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Kim IS, Yoon SJ, Park YJ, Lee HB. Inhibitory effect of ephedrannins A and B from roots of Ephedra sinica STAPF on melanogenesis. Biochim Biophys Acta Gen Subj 2015; 1850:1389-96. [DOI: 10.1016/j.bbagen.2015.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 03/30/2015] [Accepted: 04/01/2015] [Indexed: 10/23/2022]
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2
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Lingeman RG, Hickey RJ, Malkas LH. Expression of a novel peptide derived from PCNA damages DNA and reverses cisplatin resistance. Cancer Chemother Pharmacol 2014; 74:981-93. [PMID: 25190177 DOI: 10.1007/s00280-014-2574-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 08/21/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND An 8 amino acid peptide sequence derived from proliferating cell nuclear antigen (PCNA) has been shown to effectively kill several breast cancer and neuroblastoma cell lines when added exogenously to cell cultures. METHODS In this study, the expression of the 8 amino acid peptide sequence (caPeptide) was placed under control of a tetracycline responsive promoter in MDA-MB-231 cells. RESULTS Endogenous expression of the peptide resulted in an increase in genomic DNA damage. CaPeptide induction combined with treatment of sublethal doses of cisplatin resulted in a marked increase in death of the cisplatin-resistant MDA-MB-231 cell line. CaPeptide was found to interact with POLD3, one of the subunits of DNA polymerase delta necessary for binding to PCNA. CONCLUSION These results suggest an important line of inquiry into the possible role that caPeptide might play in the reversal of cisplatin resistance in breast and other cancers. This is of particular interest in those cancers where cisplatin is the first line of chemotherapy and where the acquisition of resistance is a common malady.
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Affiliation(s)
- Robert G Lingeman
- Department of Molecular Biology, Beckman Research Institute of the City of Hope, 1450 E. Duarte Rd., Duarte, CA, 91010, USA,
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3
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Liu L, Abdel Motaal B, Schmidt-Supprian M, Pohl NLB. Multigram synthesis of isobutyl-β-C-galactoside as a substitute of isopropylthiogalactoside for exogenous gene induction in mammalian cells. J Org Chem 2012; 77:1539-46. [PMID: 22283618 DOI: 10.1021/jo2024569] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Herein we report that isobutyl-β-C-galactoside (IBCG) is also a promising inducer of gene expression in mammalian cells and report a new synthetic route to the compound that should make obtaining the multigram quantities of material required for animal studies more feasible. A convenient synthesis of IBCG, an inducer of genes controlled by the lac operon system in bacterial cells, was achieved in 5 steps from galactose in 81% overall yield without any chromatographic separation steps. An optimized microwave-assisted reaction at high concentration was key to making the C-glycosidic linkage. A Wittig reaction on a per-O-silylated rather than per-O-acetylated or -benzylated substrate proved most effective in installing the final carbon atom.
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Affiliation(s)
- Lin Liu
- Department of Chemistry, Plant Sciences Institute, Hach Hall, Iowa State University, Ames, Iowa 50011-3111, USA
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4
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Milk L, Daber R, Lewis M. Functional rules for lac repressor-operator associations and implications for protein-DNA interactions. Protein Sci 2010; 19:1162-72. [PMID: 20512969 DOI: 10.1002/pro.389] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The Lac repressor has been used as a tool to understand protein-DNA recognition for many years. Recent experiments have demonstrated the ability of the Lac repressor to control gene expression in various eukaryotic systems, making the quest for an arsenal of protein-DNA binding partners desirable for potential therapeutic applications. Here, we present the results of the most exhaustive screen of Lac repressor-DNA binding partners to date, resulting in the elucidation of functional rules for Lac-DNA binding. Even within the confines of a single protein-DNA scaffold, modes of binding of different protein-DNA partners are sufficiently diverse so as to prevent elucidation of generalized rules for recognition for a single protein, much less an entire protein family.
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Affiliation(s)
- Leslie Milk
- Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6059, USA
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5
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Daber R, Lewis M. Towards evolving a better repressor. Protein Eng Des Sel 2009; 22:673-83. [PMID: 19729374 PMCID: PMC2763795 DOI: 10.1093/protein/gzp051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 07/27/2009] [Accepted: 07/27/2009] [Indexed: 11/13/2022] Open
Abstract
Transcriptional regulation is an essential component of all metabolic pathways. At the most basic level, a protein binds to a particular DNA sequence (operator) on the genome and either positively or negatively alters the level of transcription. Together, the protein and its operator form an epigenetic switch that regulates gene expression. In an effort to produce a 'better' switch, we have discovered novel facets of the lac operon that are responsible for optimal functionality. We have uncovered a relationship between operator binding affinity and inducibility and demonstrated that the operator DNA is not a passive component of a genetic switch; it is responsible for establishing binding affinity, specificity as well as translational efficiency. In addition, an operator's directionality can indirectly affect gene expression. Unraveling the basic properties of this classical epigenetic switch demonstrates that multiple factors must be optimized in designing a better switch.
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Affiliation(s)
| | - Mitchell Lewis
- Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, 37th and Hamilton Walk, Philadelphia, PA 19104-6059, USA
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6
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Bäckman CM, Zhang Y, Malik N, Shan L, Hoffer BJ, Westphal H, Tomac AC. Generalized tetracycline induced Cre recombinase expression through the ROSA26 locus of recombinant mice. J Neurosci Methods 2009; 176:16-23. [DOI: 10.1016/j.jneumeth.2008.08.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 08/14/2008] [Accepted: 08/16/2008] [Indexed: 10/21/2022]
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7
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Morozov A. Conditional gene expression and targeting in neuroscience research. ACTA ACUST UNITED AC 2008; Chapter 4:Unit 4.31. [PMID: 18633998 DOI: 10.1002/0471142301.ns0431s44] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recently developed techniques for spatially and temporally controlled genetic manipulations based on regulated homologous recombination and/or transcription are extensively used in brain research. In addition to being important for testing the role of specific proteins in the central nervous system, these techniques allow analysis of brain functions at the neuronal circuit level. This overview discusses principles of conditional inactivation and expression of genes, and their specific applications to studies of the mammalian brain.
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Affiliation(s)
- Alexei Morozov
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, National Institute of Mental Health, Bethesda, Maryland, USA
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8
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Couderc B, Penary M, Tohfe M, Pradines A, Casteignau A, Berg D, Favre G. Reversible inactivation of the transcriptional function of P53 protein by farnesylation. BMC Biotechnol 2006; 6:26. [PMID: 16732889 PMCID: PMC1481662 DOI: 10.1186/1472-6750-6-26] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Accepted: 05/29/2006] [Indexed: 11/29/2022] Open
Abstract
Background The use of integrating viral vectors in Gene therapy clinical trials has pointed out the problem of the deleterous effect of the integration of the ectopic gene to the cellular genome and the safety of this strategy. We proposed here a way to induce the death of gene modified cells upon request by acting on a pro-apoptotic protein cellular localization and on the activation of its apoptotic function. Results We constructed an adenoviral vector coding a chimeric p53 protein by fusing p53 sequence with the 21 COOH term amino acids sequence of H-Ras. Indeed, the translation products of Ras genes are cytosolic proteins that become secondarily associated with membranes through a series of post-translational modifications initiated by a CAAX motif present at the C terminus of Ras proteins. The chimeric p53HRCaax protein was farnesylated efficiently in transduced human osteosarcoma p53-/- cell line. The farnesylated form of p53 resided mainly in the cytosol, where it is non-functional. Farnesyl transferase inhibitors (FTIs) specifically inhibited farnesyl isoprenoid lipid modification of proteins. Following treatment of the cells with an FTI, p53HRCaax underwent translocation into the nucleus where it retained transcription factor activity. Shifting p53 into the nucleus resulted in the induction of p21waf1/CIP1 and Bax transcription, cell growth arrest, caspase activation and apoptosis. Conclusion Artificial protein farnesylation impaired the transcriptional activity of p53. This could be prevented by Farnesyl transferase inhibition. These data highlight the fact that the artificial prenylation of proteins provides a novel system for controlling the function of a transactivating factor.
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Affiliation(s)
- Bettina Couderc
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Marie Penary
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Mustapha Tohfe
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Anne Pradines
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Antoine Casteignau
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Danièle Berg
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
| | - Gilles Favre
- INSERM U563, Department Innovations thérapeutiques et Oncologie moléculaire, Institut Claudius Regaud and Faculté des Sciences Pharmaceutiques, Toulouse, France
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Hayashi KI, Hashimoto K, Kusaka N, Yamazoe A, Fukaki H, Tasaka M, Nozaki H. Caged gene-inducer spatially and temporally controls gene expression and plant development in transgenic Arabidopsis plant. Bioorg Med Chem Lett 2006; 16:2470-4. [PMID: 16480868 DOI: 10.1016/j.bmcl.2006.01.103] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 01/20/2006] [Accepted: 01/23/2006] [Indexed: 11/24/2022]
Abstract
Two new types of caged gene-inducers, caged 17beta-estradiol and caged dexamethazone, were synthesized. Caged gene-inducers were applied to transgenic Arabidopsis plants carrying a steroid hormone-inducible transactivation system. Light uncaged caged gene-inducers and controlled spatial and temporal expression of transgene in the transgenic plant. Furthermore, caged gene-inducers enabled the control of root development by light.
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Affiliation(s)
- Ken-ichiro Hayashi
- Department of Biochemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama City 700-0005, Japan.
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Park KH, Lee JR, Hahn HS, Kim YH, Bae CD, Yang JM, Oh S, Bae YJ, Kim DE, Hahn MJ. Inhibitory Effect of Ammonium Tetrathiotungstate on Tyrosinase and Its Kinetic Mechanism. Chem Pharm Bull (Tokyo) 2006; 54:1266-70. [PMID: 16946532 DOI: 10.1248/cpb.54.1266] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tyrosinase requires two copper ions at the active site, in order to oxidize phenols to catechols. In this study, the inhibitory effect of the copper-chelating compound, ammonium tetrathiotungstate (ATTT), on the tyrosinase activity was investigated. ATTT was determined to inactivate the activity of mushroom tyrosinase, in a dose-dependent manner. The kinetic substrate reaction revealed that ATTT functions as a kinetically competitive inhibitor in vitro, and that the enzyme-ATTT complex subsequently undergoes a reversible conformational change, resulting in the inactivation of tyrosinase. In human melanin-producing cells, ATTT evidenced a more profound tyrosinase-inhibitory effect than has been seen in the previously identified tyrosinase inhibitors, including kojic acid and hydroquinone. Our results may provide useful information for the development of whitening agent.
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Affiliation(s)
- Kyung-Hee Park
- Department of Molecular Cell Biology, Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 Korea
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11
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Karbassi F, Saboury AA, Khan MTH, Choudhary MI, Saifi ZS. Mushroom tyrosinase inhibition by two potent uncompetitive inhibitors. J Enzyme Inhib Med Chem 2005; 19:349-53. [PMID: 15558952 DOI: 10.1080/14756360409162449] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Two new bi-pyridine compounds, [1,4'] Bipiperidinyl-1'-yl-naphthan-2-yl-methanone (I) and [1,4'] Bipiperidinyl-1'-yl-4-methylphenyl-methane (II) were synthesized and examined for inhibition of the catecholase activity of mushroom tyrosinase in 10 mM phosphate buffer pH 6.8, at 293 K using UV spectrophotometry. Inhibition kinetics indicated that they were uncompetitive inhibitors and the value of the inhibition constants were 5.87 and 1.31 microM for I and II, respectively, which showed high potency. Fluorescent studies confirmed the uncompetitive type of inhibition for these two inhibitors. The inhibition mechanism presumably comes from the presence of a particular hydrophobe site which can accommodate these inhibitors. This site could be formed due to a probable conformational change that was induced by binding of substrate with the enzyme.
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Affiliation(s)
- F Karbassi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
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12
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Bäckman CM, Zhang Y, Hoffer BJ, Tomac AC. Tetracycline-inducible expression systems for the generation of transgenic animals: a comparison of various inducible systems carried in a single vector. J Neurosci Methods 2004; 139:257-62. [PMID: 15488239 DOI: 10.1016/j.jneumeth.2004.05.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 05/03/2004] [Accepted: 05/06/2004] [Indexed: 11/24/2022]
Abstract
The most often used tetracycline-regulated transgenic mice system requires the generation of two transgenic strains, one carrying an inducible promoter and the other a transactivator. In this study, we report the design of a universal and simplified regulatory gene delivery vector to facilitate the generation of conditional transgenic animals that integrate both the tetracycline regulatory and response elements in a single vector. The newly developed tetracycline reversed transactivator rtTA-M2 was used in all our constructs, based on its highly improved properties with respect to specificity, stability and inducibility. To minimize interference between the different tetracycline-inducible promoters used in this study (tetracycline-responsive element (TRE), TRE-tight, or Tk-tetO) and the rtTA-M2 transactivator, both elements were cloned in opposite directions and separated by a 5 kb human p53 intron. The functionality of this system was confirmed after in vitro transfection in a mammalian cell line. Overall induction by the tetracycline-responsive element promoter was significantly higher than that induced by the newly developed TRE-tight promoter. However, the TRE-tight promoter showed a significantly tighter expression with minimal background, and still maintained high induction levels. The minimal Tk-tetO promoter showed a very weak induction capacity. Our study demonstrates that this combination of elements, placed in a single vector is sufficient for delivering a functional tetracycline-inducible system to a mammalian cell line. Moreover, additional modifications to this regulatory gene delivery system, such as the introduction of specific cloning sites and selection markers, have been designed with the idea of creating a simplified and universal inducible system to facilitate the generation of conditional transgenic, knock-out, and knock-in animals.
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Affiliation(s)
- Cristina M Bäckman
- Cellular Neurobiology Branch, National Institute on Drug Abuse, National Institutes of Health, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA
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13
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Ueblacker P, Wagner B, Krüger A, Vogt S, DeSantis G, Kennerknecht E, Brill T, Hillemanns M, Salzmann GM, Imhoff AB, Plank C, Gänsbacher B, Martinek V. Inducible nonviral gene expression in the treatment of osteochondral defects. Osteoarthritis Cartilage 2004; 12:711-9. [PMID: 15325637 DOI: 10.1016/j.joca.2004.05.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Accepted: 05/25/2004] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The repair of osteochondral defects with chondrocytes genetically modified to express desired growth factors promises great potential in orthopaedic therapy. Controlled expression of the transgenes is required in many instances. The objective of the present study was to demonstrate the inducibility of tetracycline-responsive transgene expression in osteochondral defects in the knee joint filled with genetically modified chondrocyte implants. METHODS An expression plasmid containing the lacZ gene under the control of the minimal CMV promoter fused to the Tet-responsible element (TRE) as well as the reverse transactivator (rtTA2s-M2) was constructed and used to transfect isolated articular chondrocytes from New Zealand white rabbits. rtTA2s-M2 binds to the TRE in the presence of tetracycline and leads to the transcription of the transgene. Different concentrations of DNA and various DNA:lipid ratios were tested to determine best transfection conditions. Transfection efficiency and inducibility were analysed by histochemical analysis and flow-cytometry. To evaluate the system in vivo, collagen-sponges were seeded with transfected autologous chondrocytes and implanted in osteochondral defects in the knees of NZW-rabbits. Gene expression was induced by doxycycline and 3 weeks later, LacZ-expression in isolated knee joints was evaluated in histological sections by X-gal staining. RESULTS In vitro 13.5% (+/-1.32) of induced primary chondrocytes were LacZ-positive, while non-induced controls showed a background-staining in 0.6% (+/-0.2). In vivo, upon doxycycline treatment, induction of lacZ-gene-expression could be demonstrated in chondrocytes in 3-week-old, well-integrated implants. CONCLUSION For the first time, tetracycline-inducible gene expression is demonstrated to work in the treatment of osteochondral defects. This demonstrates the feasibility for a gene therapy-assisted approach using controlled expression of therapeutic growth factors from transplanted genetically modified chondrocytes.
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Affiliation(s)
- P Ueblacker
- Department of Orthopaedic Sports Medicine, Technical University Munich, Connollystrasse 32, 80809 Munich, Germany.
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Giménez E, Lavado A, Giraldo P, Cozar P, Jeffery G, Montoliu L. A Transgenic Mouse Model with Inducible Tyrosinase Gene Expression Using the Tetracycline (Tet-on) System Allows Regulated Rescue of Abnormal Chiasmatic Projections Found in Albinism. ACTA ACUST UNITED AC 2004; 17:363-70. [PMID: 15250938 DOI: 10.1111/j.1600-0749.2004.00158.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Congenital defects in retinal pigmentation, as in oculocutaneous albinism Type I (OCA1), where tyrosinase is defective, result in visual abnormalities affecting the retina and pathways into the brain. Transgenic animals expressing a functional tyrosinase gene on an albino genetic background display a correction of all these abnormalities, implicating a functional role for tyrosinase in normal retinal development. To address the function of tyrosinase in the development of the mammalian visual system, we have generated a transgenic mouse model with inducible expression of the tyrosinase gene using the tetracycline (TET-ON) system. We have produced two types of transgenic mice: first, mice expressing the transactivator rtTA chimeric protein under the control of mouse tyrosinase promoter and its locus control region (LCR), and; second, transgenic mice expressing a mouse tyrosinase cDNA construct driven by a minimal promoter inducible by rtTA in the presence of doxycycline. Inducible experiments have been carried out with selected double transgenic mouse lines. Tyrosinase expression has been induced from early embryo development and its impact assessed with histological and biochemical methods in heterozygous and homozygous double transgenic individuals. We have found an increase of tyrosinase activity in the eyes of induced animals, compared with littermate controls. However, there was significant variability in the activation of this gene, as reported in analogous experiments. In spite of this, we could observe corrected uncrossed chiasmatic pathways, decreased in albinism, in animals induced from their first gestational week. These mice could be instrumental in revealing the role of tyrosinase in mammalian visual development.
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Affiliation(s)
- Estela Giménez
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnología (CNB-CSIC), Campus de Cantoblanco, 28049 Madrid, Spain
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15
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Boutonnet C, Boijoux O, Bernat S, Kharrat A, Favre G, Faye JC, Vagner S. Pharmacological-based translational induction of transgene expression in mammalian cells. EMBO Rep 2004; 5:721-7. [PMID: 15192697 PMCID: PMC1299091 DOI: 10.1038/sj.embor.7400170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Revised: 04/20/2004] [Accepted: 04/20/2004] [Indexed: 11/09/2022] Open
Abstract
In the quest for the development of pharmacological switches that control gene expression, no system has been reported that regulates at the translational level. To permit small-molecule control of transgene translation, we have constructed a farnesyl transferase inhibitor-responsive translation initiation factor. This artificial protein is a three-component chimaera consisting of the ribosome recruitment core of the eIF4G1 eukaryotic translation initiation factor, the RNA-binding domain of the R17 bacteriophage coat protein and the plasma membrane localization CAAX motif of farnesylated H-Ras. This membrane-delocalized translation factor is inactive unless liberated in the cytosol. Farnesyl transferase inhibitor FTI-277 prevents the membrane association of the CAAX motif and thus increases the cytoplasmic levels of the eIF4G fusion protein, which is then capable of inducing translation of the second cistron of a bicistronic messenger RNA containing an R17-binding site in its intercistronic space. Such direct translational control by farnesyl transferase inhibitors provides a system for fast, graded and reversible regulation of transgene expression.
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Affiliation(s)
- Christel Boutonnet
- INSERM U589, Institut Louis Bugnard, CHU Rangueil, 31054 Toulouse, France
- MILLEGEN SA, Rue Pierre et Marie Curie BP 28262, 31682 Labège, France
| | - Olivier Boijoux
- INSERM U563, Centre Claudius Régaud, Rue du Pont Saint-Pierre, 31052 Toulouse, France
| | - Sandra Bernat
- MILLEGEN SA, Rue Pierre et Marie Curie BP 28262, 31682 Labège, France
| | | | - Gilles Favre
- INSERM U563, Centre Claudius Régaud, Rue du Pont Saint-Pierre, 31052 Toulouse, France
| | - Jean-Charles Faye
- INSERM U563, Centre Claudius Régaud, Rue du Pont Saint-Pierre, 31052 Toulouse, France
| | - Stéphan Vagner
- INSERM U589, Institut Louis Bugnard, CHU Rangueil, 31054 Toulouse, France
- Tel: +33 561 32 31 28; Fax: +33 561 32 21 41; E-mail:
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Nakazawa K, McHugh TJ, Wilson MA, Tonegawa S. NMDA receptors, place cells and hippocampal spatial memory. Nat Rev Neurosci 2004; 5:361-72. [PMID: 15100719 DOI: 10.1038/nrn1385] [Citation(s) in RCA: 431] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kazu Nakazawa
- Howard Hughes Medical Institute, The Picower Center for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Center for Cancer Research, Cambridge, Massachusetts 02139, USA
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Abstract
Conditional genetic modifications are used to determine how individual molecules contribute to the function of defined neuronal circuits in the mouse brain. Among various techniques for these genetic modifications, the tetracycline transactivator and the Cre-loxP systems have proved to be most successful in recent years. Here we describe the basic principles, recent developments, and potential applications of these methodologies. We discuss their impact on the study of general brain function and their use for modeling different brain disorders.
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Affiliation(s)
- Alexei Morozov
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, Department of Health and Humans Services (AM), National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892, USA
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18
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André M, Felley-Bosco E. Heme oxygenase-1 induction by endogenous nitric oxide: influence of intracellular glutathione. FEBS Lett 2003; 546:223-7. [PMID: 12832044 DOI: 10.1016/s0014-5793(03)00576-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To investigate the influence of glutathione (GSH) on cellular effects of nitric oxide (NO) formation, human colon adenocarcinoma cells were transfected with a vector allowing controlled expression of inducible nitric oxide synthase (iNOS). Protein levels of oxidative stress-sensitive heme oxygenase-1 (HO-1) were analyzed in the presence or absence of GSH depletion using L-buthionine-[S,R]-sulfoximine and iNOS induction. While no effect was observed in the presence of iNOS activity alone, a synergistic effect on HO-1 expression was observed in the presence of iNOS expression and GSH depletion. This effect was prevented by addition of N-methyl-L-arginine. Therefore, targeting of endogenous NO may be modulated by intracellular GSH.
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Affiliation(s)
- Muriel André
- Institute of Pharmacology and Toxicology, Rue du Bugnon 27, 1005 Lausanne, Switzerland
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Anastassiadis K, Kim J, Daigle N, Sprengel R, Schöler HR, Stewart AF. A predictable ligand regulated expression strategy for stably integrated transgenes in mammalian cells in culture. Gene 2002; 298:159-72. [PMID: 12426104 DOI: 10.1016/s0378-1119(02)00979-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several strategies for regulated stable transgene expression in mammalian cells have been described. These strategies have different strengths and weaknesses, however they all share a common problem, namely predictability in application. Here we address this problem using the leading strategy for ligand inducible transgene expression, the tetracycline repressor system. Initially, we found the best stable clone out of 48 examined showed only 6-fold inducibility. Hence we looked for additions and modifications that improve the chances of a successful outcome. We document three important aspects; first, use of a mammalian codon-optimized tetracycline repressor gene; second, addition of a steroid hormone receptor ligand binding domain to the tetracycline repressor-virion protein 16 fusion protein activator; third, flanking the tet-operator/transgene cassette with insulator elements from the chicken beta-globin locus. By inclusion of these three design features, 18/18 clones showed low basal and highly inducible (>50 x) expression.
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Affiliation(s)
- Konstantinos Anastassiadis
- BIOTEC, TU Dresden, c/o Max-Planck-Institut für Molekulare Zellbiologie und Genetik MPI-CBG, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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20
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Shimizu-Sato S, Huq E, Tepperman JM, Quail PH. A light-switchable gene promoter system. Nat Biotechnol 2002; 20:1041-4. [PMID: 12219076 DOI: 10.1038/nbt734] [Citation(s) in RCA: 432] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2002] [Accepted: 05/07/2002] [Indexed: 11/09/2022]
Abstract
Regulatable transgene systems providing easily controlled, conditional induction or repression of expression are indispensable tools in biomedical and agricultural research and biotechnology. Several such systems have been developed for eukaryotes. Most of these rely on the administration of either exogenous chemicals or heat shock. Despite the general success of many of these systems, the potential for problems, such as toxic, unintended, or pleiotropic effects of the inducing chemical or treatment, can impose limitations on their use. We have developed a promoter system that can be induced, rapidly and reversibly, by short pulses of light. This system is based on the known red light-induced binding of the plant photoreceptor phytochrome to the protein PIF3 and the reversal of this binding by far-red light. We show here that yeast cells expressing two chimeric proteins, a phytochrome-GAL4-DNA-binding-domain fusion and a PIF3-GAL4-activation-domain fusion, are induced by red light to express selectable or "scorable" marker genes containing promoters with a GAL4 DNA-binding site, and that this induction is rapidly abrogated by subsequent far-red light. We further show that the extent of induction can be controlled precisely by titration of the number of photons delivered to the cells by the light pulse. Thus, this system has the potential to provide rapid, noninvasive, switchable control of the expression of a desired gene to a preselected level in any suitable cell by simple exposure to a light signal.
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Affiliation(s)
- Sae Shimizu-Sato
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
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21
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Kim YM, Yun J, Lee CK, Lee H, Min KR, Kim Y. Oxyresveratrol and hydroxystilbene compounds. Inhibitory effect on tyrosinase and mechanism of action. J Biol Chem 2002; 277:16340-4. [PMID: 11864987 DOI: 10.1074/jbc.m200678200] [Citation(s) in RCA: 238] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tyrosinase is responsible for the molting process in insects, undesirable browning of fruits and vegetables, and coloring of skin, hair, and eyes in animals. To clarify the mechanism of the depigmenting property of hydroxystilbene compounds, inhibitory actions of oxyresveratrol and its analogs on tyrosinases from mushroom and murine melanoma B-16 have been elucidated in this study. Oxyresveratrol showed potent inhibitory effect with an IC(50) value of 1.2 microm on mushroom tyrosinase activity, which was 32-fold stronger inhibition than kojic acid, a depigmenting agent used as the cosmetic material with skin-whitening effect and the medical agent for hyperpigmentation disorders. Hydroxystilbene compounds of resveratrol, 3,5-dihydroxy-4'-methoxystilbene, and rhapontigenin also showed more than 50% inhibition at 100 microm on mushroom tyrosinase activity, but other methylated or glycosylated hydroxystilbenes of 3,4'-dimethoxy-5-hydroxystilbene, trimethylresveratrol, piceid, and rhaponticin did not inhibit significantly. None of the hydroxystilbene compounds except oxyresveratrol exhibited more than 50% inhibition at 100 microm on l-tyrosine oxidation by murine tyrosinase activity; oxyresveratrol showed an IC(50) value of 52.7 microm on the enzyme activity. The kinetics and mechanism for inhibition of mushroom tyrosinase exhibited the reversibility of oxyresveratrol as a noncompetitive inhibitor with l-tyrosine as the substrate. The interaction between oxyresveratrol and tyrosinase exhibited a high affinity reflected in a K(i) value of 3.2-4.2 x 10(-7) m. Oxyresveratrol did not affect the promoter activity of the tyrosinase gene in murine melanoma B-16 at 10 and 100 microm. Therefore, the depigmenting effect of oxyresveratrol works through reversible inhibition of tyrosinase activity rather than suppression of the expression and synthesis of the enzyme. The number and position of hydroxy substituents seem to play an important role in the inhibitory effects of hydroxystilbene compounds on tyrosinase activity.
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Affiliation(s)
- Yeon Mi Kim
- College of Pharmacy and Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Korea
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22
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Loy AL, Goodnow CC. Novel approaches for identifying genes regulating lymphocyte development and function. Curr Opin Immunol 2002; 14:260-5. [PMID: 11869902 DOI: 10.1016/s0952-7915(02)00331-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The draft sequence of the human and mouse genomes provides an unparalleled opportunity for understanding the genetic control of immune-cell development. Strategies can begin with a gene sequence and pursue a putative immune-system function by employing mRNA-expression profiling or creating gene knockouts in embryonic stem cells. The latter can be produced by utilising the Cre/Lox system, a tetracycline operon, a gene-trap method or chemical mutagenesis. Alternatively, mutant phenotypes (derived using the mutagen ethylnitrosourea) can be traced back to gene sequences.
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Affiliation(s)
- Adèle L Loy
- Australian Cancer Research Foundation (ACRF) Genetics Laboratory and Medical Genome Centre, John Curtin School of Medical Research, Australian National University, Canberra, Australia.
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23
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Abstract
Striking homology between signaling molecules in zebrafish and humans suggests that compounds known to inhibit human kinases may enable a chemical genetic approach to dissect signaling pathways in the zebrafish embryo. We tested this hypothesis using a vascular endothelial growth factor receptor inhibitor, PTK787/ZK222584. Zebrafish embryos treated with this compound lacked all major blood vessels. Overexpression of AKT/PKB, a putative effector of vascular endothelial growth factor signaling, allowed blood vessels to form in the presence of drug. Endothelial cell apoptosis induced by the drug is prevented by increasing AKT/PKB activity, thus establishing the physiological relevance of AKT/PKB in the angiogenic process. This approach allowed us to examine the effects of blood flow and the role of endothelial signals in organogenesis.
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Affiliation(s)
- Joanne Chan
- Department of Cancer Biology, Dana-Farber Cancer Institute and the Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA.
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Wu YY, Mujtaba T, Han SSW, Fischer I, Rao MS. Isolation of a glial-restricted tripotential cell line from embryonic spinal cord cultures. Glia 2002; 38:65-79. [PMID: 11921204 DOI: 10.1002/glia.10049] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neuroepithelial stem cells (NEPs), glial-restricted precursors (GRPs), and neuron-restricted precursors (NRPs) are present during early differentiation of the spinal cord and can be identified by cell surface markers. In this article, we describe the properties of GRP cells that have been immortalized using a regulatable v-myc retrovirus construct. Immortalized GRP cells can be maintained in an undifferentiated dividing state for long periods and can be induced to differentiate into two types of astrocytes and into oligodendrocytes in culture. A clonal cell line prepared from immortalized GRP cells, termed GRIP-1, was also shown to retain the properties of a glial-restricted tripotential precursor. Transplantation of green fluorescent protein (GFP)-labeled subclones of the immortalized cells into the adult CNS demonstrates that this cell line can also participate in the in vivo development of astrocytes and oligodendrocytes. Late passages of the immortalized cells undergo limited transdifferentiation into neurons as assessed by expression of multiple neuronal markers. The availability of a conditionally immortalized cell line obviates the difficulties of obtaining a large and homogeneous population of GRPs that can be used for studying the mechanism and signals for glial cell differentiation as well as their application in transplantation protocols.
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Affiliation(s)
- Yuan Yuan Wu
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA
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25
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Skipper M. Just add water. Nat Rev Genet 2001. [DOI: 10.1038/35080523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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