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Shen JY, Mao FH, Wang Q, Ou PP, Liu JK, Zhao Q, He QL. Efficient genome editing using CRISPR/Cas9 technology and its application for identifying Sesquiterpene synthases involved in the biosynthesis of Steperoxides in Steccherinum ochraceum. Fungal Genet Biol 2024; 175:103944. [PMID: 39592077 DOI: 10.1016/j.fgb.2024.103944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2024] [Revised: 11/20/2024] [Accepted: 11/22/2024] [Indexed: 11/28/2024]
Abstract
CRISPR technology has been widely used for gene editing in various species,but the genetic manipulation in basidiomycete mushrooms is still notoriously difficult for unknown endogenous promoters and inefficient DNA delivery. Steccherinum ochraceum is a white rot basidiomycete fungus with abundant secondary metabolites and plays an important ecological role worldwide. To facilitate the study of gene function in S. ochraceum, an effective CRISPR/Cas9 system was successfully developed by identifying highly efficient endogenous promoters, and utilizing the Agrobacterium-transformation method. Two efficient endogenous RNA polymerase II promoters (Psogpd and Psotef1) and one efficient RNA polymerase III promoter (Pu6-d) were identified and characterized, with an editing efficiency of 61.5 % at the ura3 locus. Using this optimized system, the sesquiterpene gene A0064, which could produce 10 possible sesquiterpenes in the heterologous expression system of A. oryzae, was knocked out to obtain A0064 knockout strain S. ochraceum (∆A0064). Steperoxide A could not be detected in S. ochraceum (∆A0064), demonstrating that A0064 was the only enzyme responsible for the biosynthesis of β-chamigrene (the sesquiterpene skeleton of steperoxide A) in S. ochraceum. This efficient system will enable precise targeting and multiplex editing of S. ochraceum genes, facilitating functional studies of genes involved in lignin degradation and natural product biosynthesis in S. ochraceum, and providing some valuable guidance for gene editing in tens of thousands of macrofungi.
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Affiliation(s)
- Jia-Yu Shen
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Fei-Hong Mao
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.
| | - Qiwen Wang
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Pei-Pei Ou
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China
| | - Ji-Kai Liu
- National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan 430074, China
| | - Qunfei Zhao
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.
| | - Qing-Li He
- Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, China.
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Zhang Z, Wang J, Li J, Liu X, Liu L, Zhao C, Tao W, Wang D, Wei J. Establishment of an Integrated CRISPR/Cas9 Plasmid System for Simple and Efficient Genome Editing in Medaka In Vitro and In Vivo. BIOLOGY 2023; 12:biology12020336. [PMID: 36829610 PMCID: PMC9953409 DOI: 10.3390/biology12020336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/25/2023]
Abstract
Although CRISPR/Cas9 has been used in gene manipulation of several fish species in vivo, its application in fish cultured cells is still challenged and limited. In this study, we established an integrated CRISPR/Cas9 plasmid system and evaluated its efficiency of gene knock-out or knock-in at a specific site in medaka (Oryzias latipes) in vitro and in vivo. By using the enhanced green fluorescent protein reporter plasmid pGNtsf1, we demonstrate that pCas9-U6sgRNA driven by endogenous U6 promoter (pCas9-mU6sgRNA) mediated very high gene editing efficiency in medaka cultured cells, but not by exogenous U6 promoters. After optimizing the conditions, the gene editing efficiencies of eight sites targeting for four endogenous genes were calculated, and the highest was up to 94% with no detectable off-target. By one-cell embryo microinjection, pCas9-mU6sgRNA also mediated efficient gene knock-out in vivo. Furthermore, pCas9-mU6sgRNA efficiently mediated gene knock-in at a specific site in medaka cultured cells as well as embryos. Collectively, our study demonstrates that the genetic relationship of U6 promoter is critical to gene editing efficiency in medaka cultured cells, and a simple and efficient system for medaka genome editing in vitro and in vivo has been established. This study provides an insight into other fish genome editing and promotes gene functional analysis.
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Affiliation(s)
- Zeming Zhang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Jie Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
- Sichuan Province Yuechi Middle School, Guang’an 638300, China
| | - Jianeng Li
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Xiang Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Lei Liu
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Changle Zhao
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Wenjing Tao
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Deshou Wang
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
- Correspondence: (D.W.); (J.W.)
| | - Jing Wei
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, Laboratory of Aquatic Science of Chongqing, School of Life Sciences, Southwest University, Chongqing 400715, China
- Correspondence: (D.W.); (J.W.)
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Guo R, Liu T, Guo C, Chen G, Fan J, Zhang Q. Carotenoid biosynthesis is associated with low-temperature adaptation in Rhodosporidium kratochvilovae. BMC Microbiol 2022; 22:319. [PMID: 36564716 PMCID: PMC9789556 DOI: 10.1186/s12866-022-02728-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/08/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Low temperatures greatly limit the growth of microorganisms. Low-temperature adaptation in microorganisms involves multiple mechanisms. Carotenoids are naturally occurring lipid-soluble pigments that act as antioxidants and protect cells and tissues from the harmful effects of free radicals and singlet oxygen. However, studies on the regulation of carotenoid biosynthesis at low temperatures in microorganisms are limited. In this study, we investigated the correlation between carotenoids and low-temperature adaptation in the cold-adapted strain of Rhodosporidium kratochvilovae YM25235. RESULTS Carotenoid biosynthesis in YM25235 was inhibited by knocking out the bifunctional lycopene cyclase/phytoene synthase gene (RKCrtYB) using the established CRISPR/Cas9 gene-editing system based on endogenous U6 promoters. The carotenoids were extracted with acetone, and the content and composition of the carotenoids were analyzed by spectrophotometry and HPLC. Then, the levels of reactive oxygen species (ROS) and the growth rate in YM25235 were determined at a low temperature. The results indicated that the carotenoid biosynthesis and ROS levels were increased in the YM25235 strain at a low temperature and inhibition of carotenoid biosynthesis was associated with higher ROS levels and a significant decrease in the growth rate of YM25235 at a low temperature. CONCLUSIONS The regulation of carotenoid biosynthesis was associated with low-temperature adaptation in YM25235. Our findings provided a strong foundation for conducting further studies on the mechanism by which YM25235 can adapt to low-temperature stress.
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Affiliation(s)
- Rui Guo
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Tao Liu
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Caina Guo
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Gongshui Chen
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Jingdie Fan
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Qi Zhang
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
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Garcia-Marques J, Espinosa-Medina I, Ku KY, Yang CP, Koyama M, Yu HH, Lee T. A programmable sequence of reporters for lineage analysis. Nat Neurosci 2020; 23:1618-1628. [PMID: 32719561 DOI: 10.1038/s41593-020-0676-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 06/19/2020] [Indexed: 12/22/2022]
Abstract
We present CLADES (cell lineage access driven by an edition sequence), a technology for cell lineage studies based on CRISPR-Cas9 techniques. CLADES relies on a system of genetic switches to activate and inactivate reporter genes in a predetermined order. Targeting CLADES to progenitor cells allows the progeny to inherit a sequential cascade of reporters, thereby coupling birth order to reporter expression. This system, which can also be temporally induced by heat shock, enables the temporal resolution of lineage development and can therefore be used to deconstruct an extended cell lineage by tracking the reporters expressed in the progeny. When targeted to the germ line, the same cascade progresses across animal generations, predominantly marking each generation with the corresponding combination of reporters. CLADES therefore offers an innovative strategy for making programmable cascades of genes that can be used for genetic manipulation or to record serial biological events.
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Affiliation(s)
| | | | - Kai-Yuan Ku
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Ching-Po Yang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Hung-Hsiang Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Tzumin Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
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Canzler S, Stadler PF, Hertel J. U6 snRNA intron insertion occurred multiple times during fungi evolution. RNA Biol 2016; 13:119-27. [PMID: 26828373 DOI: 10.1080/15476286.2015.1132139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
U6 small nuclear RNAs are part of the splicing machinery. They exhibit several unique features setting them appart from other snRNAs. Reports of introns in structured non-coding RNAs have been very rare. U6 genes, however, were found to be interrupted by an intron in several Schizosaccharomyces species and in 2 Basidiomycota. We conducted a homology search across 147 currently available fungal genome and identified the U6 genes in all but 2 of them. A detailed comparison of their sequences and predicted secondary structures showed that intron insertion events in the U6 snRNA were much more common in the fungal lineage than previously thought. Their positional distribution across the entire mature snRNA strongly suggests a large number of independent events. All the intron sequences reported here show canonical splice site and branch site motifs indicating that they require the splicesomal pathway for their removal.
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Affiliation(s)
- Sebastian Canzler
- a Bioinformatics Group , Department of Computer Science,and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18 , D-04107 Leipzig , Germany
| | - Peter F Stadler
- a Bioinformatics Group , Department of Computer Science,and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18 , D-04107 Leipzig , Germany.,b Computational EvoDevo Group , Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18 , D-04107 Leipzig , Germany.,c LIFE - Leipzig Research Center for Civilization Diseases, Universität Leipzig , Germany.,d Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22 , D-04103 Leipzig , Germany.,e Fraunhofer Institut für Zelltherapie und Immunologie - IZI Perlickstraße 1 , D-04103 Leipzig , Germany.,f Department of Theoretical Chemistry , University of Vienna, Währingerstraße 17, A-1090 Wien , Austria.,g Center for non-coding RNA in Technology and Health , University of Copenhagen, Grønnegårdsvej 3 , DK-1870 Frederiksberg C, Denmark.,h Santa Fe Institute; 1399 Hyde Park Rd. ; Santa Fe ; NM 87501 , USA
| | - Jana Hertel
- a Bioinformatics Group , Department of Computer Science,and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18 , D-04107 Leipzig , Germany.,i Department of Proteomics , Helmholtz Centre for Environmental Research - UFZ , Permoserstrabe 15, 04318 Leipzig , Germany
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6
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Optimization of methods for the genetic modification of human T cells. Immunol Cell Biol 2015; 93:896-908. [PMID: 26027856 PMCID: PMC4659746 DOI: 10.1038/icb.2015.59] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 12/18/2022]
Abstract
CD4+ T cells are critical in the fight against parasitic, bacterial, and viral infections, but are also involved in many autoimmune and pathological disorders. Studies of protein function in human T cells are confined to techniques such as RNAi due to ethical reasons and relative simplicity of these methods. However, introduction of RNAi or genes into primary human T cells is often hampered by toxic effects from transfection or transduction methods that yield cell numbers inadequate for downstream assays. Additionally, the efficiency of recombinant DNA expression is frequently low due to multiple factors including efficacy of the method and strength of the targeting RNAs. Here, we describe detailed protocols that will aid in the study of primary human CD4+ T cells. First, we describe a method for development of effective microRNA/shRNAs using available online algorithms. Second, we illustrate an optimized protocol for high efficacy retroviral or lentiviral transduction of human T cell lines. Importantly, we demonstrate that activated primary human CD4+ T cells can be transduced efficiently with lentiviruses, with a highly activated population of T cells receiving the largest number of copies of integrated DNA. We also illustrate a method for efficient lentiviral transduction of hard-to-transduce un-activated primary human CD4+ T cells. These protocols will significantly assist in understanding the activation and function of human T cells and will ultimately aid in the development or improvement of current drugs that target human CD4+ T cells.
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7
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Optimized gene editing technology for Drosophila melanogaster using germ line-specific Cas9. Proc Natl Acad Sci U S A 2013; 110:19012-7. [PMID: 24191015 DOI: 10.1073/pnas.1318481110] [Citation(s) in RCA: 302] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The ability to engineer genomes in a specific, systematic, and cost-effective way is critical for functional genomic studies. Recent advances using the CRISPR-associated single-guide RNA system (Cas9/sgRNA) illustrate the potential of this simple system for genome engineering in a number of organisms. Here we report an effective and inexpensive method for genome DNA editing in Drosophila melanogaster whereby plasmid DNAs encoding short sgRNAs under the control of the U6b promoter are injected into transgenic flies in which Cas9 is specifically expressed in the germ line via the nanos promoter. We evaluate the off-targets associated with the method and establish a Web-based resource, along with a searchable, genome-wide database of predicted sgRNAs appropriate for genome engineering in flies. Finally, we discuss the advantages of our method in comparison with other recently published approaches.
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8
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Verma N, Hung KH, Kang JJ, Barakat NH, Stumph WE. Differential utilization of TATA box-binding protein (TBP) and TBP-related factor 1 (TRF1) at different classes of RNA polymerase III promoters. J Biol Chem 2013; 288:27564-27570. [PMID: 23955442 DOI: 10.1074/jbc.c113.503094] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In the fruit fly Drosophila melanogaster, RNA polymerase III transcription was found to be dependent not upon the canonical TATA box-binding protein (TBP) but instead upon the TBP-related factor 1 (TRF1) (Takada, S., Lis, J. T., Zhou, S., and Tjian, R. (2000) Cell 101, 459-469). Here we confirm that transcription of fly tRNA genes requires TRF1. However, we unexpectedly find that U6 snRNA gene promoters are occupied primarily by TBP in cells and that knockdown of TBP, but not TRF1, inhibits U6 transcription in cells. Moreover, U6 transcription in vitro effectively utilizes TBP, whereas TBP cannot substitute for TRF1 to promote tRNA transcription in vitro. Thus, in fruit flies, different classes of RNA polymerase III promoters differentially utilize TBP and TRF1 for the initiation of transcription.
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Affiliation(s)
- Neha Verma
- Molecular Biology Institute; Departments of Biology
| | - Ko-Hsuan Hung
- Molecular Biology Institute; Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Jin Joo Kang
- Molecular Biology Institute; Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Nermeen H Barakat
- Molecular Biology Institute; Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - William E Stumph
- Molecular Biology Institute; Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030.
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9
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Hung KH, Stumph WE. Regulation of snRNA gene expression by the Drosophila melanogaster small nuclear RNA activating protein complex (DmSNAPc). Crit Rev Biochem Mol Biol 2010; 46:11-26. [PMID: 20925482 DOI: 10.3109/10409238.2010.518136] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The small nuclear RNAs (snRNAs) are an essential class of non-coding RNAs first identified over 30 years ago. Many of the well-characterized snRNAs are involved in RNA processing events. However, it is now evident that other small RNAs, synthesized using similar mechanisms, play important roles at many stages of gene expression. The accurate and efficient control of the expression of snRNA (and related) genes is thus critical for cell survival. All snRNA genes share a very similar promoter structure, and their transcription is dependent upon the same multi-subunit transcription factor, termed the snRNA activating protein complex (SNAPc). Despite those similarities, some snRNA genes are transcribed by RNA polymerase II (Pol II), but others are transcribed by RNA polymerase III (Pol III). Thus snRNA genes provide a unique opportunity to understand how RNA polymerase specificity is determined and how distinct transcription machineries can interact with a common factor. This review will describe efforts taken toward solving those questions by using the fruit fly as a model organism. Drosophila melanogaster SNAPc (DmSNAPc) binds to a proximal sequence element (PSEA) present in both Pol II and Pol III snRNA promoters. Just a few differences in nucleotide sequence in the Pol II and Pol III PSEAs play a major role in determining RNA polymerase specificity. Furthermore, these same nucleotide differences result in alternative conformations of DmSNAPc on Pol II and Pol III snRNA gene promoters. It seems likely that these DNA-induced alternative DmSNAPc conformations are responsible for the differential recruitment of the distinct transcriptional machineries.
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Affiliation(s)
- Ko-Hsuan Hung
- Department of Biology and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
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10
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Of mice and men: human RNA polymerase III promoter U6 is more efficient than its murine homologue for shRNA expression from a lentiviral vector in both human and murine progenitor cells. Exp Hematol 2010; 38:792-7. [PMID: 20685233 DOI: 10.1016/j.exphem.2010.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 04/27/2010] [Accepted: 05/17/2010] [Indexed: 11/22/2022]
Abstract
OBJECTIVE RNA interference mediated by transcription of short hairpin RNAs (shRNAs) from lentiviral expression vectors has emerged as an efficient method to effectively and specifically silence gene expression in a vast variety of mammalian cells. shRNA expression is routinely driven by a RNA polymerase III promoter, most often by the U6 promoter. Here we demonstrate that U6 promoter activity-and consequently gene silencing success-differs significantly among species. MATERIALS AND METHODS We have modified pLeGO-G, an HIV-based third-generation lentivector, to express a 19nt shRNA sequence against the human transcription factor nuclear factor erythroid 2 or against its murine homologue, as well as an shRNA against murine JAK2, from either the human or the murine U6 promoter. Gene silencing efficiency was analyzed in a human erythroleukemic cell line, in primary human CD34(+) cells, as well as in a murine erythroleukemic cell line and in primary murine bone marrow. RESULTS ShRNA expression from the human U6 promoter resulted in a fourfold increase in knockdown efficiency compared to expression from the murine U6 promoter in both human and murine cells. CONCLUSIONS The U6 promoter constitutes an important determinant for efficient gene silencing by shRNAs.
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Kim MK, Kang YS, Lai HT, Barakat NH, Magante D, Stumph WE. Identification of SNAPc subunit domains that interact with specific nucleotide positions in the U1 and U6 gene promoters. Mol Cell Biol 2010; 30:2411-23. [PMID: 20212087 PMCID: PMC2863707 DOI: 10.1128/mcb.01508-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 12/15/2009] [Accepted: 02/25/2010] [Indexed: 11/20/2022] Open
Abstract
The small nuclear RNA (snRNA)-activating protein complex (SNAPc) is essential for transcription of genes coding for the snRNAs (U1, U2, etc.). In Drosophila melanogaster, the heterotrimeric DmSNAPc recognizes a 21-bp DNA sequence, the proximal sequence element A (PSEA), located approximately 40 to 60 bp upstream of the transcription start site. Upon binding the PSEA, DmSNAPc establishes RNA polymerase II preinitiation complexes on U1 to U5 promoters but RNA polymerase III preinitiation complexes on U6 promoters. Minor differences in nucleotide sequence of the U1 and U6 PSEAs determine RNA polymerase specificity; moreover, DmSNAPc adopts different conformations on these different PSEAs. We have proposed that such conformational differences in DmSNAPc play a key role in determining the different polymerase specificities of the U1 and U6 promoters. To better understand the structure of DmSNAPc-PSEA complexes, we have developed a novel protocol that combines site-specific protein-DNA photo-cross-linking with site-specific chemical cleavage of the protein. This protocol has allowed us to map regions within each of the three DmSNAPc subunits that contact specific nucleotide positions within the U1 and U6 PSEAs. These data help to establish the orientation of each DmSNAPc subunit on the DNA and have revealed cases in which different domains of the subunits differentially contact the U1 versus U6 PSEAs.
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Affiliation(s)
- Mun Kyoung Kim
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Yoon Soon Kang
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Hsien-Tsung Lai
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Nermeen H. Barakat
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Deodato Magante
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - William E. Stumph
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
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12
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Boonanuntanasarn S, Panyim S, Yoshizaki G. Usage of putative zebrafish U6 promoters to express shRNA in Nile tilapia and shrimp cell extracts. Transgenic Res 2009; 18:323-5. [PMID: 19225901 DOI: 10.1007/s11248-009-9249-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Accepted: 01/21/2009] [Indexed: 11/30/2022]
Abstract
We conducted in vitro transcription activities of the three zebrafish U6 putative promoters across species in cell extracts prepared from Nile tilapia (Oreochromis niloticus) and shrimps. The transcription efficiency of these putative U6 promoters in Nile tilapia cell extracts was similar to that of zebrafish cell extracts. In addition, all three zebrafish U6 snRNA promoters were able to express the shRNA in cell extracts prepared from two shrimp species, Penaeus monodon and Litopenaeus vannamei. However, the shRNA transcription products in shrimp cell extracts showed weaker signals. These U6 promoters could promote shRNA expression, suggesting that they have the potential for use for vector-based RNAi in Nile tilapia and shrimps. A putative U6 promoter would provide a powerful tool for long-term GKD in these aquaculture-related species.
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Boonanuntanasarn S, Panyim S, Yoshizaki G. Characterization and organization of the U6 snRNA gene in zebrafish and usage of their promoters to express short hairpin RNA. Mar Genomics 2008; 1:115-21. [PMID: 21798162 DOI: 10.1016/j.margen.2008.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 10/23/2008] [Indexed: 10/21/2022]
Abstract
We have characterized three U6 snRNA genes in zebrafish and randomly designated them as U6-1, U6-2, and U6-3. The U6-1 gene is closely related to the mammal U6 snRNA genes and that the U6-2 and U6-3 genes are more closely related to the Drosophila and Xenopus U6 snRNA genes. The upstream regulatory sequences were located based on their conserved position relative to the transcription start site. Furthermore, we speculate that the "CCAAT box" functions as the distal sequence element in the zebrafish U6 snRNA genes. Genomic BLASTn analysis revealed that at least 555 copies of the U6-1 gene are dispersed throughout the zebrafish genome, whereas the U6-2 and U6-3 genes are each present as a single copy. Three U6 snRNA genes are functionally expressed in various tissues. All three putative promoters were able to transcribe short hairpin RNA (shRNA) in zebrafish cell extracts. Our findings demonstrate that these putative promoters have the potential to be used for vector-based RNA interference (RNAi) in zebrafish. Another U6 snRNA was found from the genomic BLASTn search and designated as U6-4, demonstrating that there are four different types of zebrafish U6 snRNA genes.
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Affiliation(s)
- Surintorn Boonanuntanasarn
- School of Animal Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Muang, Nakhon Ratchasima, 30000 Thailand
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14
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Barakat NH, Stumph WE. TBP recruitment to the U1 snRNA gene promoter is disrupted by substituting a U6 proximal sequence element A (PSEA) for the U1 PSEA. FEBS Lett 2008; 582:2413-6. [PMID: 18547530 DOI: 10.1016/j.febslet.2008.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 05/28/2008] [Accepted: 06/01/2008] [Indexed: 11/19/2022]
Abstract
Transcription of Drosophila U1 or U6 snRNAs by RNA polymerases II and III respectively requires a unique approximately 21 base-pair promoter element termed the proximal sequence element A (PSEA) recognized by the snRNA activating protein complex (DmSNAPc). A five-nucleotide substitution that changed the U1 PSEA to a U6 PSEA inactivated the U1 promoter. Chromatin immunoprecipitation assays indicated this substitution did not affect DmSNAPc DNA binding but instead interfered with SNAPc recruitment of TBP to the TATA-less U1 promoter. These findings support a model wherein sequence differences between the U1 and U6 PSEAs induce distinct DmSNAPc conformational states involved in RNA polymerase selectivity.
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Affiliation(s)
- Nermeen H Barakat
- Department of Chemistry and Biochemistry and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, United States
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15
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Hernandez G, Valafar F, Stumph WE. Insect small nuclear RNA gene promoters evolve rapidly yet retain conserved features involved in determining promoter activity and RNA polymerase specificity. Nucleic Acids Res 2006; 35:21-34. [PMID: 17148477 PMCID: PMC1761439 DOI: 10.1093/nar/gkl982] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In animals, most small nuclear RNAs (snRNAs) are synthesized by RNA polymerase II (Pol II), but U6 snRNA is synthesized by RNA polymerase III (Pol III). In Drosophila melanogaster, the promoters for the Pol II-transcribed snRNA genes consist of approximately 21 bp PSEA and approximately 8 bp PSEB. U6 genes utilize a PSEA but have a TATA box instead of the PSEB. The PSEAs of the two classes of genes bind the same protein complex, DmSNAPc. However, the PSEAs that recruit Pol II and Pol III differ in sequence at a few nucleotide positions that play an important role in determining RNA polymerase specificity. We have now performed a bioinformatic analysis to examine the conservation and divergence of the snRNA gene promoter elements in other species of insects. The 5' half of the PSEA is well-conserved, but the 3' half is divergent. Moreover, within each species positions exist where the PSEAs of the Pol III-transcribed genes differ from those of the Pol II-transcribed genes. Interestingly, the specific positions vary among species. Nevertheless, we speculate that these nucleotide differences within the 3' half of the PSEA act similarly to induce conformational alterations in DNA-bound SNAPc that result in RNA polymerase specificity.
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Affiliation(s)
- Genaro Hernandez
- Department of Chemistry and Biochemistry, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
- Department of Computer Science, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
| | - Faramarz Valafar
- Department of Computer Science, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
| | - William E. Stumph
- Department of Chemistry and Biochemistry, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
- To whom correspondence should be addressed. Tel: +1 619 594 5575; Fax: +1 619 594-4634;
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16
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Li M, Rohrer B. Gene silencing in Xenopus laevis by DNA vector-based RNA interference and transgenesis. Cell Res 2006; 16:99-105. [PMID: 16467881 DOI: 10.1038/sj.cr.7310013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
A vector-based RNAi expression system was developed using the Xenopus tropicalis U6 promoter, which transcribes small RNA genes by RNA polymerase III. The system was first validated in a Xenopus laevis cell line, designing a short hairpin DNA specific for the GFP gene. Co-transfection of the vector-based RNAi and the GFP gene into Xenopus XR1 cells significantly decreased the number of GFP-expressing cells and overall GFP fluorescence. Vector-based RNAi was subsequently validated in GFP transgenic Xenopus embryos. Sperm nuclei from GFP transgenic males and RNAi construct-incubated-sperm nuclei were used for fertilization, respectively. GFP mRNA and protein were reduced by approximately 60% by RNAi in these transgenic embryos compared with the control. This transgene-driven RNAi is specific and stable in inhibiting GFP expression in the Xenopus laevis transgenic line. Gene silencing by vector-based RNAi and Xenopus transgenesis may provide an alternative for 'repression of gene function' studies in vertebrate model systems.
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Affiliation(s)
- Ming Li
- Department of Neurosciences, Division of Research, Medical University of South Carolina, 167 Ashley Ave, SEI 511, Charleston, 29425, USA
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17
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Wakiyama M, Matsumoto T, Yokoyama S. Drosophila U6 promoter-driven short hairpin RNAs effectively induce RNA interference in Schneider 2 cells. Biochem Biophys Res Commun 2005; 331:1163-70. [PMID: 15882998 DOI: 10.1016/j.bbrc.2005.03.240] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Indexed: 10/25/2022]
Abstract
The effect of RNA interference (RNAi) is generally more potent in Drosophila Schneider 2 (S2) cells than in mammalian cells. In mammalian cells, PolIII promoter-based DNA vectors can be used to express small interfering RNA (siRNA) or short hairpin RNA (shRNA); however, this has not been demonstrated in cultured Drosophila cells. Here we show that shRNAs transcribed from the Drosophila U6 promoter can efficiently trigger gene silencing in S2 cells. By targeting firefly luciferase mRNA, we assessed the efficacy of the shRNAs and examined the structural requirements for highly effective shRNAs. The silencing effect was dependent on the length of the stem region and the sequence of the loop region. Furthermore, we demonstrate that the expression of the endogenous cyclin E protein can be repressed by the U6 promoter-driven shRNAs. Drosophila U6 promoter-based shRNA expression systems may permit stable gene silencing in S2 cells.
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Affiliation(s)
- Motoaki Wakiyama
- RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
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18
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Otake LR, Scamborova P, Hashimoto C, Steitz JA. The divergent U12-type spliceosome is required for pre-mRNA splicing and is essential for development in Drosophila. Mol Cell 2002; 9:439-46. [PMID: 11864616 DOI: 10.1016/s1097-2765(02)00441-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A minor class of pre-mRNA introns whose excision requires a spliceosome containing U11, U12, U4atac/U6atac, and U5 snRNPs has been identified in plants, insects, and vertebrates. We have characterized single loci that specify the U6atac and U12 snRNAs of Drosophila melanogaster. P element-mediated disruptions of the U6atac and U12 genes cause lethality during the third instar larval and embryonic stages, respectively, and are rescued by U6atac and U12 transgenes. The P element disruption of U6atac results in excision defects of U12-type introns from several transcripts including an alternative U12-dependent spliced isoform of prospero, a homeodomain protein required for CNS development. Thus, we demonstrate the requirement for the U12 spliceosome in the development of a metazoan organism.
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MESH Headings
- Alternative Splicing
- Animals
- Animals, Genetically Modified
- Base Sequence
- Drosophila Proteins/genetics
- Drosophila Proteins/physiology
- Drosophila melanogaster/embryology
- Drosophila melanogaster/genetics
- Drosophila melanogaster/growth & development
- Drosophila melanogaster/metabolism
- Genes, Lethal
- Introns/genetics
- Larva
- Molecular Sequence Data
- Mutagenesis, Insertional
- Nerve Tissue Proteins/genetics
- Nuclear Proteins/genetics
- Nucleic Acid Conformation
- Protein Isoforms/genetics
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA Splicing
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Ribonucleoprotein, U4-U6 Small Nuclear/genetics
- Ribonucleoprotein, U4-U6 Small Nuclear/physiology
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/physiology
- Sequence Alignment
- Sequence Homology, Nucleic Acid
- Spliceosomes/physiology
- Transcription Factors
- Transgenes
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Affiliation(s)
- Leo R Otake
- Department of Cell Biology, Yale University, Howard Hughes Medical Institute, New Haven, CT 06536, USA
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19
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McNamara-Schroeder KJ, Hennessey RF, Harding GA, Jensen RC, Stumph WE. The Drosophila U1 and U6 gene proximal sequence elements act as important determinants of the RNA polymerase specificity of small nuclear RNA gene promoters in vitro and in vivo. J Biol Chem 2001; 276:31786-92. [PMID: 11431466 DOI: 10.1074/jbc.m101273200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription of genes coding for metazoan spliceosomal snRNAs by RNA polymerase II (U1, U2, U4, U5) or RNA polymerase III (U6) is dependent upon a unique, positionally conserved regulatory element referred to as the proximal sequence element (PSE). Previous studies in the organism Drosophila melanogaster indicated that as few as three nucleotide differences in the sequences of the U1 and U6 PSEs can play a decisive role in recruiting the different RNA polymerases to transcribe the U1 and U6 snRNA genes in vitro. Those studies utilized constructs that contained only the minimal promoter elements of the U1 and U6 genes in an artificial context. To overcome the limitations of those earlier studies, we have now performed experiments that demonstrate that the Drosophila U1 and U6 PSEs have functionally distinct properties even in the environment of the natural U1 and U6 gene 5'-flanking DNAs. Moreover, assays in cells and in transgenic flies indicate that expression of genes from promoters that contain the "incorrect" PSE is suppressed in vivo. The Drosophila U6 PSE is incapable of recruiting RNA polymerase II to initiate transcription from the U1 promoter region, and the U1 PSE is unable to recruit RNA polymerase III to transcribe the U6 gene.
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Affiliation(s)
- K J McNamara-Schroeder
- Department of Chemistry and Molecular Biology Institute, San Diego State University, San Diego, California 92182-1030, USA
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20
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Affiliation(s)
- S M Mount
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, College Park, Maryland 20742-5815, USA.
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21
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Abstract
It has been generally accepted that the TATA binding protein (TBP) is a universal mediator of transcription by RNA polymerase I, II, and III. Here we report that the TBP-related factor TRF1 rather than TBP is responsible for RNA polymerase III transcription in Drosophila. Immunoprecipitation and in vitro transcription assays using immunodepleted extracts supplemented with recombinant proteins reveals that a TRF1:BRF complex is required to reconstitute transcription of tRNA, 5S and U6 RNA genes. In vivo, the majority of TRF1 is complexed with BRF and these two proteins colocalize at many polytene chromosome sites containing RNA pol III genes. These data suggest that in Drosophila, TRF1 rather than TBP forms a complex with BRF that plays a major role in RNA pol III transcription.
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Affiliation(s)
- S Takada
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, 94720, USA
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22
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Müller J, Benecke BJ. Analysis of transcription factors binding to the human 7SL RNA gene promoter. Biochem Cell Biol 1999. [DOI: 10.1139/o99-051] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transcription of the human 7SL RNA gene by RNA polymerase III depends on the concerted action of transcription factors binding to the gene-internal and gene-external parts of its promoter. Here, we investigated which transcription factors interact with the human 7SL RNA gene promoter and which are required for transcription of the human 7SL RNA gene. A-box/B-box elements were previously identified in 5S RNA, tRNA, and virus associated RNA genes and are recognized by transcription factor IIIC (TFIIIC). The gene-internal promoter region of the human 7SL RNA gene shows only limited similarity to those elements. Nevertheless, competition experiments and the use of highly enriched factor preparations demonstrate that TFIIIC is required for human 7SL transcription. The gene-external part of the promoter includes an authentic cAMP-responsive element previously identified in various RNA polymerase II promoters. Here we demonstrate that members of the activating transcription factor/cyclic AMP-responsive element binding protein (ATF/CREB) transcription factor family bind specifically to this element in vitro. However, the human 7SL RNA gene is not regulated by cAMP in vivo. Furthermore, in vitro transcription of the gene does not depend on ATF/CREB transcription factors. It rather appears that a transcription factor with DNA-binding characteristics like ATF/CREB proteins but otherwise different properties is required for human 7SL RNA transcription.Key words: 7SL RNA, ATF, CRE, TFIIIC, RNA polymerase III.
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23
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Wang Y, Stumph WE. Identification and topological arrangement of Drosophila proximal sequence element (PSE)-binding protein subunits that contact the PSEs of U1 and U6 small nuclear RNA genes. Mol Cell Biol 1998; 18:1570-9. [PMID: 9488474 PMCID: PMC108872 DOI: 10.1128/mcb.18.3.1570] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Most small nuclear RNAs (snRNAs) are synthesized by RNA polymerase II, but U6 and a few others are synthesized by RNA polymerase III. Transcription of snRNA genes by either polymerase is dependent on a proximal sequence element (PSE) located upstream of position -40 relative to the transcription start site. In contrast to findings in vertebrates, sea urchins, and plants, the RNA polymerase specificity of Drosophila snRNA genes is intrinsically encoded in the PSE sequence itself. We have investigated the differential interaction of the Drosophila melanogaster PSE-binding protein (DmPBP) with U1 and U6 gene PSEs. By using a site specific protein-DNA photo-cross-linking assay, we identified three polypeptide subunits of DmPBP with apparent molecular masses of 95, 49, and 45 kDa that are in close proximity to the DNA and two additional putative polypeptides of 230 and 52 kDa that may be integral to the complex. The 95-kDa subunit cross-linked at positions spanning the entire length of the PSE, but the 49- and 45-kDa subunits cross-linked only to the 3' half of the PSE. The same polypeptides cross-linked to both the U1 and U6 PSE sequences. However, there were significant differences in the cross-linking patterns of these subunits at a subset of the phosphate positions, depending on whether binding was to a U1 or U6 gene PSE. These data suggest that RNA polymerase specificity is associated with distinct modes of interaction of DmPBP with the DNA at U1 and U6 promoters.
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Affiliation(s)
- Y Wang
- Department of Chemistry and Molecular Biology Institute, San Diego State University, California 92182-1030, USA
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24
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Jensen RC, Wang Y, Hardin SB, Stumph WE. The proximal sequence element (PSE) plays a major role in establishing the RNA polymerase specificity of Drosophila U-snRNA genes. Nucleic Acids Res 1998; 26:616-22. [PMID: 9421524 PMCID: PMC147272 DOI: 10.1093/nar/26.2.616] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Most small nuclear RNA (snRNA) genes are transcribed by RNA polymerase II, but some (e.g., U6) are transcribed by RNA polymerase III. In vertebrates a TATA box at a fixed distance downstream of the proximal sequence element (PSE) acts as a dominant determinant for recruiting RNA polymerase III to U6 gene promoters. In contrast, vertebrate snRNA genes that contain a PSE but lack a TATA box are transcribed by RNA polymerase II. In plants, transcription of both classes of snRNA genes requires a TATA box in addition to an upstream sequence element (USE), and polymerase specificity is determined by the spacing between these two core promoter elements. In these examples, the PSE (or USE) is interchangeable between the two classes of snRNA genes. Here we report the surprising finding that the Drosophila U1 and U6 PSEs cannot functionally substitute for each other; rather, determination of RNA polymerase specificity is an intrinsic property of the PSE sequence itself. The alteration of two or three base pairs near the 3'-end of the U1 and U6 PSEs was sufficient to switch the RNA polymerase specificity of Drosophila snRNA promoters in vitro. These findings reveal a novel mechanism for achieving RNA polymerase specificity at insect snRNA promoters.
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Affiliation(s)
- R C Jensen
- Department of Chemistry and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
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25
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Su Y, Song Y, Wang Y, Jessop L, Zhan L, Stumph WE. Characterization of a Drosophila proximal-sequence-element-binding protein involved in transcription of small nuclear RNA genes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 248:231-7. [PMID: 9310383 DOI: 10.1111/j.1432-1033.1997.t01-1-00231.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In a wide variety of eukaryotic organisms, transcription of small nuclear RNA (snRNA) genes is dependent upon a proximal sequence element (PSE) located upstream of position -40 relative to the transcription start site. There is little or no existent knowledge concerning the PSE-binding proteins of organisms other than human. Here, we report the purification of a fraction enriched in the Drosophila melanogaster PSE-binding protein (DmPBP). DmPBP forms a highly specific complex with the PSE. The protein stimulates transcription from the U1 gene promoter by RNA polymerase II and from the U6 gene promoter by RNA polymerase III in Drosophila nuclear extracts, and activation is dependent upon the presence of a PSE. The molecular mass of native DmPBP as measured by gel-filtration chromatography is 375 kDa. Two polypeptides (apparent molecular masses 59 kDa and 61 kDa) appear to be in close contact with the DNA in that they can be very efficiently and specifically crosslinked to the PSE sequence by ultraviolet irradiation.
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Affiliation(s)
- Y Su
- Department of Chemistry and Molecular Biology Institute, San Diego State University, CA 92182-1030, USA
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26
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Sakallah SA, Norton DR, Zhang W, Marzluff WF. Isolation and characterization of the tandemly repeated U6 genes from the sea urchin Strongylocentrotus purpuratus. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1218:439-42. [PMID: 8049270 DOI: 10.1016/0167-4781(94)90201-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The tandemly repeated U6 genes were isolated from the sea urchin Strongylocentrotus purpuratus. Each 1.8 kb repeat unit contains a single U6 RNA sequence. There are no sequence similarities between the U6 promoter and other sea urchin snRNA genes, other than a long polypyrimidine tract 3' of the U6 sequence.
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Affiliation(s)
- S A Sakallah
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill 27599
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27
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Garber ME, Vilalta A, Johnson DL. Induction of Drosophila RNA polymerase III gene expression by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) is mediated by transcription factor IIIB. Mol Cell Biol 1994; 14:339-47. [PMID: 8264601 PMCID: PMC358383 DOI: 10.1128/mcb.14.1.339-347.1994] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We have previously found that the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) induces specific transcription of tRNA and 5S RNA genes in Drosophila Schneider S-2 cells (M. Garber, S. Panchanathan, R. F. Fan, and D. L. Johnson, J. Biol. Chem. 266:20598-20601, 1991). Having derived cellular extracts from TPA-treated cells, that are capable of reproducing this stimulation in vitro, we have examined the mechanism for this regulatory event. Using conditions that limit reinitiation and produce single rounds of transcription from active gene complexes, we find that the number of functional transcription complexes is increased in extracts prepared from TPA-induced cells. We have analyzed the activities of the transcription factors TFIIIB and TFIIIC derived from extracts prepared from TPA-induced and noninduced cells. Examination of the relative activities of TFIIIC showed that both its ability to reconstitute transcription with TFIIIB and RNA polymerase III and its ability to stably bind to the DNA template are unchanged. However, the activity of TFIIIB derived from the TPA-induced cells is substantially increased compared with that derived from the noninduced cells. The differences in TFIIIB activity account for the differences in the overall transcriptional activities observed in the unfractionated extracts. Western blot analysis of the TATA-binding protein subunit of TFIIIB revealed that there is an increase in the amount of this polypeptide present in the induced cell extracts and TFIIIB fraction. Together, these results indicate that the TPA response in Drosophila cells stimulates specific transcription of RNA polymerase III genes by increasing the activity of the limiting transcription component, TFIIIB, and thereby increasing the number of functional transcription complexes.
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Affiliation(s)
- M E Garber
- Department of Molecular Pharmacology and Toxicology, University of Southern California, Los Angeles 90033
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28
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Guerineau F, Waugh R. The U6 small nuclear RNA gene family of potato. PLANT MOLECULAR BIOLOGY 1993; 22:807-818. [PMID: 8358031 DOI: 10.1007/bf00027367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Using the inverse polymerase chain reaction (IPCR), 19 U6snRNA gene promoters were isolated from the potato genome. Analysis of their nucleotide sequences revealed the existence of two subfamilies. Promoters from class 1 harbour the typical sequence elements required for plant snRNA gene transcription whereas those from class 2 do not have a TATA box. Three promoters were fused to a modified U6snRNA-coding sequence to allow their activity to be monitored in tobacco protoplasts. Two of the promoters, one from either class, were found to be active. Comparison of potato U6snRNA gene promoter sequences with those found in other plant species showed various degrees of homology. In addition, the entire nucleotide sequences of seven potato U6snRNA genes and one pseudogene were determined. The overall frequency of nucleotide changes after PCR was found to be 1.15 x 10(-3). The mutations appeared to be clustered in a distinct area and were all A-to-G/T-to-C substitutions.
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Affiliation(s)
- F Guerineau
- Scottish Crop Research Institute, Invergowrie, Dundee, UK
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29
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RNA polymerase III transcription of genes that lack internal control regions. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1088:1-9. [PMID: 1989689 DOI: 10.1016/0167-4781(91)90146-d] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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30
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Moon IS, Krause MO. Common RNA polymerase I, II, and III upstream elements in mouse 7SK gene locus revealed by the inverse polymerase chain reaction. DNA Cell Biol 1991; 10:23-32. [PMID: 1671331 DOI: 10.1089/dna.1991.10.23] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
7SK RNA in mammalian cells is derived from a gene or genes belonging to a middle-repetitive family in the genome. Standard library search techniques applied to isolating such genes are complicated by the finding of multiple truncated or otherwise modified versions of the sequence, whereas the true gene loci can sometimes be eliminated from amplified libraries. After an unsuccessful search for the 7SK RNA gene in four mouse genomic libraries, we used the inverse polymerase chain reaction (IPCR) on fractionated genomic DNA to characterize sequences containing complete copies of 7SK plus flanking regions for analysis of putative transcription regulatory sequences. Direct sequence of IPCR-amplified material allowed for selection of upstream and downstream primers which could then be used for direct PCR, sequencing, and characterization of the mouse 7SK gene locus. So far, we found only one complete copy of the canonical 7SK gene that differed from the human sequence in only 4 bases. The gene is flanked by a very well-conserved upstream control region that includes a TATA motif, two direct repeats, and a proximal sequence element common to mammalian genes transcribed by all three RNA polymerases. The 3' region contains multiple stretches of T residues, typical of class III terminators.
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Affiliation(s)
- I S Moon
- Department of Biology, University of New Brunswick, Fredericton, Canada
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31
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Lührmann R, Kastner B, Bach M. Structure of spliceosomal snRNPs and their role in pre-mRNA splicing. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1087:265-92. [PMID: 2147394 DOI: 10.1016/0167-4781(90)90001-i] [Citation(s) in RCA: 293] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- R Lührmann
- Institut für Molekularbiologie und Tumorforschung, Philipps-Universität Marburg F.R.G
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32
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Bredow S, Kleinert H, Benecke BJ. Sequence and factor requirements for faithful in vitro transcription of human 7SL DNA. Gene 1990; 86:217-25. [PMID: 2323574 DOI: 10.1016/0378-1119(90)90282-v] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have analysed the transcription of a functional human 7SL gene by RNA polymerase III (RNAPIII) in S100 extracts in vitro. Accurate and efficient synthesis of 7S L RNA depends on the presence of (i) an upstream sequence and (ii) an internal promoter element located within the first 22 bp of the gene. These findings were substantiated by DNase I footprinting. Mutations of the internal promoter identified the doublet CG [nucleotide (nt) +15/+16] outside the A-box homologue (nt +5 to +14) as being essential for both proper promoter function in the in vitro transcription assay and competition in the template-exclusion assay. Fractionation of S100 extracts identified two fractions required in addition to RNAPIII for faithful transcription of the gene. Each of these two fractions gave rise to one of two footprints observed in DNase I protection experiments, indicating that at least two DNA-binding factors are involved.
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Affiliation(s)
- S Bredow
- Department of Biochemistry, Ruhr University, Bochum, F.R.G
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33
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Affiliation(s)
- G W Zieve
- Department of Basic Sciences, Hutchinson Cancer Research, Seattle, Washington
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34
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Yuan Y, Reddy R. Genes for human U3 small nucleolar RNA contain highly conserved flanking sequences. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1008:14-22. [PMID: 2719960 DOI: 10.1016/0167-4781(89)90164-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Six human genomic clones containing sequences homologous to the U3 small nuclear RNA (snRNA) were isolated and characterized. Four of these clones were real U3 snRNA genes because they were transcribed in frog oocytes and the DNA sequences corresponding to the U3 snRNA were identical to the U3 snRNA of HeLa cells. The nucleotide sequences of four true U3 snRNA genes, 537 nucleotides on the 5'-flanking region and 340 nucleotides on the 3'-flanking region, were found to be identical. In addition, the restriction patterns, upto 2 kb on the 5' side and 2.2 kb on the 3' side, appeared to be same. All the isolated U3 clones, containing 15-20 kb of genomic DNA, contained only one U3 snRNA gene, indicating that the human U3 snRNA genes are several kilobases apart. One of the U3 clones contained a full-length U3 pseudogene. Southern blot analysis of genomic DNA with cloned U3 DNA as probe indicated that human DNA contains two families of U3 genes which differ in their flanking sequences. In the 5' flanking region of human U3 snRNA genes, homology to U-gene promoter element, an octamer motif, the 'U3 box', SP1 binding sites and a consensus 3' box in the 3' flanking region, were observed. These data show that the genomic organization and the sequence motifs that control transcription of human nucleolar U3 snRNA genes are similar to those of human U1 and U2 snRNA genes and suggest common mechanism(s) in the evolution of snRNA genes.
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Affiliation(s)
- Y Yuan
- Baylor College of Medicine, Department of Pharmacology, Houston, TX 77030
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35
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Transcription of Xenopus selenocysteine tRNASer (formerly designated opal suppressor phosphoserine tRNA) gene is directed by multiple 5′-extragenic regulatory elements. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60586-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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36
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Abstract
The small nuclear RNAs (snRNAs) are a class of metabolically stable small RNAs present in the nuclei of eukaryotic cells. In mammalian cells, there are six major molecular species (U1 to U6 snRNA), which are complexed with proteins, forming small nuclear ribonucleoprotein particles, snRNPs. Of these, the U1, U2, U4, U5, U6 snRNPs are thought to participate in pre-mRNA splicing as part of the spliceosome. Here, we describe the characterization of the gene coding for the Schizosaccharomyces pombe U6 snRNA. Unexpectedly, the Schiz. pombe U6 RNA gene was found to contain an intron-like sequence of 50 base pairs. Northern blot analysis and RNA sequencing revealed that this intron-like sequence is precisely removed from the transcript. The mature U6 RNA of Schiz. pombe has 77% sequence homology with the mammalian U6 RNA. In Schiz. pombe, it is possible that U6 RNA is not only involved in pre-mRNA splicing, but is also a splicing substrate. This is the first report of an intron in a snRNA gene.
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Affiliation(s)
- T Tani
- Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan
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37
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Abstract
U6 RNA is an abundant small nuclear RNA (snRNA) required for splicing of pre-mRNAs. In mammalian cells, the genes for U1 to U4 snRNAs consist of multigene families ranging from 10 to 100 copies of real genes per haploid genome, and are transcribed by RNA polymerase II. In contrast, results obtained in this study indicate that U6 RNA, which is transcribed by RNA polymerase II and III, may be coded for in mouse cells by only two genes. These two U6 genes are at least 9 kb apart from each other, and the flanking sequences are highly conserved, indicating that the organization of U6 genes is similar to that observed for other mammalian U-snRNA genes.
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Affiliation(s)
- Y Yuan
- Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030
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38
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39
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Transcription of a U6 small nuclear RNA gene in vitro. Transcription of a mouse U6 small nuclear RNA gene in vitro by RNA polymerase III is dependent on transcription factor(s) different from transcription factors IIIA, IIIB, and IIIC. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37545-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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40
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Abstract
The small nuclear RNA U6 and its gene have been isolated from yeast. In striking contrast to other yeast spliceosomal RNAs, U6 is very similar in size, sequence and structure to its mammalian homologue. The single-copy gene is essential. These properties suggest a central role in pre-mRNA processing. An extensive base-pairing interaction with U4 snRNA is described; the destabilization of the U4/U6 complex seen during splicing thus requires a large conformational change.
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Affiliation(s)
- D A Brow
- Department of Biochemistry and Biophysics, University of California, San Francisco 94143
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41
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Kunkel GR, Pederson T. Upstream elements required for efficient transcription of a human U6 RNA gene resemble those of U1 and U2 genes even though a different polymerase is used. Genes Dev 1988; 2:196-204. [PMID: 3360322 DOI: 10.1101/gad.2.2.196] [Citation(s) in RCA: 133] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
U6 small nuclear RNA is transcribed by a different polymerase than U1-U5 RNAs, likely to be RNA polymerase III. Transcription from human U6 gene deletion-substitution templates in a HeLa S100 extract delineated the 5' border of a control element lying between 67 and 43 bp upstream from the initiation site. This region matches the location of, and shows considerable sequence similarity with, the proximal control element of U1 and U2 RNA genes, which are transcribed by RNA polymerase II. Transfection of human 293 cells with 5'-flanking deletion-substitution mutants of a U6 maxigene revealed a dominant control element between 245 and 149 bp upstream of the transcription start site. An octamer motif was found in this region in an inverted orientation relative to that of the human U1 and U2 RNA gene enhancers but in the same orientation as a human U4 RNA gene, the transcript of which functions together with U6 RNA in a single small nuclear ribonucleoprotein (snRNP) particle. The human U2 gene enhancer joined to the U6 maxigene was able to functionally replace the U6 distal control element(s).
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Affiliation(s)
- G R Kunkel
- Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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42
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Abstract
Precursors to mRNA become substrates for splicing by being assembled into a complex multisubunit structure, the spliceosome. To study the assembly of the yeast spliceosome, intermediate complexes were separated by electrophoresis on nondenaturing polyacrylamide gels. Four splicing-dependent complexes, A1, A2-1, A2-2, and B, were observed. The order of assembly of these complexes was determined to be B----A2-1----A1----A2-2. The assembly process can be blocked at complex A1 by addition of 5 mM EDTA or by carrying out the assembly process in heat-inactivated rna2 extracts. The snRNA composition of the complexes was determined by hybridization with probes for five yeast snRNAs. snR14 (U4) was only found in complex A2-1, snR6 (U6) and snR7 (U5) were in complexes A1, A2-1, and A2-2, whereas snR20 (U2) was in all four of the complexes. snR19 (U1) was not present in any of the complexes. Hybridization with these probes was also employed to detect snRNPs present in yeast splicing extracts. We found that snR6, snR7, and snR14 were present together in a large complex. This complex underwent an ATP-dependent dissociation to give snR7 and snR6-snR14 complexes. snR19 and snR20 are present in distinct RNPs but the mobility of these is not affected by ATP. A mechanism for spliceosome assembly is proposed.
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Affiliation(s)
- S C Cheng
- Division of Biology, California Institute of Technology, Pasadena 91125
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