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Jończyk R, Beuter C, Bulawa B, Buller S, Eibl C, Elling C, Gautrois M, Rengelshausen J, Schmidt C, Thömmes G, Khalil F. Multiple Dose Pharmacokinetics of Tapentadol Oral Solution for the Treatment of Moderate to Severe Acute Pain in Children Aged 2 to. J Pain Res 2022; 15:3103-3114. [PMID: 36203787 PMCID: PMC9531608 DOI: 10.2147/jpr.s364902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background Patients and Methods Results Conclusion
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Affiliation(s)
- Renata Jończyk
- Center for Hospital Health Care Services, Clinic of Pediatric Surgery, Subdivision of Pediatric Urology, Rzeszow, Poland
| | | | | | | | | | | | | | | | | | | | - Feras Khalil
- Grünenthal GmbH, Aachen, Germany
- Correspondence: Feras Khalil, Grünenthal GmbH, Zieglerstraße 6, Aachen, 52078, Germany, Tel +49 241 569 3295, Email
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Überall MA, Elling C, Eibl C, Müller-Schwefe GH, Lefeber C, Heine M, Heckes B. Tapentadol prolonged release in patients with chronic low back pain: real-world data from the German Pain eRegistry. Pain Manag 2021; 12:211-227. [PMID: 34376059 DOI: 10.2217/pmt-2021-0058] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Comparison of tapentadol prolonged release (PR) with other oral WHO-III PR opioid analgesics (morphine, oxycodone ± naloxone, hydromorphone) in routine medical care of chronic low back pain. Patients & methods: Noninterventional, retrospective 12-week study using anonymized clinical practice data from the German Pain eRegistry. Six effectiveness, tolerability, and safety criteria were aggregated in a primary composite end point (treatment responder). Propensity scoring matched 2331 datasets per treatment cohort. Results: All six single criteria showed significantly better outcomes for tapentadol PR (all parameters p < 0.001). There were significantly more treatment responders under tapentadol PR (65.7 vs 14.2%; p < 0.001). Conclusion: Tapentadol PR showed significantly better effectiveness and tolerability in severe chronic low back pain unsuccessfully treated with WHO-I/II analgesics compared with the other oral WHO-III PR opioids investigated.
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Eibl C, Munoz L, Tomassoli I, Stokes C, Papke RL, Gündisch D. The 3,7-diazabicyclo[3.3.1]nonane scaffold for subtype selective nicotinic acetylcholine receptor ligands. Part 2: carboxamide derivatives with different spacer motifs. Bioorg Med Chem 2013; 21:7309-29. [PMID: 24145137 DOI: 10.1016/j.bmc.2013.09.060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [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: 06/23/2013] [Revised: 09/15/2013] [Accepted: 09/24/2013] [Indexed: 11/30/2022]
Abstract
3,7-Diazabicyclo[3.3.1]nonane (bispidine) based nicotinic acetylcholine receptor (nAChR) ligands have been synthesized and evaluated for nAChRs interaction. Diverse spacer motifs were incorporated between the hydrogen bond acceptor (HBA) part and a variety of substituted (hetero)aryl moieties. Bispidine carboxamides bearing spacer motifs often showed high affinity in the low nanomolar range and selectivity for the α4β2(∗) nAChR. Compounds 15, 25, and 47 with Ki values of about 1 nM displayed the highest affinities for α4β2(∗) nAChR. All evaluated compounds are partial agonists or antagonists at α4β2(∗), with reduced or no effects on α3β4(∗) with the exception of compound 15 (agonist), and reduced or no effect at α7 and muscle subtypes.
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Affiliation(s)
- Christoph Eibl
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany; Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA
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Eibl C, Tomassoli I, Munoz L, Stokes C, Papke RL, Gündisch D. The 3,7-diazabicyclo[3.3.1]nonane scaffold for subtype selective nicotinic acetylcholine receptor (nAChR) ligands. Part 1: the influence of different hydrogen bond acceptor systems on alkyl and (hetero)aryl substituents. Bioorg Med Chem 2013; 21:7283-308. [PMID: 24156938 PMCID: PMC4519239 DOI: 10.1016/j.bmc.2013.09.059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [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: 06/23/2013] [Revised: 09/15/2013] [Accepted: 09/24/2013] [Indexed: 12/21/2022]
Abstract
3,7-Diazabicyclo[3.3.1]nonane is a naturally occurring scaffold interacting with nicotinic acetylcholine receptors (nAChRs). When one nitrogen of the 3,7-diazabicyclo[3.3.1]nonane scaffold was implemented in a carboxamide motif displaying a hydrogen bond acceptor (HBA) functionality, compounds with higher affinities and subtype selectivity for α4β2(∗) were obtained. The nature of the HBA system (carboxamide, sulfonamide, urea) had a strong impact on nAChR interaction. High affinity ligands for α4β2(∗) possessed small alkyl chains, small un-substituted hetero-aryl groups or para-substituted phenyl ring systems along with a carboxamide group. Electrophysiological responses of selected 3,7-diazabicyclo[3.3.1]nonane derivatives to Xenopus oocytes expressing various nAChR subtypes showed diverse activation profiles. Compounds with strongest agonistic profiles were obtained with small alkyl groups whereas a shift to partial agonism/antagonism was observed for aryl substituents.
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Affiliation(s)
- Christoph Eibl
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-533121 Bonn, Germany
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai’i at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA
| | - Isabelle Tomassoli
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai’i at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA
| | - Lenka Munoz
- Department of Pharmacology, School of Medical Sciences, The University of Sydney, NSW 2006, Australia
| | - Clare Stokes
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL32610, USA
| | - Roger L. Papke
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, FL32610, USA
| | - Daniela Gündisch
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-533121 Bonn, Germany
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai’i at Hilo, 34 Rainbow Drive, Hilo, HI 96720, USA
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Peng C, Stokes C, Mineur YS, Picciotto MR, Tian C, Eibl C, Tomassoli I, Guendisch D, Papke RL. Differential modulation of brain nicotinic acetylcholine receptor function by cytisine, varenicline, and two novel bispidine compounds: emergent properties of a hybrid molecule. J Pharmacol Exp Ther 2013; 347:424-37. [PMID: 23959137 DOI: 10.1124/jpet.113.206904] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Partial agonist therapies for the treatment of nicotine addiction and dependence depend on both agonistic and antagonistic effects of the ligands, and side effects associated with other nAChRs greatly limit the efficacy of nicotinic partial agonists. We evaluated the in vitro pharmacological properties of four partial agonists, two current smoking cessation drugs, varenicline and cytisine, and two novel bispidine compounds, BPC and BMSP, by using defined nAChR subtypes expressed in Xenopus laevis oocytes and human embryonic kidney 293 cells. Similar to varenicline and cytisine, BPC and BMSP are partial agonists of α4β2 nAChRs, although BMSP produced very little activation of these receptors. Unlike varenicline and cytisine, BPC and BMSP showed desired low activity. BPC produced mecamylamine-sensitive steady-state activation of α4* receptors that was not evident with BMSP. We evaluated the modulation of α4*- and α7-mediated responses in rat lateral geniculate nucleus (LGN) neurons and hippocampal stratum radiatum (SR) interneurons, respectively. The LGN neurons were sensitive to a very low concentration of varenicline, and the SR interneuron responses were also sensitive to varenicline at a submicromolar concentration. Although 300 nM BPC strongly inhibited the ACh-evoked responses of LGN neurons, it did not inhibit the α7 currents of SR interneurons. Similar results were observed with 300 nM BMSP. Additionally, the bispidine compounds were efficacious in the mouse tail suspension test, demonstrating that they affect receptors in the brain when delivered systemically. Our data indicate that BPC and BMSP are promising α4β2* partial agonists for pharmacotherapeutics.
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Affiliation(s)
- Can Peng
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida (C.P., C.S., C.T., R.L.P.); Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut (Y.S.M., M.R.P.); and Department of Pharmaceutical Sciences, College of Pharmacy, University of Hawaii, Hilo, Hawaii (C.E., I.T., D.G.)
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Pérez EG, Cassels BK, Eibl C, Gündisch D. Synthesis and evaluation of N1-alkylindole-3-ylalkylammonium compounds as nicotinic acetylcholine receptor ligands. Bioorg Med Chem 2012; 20:3719-27. [DOI: 10.1016/j.bmc.2012.04.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 04/17/2012] [Accepted: 04/25/2012] [Indexed: 10/28/2022]
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Turcanu D, Kirtok N, Eibl C, Guendisch D, LaGamma E, Nankova B. Nicotinic receptor partial agonists alter catecholamine homeostasis and response to nicotine in PC12 cells. Neurosci Lett 2012; 516:212-6. [DOI: 10.1016/j.neulet.2012.03.088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/16/2012] [Accepted: 03/29/2012] [Indexed: 12/22/2022]
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Abstract
INTRODUCTION Nicotinic acetylcholine receptors (nAChRs), pentameric ligand-gated cation channels, are potential targets for the development of therapeutics for a variety of disease states. AREAS COVERED This article is reviewing recent advances in the development of small-molecule ligands for diverse nAChR subtypes and is a continuation of an earlier review in this journal. EXPERT OPINION The development of nAChR ligands with preference for α4β2 or α7 subtypes for the treatment of central nervous system disorders are in the most advanced developmental stage. In addition, there is a fast growing interest to generate so-called PAMs, positive allosteric modulators, to influence the channels' functionalities.
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Affiliation(s)
- Daniela Gündisch
- University of Hawai'i at Hilo, College of Pharmacy, Department of Pharmaceutical Sciences, 34 Rainbow Drive, Hilo, HI 96720, USA.
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Gündisch D, Eibl C. From acetyl bispidine to an extended bispidine amide framework: Synthesis and structure–affinity relationships for nicotinic acetylcholine receptors (nAChRs). Biochem Pharmacol 2009. [DOI: 10.1016/j.bcp.2009.06.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Mineur YS, Eibl C, Young G, Kochevar C, Papke RL, Gündisch D, Picciotto MR. Cytisine-based nicotinic partial agonists as novel antidepressant compounds. J Pharmacol Exp Ther 2009; 329:377-86. [PMID: 19164465 DOI: 10.1124/jpet.108.149609] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nicotine and other nicotinic agents are thought to regulate mood in human subjects and have antidepressant-like properties in animal models. Recent studies have demonstrated that blockade of nicotinic acetylcholine receptors (nAChRs) including those containing the beta2 subunit (beta2(*)), results in antidepressant-like effects. Previous studies have shown that cytisine, a partial agonist at alpha4/beta2(*) nAChRs, and a full agonist at alpha3/beta4(*) and alpha7 nAChRs, has antidepressant-like properties in several rodent models of antidepressant efficacy; however, it is not clear whether more selective partial agonists will also be effective in these models. We tested cytisine and two derivatives, 5-bromo-cytisine (5-Br-Cyt) and 3-(pyridin-3'-yl)-cytisine (3-pyr-Cyt) for their ability to act as a partial agonist of different nAChR subtypes and to show antidepressant-like activity in C57/BL6 mice in the tail suspension, the forced-swim, and the novelty-suppressed feeding tests. 3-pyr-Cyt was a partial agonist with very low efficacy at alpha4/beta2(*) nAChRS but had no agonist effects at other nAChRs normally targeted by cytisine, and it was effective in mouse models of antidepressant efficacy. Animals showed dose-dependent antidepressant-like effects in all three behavioral paradigms. 5-Br-Cyt was not effective in behavioral tests when administered peripherally, probably because of its inability to penetrate the blood-brain barrier, because it efficiently reduced immobility in the tail suspension test when administered intraventricularly. These results suggest that novel nicotinic partial agonists may provide new possibilities for development of drugs to treat mood disorders.
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Affiliation(s)
- Yann S Mineur
- Department of Psychiatry, Yale School of Medicine, New Haven, CT 06508, USA
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Zou Z, Eibl C, Koop HU. The stem-loop region of the tobacco psbA 5'UTR is an important determinant of mRNA stability and translation efficiency. Mol Genet Genomics 2003; 269:340-9. [PMID: 12690442 DOI: 10.1007/s00438-003-0842-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2002] [Accepted: 03/12/2003] [Indexed: 11/29/2022]
Abstract
Regulation of chloroplast gene expression involves networked and concerted interactions of nucleus-encoded factors with their target sites on untranslated regions (UTRs) of chloroplast transcripts. So far, only a few cis-acting elements within such 5'UTR sequences have been identified as functional determinants of mRNA stability and efficient translation in Chlamydomonas in vivo. In this study, we have used chloroplast transformation and site-directed mutagenesis to analyse the functions of the 5'UTRs of tobacco psbA and rbcL fused to the coding region of the reporter gene uidA. Various mutant versions of the psbA leader, as well as rbcL/psbA hybrid leader elements, were investigated. Our results showed a 1.5- to 3-fold decrease in uidA mRNA levels and a 1.5- to 6-fold reduction in uidA translation efficiency in all psbA 5'UTR stem-loop mutants generated by sequence deletions and base alterations. This indicates that the correct primary sequence and secondary structure of the psbA 5'UTR stem-loop are required for mRNA stabilisation and translation. The 5'-terminal segment of the rbcL 5'UTR did not enhance the stability or translational activity of chimeric uidA mRNA under the standard light-dark regime of 16 h light and 8 h dark. Stabilising effects were, however, observed when the cells were kept continuously in the dark. Possible reasons for the influence of the 5'UTR of the tobacco psbA on mRNA stability and translation efficiency are discussed.
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Affiliation(s)
- Z Zou
- Botanisches Institut, Ludwig-Maximilians-Universität, Menzinger Strasse 67, 80638 Munich, Germany
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Lössl A, Eibl C, Harloff HJ, Jung C, Koop HU. Polyester synthesis in transplastomic tobacco (Nicotiana tabacum L.): significant contents of polyhydroxybutyrate are associated with growth reduction. Plant Cell Rep 2003; 21:891-9. [PMID: 12789507 DOI: 10.1007/s00299-003-0610-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2002] [Revised: 01/31/2003] [Accepted: 02/14/2003] [Indexed: 05/24/2023]
Abstract
The pathway for synthesis of polyhydroxybutyrate (PHB), a polyester produced by three bacterial enzymes, was transferred to the tobacco plastid genome by the biolistic transformation method. The polycistronic phb operon encoding this biosynthetic pathway was cloned into plastome transformation vectors. Following selection and regeneration, the content and structure of plant-produced hydroxybutyrate was analysed by gas chromatography. Significant PHB synthesis was limited to the early stages of in vitro culture. Within the transformants, PHB synthesis levels were highly variable. In the early regeneration stage, single regenerates reached up to 1.7% PHB in dry weight. At least 70% of plant-produced hydroxybutyric acid was proven to be polymer with a molecular mass of up to 2,500 kDa. PHB synthesis levels of the transplastomic lines were decreasing when grown autotrophically but their phb transcription levels remained stable. Transcription of the three genes is divided into two transcripts with phbB being transcribed separately from phbC and phbA. In mature plants even low amounts of PHB were associated with male sterility. Fertility was only observed in a mutant carrying a defective phb operon. These results prove successful expression of the entire PHB pathway in plastids, concomitant, however, with growth deficiency and male sterility.
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Affiliation(s)
- A Lössl
- Department of Botany, Ludwig-Maximilians-Universität, Menzinger Strasse 67, 80638, Munich, Germany.
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Thum KE, Kim M, Morishige DT, Eibl C, Koop HU, Mullet JE. Analysis of barley chloroplast psbD light-responsive promoter elements in transplastomic tobacco. Plant Mol Biol 2001; 47:353-66. [PMID: 11587507 DOI: 10.1023/a:1011616400264] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The plastid gene psbD encodes D2, a photosystem II reaction center chlorophyll-binding protein. psbD is transcribed from a conserved chloroplast promoter that is activated by blue, white, or UV-A light. In this study, various forms of the barley (Hordeum vulgare L.) chloroplast psbD-LRP were fused to the uidA reporter gene and introduced into the tobacco (Nicotiana tabacum L.) plastid genome through homologous recombination. Primer extension analysis of transcripts from the psbD-LRP-uidA construct showed that the barley psbD-LRP was activated in tobacco by blue or white light. Transcription from this construct was also regulated by circadian cycling indicating that the barley psbD-LRP could respond to light modulated regulatory pathways in tobacco. Mutation of the psbD-LRP prokaryotic -10 promoter element reduced transcription to very low levels in all light regimes. In contrast, mutation of a prokaryotic -35 promoter element had no effect on transcription from the psbD-LRP. Deletion or mutation of an upstream activating element, the AAG-box (-36 to -64), also reduced transcription from the construct to very low levels. In contrast, deletion of the upstream PGT-box (-71 to -100) did not alter promoter activation by blue light, or responsiveness to circadian cycling. These in vivo studies confirm the importance of the psbD-LRP -10 promoter element and AAG-box in light regulation and demonstrate that these elements are sufficient to mediate circadian cycling of the barley psbD promoter.
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Affiliation(s)
- K E Thum
- Department of Biochemistry and Biophysics, Texas A&M University, College Station 77843, USA
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Eibl C, Zou Z, Beck A, Kim M, Mullet J, Koop HU. In vivo analysis of plastid psbA, rbcL and rpl32 UTR elements by chloroplast transformation: tobacco plastid gene expression is controlled by modulation of transcript levels and translation efficiency. Plant J 1999; 19:333-345. [PMID: 10476080 DOI: 10.1046/j.1365-313x.1999.00543.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
5' and 3' untranslated regions (UTRs) of plastid RNAs act as regulatory elements for post-transcriptional control of gene expression. Polyethylene glycol-mediated plastid transformation with UTR-GUS reporter gene fusions was used to study the function of the psbA, rbcL and rpl32 UTRs in vivo. All gene fusions were expressed from the same promoter, i.e. the promoter of the 16S-rRNA gene, such that variations in RNA and protein levels would be due to the involved UTR elements alone. Transgenic tobacco lines containing different combinations of UTRs showed fivefold variation in the uidA-mRNA level (RNA stability) and approximately 100-fold differences in GUS activity, a measure of translation activity. The rbcL 5'-UTR conferred greater mRNA stability than the psbA 5'-UTR on uidA transcripts. In contrast, the psbA 5'-UTR enhanced translation of GUS to a much greater extent compared to the rbcL 5'-UTR. The psbA 5'-UTR also mediated light-induced activation of translation which was not observed with other constructs. Deletion mutagenesis of an unanalysed terminal sequence element of the psbA 5'-UTR resulted in a twofold drop in uidA-mRNA level and a fourfold decrease in translation efficiency. Exchange of 3'-UTRs results in up to fivefold changes of mRNA levels and does not significantly influence translation efficiency. The mechanical impacts of these results on plastid translation regulation are discussed.
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Koop HU, Steinmüller K, Wagner H, Rössler C, Eibl C, Sacher L. Integration of foreign sequences into the tobacco plastome via polyethylene glycol-mediated protoplast transformation. Planta 1996; 199:193-201. [PMID: 8680308 DOI: 10.1007/bf00196559] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A new vector, pFaadAII, for transformation of plastids of Nicotiana tabacum L. has been developed. It harbours a chimeric gene consisting of the aadA coding region from Escherichia coli, the 16S rDNA promoter from tobacco combined with a synthetic ribosome-binding site, a 500-bp fragment containing the 3' untranslated transcript region (UTR) of the Chlamydomonas rbcL gene and 3.75-kb (5') and 0.95-kb (3') tobacco plastome sequences allowing for targeting the foreign sequences to the intergenic region between the rpl32 and trnL genes of the tobacco plastome. The vector thus targets foreign sequences to the small single-copy region of the plastome, which has so far not been modified by transformation. Leaf protoplasts of Nicotiana tabacum L. were treated with polyethylene glycol (PEG) in the presence of the vector. The protocol for PEG treatment aiming at plastome transformation was optimized. Cell lines were cultured in the presence of spectinomycin and streptomycin using a novel and efficient protoplast culture and selection system. Regenerants were characterized by polymerase chain reaction (PCR) analysis, Southern hybridization and reciprocal crossing. The transformation procedure is described in detail and parameters influencing its efficiency are presented. Special effort is placed on analyzing suitable selection conditions. Only a proportion of the cell lines with a resistant phenotype could be confirmed by molecular analysis and/or reciprocal crossings to represent plastome transformants. Integration of the plastome specific aadA cassette into the nuclear genome accounted for a fraction of the resistant cell lines. Still, as many as 20-40 plastome transformants can be expected from the treatment of 10(6) protoplasts. Therefore, the improved protocol for PEG-mediated plastome transformation in combination with the new aadA-vector supplies a simple, reproducible and cost-efficient alternative to the biolistic procedure.
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Affiliation(s)
- H U Koop
- Botanisches Institut der Universität München, Germany.
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