni
- Dipartimento di Scienze Chimiche e Fisiche, Università degli Studi dell'Aquila, Italy
| | - Gianni Colotti
- Institute of Molecular Biology and Pathology of The National Research Council of Italy (CNR), P.le A. Moro 5, 00185 Rome, Italy.
| | - Andrea Ilari
- Institute of Molecular Biology and Pathology of The National Research Council of Italy (CNR), P.le A. Moro 5, 00185 Rome, Italy.
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Park J, Lee S, Kim Y, Yoo TH. Methods to generate site-specific conjugates of antibody and protein. Bioorg Med Chem 2021; 30:115946. [DOI: 10.1016/j.bmc.2020.115946] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023]
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Inteins in Science: Evolution to Application. Microorganisms 2020; 8:microorganisms8122004. [PMID: 33339089 PMCID: PMC7765530 DOI: 10.3390/microorganisms8122004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/20/2022] Open
Abstract
Inteins are mobile genetic elements that apply standard enzymatic strategies to excise themselves post-translationally from the precursor protein via protein splicing. Since their discovery in the 1990s, recent advances in intein technology allow for them to be implemented as a modern biotechnological contrivance. Radical improvement in the structure and catalytic framework of cis- and trans-splicing inteins devised the development of engineered inteins that contribute to various efficient downstream techniques. Previous literature indicates that implementation of intein-mediated splicing has been extended to in vivo systems. Besides, the homing endonuclease domain also acts as a versatile biotechnological tool involving genetic manipulation and control of monogenic diseases. This review orients the understanding of inteins by sequentially studying the distribution and evolution pattern of intein, thereby highlighting a role in genetic mobility. Further, we include an in-depth summary of specific applications branching from protein purification using self-cleaving tags to protein modification, post-translational processing and labelling, followed by the development of intein-based biosensors. These engineered inteins offer a disruptive approach towards research avenues like biomaterial construction, metabolic engineering and synthetic biology. Therefore, this linear perspective allows for a more comprehensive understanding of intein function and its diverse applications.
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Abstract
BACKGROUND RNA trans-splicing joins exons from different pre-mRNA transcripts to generate a chimeric product. Trans-splicing can also occur at the protein level, with split inteins mediating the ligation of separate gene products to generate a mature protein. SOURCES OF DATA Comprehensive literature search of published research papers and reviews using Pubmed. AREAS OF AGREEMENT Trans-splicing techniques have been used to target a wide range of diseases in both in vitro and in vivo models, resulting in RNA, protein and functional correction. AREAS OF CONTROVERSY Off-target effects can lead to therapeutically undesirable consequences. In vivo efficacy is typically low, and delivery issues remain a challenge. GROWING POINTS Trans-splicing provides a promising avenue for developing novel therapeutic approaches. However, much more research needs to be done before developing towards preclinical studies. AREAS TIMELY FOR DEVELOPING RESEARCH Increasing trans-splicing efficacy and specificity by rational design, screening and competitive inhibition of endogenous cis-splicing.
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Affiliation(s)
- Elizabeth M Hong
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK
| | - Carin K Ingemarsdotter
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK
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Kagiya G, Sato A, Ogawa R, Hatashita M, Kato M, Kubo M, Kojima F, Kawakami F, Nishimura Y, Abe N, Hyodo F. Real-time visualization of intratumoral necrosis using split-luciferase reconstitution by protein trans-splicing. MOLECULAR THERAPY-ONCOLYTICS 2020; 20:48-58. [PMID: 33575470 PMCID: PMC7851486 DOI: 10.1016/j.omto.2020.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/05/2020] [Indexed: 11/07/2022]
Abstract
Necrosis, a form of cell death, occurs not only with the development of various diseases but also with a tumor tissue response to cancer treatment. Therefore, pursuing progress for cancer therapy through induction of necrosis may be one of the most effective approaches for cancer eradication. We herein describe the development of a real-time imaging system to visualize intratumoral necrosis. The system is composed of two types of cells expressing either one of two necrosis imaging reporters that consist of a DnaE intein sequence linking to one of two split-luciferase fragments. When necrosis occurs in a tumor composed of both of the cells, the two types of leaked reporters can reconstitute the enzymatic activity as a result of protein trans-splicing and thereby emit bioluminescence in the presence of the substrate. This system, which was constructed with shrimp-derived luciferase, allowed in vitro imaging of necrosis. We further confirmed real-time imaging of intratumoral necrosis caused by physical or chemical tissue disruption, validating its application in in vivo necrosis imaging. Thus, the constructed imaging system could be a powerful tool for the optimization of the therapeutic condition for cancer therapy and for the evaluation of novel anticancer drugs targeting necrosis.
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Affiliation(s)
- Go Kagiya
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.,Regenerative Medicine and Cell Design Research Facility, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Ayaka Sato
- Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae, Kawasaki, Kanagawa 216-8511, Japan
| | - Ryohei Ogawa
- Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Masanori Hatashita
- Biotechnology Division, The Wakasa Wan Energy Research Center, 64-52-1 Nagatani, Tsuruga, Fukui 914-0192, Japan
| | - Mana Kato
- Department of Radiological Services, Tokyo Women's Medical University Hospital, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Makoto Kubo
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.,Regenerative Medicine and Cell Design Research Facility, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Fumiaki Kojima
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.,Regenerative Medicine and Cell Design Research Facility, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Fumitaka Kawakami
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.,Regenerative Medicine and Cell Design Research Facility, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Yukari Nishimura
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Naoya Abe
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
| | - Fuminori Hyodo
- Department of Radiology Frontier Science for Imaging, School of Medicine, Gifu University, 1-1 Yanagida, Gifu 501-1194, Japan
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Zatopek KM, Alpaslan E, Evans T, Sauguet L, Gardner A. Novel ribonucleotide discrimination in the RNA polymerase-like two-barrel catalytic core of Family D DNA polymerases. Nucleic Acids Res 2020; 48:12204-12218. [PMID: 33137176 PMCID: PMC7708050 DOI: 10.1093/nar/gkaa986] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Family D DNA polymerase (PolD) is the essential replicative DNA polymerase for duplication of most archaeal genomes. PolD contains a unique two-barrel catalytic core absent from all other DNA polymerase families but found in RNA polymerases (RNAPs). While PolD has an ancestral RNA polymerase catalytic core, its active site has evolved the ability to discriminate against ribonucleotides. Until now, the mechanism evolved by PolD to prevent ribonucleotide incorporation was unknown. In all other DNA polymerase families, an active site steric gate residue prevents ribonucleotide incorporation. In this work, we identify two consensus active site acidic (a) and basic (b) motifs shared across the entire two-barrel nucleotide polymerase superfamily, and a nucleotide selectivity (s) motif specific to PolD versus RNAPs. A novel steric gate histidine residue (H931 in Thermococcus sp. 9°N PolD) in the PolD s-motif both prevents ribonucleotide incorporation and promotes efficient dNTP incorporation. Further, a PolD H931A steric gate mutant abolishes ribonucleotide discrimination and readily incorporates a variety of 2' modified nucleotides. Taken together, we construct the first putative nucleotide bound PolD active site model and provide structural and functional evidence for the emergence of DNA replication through the evolution of an ancestral RNAP two-barrel catalytic core.
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Affiliation(s)
| | - Ece Alpaslan
- New England Biolabs, 240 County Road Ipswich, MA 01938, USA
| | - Thomas C Evans
- New England Biolabs, 240 County Road Ipswich, MA 01938, USA
| | - Ludovic Sauguet
- Institut Pasteur, Unité de Dynamique Structurale des Macromolécules, 75015 Paris, France
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Beyer HM, Virtanen SI, Aranko AS, Mikula KM, Lountos GT, Wlodawer A, Ollila OHS, Iwaï H. The Convergence of the Hedgehog/Intein Fold in Different Protein Splicing Mechanisms. Int J Mol Sci 2020; 21:ijms21218367. [PMID: 33171880 PMCID: PMC7664689 DOI: 10.3390/ijms21218367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/01/2020] [Accepted: 11/05/2020] [Indexed: 11/16/2022] Open
Abstract
Protein splicing catalyzed by inteins utilizes many different combinations of amino-acid types at active sites. Inteins have been classified into three classes based on their characteristic sequences. We investigated the structural basis of the protein splicing mechanism of class 3 inteins by determining crystal structures of variants of a class 3 intein from Mycobacterium chimaera and molecular dynamics simulations, which suggested that the class 3 intein utilizes a different splicing mechanism from that of class 1 and 2 inteins. The class 3 intein uses a bond cleavage strategy reminiscent of proteases but share the same Hedgehog/INTein (HINT) fold of other intein classes. Engineering of class 3 inteins from a class 1 intein indicated that a class 3 intein would unlikely evolve directly from a class 1 or 2 intein. The HINT fold appears as structural and functional solution for trans-peptidyl and trans-esterification reactions commonly exploited by diverse mechanisms using different combinations of amino-acid types for the active-site residues.
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Affiliation(s)
- Hannes M. Beyer
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
| | - Salla I. Virtanen
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
| | - A. Sesilja Aranko
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
| | - Kornelia M. Mikula
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
| | - George T. Lountos
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA;
| | - Alexander Wlodawer
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA;
| | - O. H. Samuli Ollila
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
| | - Hideo Iwaï
- Institute of Biotechnology, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland; (H.M.B.); (S.I.V.); (A.S.A.); (K.M.M.); (O.H.S.O.)
- Correspondence: ; Tel.: +358-2941-59752
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