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Toledo-Patiño S, Goetz SK, Shanmugaratnam S, Höcker B, Farías-Rico JA. Molecular handcraft of a well-folded protein chimera. FEBS Lett 2024. [PMID: 38508768 DOI: 10.1002/1873-3468.14856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 03/22/2024]
Abstract
Modular assembly is a compelling pathway to create new proteins, a concept supported by protein engineering and millennia of evolution. Natural evolution provided a repository of building blocks, known as domains, which trace back to even shorter segments that underwent numerous 'copy-paste' processes culminating in the scaffolds we see today. Utilizing the subdomain-database Fuzzle, we constructed a fold-chimera by integrating a flavodoxin-like fragment into a periplasmic binding protein. This chimera is well-folded and a crystal structure reveals stable interfaces between the fragments. These findings demonstrate the adaptability of α/β-proteins and offer a stepping stone for optimization. By emphasizing the practicality of fragment databases, our work pioneers new pathways in protein engineering. Ultimately, the results substantiate the conjecture that periplasmic binding proteins originated from a flavodoxin-like ancestor.
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Affiliation(s)
- Saacnicteh Toledo-Patiño
- Max Planck Institute for Developmental Biology, Tübingen, Germany
- Okinawa Institute of Science and Technology Graduate University, Japan
| | | | - Sooruban Shanmugaratnam
- Max Planck Institute for Developmental Biology, Tübingen, Germany
- Department of Biochemistry, University of Bayreuth, Germany
| | - Birte Höcker
- Max Planck Institute for Developmental Biology, Tübingen, Germany
- Department of Biochemistry, University of Bayreuth, Germany
| | - José Arcadio Farías-Rico
- Max Planck Institute for Developmental Biology, Tübingen, Germany
- Synthetic Biology Program, Center for Genome Sciences, National Autonomous University of Mexico, Cuernavaca, Mexico
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2
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Grąźlewska W, Holec-Gąsior L, Sołowińska K, Chmielewski T, Fiecek B, Contreras M. Epitope Mapping of BmpA and BBK32 Borrelia burgdorferi Sensu Stricto Antigens for the Design of Chimeric Proteins with Potential Diagnostic Value. ACS Infect Dis 2023; 9:2160-2172. [PMID: 37803965 PMCID: PMC10722512 DOI: 10.1021/acsinfecdis.3c00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Indexed: 10/08/2023]
Abstract
Lyme disease is a tick-borne zoonosis caused by Gram-negative bacteria belonging to the Borrelia burgdorferi sensu lato (s.l.) group. In this study, IgM- and IgG-specific linear epitopes of two B. burgdorferi sensu stricto (s.s.) antigens BmpA and BBK32 were mapped using a polypeptide array. Subsequently, two chimeric proteins BmpA-BBK32-M and BmpA-BBK32-G were designed to validate the construction of chimeras using the identified epitopes for the detection of IgM and IgG, respectively, by ELISA. IgG-ELISA based on the BmpA-BBK32-G antigen showed 71% sensitivity and 95% specificity, whereas a slightly lower diagnostic utility was obtained for IgM-ELISA based on BmpA-BBK32-M, where the sensitivity was also 71% but the specificity decreased to 89%. The reactivity of chimeric proteins with nondedicated antibodies was much lower. These results suggest that the identified epitopes may be useful in the design of new forms of antigens to increase the effectiveness of Lyme disease serodiagnosis. It has also been proven that appropriate selection of epitopes enables the construction of chimeric proteins exhibiting reactivity with a specific antibody isotype.
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Affiliation(s)
- Weronika Grąźlewska
- Department
of Molecular Biotechnology and Microbiology, Faculty of Chemistry, University of Gdańsk Technology, 80-233 Gdańsk, Poland
- SaBio,
Instituto de Investigación en Recursos Cinegéticos IREC−CSIC-UCLM-JCCM, 13005 Ciudad Real, Spain
| | - Lucyna Holec-Gąsior
- Department
of Molecular Biotechnology and Microbiology, Faculty of Chemistry, University of Gdańsk Technology, 80-233 Gdańsk, Poland
| | - Karolina Sołowińska
- Department
of Molecular Biotechnology and Microbiology, Faculty of Chemistry, University of Gdańsk Technology, 80-233 Gdańsk, Poland
| | - Tomasz Chmielewski
- Department
of Parasitology and Diseases Transmitted by Vectors, National Institute of Public Health NIH - National Research Institute, 00-791 Warsaw, Poland
| | - Beata Fiecek
- Department
of Parasitology and Diseases Transmitted by Vectors, National Institute of Public Health NIH - National Research Institute, 00-791 Warsaw, Poland
| | - Marinela Contreras
- SaBio,
Instituto de Investigación en Recursos Cinegéticos IREC−CSIC-UCLM-JCCM, 13005 Ciudad Real, Spain
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Shirakawa KT, Sala FA, Miyachiro MM, Job V, Trindade DM, Dessen A. Architecture and genomic arrangement of the MurE-MurF bacterial cell wall biosynthesis complex. Proc Natl Acad Sci U S A 2023; 120:e2219540120. [PMID: 37186837 PMCID: PMC10214165 DOI: 10.1073/pnas.2219540120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Peptidoglycan (PG) is a central component of the bacterial cell wall, and the disruption of its biosynthetic pathway has been a successful antibacterial strategy for decades. PG biosynthesis is initiated in the cytoplasm through sequential reactions catalyzed by Mur enzymes that have been suggested to associate into a multimembered complex. This idea is supported by the observation that in many eubacteria, mur genes are present in a single operon within the well conserved dcw cluster, and in some cases, pairs of mur genes are fused to encode a single, chimeric polypeptide. We performed a vast genomic analysis using >140 bacterial genomes and mapped Mur chimeras in numerous phyla, with Proteobacteria carrying the highest number. MurE-MurF, the most prevalent chimera, exists in forms that are either directly associated or separated by a linker. The crystal structure of the MurE-MurF chimera from Bordetella pertussis reveals a head-to-tail, elongated architecture supported by an interconnecting hydrophobic patch that stabilizes the positions of the two proteins. Fluorescence polarization assays reveal that MurE-MurF interacts with other Mur ligases via its central domains with KDs in the high nanomolar range, backing the existence of a Mur complex in the cytoplasm. These data support the idea of stronger evolutionary constraints on gene order when encoded proteins are intended for association, establish a link between Mur ligase interaction, complex assembly and genome evolution, and shed light on regulatory mechanisms of protein expression and stability in pathways of critical importance for bacterial survival.
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Affiliation(s)
- Karina T. Shirakawa
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo13084-971, Brazil
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, CEP Campinas, São Paulo13083-862, Brazil
| | - Fernanda Angélica Sala
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo13084-971, Brazil
| | - Mayara M. Miyachiro
- Univ. Grenoble Alpes, CNRS, Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Structurale, Bacterial Pathogenesis Group, GrenobleF-38044, France
| | - Viviana Job
- Univ. Grenoble Alpes, CNRS, Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Structurale, Bacterial Pathogenesis Group, GrenobleF-38044, France
| | - Daniel Maragno Trindade
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo13084-971, Brazil
| | - Andréa Dessen
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, São Paulo13084-971, Brazil
- Univ. Grenoble Alpes, CNRS, Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Structurale, Bacterial Pathogenesis Group, GrenobleF-38044, France
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4
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Hauser N, Hirbawi J, Saban Golub M, Zabit S, Lichtenstein M, Lorberboum-Galski H. Exploiting the Endogenous Ubiquitin Proteasome System in Targeted Cancer Treatment. Cancers (Basel) 2022; 15. [PMID: 36612252 DOI: 10.3390/cancers15010256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/15/2022] [Accepted: 12/26/2022] [Indexed: 01/03/2023] Open
Abstract
To overcome the lack of specificity of cancer therapeutics and thus create a more potent and effective treatment, we developed a novel chimeric protein, IL2-Smurf2. Here, we describe the production of this chimeric IL2-Smurf2 protein and its variants, with inactive or over-active killing components. Using Western blots, we demonstrated the chimeric protein's ability to specifically enter target cells alone. After entering the cells, the protein showed biological activity, causing cell death that was not seen with an inactive variant, and that was shown to be apoptotic. The chimeric protein also proved to be active as an E3 ligase, as demonstrated by testing total ubiquitination levels along with targeted ubiquitination for degradation. Finally, we tested IL2-Smurf2 and its variants in an in vivo mouse model of leukemia and demonstrated its potential as a drug for the targeted treatment of cancer cells. In the course of this work, we established for the first time the feasibility of the use of Smurf2 as a killing component in chimeric targeting proteins. Utilizing the IL2 cytokine to target cells overexpressing IL-2R and Smurf2 to cause protein degradation, we were able to produce a chimeric protein with dual functionality which causes targeted cell death.
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Kechin AA, Ivanov AA, Kel AE, Kalmykov AS, Oskorbin IP, Boyarskikh UA, Kharpov EA, Bakharev SY, Oskina NA, Samuilenkova OV, Vikhlyanov IV, Kushlinskii NE, Filipenko ML. Prediction of EVT6-NTRK3-Dependent Papillary Thyroid Cancer Using Minor Expression Profile. Bull Exp Biol Med 2022; 173:252-256. [PMID: 35737155 DOI: 10.1007/s10517-022-05528-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Indexed: 10/17/2022]
Abstract
Solid tumors resulting from oncogenic stimulation of neurotrophin receptors (TRK) by chimeric proteins are a group of rare tumors of various localization that respond to therapy with targeted drugs entrectinib and larotrectinib. The standard method for detecting chimeric TRK genes in tumor samples today is considered to be next generation sequencing with the determination of the prime structure of the chimeric transcripts. We hypothesized that expression of the chimeric tyrosine kinase proteins in tumors can determine the specific transcriptomic profile of tumor cells. We detected differentially expressed genes allowing distinguishing between TRK-dependent tumors papillary thyroid cancer (TC) from other molecular variants of tumors of this type. Using PCR with reverse transcription (RT-PCR), we identified 7 samples of papillary TC carrying a EVT6-NTRK3 rearrangement (7/215, 3.26%). Using machine learning and the data extracted from TCGA, we developed of a recognition function for predicting the presence of rearrangement in NTRK genes based on the expression of 10 key genes: AUTS2, DTNA, ERBB4, HDAC1, IGF1, KDR, NTRK1, PASK, PPP2R5B, and PRSS1. The recognition function was used to analyze the expression data of the above genes in 7 TRK-dependent and 10 TRK-independent thyroid tumors obtained by RT-PCR. On the test samples from TCGA, the sensitivity was 72.7%, the specificity - 99.6%. On our independent validation samples tested by RT-PCR, sensitivity was 100%, specificity - 70%. We proposed an mRNA profile of ten genes that can classify TC in relation to the presence of driver NTRK-chimeric TRK genes with acceptable sensitivity and specificity.
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Affiliation(s)
- A A Kechin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | - A A Ivanov
- Altay Regional Oncological Center, Barnaul, Russia
| | - A E Kel
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | | | - I P Oskorbin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | - U A Boyarskikh
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | - E A Kharpov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | | | - N A Oskina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
| | | | | | - N E Kushlinskii
- N. N. Blokhin National Medical Research Center of Oncology, Ministry of Health of the Russian Federation, Moscow, Russia
| | - M L Filipenko
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia.
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König E, Gagliardi A, Riedmiller I, Andretta C, Tomasi M, Irene C, Frattini L, Zanella I, Berti F, Grandi A, Caproni E, Fantappiè L, Grandi G. Multi-Antigen Outer Membrane Vesicle Engineering to Develop Polyvalent Vaccines: The Staphylococcus aureus Case. Front Immunol 2021; 12:752168. [PMID: 34819933 PMCID: PMC8606680 DOI: 10.3389/fimmu.2021.752168] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/14/2021] [Indexed: 11/13/2022] Open
Abstract
Modification of surface antigens and differential expression of virulence factors are frequent strategies pathogens adopt to escape the host immune system. These escape mechanisms make pathogens a "moving target" for our immune system and represent a challenge for the development of vaccines, which require more than one antigen to be efficacious. Therefore, the availability of strategies, which simplify vaccine design, is highly desirable. Bacterial Outer Membrane Vesicles (OMVs) are a promising vaccine platform for their built-in adjuvanticity, ease of purification and flexibility to be engineered with foreign proteins. However, data on if and how OMVs can be engineered with multiple antigens is limited. In this work, we report a multi-antigen expression strategy based on the co-expression of two chimeras, each constituted by head-to-tail fusions of immunogenic proteins, in the same OMV-producing strain. We tested the strategy to develop a vaccine against Staphylococcus aureus, a Gram-positive human pathogen responsible for a large number of community and hospital-acquired diseases. Here we describe an OMV-based vaccine in which four S. aureus virulent factors, ClfAY338A, LukE, SpAKKAA and HlaH35L have been co-expressed in the same OMVs (CLSH-OMVsΔ60). The vaccine elicited antigen-specific antibodies with functional activity, as judged by their capacity to promote opsonophagocytosis and to inhibit Hla-mediated hemolysis, LukED-mediated leukocyte killing, and ClfA-mediated S. aureus binding to fibrinogen. Mice vaccinated with CLSH-OMVsΔ60 were robustly protected from S. aureus challenge in the skin, sepsis and kidney abscess models. This study not only describes a generalized approach to develop easy-to-produce and inexpensive multi-component vaccines, but also proposes a new tetravalent vaccine candidate ready to move to development.
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Affiliation(s)
- Enrico König
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | | | - Ilary Riedmiller
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Chiara Andretta
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Michele Tomasi
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Carmela Irene
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Luca Frattini
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Ilaria Zanella
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Francesco Berti
- Technical Research and Development, GlaxoSmithKline Vaccines, Siena, Italy
| | - Alberto Grandi
- ERC Vaccibiome Unit, Toscana Life Sciences Foundation, Siena, Italy.,Infectious Diseases and Cancer Immunotherapy Unit, BiOMViS Srl, Siena, Italy
| | - Elena Caproni
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
| | - Laura Fantappiè
- ERC Vaccibiome Unit, Toscana Life Sciences Foundation, Siena, Italy
| | - Guido Grandi
- Department of Cellular, Computational and Integrative Biology, University of Trento, Trento, Italy
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Celedon PAF, Leony LM, Oliveira UD, Freitas NEM, Silva ÂAO, Daltro RT, Santos EF, Krieger MA, Zanchin NIT, Santos FLN. Stability Assessment of Four Chimeric Proteins for Human Chagas Disease Immunodiagnosis. Biosensors (Basel) 2021; 11:289. [PMID: 34436091 DOI: 10.3390/bios11080289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/25/2021] [Accepted: 07/26/2021] [Indexed: 12/24/2022]
Abstract
The performance of an immunoassay relies on antigen-antibody interaction; hence, antigen chemical stability and structural integrity are paramount for an efficient assay. We conducted a functional, thermostability and long-term stability analysis of different chimeric antigens (IBMP), in order to assess effects of adverse conditions on four antigens employed in ELISA to diagnose Chagas disease. ELISA-based immunoassays have served as a model for biosensors development, as both assess molecular interactions. To evaluate thermostability, samples were heated and cooled to verify heat-induced denaturation reversibility. In relation to storage stability, the antigens were analyzed at 25 °C at different moments. Long-term stability tests were performed using eight sets of microplates sensitized. Antigens were structurally analyzed through circular dichroism (CD), dynamic light scattering, SDS-PAGE, and functionally evaluated by ELISA. Data suggest that IBMP antigens are stable, over adverse conditions and for over a year. Daily analysis revealed minor changes in the molecular structure. Functionally, IBMP-8.2 and IBMP-8.3 antigens showed reactivity towards anti-T. cruzi antibodies, even after 72 h at 25 °C. Long-term stability tests showed that all antigens were comparable to the control group and all antigens demonstrated stability for one year. Data suggest that the antigens maintained their function and structural characteristics even in adverse conditions, making them a sturdy and reliable candidate to be employed in future in vitro diagnostic tests applicable to different models of POC devices, such as modern biosensors in development.
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Grąźlewska W, Ferra B, Rudzińska M, Holec-Gąsior L. Borrelia burgdorferi BmpA-BBK32 and BmpA-BBA64: New Recombinant Chimeric Proteins with Potential Diagnostic Value. Pathogens 2021; 10:767. [PMID: 34207025 DOI: 10.3390/pathogens10060767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 11/17/2022] Open
Abstract
Currently, the diagnosis of Lyme disease is based mostly on two-tiered serologic testing. In the new generation of immunoenzymatic assays, antigens comprise whole-cell lysates of members of the Borrelia burgdorferi sensu lato (s.l.) species complex, with the addition of selected recombinant proteins. Due to the high diversity of members of the B. burgdorferi s.l. genospecies and the low degree of conservation among the amino acid sequences of their proteins, serodiagnostic methods currently in use are not sufficient for the correct diagnosis of borreliosis. Two divalent chimeric proteins (BmpA-BBK32 and BmpA-BBA64) were expressed in Escherichia coli. Following purification by one-step metal-affinity chromatography, preparations were obtained containing milligram levels of chimeric protein exhibiting electrophoretic purity in excess of 98%. Reactivity of the new chimeric proteins with specific human IgG antibodies was preliminarily determined by Western blot. For this purpose, 20 negative sera and 20 positive sera was used. The new chimeric proteins were highly reactive with IgG antibodies contained in the serum of patients suffering from borreliosis. Moreover, no immunoreactivity of chimeric proteins was observed with antibodies in the sera of healthy people. These promising results suggest that new chimeric proteins have the potential to discriminate between positive and negative sera.
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Karthik K, Negi J, Rathinam M, Saini N, Sreevathsa R. Exploitation of Novel Bt ICPs for the Management of Helicoverpa armigera (Hübner) in Cotton ( Gossypium hirsutum L.): A Transgenic Approach. Front Microbiol 2021; 12:661212. [PMID: 33995323 PMCID: PMC8116509 DOI: 10.3389/fmicb.2021.661212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/18/2021] [Indexed: 12/02/2022] Open
Abstract
Cotton is a commercial crop of global importance. The major threat challenging the productivity in cotton has been the lepidopteron insect pest Helicoverpa armigera or cotton bollworm which voraciously feeds on various plant parts. Biotechnological interventions to manage this herbivore have been a universally inevitable option. The advent of plant genetic engineering and exploitation of Bacillus thuringiensis (Bt) insecticidal crystal proteins (ICPs) marked the beginning of plant protection in cotton through transgenic technology. Despite phenomenal success and widespread acceptance, the fear of resistance development in insects has been a perennial concern. To address this issue, alternate strategies like introgression of a combination of cry protein genes and protein-engineered chimeric toxin genes came into practice. The utility of chimeric toxins produced by domain swapping, rearrangement of domains, and other strategies aid in toxins emerging with broad spectrum efficacy that facilitate the avoidance of resistance in insects toward cry toxins. The present study demonstrates the utility of two Bt ICPs, cry1AcF (produced by domain swapping) and cry2Aa (produced by codon modification) in transgenic cotton for the mitigation of H. armigera. Transgenics were developed in cotton cv. Pusa 8–6 by the exploitation of an apical meristem-targeted in planta transformation protocol. Stringent trait efficacy-based selective screening of T1 and T2 generation transgenic plants enabled the identification of plants resistant to H. armigera upon deliberate challenging. Evaluation of shortlisted events in T3 generation identified a total of nine superior transgenic events with both the genes (six with cry1AcF and three with cry2Aa). The transgenic plants depicted 80–100% larval mortality of H. armigera and 10–30% leaf damage. Molecular characterization of the shortlisted transgenics demonstrated stable integration, inheritance and expression of transgenes. The study is the first of its kind to utilise a non-tissue culture-based transformation strategy for the development of stable transgenics in cotton harbouring two novel genes, cry1AcF and cry2Aa for insect resistance. The identified transgenic events can be potential options toward the exploitation of unique cry genes for the management of the polyphagous insect pest H. armigera.
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Affiliation(s)
- Kesiraju Karthik
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| | - Jyotsana Negi
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| | - Maniraj Rathinam
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| | - Navinder Saini
- Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, India
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Arachchige SP, Henke W, Kalamvoki M, Stephens EB. Structural Domains of the Herpes Simplex Type 1 gD Protein that Restrict HIV-1 Particle Infectivity. J Virol 2021; 95:JVI. [PMID: 33536165 DOI: 10.1128/JVI.02355-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, we showed that the presence of the herpes simplex virus type 1 (HSV-1) gD glycoprotein but not gB potently restricted HIV-1 particle infectivity. This restriction was characterized by incorporation of HSV-1 gD and the exclusion of the HIV-1 gp120/gp41 from budding virus particles. To determine the structural domains involved in gD restriction of HIV-1, a series of deletion mutants and chimeric proteins between gD and the non-restrictive gB were generated. Our results show that deletion of the cytoplasmic tail domain (CTD) of gD or that replacement of the transmembrane domain (TMD) with the TMD from gB slightly reduced restriction activity. However, replacement of the gD CTD with that of gB resulted in lower cell surface expression, significantly less incorporation into HIV-1 particles, and inefficient restriction of the release of infectious HIV-1. Analysis of gB/gD chimeric proteins revealed that removal of the gB CTD or replacement with gD CTD resulted in enhanced surface expression and an increase in restriction activity. Finally, we show that expression of gD without other HSV-1 proteins resulted in gD fractionation into detergent resistant membranes (DRM) and that gD co-localized with the raft marker GM1, which may partially explain its incorporation into budding virus particles. Taken together, our results suggest that expression of gD at the cell surface is likely a major factor but that other intrinsic properties are also involved in the gD-mediated restriction of HIV-1 particle infectivity.IMPORTANCE Previously, we showed that unlike the HSV-1, the presence of the gD glycoprotein in virus producer cells but not gB potently restricted HIV-1 particle infectivity. To better understand the relationship between cell surface expression, virus incorporation and restriction of HIV-1, we analyzed a series of deletion mutants and chimeric proteins in which domains of gD and gB were swapped. Our results indicate that: a) gD/gB chimeras having the cytoplasmic domain (CTD) of gB significantly reduced cell surface expression, release from cells, incorporation into virus, and reduced HIV-1 restriction; b) removal of the gB CTD or replacement with the gD CTD resulted in better surface expression, incorporation into HIV-1, and enhanced restriction; and c) the transmembrane domain of gB can influence transport and ultimately effect incorporation of gB into HIV-1. Overall, these data support a role for gD surface expression as crucial to restriction of infectious HIV-1 release.
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11
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Sadeghi SJ, Di Nardo G, Gilardi G. Chimeric cytochrome P450 3A4 used for in vitro prediction of food-drug interactions. Biotechnol Appl Biochem 2020; 67:541-548. [PMID: 32713008 DOI: 10.1002/bab.1993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/18/2020] [Indexed: 12/26/2022]
Abstract
Inhibition of cytochrome P450 (CYP)-mediated drug metabolism by dietary substances is the main cause of drug-food interactions in humans. The present study reports on the in vitro inhibition assays of human CYP3A4 genetically linked to the reductase domain of bacterial BM3 of Bacillus megaterium (BMR) resulting in the chimeric protein CYP3A4-BMR. The activity of this chimeric enzyme was initially measured colorimetrically with erythromycin as the substrate where KM values similar to published data were determined. Subsequently, the inhibition assays with three different dietary products, grapefruit juice, curcumin, and resveratrol, were carried out with the chimeric enzyme both in solution and immobilized on electrode surfaces. For the solution studies, nicotinamide adenine dinucleotide phosphate was added as the electron donor, whereas the need for this cofactor was obviated in the immobilized enzyme as it was supplied by the electrode. Inhibition of the N-demethylation of erythromycin by CYP3A4-BMR chimera was measured at increasing concentrations of the different dietary compounds with calculated IC50 values of 0.5%, 31 μM, and 250 μM for grapefruit juice, curcumin, and resveratrol measured in solution compared with 0.7%, 24 μM, and 208 μM measured electrochemically, respectively. These data demonstrate the feasibility of the use of both CYP3A4-BMR chimera as well as bioelectrochemistry for in vitro studies of not only drug-food interactions but also prediction of adverse drug reactions in this important P450 enzyme.
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Affiliation(s)
- Sheila J Sadeghi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.,Centre for Nanostructured Interfaces and Surfaces, University of Torino, Torino, Italy
| | - Giovanna Di Nardo
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Gianfranco Gilardi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.,Centre for Nanostructured Interfaces and Surfaces, University of Torino, Torino, Italy
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Ho JSY, Angel M, Ma Y, Sloan E, Wang G, Martinez-Romero C, Alenquer M, Roudko V, Chung L, Zheng S, Chang M, Fstkchyan Y, Clohisey S, Dinan AM, Gibbs J, Gifford R, Shen R, Gu Q, Irigoyen N, Campisi L, Huang C, Zhao N, Jones JD, van Knippenberg I, Zhu Z, Moshkina N, Meyer L, Noel J, Peralta Z, Rezelj V, Kaake R, Rosenberg B, Wang B, Wei J, Paessler S, Wise HM, Johnson J, Vannini A, Amorim MJ, Baillie JK, Miraldi ER, Benner C, Brierley I, Digard P, Łuksza M, Firth AE, Krogan N, Greenbaum BD, MacLeod MK, van Bakel H, Garcìa-Sastre A, Yewdell JW, Hutchinson E, Marazzi I. Hybrid Gene Origination Creates Human-Virus Chimeric Proteins during Infection. Cell 2020; 181:1502-1517.e23. [PMID: 32559462 PMCID: PMC7323901 DOI: 10.1016/j.cell.2020.05.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 02/26/2020] [Accepted: 05/18/2020] [Indexed: 01/12/2023]
Abstract
RNA viruses are a major human health threat. The life cycles of many highly pathogenic RNA viruses like influenza A virus (IAV) and Lassa virus depends on host mRNA, because viral polymerases cleave 5'-m7G-capped host transcripts to prime viral mRNA synthesis ("cap-snatching"). We hypothesized that start codons within cap-snatched host transcripts could generate chimeric human-viral mRNAs with coding potential. We report the existence of this mechanism of gene origination, which we named "start-snatching." Depending on the reading frame, start-snatching allows the translation of host and viral "untranslated regions" (UTRs) to create N-terminally extended viral proteins or entirely novel polypeptides by genetic overprinting. We show that both types of chimeric proteins are made in IAV-infected cells, generate T cell responses, and contribute to virulence. Our results indicate that during infection with IAV, and likely a multitude of other human, animal and plant viruses, a host-dependent mechanism allows the genesis of hybrid genes.
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Affiliation(s)
- Jessica Sook Yuin Ho
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Matthew Angel
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Yixuan Ma
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Elizabeth Sloan
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Guojun Wang
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Carles Martinez-Romero
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Marta Alenquer
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Vladimir Roudko
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Liliane Chung
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Simin Zheng
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Max Chang
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Yesai Fstkchyan
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sara Clohisey
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Adam M Dinan
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 0SP, UK
| | - James Gibbs
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Robert Gifford
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Rong Shen
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Quan Gu
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Nerea Irigoyen
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 0SP, UK
| | - Laura Campisi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Cheng Huang
- Department of Pathology, the University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Nan Zhao
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Joshua D Jones
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 0SP, UK
| | | | - Zeyu Zhu
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Natasha Moshkina
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Léa Meyer
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Justine Noel
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Zuleyma Peralta
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Veronica Rezelj
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
| | - Robyn Kaake
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Brad Rosenberg
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bo Wang
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Jiajie Wei
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Slobodan Paessler
- Department of Pathology, the University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Helen M Wise
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Jeffrey Johnson
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK; Fondazione Human Technopole, Structural Biology Research Centre, 20157 Milan, Italy
| | | | - J Kenneth Baillie
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Emily R Miraldi
- Divisions of Immunobiology and Biomedical Informatics, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45257, USA
| | - Christopher Benner
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92037, USA
| | - Ian Brierley
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 0SP, UK
| | - Paul Digard
- The Roslin Institute, University of Edinburgh, Edinburgh EH25 9PS, UK
| | - Marta Łuksza
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 0SP, UK
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Benjamin D Greenbaum
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Megan K MacLeod
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, UK
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Adolfo Garcìa-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jonathan W Yewdell
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Edward Hutchinson
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK.
| | - Ivan Marazzi
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Arenaccio C, Chiozzini C, Ferrantelli F, Leone P, Olivetta E, Federico M. Exosomes in Therapy: Engineering, Pharmacokinetics and Future Applications. Curr Drug Targets 2020; 20:87-95. [PMID: 29779478 DOI: 10.2174/1389450119666180521100409] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/04/2018] [Accepted: 05/16/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND Eukaryotic cells release vesicles of different sizes under both physiological and pathological conditions. On the basis of the respective biogenesis, extracellular vesicles are classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are considered tools for innovative therapeutic interventions, especially when engineered with effector molecules. The delivery functions of exosomes are favored by a number of typical features. These include their small size (i.e., 50-200 nm), the membrane composition tightly similar to that of producer cells, lack of toxicity, stability in serum as well as other biological fluids, and accession to virtually any organ and tissue including central nervous system. However, a number of unresolved questions still affects the possible use of exosomes in therapy. Among these are the exact identification of both in vitro and ex vivo produced vesicles, their large-scale production and purification, the uploading efficiency of therapeutic macromolecules, and the characterization of their pharmacokinetics. OBJECTIVE Here, we discuss two key aspects to be analyzed before considering exosomes as a tool of delivery for the desired therapeutic molecule, i.e., techniques of engineering, and their in vivo biodistribution/ pharmacokinetics. In addition, an innovative approach aimed at overcoming at least part of the obstacles towards a safe and efficient use of exosomes in therapy will be discussed. CONCLUSION Several biologic features render exosomes an attractive tool for the delivery of therapeutic molecules. They will surely be a part of innovative therapeutic interventions as soon as few still unmet technical hindrances will be overcome.
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Affiliation(s)
- Claudia Arenaccio
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
| | - Chiara Chiozzini
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
| | - Flavia Ferrantelli
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
| | - Patrizia Leone
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
| | - Eleonora Olivetta
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
| | - Maurizio Federico
- National Center for Global Health, Istituto Superiore di Sanità (ISS), Viale Regina Elena 299, 00161, Rome, Italy
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Holec-Gąsior L, Ferra B, Grąźlewska W. Toxoplasma gondii Tetravalent Chimeric Proteins as Novel Antigens for Detection of Specific Immunoglobulin G in Sera of Small Ruminants. Animals (Basel) 2019; 9:ani9121146. [PMID: 31847285 PMCID: PMC6940879 DOI: 10.3390/ani9121146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Toxoplasma gondii infection leads to large economic losses in the sheep and goat industry worldwide and is considered to be one of the main causes of infectious ovine and caprine abortion. Moreover, in countries where sheep and goat meat are frequently consumed, T. gondii infection in small ruminants may also pose a public health risk. Due to its medical and veterinary importance, it is essential to study the seroprevalence of T. gondii infection among farm animals and humans. This requires the development of new, low-cost diagnostic methods such as enzyme immunoassays based on recombination antigens. Thus, the study aimed to evaluate the reactivity of four different tetravalent chimeric proteins containing immunodominant regions from the AMA1 (apical membrane antigen 1), SAG2 (surface antigen 2), GRA1 (dense granule antigen 1), GRA2 (dense granule antigen 2), and ROP1 (rhoptry antigen 1) T. gondii antigens with specific IgG from the sera of small ruminants. The results demonstrate that an IgG ELISA (enzyme-linked immunosorbent assay) based on one of these chimeric proteins (AMA1-SAG2-GRA1-ROP1) may be a useful test for the determination of T. gondii infection in small ruminants. Abstract The detection of Toxoplasma gondii infection in small ruminants has important significance for public health and veterinary medicine. This study, for the first time, describes the reactivity of four tetravalent chimeric proteins (AMA1N-SAG2-GRA1-ROP1, AMA1C-SAG2-GRA1-ROP1, AMA1-SAG2-GRA1-ROP1, and SAG2-GRA1-ROP1-GRA2) containing immunodominant regions from the AMA1 (apical membrane antigen 1), SAG2 (surface antigen 2), GRA1 (dense granule antigen 1), GRA2 (dense granule antigen 2), and ROP1 (rhoptry antigen 1) with specific IgG antibodies from the sera of small ruminants with the use of an indirect enzyme-linked immunosorbent assay (ELISA). The reactivity of individual chimeric antigens was analyzed in relation to the results obtained in IgG ELISA based on a Toxoplasma lysate antigen (TLA). All chimeric proteins were characterized by high specificity (between 96.39% to 100%), whereas the sensitivity of the IgG ELISAs was variable (between 78.49% and 96.77%). The highest sensitivity was observed in the IgG ELISA test based on the AMA1-SAG2-GRA1-ROP1. These data demonstrate that this chimeric protein can be a promising serodiagnostic tool for T. gondii infection in small ruminants.
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Pérez-Alós L, Bayarri-Olmos R, Skjoedt MO, Garred P. Combining MAP-1:CD35 or MAP-1:CD55 fusion proteins with pattern-recognition molecules as novel targeted modulators of the complement cascade. FASEB J 2019; 33:12723-12734. [PMID: 31469600 DOI: 10.1096/fj.201901643r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Dysregulation of the complement system is involved in the pathogenesis of several diseases, and its inhibition has been shown to be a feasible therapeutic option. Therefore, there is an interest in the development of complement modulators to treat complement activation-related inflammatory pathologies. Mannose-binding lectin (MBL)/ficolin/collectin-associated protein-1 (MAP-1) is a regulatory molecule of the lectin pathway (LP), whereas complement receptor 1 (CD35) and decay-accelerating factor (CD55) are membrane-anchored regulators with effects on the central effector molecule C3. In this study, we developed 2 novel soluble chimeric inhibitors by fusing MAP-1 to the 3 first domains of CD35 (CD351-3) or the 4 domains of CD55 (CD551-4) to modulate the complement cascade at 2 different stages. The constructs showed biologic properties similar to those of the parent molecules. In functional complement activation assays, the constructs were very efficient in inhibiting LP activation at the level of C3 and in the formation of terminal complement complex. This activity was enhanced when coincubated with recombinant LP recognition molecules MBL and ficolin-3. Recombinant MAP-1 fusion proteins, combined with recombinant LP recognition molecules to target sites of inflammation, represent a novel and effective therapeutic approach involving the initiation and the central and terminal effector functions of the complement cascade.-Pérez-Alós, L., Bayarri-Olmos, R., Skjoedt, M.-O., Garred, P. Combining MAP-1:CD35 or MAP-1:CD55 fusion proteins with pattern-recognition molecules as novel targeted modulators of the complement cascade.
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Affiliation(s)
- Laura Pérez-Alós
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Copenhagen, Denmark
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Copenhagen, Denmark
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet, Copenhagen, Denmark
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Wanitchang A, Saenboonrueng J, Kaewborisuth C, Srisutthisamphan K, Jongkaewwattana A. A Single V672F Substitution in the Spike Protein of Field-Isolated PEDV Promotes Cell⁻Cell Fusion and Replication in VeroE6 Cells. Viruses 2019; 11:v11030282. [PMID: 30897856 PMCID: PMC6466060 DOI: 10.3390/v11030282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 02/07/2023] Open
Abstract
While porcine epidemic diarrhea virus (PEDV) infects and replicates in enterocytes lining villi of neonatal piglets with high efficiency, naturally isolated variants typically grow poorly in established cell lines, unless adapted by multiple passages. Cells infected with most cell-adapted PEDVs usually displayed large syncytia, a process triggered by the spike protein (S). To identify amino acids responsible for S-mediated syncytium formation, we constructed and characterized chimeric S proteins of the cell-adapted variant, YN144, in which the receptor binding domain (RBD) and S1/S2 cleavage site were replaced with those of a poorly culturable field isolate (G2). We demonstrated that the RBD, not the S1/S2 cleavage site, is critical for syncytium formation mediated by chimeric S proteins. Further mutational analyses revealed that a single mutation at the amino acid residue position 672 (V672F) could enable the chimeric S with the entire RBD derived from the G2 strain to trigger large syncytia. Moreover, recombinant PEDV viruses bearing S of the G2 strain with the single V672F substitution could induce extensive syncytium formation and replicate efficiently in VeroE6 cells stably expressing porcine aminopeptidase N (VeroE6-APN). Interestingly, we also demonstrated that while the V672F mutation is critical for the syncytium formation in VeroE6-APN cells, it exerts a minimal effect in Huh-7 cells, thereby suggesting the difference in receptor preference of PEDV among host cells.
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Affiliation(s)
- Asawin Wanitchang
- Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
| | - Janya Saenboonrueng
- Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
| | - Challika Kaewborisuth
- Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
| | - Kanjana Srisutthisamphan
- Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
| | - Anan Jongkaewwattana
- Virology and Cell Technology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani 12120, Thailand.
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Tramonti A, Nardella C, di Salvo ML, Pascarella S, Contestabile R. The MocR-like transcription factors: pyridoxal 5'-phosphate-dependent regulators of bacterial metabolism. FEBS J 2018; 285:3925-3944. [PMID: 29974999 DOI: 10.1111/febs.14599] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/14/2018] [Accepted: 06/25/2018] [Indexed: 12/22/2022]
Abstract
Many biological functions played by current proteins were not created by evolution from scratch, rather they were obtained combining already available protein scaffolds. This is the case of MocR-like bacterial transcription factors (MocR-TFs), a subclass of GntR transcription regulators, whose structure is the outcome of the fusion between DNA-binding proteins and pyridoxal 5'-phosphate (PLP)-dependent enzymes. The resultant chimeras can count on the properties of both protein classes, i.e. the capability to recognize specific DNA sequences and to bind PLP and amino-compounds; it is the modulation of such binding properties to confer to MocR-TFs chimeras the ability to interact with effector molecules and DNA so as to regulate transcription. MocR-TFs control different metabolic processes involving vitamin B6 and amino acids, which are canonical ligands of PLP-dependent enzymes. However, MocR-TFs are also implicated in the metabolism of compounds that are not substrates of PLP-dependent enzymes, such as rhizopine and ectoine. Genomic analyses show that MocR-TFs are widespread among eubacteria, implying an essential role in their metabolism and highlighting the scarcity of our knowledge on these important players in microbial metabolism. Although MocR-TFs have been discovered 15 years ago, the research activity on these transcriptional regulators has only recently intensified, producing a wealth of information that needs to be brought back to general principles. This is the main task of this review, which reports and analyses the available information concerning MocR-TFs functional role, structural features, interaction with effector molecules and the characteristics of DNA transcriptional factor-binding sites of MocR-based regulatory systems.
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Affiliation(s)
- Angela Tramonti
- Istituto di Biologia e Patologia Molecolari, Consiglio Nazionale delle Ricerche, Roma, Italy.,Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Caterina Nardella
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Martino L di Salvo
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Stefano Pascarella
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
| | - Roberto Contestabile
- Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza Università di Roma, Italy
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Patidar M, Yadav N, Dalai SK. Influence of Length and Amino Acid Composition on Dimer Formation of Immunoglobulin based Chimera. Curr Pharm Des 2018; 24:1211-1223. [PMID: 29046143 DOI: 10.2174/1381612823666171018115206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/05/2017] [Accepted: 10/11/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND The dimeric immunoglobulin (Ig) chimeras used for drug targeting and delivery are preferred biologics over their monomeric forms. Designing these Ig chimeras involves critical selection of a suitable Ig base that ensures dimer formation. In the present study, we systematically analyzed several factors that influence the formation of dimeric chimera. We designed and predicted 608 cytokine-Ig chimeras where we tested the contributions of (1) different domains of Ig constant heavy chain, (2) length of partner proteins, (3) amino acid (AA) composition and (4) position of cysteine in the formation of homodimer. METHOD The sequences of various Ig and cytokines were procured from Uniprot database, fused and submitted to COTH (CO-THreader) server for the prediction of dimer formation. Contributions of different domains of Ig constant heavy chain, length of chimeric proteins, AA composition and position of cysteine to the homodimer formation of 608 cytokine-Ig chimeras were tested. Various in silico approaches were adopted for validating the in silico findings. Experimentally we also validated our approach by expressing the chimeric design of shorter cytokine with Ig domain in CHO cells and analyzing the protein by SDS-PAGE. RESULTS Our results advocate that while the CH1 region and the Hinge region of Ig heavy chain are critical, the length of partner proteins also crucially influences homodimer formation of the Ig-based chimera. We also report that the CH1 domain of Ig is not required for dimer formation of Ig based chimera in the presence of larger partner proteins. For shorter partner proteins fused to CH2-CH3, careful selection of partner sequence is critical, particularly the hydrophobic AA composition, cysteine content & their positions, disulphide bond formation property, and the linker sequences. We validated our in silico observation by various bioinformatics tools and checked the ability of chimeras to bind with the receptors of native protein by docking studies. As a proof of concept, we have expressed the chimeric proteins in CHO cells and found that our design favors the synthesis of dimeric proteins. CONCLUSION Our structural prediction study suggests that extra amino acids in the range of 15-20 added to the CH2 domain of Ig is a critical requirement to make homodimer. This information from our study will have implication in designing efficacious homodimeric chimera.
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Affiliation(s)
- Manoj Patidar
- Institute of Science, Nirma University, Ahmedabad-382481, India
| | - Naveen Yadav
- Institute of Science, Nirma University, Ahmedabad-382481, India
| | - Sarat K Dalai
- Institute of Science, Nirma University, Ahmedabad-382481, India
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19
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Abstract
INTRODUCTION The architecture of the complement system has evolved during the last 600 - 700 million years to become an amazingly efficient and highly versatile alerting and cell killing device. Under physiological conditions, this system acts as a well-regulated cascade, protecting the organism against pathogens and participating during the initial defensive steps of humoral and cellular response. The unregulated activation of this system may cause or even aggravate diseases; therefore, its modulation is currently considered of high importance. AREAS COVERED This review is a critical examination on patent literature published between 2008 and 2013. An insight is provided about the discovery and development of novel therapeutic agents. These include macromolecules, polysaccharides and proteins, specific antibodies, and hybrid or chimeric products. Peptides and low molecular weight organic compounds (natural products, their derivatives and fully synthetic molecules) are covered as well. EXPERT OPINION The search of specific inhibitors of the complement cascade has become one of the Holy Grails of Medicinal Chemistry for the last 30 - 40 years, with very few cases of success. Some highly specific macromolecules are currently available as modulators of the complement. However, there is still a marked need to find new, more specific, efficient and convenient alternatives, especially suited for chronic administration, including novel inexpensive small molecule inhibitors. Analogously, despite the initial success with specific monoclonal antibodies, a vast territory is awaiting to be explored and conquered, regarding the regulation of complement activation by antibody-mediated blockage of specific polypeptides or receptor sites.
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Affiliation(s)
- Enrique L Larghi
- Universidad Nacional de Rosario, Instituto de Química Rosario (IQUIR, CONICET-UNR) and Departamento Química Orgánica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Suipacha 531, S2002LRK Rosario , República Argentina
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20
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Kong Y, Zhang H, Chen X, Zhang W, Zhao C, Wang N, Wu N, He Y, Nan G, Zhang H, Wen S, Deng F, Liao Z, Wu D, Zhang J, Qin X, Haydon RC, Luu HH, He TC, Zhou L. Destabilization of heterologous proteins mediated by the GSK3β phosphorylation domain of the β-catenin protein. Cell Physiol Biochem 2013; 32:1187-99. [PMID: 24335169 PMCID: PMC4064945 DOI: 10.1159/000354518] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2013] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND AND AIMS Wnt/β-catenin signaling plays important roles in development and cellular processes. The hallmark of canonical Wnt signaling activation is the stabilization of β-catenin protein in cytoplasm and/or nucleus. The stability of β-catenin is the key to its biological functions and is controlled by the phosphorylation of its amino-terminal degradation domain. Aberrant activation of β-catenin signaling has been implicated in the development of human cancers. It has been recently suggested that GSK3βmay play an essential role in regulating global protein turnover. Here, we investigate if the GSK3β phosphorylation site-containing degradation domain of β-catenin is sufficient to destabilize heterologous proteins. METHODS AND RESULTS We engineer chimeric proteins by fusing β-catenin degradation domain at the N- and/or C-termini of the enhanced green fluorescent protein (eGFP). In both transient and stable expression experiments, the chimeric GFP proteins exhibit a significantly decreased stability, which can be effectively antagonized by lithium and Wnt1. An activating mutation in the destruction domain significantly stabilizes the fusion protein. Furthermore, GSK3 inhibitor SB-216763 effectively increases the GFP signal of the fusion protein. Conversely, the inhibition of Wnt signaling with tankyrase inhibitor XAV939 results in a decrease in GFP signal of the fusion proteins, while these small molecules have no significant effects on the mutant destruction domain-GFP fusion protein. CONCLUSION Our findings strongly suggest that the β-catenin degradation domain may be sufficient to destabilize heterologous proteins in Wnt signaling-dependent manner. It is conceivable that the chimeric GFP proteins may be used as a functional reporter to measure the dynamic status of β-catenin signaling, and to identify potential anticancer drugs that target β-catenin signaling.
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Affiliation(s)
- Yuhan Kong
- The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
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21
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Nyman E, Franzén B, Nolting A, Klement G, Liu G, Nilsson M, Rosén A, Björk C, Weigelt D, Wollberg P, Karila P, Raboisson P. In vitro pharmacological characterization of a novel TRPA1 antagonist and proof of mechanism in a human dental pulp model. J Pain Res 2013; 6:59-70. [PMID: 23403691 PMCID: PMC3565573 DOI: 10.2147/jpr.s37567] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AZ465 is a novel selective transient receptor potential cation channel, member A1 (TRPA1) antagonist identified during a focused drug discovery effort. In vitro, AZ465 fully inhibits activation by zinc, O-chlorobenzylidene malononitrile (CS), or cinnamaldehyde of the human TRPA1 channel heterologously expressed in human embryonic kidney cells. Our data using patch-clamp recordings and mouse/human TRPA1 chimeras suggest that AZ465 binds reversibly in the pore region of the human TRPA1 channel. Finally, in an ex vivo model measuring TRPA1 agonist-stimulated release of neuropeptides from human dental pulp biopsies, AZD465 was able to block 50%–60% of CS-induced calcitonin gene-related peptide release, confirming that AZ465 inhibits the native human TRPA1 channel in neuronal tissue.
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Affiliation(s)
- Eva Nyman
- Neuroscience, Innovative Medicines CNS/Pain, AstraZeneca R&D, Södertälje, Sweden
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22
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Abstract
To overcome the limitations of traditionally used autografts, allografts and, to a lesser extent, synthetic materials, there is the need to develop a new generation of scaffolds with adequate mechanical and structural support, control of cell attachment, migration, proliferation and differentiation and with bio-resorbable features. This suite of properties would allow the body to heal itself at the same rate as implant degradation. Genetic engineering offers a route to this level of control of biomaterial systems. The possibility of expressing biological components in nature and to modify or bioengineer them further, offers a path towards multifunctional biomaterial systems. This includes opportunities to generate new protein sequences, new self-assembling peptides or fusions of different bioactive domains or protein motifs. New protein sequences with tunable properties can be generated that can be used as new biomaterials. In this review we address some of the most frequently used proteins for tissue engineering and biomedical applications and describe the techniques most commonly used to functionalize protein-based biomaterials by combining them with bioactive molecules to enhance biological performance. We also highlight the use of genetic engineering, for protein heterologous expression and the synthesis of new protein-based biopolymers, focusing the advantages of these functionalized biopolymers when compared with their counterparts extracted directly from nature and modified by techniques such as physical adsorption or chemical modification.
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Affiliation(s)
- Sílvia Gomes
- 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal
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23
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Chung DH, Min Z, Wang BC, Kushner SR. Single amino acid changes in the predicted RNase H domain of Escherichia coli RNase G lead to complementation of RNase E deletion mutants. RNA 2010; 16:1371-1385. [PMID: 20507976 PMCID: PMC2885686 DOI: 10.1261/rna.2104810] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 04/12/2010] [Indexed: 05/29/2023]
Abstract
The endoribonuclease RNase E of Escherichia coli is an essential enzyme that plays a major role in all aspects of RNA metabolism. In contrast, its paralog, RNase G, seems to have more limited functions. It is involved in the maturation of the 5' terminus of 16S rRNA, the processing of a few tRNAs, and the initiation of decay of a limited number of mRNAs but is not required for cell viability and cannot substitute for RNase E under normal physiological conditions. Here we show that neither the native nor N-terminal extended form of RNase G can restore the growth defect associated with either the rne-1 or rneDelta1018 alleles even when expressed at very high protein levels. In contrast, two distinct spontaneously derived single amino acid substitutions within the predicted RNase H domain of RNase G, generating the rng-219 and rng-248 alleles, result in complementation of the growth defect associated with various RNase E mutants, suggesting that this region of the two proteins may help distinguish their in vivo biological activities. Analysis of rneDelta1018/rng-219 and rneDelta1018/rng-248 double mutants has provided interesting insights into the distinct roles of RNase E and RNase G in mRNA decay and tRNA processing.
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Affiliation(s)
- Dae-hwan Chung
- Department of Genetics, University of Georgia, Athens, Georgia 30602, USA
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Mariño-Ramírez L, Hu JC. Isolation and mapping of self-assembling protein domains encoded by the Saccharomyces cerevisiae genome using lambda repressor fusions. Yeast 2002; 19:641-50. [PMID: 11967834 PMCID: PMC1955323 DOI: 10.1002/yea.867] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Understanding how proteins are able to form stable complexes is of fundamental interest from the perspective of protein structure and function. Here we show that lambda repressor fusions can be used to identify and characterize homotypic interaction domains encoded by the genome of Saccharomyces cerevisiae, using a selection for polypeptides that can drive the assembly of the DNA binding domain of bacteriophage lambda repressor. Three high complexity libraries were constructed by cloning random fragments of S. cerevisiae DNA as lambda repressor fusions. Repressor fusions encoding homotypic interactions were recovered, identifying oligomerization units in 35 yeast proteins. Seventeen of these interaction domains have not been previously reported, while the other 18 represent homotypic interactions that have been characterized at varying levels of detail. The novel interactions include several predicted coiled-coils as well as domains of unknown structure. With the availability of genomic sequences it should be possible to apply this approach, which provides information about protein-protein interactions that is complementary to that obtained from yeast two-hybrid screens, on a genome-wide scale in yeast or other organisms where large-scale protein-protein interaction data is not available.
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Affiliation(s)
- Leonardo Mariño-Ramírez
- Department of Biochemistry and Biophysics, Center for Advanced Biomolecular Research, Texas A&M University, College Station, TX 77843-2128, USA
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Zhou J, Weiner H. The N-terminal portion of mature aldehyde dehydrogenase affects protein folding and assembly. Protein Sci 2001; 10:1490-7. [PMID: 11468345 PMCID: PMC2374079 DOI: 10.1110/ps.5301] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2001] [Revised: 04/19/2001] [Accepted: 04/26/2001] [Indexed: 10/16/2022]
Abstract
Human liver cytosolic (ALDH1) and mitochondrial (ALDH2) aldehyde dehydrogenases are both encoded in the nucleus and synthesized in the cytosol. ALDH1 must fold in the cytosol, but ALDH2 is first synthesized as a precursor and must remain unfolded during import into mitochondria. The two mature forms share high identity (68%) at the protein sequence level except for the first 21 residues (14%); their tertiary structures were found to be essentially identical. ALDH1 folded faster in vitro than ALDH2 and could assemble to tetramers while ALDH2 remained as monomers. Import assay was used as a tool to study the folding status of ALDH1 and ALDH2. pALDH1 was made by fusing the presequence of precursor ALDH2 to the N-terminal end of ALDH1. Its import was reduced about 10-fold compared to the precursor ALDH2. The exchange of the N-terminal 21 residues from the mature portion altered import, folding, and assembly of precursor ALDH1 and precursor ALDH2. More of chimeric ALDH1 precursor was imported into mitochondria compared to its parent precursor ALDH1. The import of chimeric ALDH2 precursor, the counterpart of chimeric ALDH1 precursor, was reduced compared to its parent precursor ALDH2. Mature ALDH1 proved to be more stable against urea denaturation than ALDH2. Urea unfolding improved the import of precursor ALDH1 and the chimeric precursors but not precursor ALDH2, consistent with ALDH1 and the chimeric ALDHs being more stable than ALDH2. The N-terminal segment of the mature protein, and not the presequence, makes a major contribution to the folding, assembly, and stability of the precursor and may play a role in folding and hence the translocation of the precursor into mitochondria.
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Affiliation(s)
- J Zhou
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153, USA
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Abstract
As a step toward selecting folded proteins from libraries of randomized sequences, we have designed a 'loop entropy reduction'-based phage-display method. The basic premise is that insertion of a long disordered sequence into a loop of a host protein will substantially destabilize the host because of the entropic cost of closing a loop in a disordered chain. If the inserted sequence spontaneously folds into a stable structure with the N and C termini close in space, however, this entropic cost is diminished. The host protein function can, therefore, be used to select folded inserted sequences without relying on specific properties of the inserted sequence. This principle is tested using the IgG binding domain of protein L and the lck SH2 domain as host proteins. The results indicate that the loop entropy reduction screen is capable of discriminating folded from unfolded sequences when the proper host protein and insertion point are chosen.
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Affiliation(s)
- P Minard
- Department of Biochemistry, Howard Hughes Medical Institute, University of Washington, Seattle, Washington 98195, USA
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Abstract
The display of peptide segments on the surface of bacteria offers many new and exciting applications in biotechnology and medical research. Fimbria-assisted display of heterologous sequences is a paradigm for chimeric organelle display on bacteria. Fimbriae are particularly attractive candidates for epitope display for several reasons: (1) they are present in extremely high numbers at the cell surface, (2) they are strong immunogens, (3) they possess inherent adhesive properties, and (4) they can be easily purified. The majority of work dealing with fimbria-assisted peptide display has been focused on the development of recombinant vaccines. A number of different fimbrial types have been used to display immune-relevant sectors of various foreign proteins. Chimeric fimbrial vaccines can be used in the context of purified proteins, however the potential also exists to exploit this technology for the development of live recombinant vaccines. Work has also been performed demonstrating the amenability of fimbriae towards the powerful technology of random peptide display. This review summarises the current state of research in this field.
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Affiliation(s)
- P Klemm
- Department of Microbiology, Technical University of Denmark, Lyngby.
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Peraus GC, Masters CL, Beyreuther K. Late compartments of amyloid precursor protein transport in SY5Y cells are involved in beta-amyloid secretion. J Neurosci 1997; 17:7714-24. [PMID: 9315893 PMCID: PMC6793894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Amyloid plaques, composed mainly of the 39-43 amino acid betaA4 peptide, are a characteristic feature of Alzheimer's disease. Generation of betaA4 by proteolytic processing of the amyloid precursor protein (APP) is thought to occur in a pathway that includes the activity of two as yet unknown proteases, with beta-secretase cleaving at the N terminus and gamma-secretase releasing the C terminus of betaA4. Inhibition studies and the finding that cell surface APP can serve as a direct precursor of betaA4 suggest that the endosomal/lysosomal compartment is involved in the proteolysis of APP into betaA4. In this study we targeted APP695 chimeric proteins directly into the endosomal/lysosomal compartment. This decreased the amount of released betaA4, while the generation of the betaA4 N terminus continued. APP695 proteins were constructed also, which carried sorting signals responsible for recycling between the trans-Golgi network (TGN) and the cell surface. These proteins were processed into secreted betaA4 at even higher levels than wild-type APP695. Moreover, retention of APP695 proteins in the endoplasmic reticulum led to neither betaA4 secretion nor to processing by beta-secretase in human SH-SY5Y neuroblastoma cells. These data suggest that a beta-cleavage activity resides in a late endosomal compartment and that a gamma-cleavage occurs in early endosomes, resulting in the generation of betaA4 peptides with the majority ending at residue 40.
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Affiliation(s)
- G C Peraus
- Center for Molecular Biology Heidelberg, The University of Heidelberg, D-69120 Heidelberg, Germany
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29
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Abstract
We investigated the molecular basis for Ca-dependent inactivation of the cardiac L-type Ca channel. Transfection of HEK293 cells with the wild-type alpha or its 3' deletion mutant (alpha) produced channels that exhibited prominent Ca-dependent inactivation. To identify structural regions of alpha involved in this process, we analyzed chimeric alpha subunits in which one of the major intracellular domains of alpha was replaced by the corresponding region from the skeletal muscle alpha subunit (which lacks Ca-dependent inactivation). Replacing the NH terminus or the III-IV loop of alpha with its counterpart from alpha had no appreciable effect on Ca channel inactivation. In contrast, replacing the I-II loop of alpha with the corresponding region from alpha dramatically slowed the inactivation of Ba currents while preserving Ca-dependent inactivation. A similar but less pronounced result was obtained with a II-III loop chimera. These results suggest that the I-II and II-III loops of alpha may participate in the mechanism of Ca-dependent inactivation. Replacing the final 80% of the COOH terminus of alpha with the corresponding region from alpha completely eliminated Ca-dependent inactivation without affecting inactivation of Ba currents. Significantly, Ca-dependent inactivation was restored to this chimera by deleting a nonconserved, 211-amino acid segment from the end of the COOH terminus. These results suggest that the distal COOH terminus of alpha can block Ca-dependent inactivation, possibly by interacting with other proteins or other regions of the Ca channel. Our findings suggest that structural determinants of Ca-dependent inactivation are distributed among several major cytoplasmic domains of alpha.
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Affiliation(s)
- B Adams
- Department of Physiology and Biophysics, University of Iowa, Iowa City, Iowa 52242, USA.
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