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Wu Q, Fu J, Sun J, Wang X, Tang X, Lu W, Tan C, Li L, Deng X, Xu Q. A plant CitPITP1 protein-coding exon sequence serves as a promoter in bacteria. J Biotechnol 2021; 339:1-13. [PMID: 34298024 DOI: 10.1016/j.jbiotec.2021.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/17/2021] [Accepted: 07/18/2021] [Indexed: 11/19/2022]
Abstract
Genetic manipulation of plant genes in prokaryotes has been widely used in molecular biology, but the function of a DNA sequence is far from being fully known. Here, we discovered that a plant protein-coding gene containing the CRAL_TRIO domain serves as a promoter in bacteria. We firstly characterized CitPITP1 from Citrus, which contains the CRAL_TRIO domain, and identified a 64-bp sequence (key64) that is critical for prokaryotic promoter activity. In vitro experiments indicated that the bacterial RNA polymerase subunit RpoD specifically binds to key64. We then expanded our research to fungi, plant and animal species to identify key64-like sequences. Five such prokaryotic promoters were isolated from Amborella, Rice, Arabidopsis and Citrus. Two conserved motifs were identified, and mutation analysis indicated that the nucleotides at positions 7, 29 and 30 are crucial for key64-like transcription activity. We detected full-length recombinant CitPITP1 from E. coli, and visualized a CitPITP1-GFP fusion protein in plant cells, supporting the idea that CitPITP1 encodes a protein. However, although exon 4 of CitPITP1 contained key64, it did not demonstrate promoter activity in plants. Our study describes a new basal promoter, provides evidence for neofunction of gene elements across different kingdoms, and provides new knowledge for the modular design of promoters.
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Affiliation(s)
- Qingjiang Wu
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Jialing Fu
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Juan Sun
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Xia Wang
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Xiaomei Tang
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Wenjia Lu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430000, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430000, China
| | - Li Li
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA; Robert W. Holley Center for Agriculture and Health, USDA-Agricultural Research Service, Cornell University, Ithaca, NY, 14853, USA
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, Huazhong Agricultural University, Wuhan, 430000, China.
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Kleter GA, Peijnenburg AACM, Aarts HJM. Health considerations regarding horizontal transfer of microbial transgenes present in genetically modified crops. J Biomed Biotechnol 2010; 2005:326-52. [PMID: 16489267 PMCID: PMC1364539 DOI: 10.1155/jbb.2005.326] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The potential effects of horizontal gene transfer on human health
are an important item in the safety assessment of genetically
modified organisms. Horizontal gene transfer from genetically
modified crops to gut microflora most likely occurs with
transgenes of microbial origin. The characteristics of microbial
transgenes other than antibiotic-resistance genes in
market-approved genetically modified crops are reviewed. These
characteristics include the microbial source, natural function,
function in genetically modified crops, natural prevalence,
geographical distribution, similarity to other microbial genes,
known horizontal transfer activity, selective conditions and
environments for horizontally transferred genes, and potential
contribution to pathogenicity and virulence in humans and animals.
The assessment of this set of data for each of the microbial genes
reviewed does not give rise to health concerns. We recommend
including the above-mentioned items into the premarket safety
assessment of genetically modified crops carrying transgenes other
than those reviewed in the present study.
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Affiliation(s)
- Gijs A Kleter
- RIKILT, Institute of Food Safety, Wageningen University and Research Center, Wageningen, The Netherlands.
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Watson AT, Garcia V, Bone N, Carr AM, Armstrong J. Gene tagging and gene replacement using recombinase-mediated cassette exchange in Schizosaccharomyces pombe. Gene 2007; 407:63-74. [PMID: 18054176 DOI: 10.1016/j.gene.2007.09.024] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 09/21/2007] [Indexed: 11/29/2022]
Abstract
Cre/lox site-specific recombination systems provide important tools for genetic manipulation. Here we present an efficient method for gene tagging and gene replacement using Cre recombinase-mediated cassette exchange (RMCE). The cassette consists of the S. pombe ura4(+) selectable marker flanked by a wild-type loxP site at one end and by a modified heterospecific lox site (loxM3) at the other. The cassette is stable because the flanking lox sites cannot recombine with each other. Following integration of the cassette at the chosen chromosomal locus, exchange is achieved by introducing a Cre-expression plasmid containing an equivalent cassette containing the required tag or gene sequence. Recombinants are selected by uracil prototrophy using the reagent 5-fluoroorotic acid (5-FOA). The cassette exchange system provides for repetitive integrations at the same locus, allowing different protein tags or gene sequences to be integrated quickly and efficiently. We have established a range of reagents and verified utility by C-terminally tagging the S. pombe rad4 and swi1 genes with yEGFP and the yEGFP derivatives yECFP and yECitrine and by transferring the coding sequence for both genes.
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Affiliation(s)
- Adam T Watson
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Sussex, UK
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Lewin A, Mayer M, Chusainow J, Jacob D, Appel B. Viral promoters can initiate expression of toxin genes introduced into Escherichia coli. BMC Biotechnol 2005; 5:19. [PMID: 15967027 PMCID: PMC1181807 DOI: 10.1186/1472-6750-5-19] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Accepted: 06/20/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The expression of recombinant proteins in eukaryotic cells requires the fusion of the coding region to a promoter functional in the eukaryotic cell line. Viral promoters are very often used for this purpose. The preceding cloning procedures are usually performed in Escherichia coli and it is therefore of interest if the foreign promoter results in an expression of the gene in bacteria. In the case molecules toxic for humans are to be expressed, this knowledge is indispensable for the specification of safety measures. RESULTS We selected five frequently used viral promoters and quantified their activity in E. coli with a reporter system. Only the promoter from the thymidine kinase gene from HSV1 showed no activity, while the polyhedrin promoter from baculovirus, the early immediate CMV promoter, the early SV40 promoter and the 5' LTR promoter from HIV-1 directed gene expression in E. coli. The determination of transcription start sites in the immediate early CMV promoter and the polyhedrin promoter confirmed the existence of bacterial -10 and -35 consensus sequences. The importance of this heterologous gene expression for safety considerations was further supported by analysing fusions between the aforementioned promoters and a promoter-less cytotoxin gene. CONCLUSION According to our results a high percentage of viral promoters have the ability of initiating gene expression in E. coli. The degree of such heterologous gene expression can be sufficient for the expression of toxin genes and must therefore be considered when defining safety measures for the handling of corresponding genetically modified organisms.
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Affiliation(s)
- Astrid Lewin
- Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany
| | - Martin Mayer
- HU-Berlin, Abt. Bakterienphysiologie, Chausseestr.117, 10115 Berlin, Germany
| | - Janet Chusainow
- Bioprocessing Technology Institute (BTI) 20 Biopolis Way, Centros Singapore 138668
| | - Daniela Jacob
- Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany
| | - Bernd Appel
- Bundesintitut für Risikobewertung, Diedersdorfer Weg 112277 Berlin, Germany
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