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Kling E, Spaller T, Schiefner J, Bönisch D, Winckler T. Convergent evolution of integration site selection upstream of tRNA genes by yeast and amoeba retrotransposons. Nucleic Acids Res 2019; 46:7250-7260. [PMID: 29945249 PMCID: PMC6101501 DOI: 10.1093/nar/gky582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/15/2018] [Indexed: 12/17/2022] Open
Abstract
Transposable elements amplify in genomes as selfish DNA elements and challenge host fitness because their intrinsic integration steps during mobilization can compromise genome integrity. In gene-dense genomes, transposable elements are notably under selection to avoid insertional mutagenesis of host protein-coding genes. We describe an example of convergent evolution in the distantly related amoebozoan Dictyostelium discoideum and the yeast Saccharomyces cerevisiae, in which the D. discoideum retrotransposon DGLT-A and the yeast Ty3 element developed different mechanisms to facilitate position-specific integration at similar sites upstream of tRNA genes. Transcription of tRNA genes by RNA polymerase III requires the transcription factor complexes TFIIIB and TFIIIC. Whereas Ty3 recognizes tRNA genes mainly through interactions of its integrase with TFIIIB subunits, the DGLT-A-encoded ribonuclease H contacts TFIIIC subunit Tfc4 at an interface that covers tetratricopeptide repeats (TPRs) 7 and 8. A major function of this interface is to connect TFIIIC subcomplexes τA and τB and to facilitate TFIIIB assembly. During the initiation of tRNA gene transcription τB is displaced from τA, which transiently exposes the TPR 7/8 surface of Tfc4 on τA. We propose that the DGLT-A intasome uses this binding site to obtain access to genomic DNA for integration during tRNA gene transcription.
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Affiliation(s)
- Eva Kling
- Pharmaceutical Biology, Institute of Pharmacy, Friedrich Schiller University Jena, Germany
| | - Thomas Spaller
- Pharmaceutical Biology, Institute of Pharmacy, Friedrich Schiller University Jena, Germany
| | - Jana Schiefner
- Pharmaceutical Biology, Institute of Pharmacy, Friedrich Schiller University Jena, Germany
| | - Doreen Bönisch
- Pharmaceutical Biology, Institute of Pharmacy, Friedrich Schiller University Jena, Germany
| | - Thomas Winckler
- Pharmaceutical Biology, Institute of Pharmacy, Friedrich Schiller University Jena, Germany
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Yang SP, Chen SR, Liu SW, Tang XY, Qin L, Qiu GH, Chen JX, Chen WH. Platforms Formed from a Three-Dimensional Cu-Based Zwitterionic Metal-Organic Framework and Probe ss-DNA: Selective Fluorescent Biosensors for Human Immunodeficiency Virus 1 ds-DNA and Sudan Virus RNA Sequences. Anal Chem 2015; 87:12206-14. [PMID: 26619043 DOI: 10.1021/acs.analchem.5b03084] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We herein report a water-stable three-dimensional Cu-based metal-organic framework (MOF) 1 supported by a tritopic quaternized carboxylate and 4,4'-dipyridyl sulfide as an ancillary ligand. This MOF exhibits unique pore shapes with aromatic rings, positively charged pyridinium and unsaturated Cu(II) cation centers, free carboxylates, tessellating H2O, and coordinating SO4(2-) on the pore surface. Compound 1 can interact with two carboxyfluorescein (FAM)-labeled single-stranded DNA sequences (probe ss-DNA, delineated as P-DNA) through electrostatic, π-stacking, and/or hydrogen-bonding interactions to form two P-DNA@1 systems, and thus quench the fluorescence of FAM via a photoinduced electron-transfer process. These P-DNA@1 systems can be used as effective fluorescent sensors for human immunodeficiency virus 1 double-stranded DNA and Sudan virus RNA sequences, respectively, with detection limits of 196 and 73 pM, respectively.
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Affiliation(s)
- Shui-Ping Yang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Shao-Rui Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Shu-Wen Liu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Xiao-Yan Tang
- Department of Chemistry and Materials Engineering, Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology , Changshu 215500, Jiangsu P. R. China
| | - Liang Qin
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Gui-Hua Qiu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Jin-Xiang Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
| | - Wen-Hua Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University , Guangzhou 510515, P. R. China
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Esnault C, Levin HL. The Long Terminal Repeat Retrotransposons Tf1 and Tf2 of Schizosaccharomyces pombe. Microbiol Spectr 2015; 3:10.1128/microbiolspec.MDNA3-0040-2014. [PMID: 26350316 PMCID: PMC6388632 DOI: 10.1128/microbiolspec.mdna3-0040-2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Indexed: 12/15/2022] Open
Abstract
The long terminal repeat (LTR) retrotransposons Tf1 and Tf2 of Schizosaccharomyces pombe are active mobile elements of the Ty3/gypsy family. The mobilization of these retrotransposons depends on particle formation, reverse transcription and integration, processes typical of other LTR retrotransposons. However, Tf1 and Tf2 are distinct from other LTR elements in that they assemble virus-like particles from a single primary translation product, initiate reverse transcription with an unusual self-priming mechanism, and, in the case of Tf1, integrate with a pattern that favors specific promoters of RNA pol II-transcribed genes. To avoid the chromosome instability and genome damage that results from increased copy number, S. pombe applies a variety of defense mechanisms that restrict Tf1 and Tf2 activity. The mRNA of the Tf elements is eliminated by an exosome-based pathway when cells are in favorable conditions whereas nutrient deprivation triggers an RNA interference-dependent pathway that results in the heterochromatization of the elements. Interestingly, Tf1 integrates into the promoters of stress-induced genes and these insertions are capable of increasing the expression of adjacent genes. These properties of Tf1 transposition raise the possibility that Tf1 benefits cells with specific insertions by providing resistance to environmental stress.
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Affiliation(s)
- Caroline Esnault
- Section on Eukaryotic Transposable Elements, Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Henry L Levin
- Section on Eukaryotic Transposable Elements, Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
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Peng Z, Yuan C, Zellmer L, Liu S, Xu N, Liao DJ. Hypothesis: Artifacts, Including Spurious Chimeric RNAs with a Short Homologous Sequence, Caused by Consecutive Reverse Transcriptions and Endogenous Random Primers. J Cancer 2015; 6:555-67. [PMID: 26000048 PMCID: PMC4439942 DOI: 10.7150/jca.11997] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/02/2015] [Indexed: 12/21/2022] Open
Abstract
Recent RNA-sequencing technology and associated bioinformatics have led to identification of tens of thousands of putative human chimeric RNAs, i.e. RNAs containing sequences from two different genes, most of which are derived from neighboring genes on the same chromosome. In this essay, we redefine "two neighboring genes" as those producing individual transcripts, and point out two known mechanisms for chimeric RNA formation, i.e. transcription from a fusion gene or trans-splicing of two RNAs. By our definition, most putative RNA chimeras derived from canonically-defined neighboring genes may either be technical artifacts or be cis-splicing products of 5'- or 3'-extended RNA of either partner that is redefined herein as an unannotated gene, whereas trans-splicing events are rare in human cells. Therefore, most authentic chimeric RNAs result from fusion genes, about 1,000 of which have been identified hitherto. We propose a hypothesis of "consecutive reverse transcriptions (RTs)", i.e. another RT reaction following the previous one, for how most spurious chimeric RNAs, especially those containing a short homologous sequence, may be generated during RT, especially in RNA-sequencing wherein RNAs are fragmented. We also point out that RNA samples contain numerous RNA and DNA shreds that can serve as endogenous random primers for RT and ensuing polymerase chain reactions (PCR), creating artifacts in RT-PCR.
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Affiliation(s)
- Zhiyu Peng
- 1. Beijing Genomics Institute at Shenzhen, Building No.11, Beishan Industrial Zone, Yantian District, Shenzhen 518083, P. R. China
| | - Chengfu Yuan
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Lucas Zellmer
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Siqi Liu
- 3. CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Ningzhi Xu
- 4. Laboratory of Cell and Molecular Biology, Cancer Institute, Chinese Academy of Medical Science, Beijing 100021, P. R. China
| | - D Joshua Liao
- 2. Hormel Institute, University of Minnesota, Austin, MN 55912, USA
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Voronin N, Herzig E, Hizi A. The dUTPase-related gene of bovine immunodeficiency virus is critical for viral replication, despite the lack of dUTPase activity of the encoded protein. Retrovirology 2014; 11:60. [PMID: 25117862 PMCID: PMC4261571 DOI: 10.1186/1742-4690-11-60] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/09/2014] [Indexed: 01/03/2023] Open
Abstract
Background Deoxyuridine 5′-triphosphate nucleotide-hydrolases (dUTPases) are essential for maintaining low intra-cellular dUTP/dTTP ratios. Therefore, many viruses encode this enzyme to prevent dUTP incorporation into their genomes instead of dTTP. Among the lentiviruses, the non-primate viruses express dUTPases. In bovine immunodeficiency virus (BIV), the putative dUTPase protein is only 74 residues-long, compared to ~130 residues in other lentiviruses. Results In this study, the recombinant BIV dUTPase, as well as infectious wild-type (WT) BIV virions, were shown to lack any detectable dUTPase activity. Controls of recombinant dUTPase from equine infectious anemia virus (EIAV) or of EIAV virions showed substantial dUTPase activities. To assess the importance of the dUTPase to BIV replication, we have generated virions of WT BIV or BIV with mutations in the dUTPase gene. The two mutant viral dUTPases were the double mutant D48E/N57S (in the putative enzyme active site and its vicinity) and a deletion of 36 residues. In dividing Cf2Th cells and under conditions where the WT virus was infectious and generated progeny virions, both mutant viruses were defective, as no progeny viruses were generated. Analyses of the integrated viral cDNA showed that cells infected with the mutant virions carry in their genomic DNA levels of integrated BIV DNA that are comparable to those in WT BIV-infected cells. Conclusions The herby presented results show that the two BIV mutants with the modified dUTPase gene could infect cells, as viral cDNA was synthesized and integrated into the host cell DNA. However, no virions were generated by cells infected by these mutants. The most likely explanation is that either the integrated cDNA of the mutants is defective (due to potential multiple mutations, introduced during reverse-transcription) or that the original dUTPase mutations have led to severe blocks in viral replication at steps post integration. These results emphasize the importance of the dUTPase-related sequence to BIV replication, despite the lack of any detectable catalytic activity. Electronic supplementary material The online version of this article (doi:10.1186/1742-4690-11-60) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Amnon Hizi
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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Yuan C, Liu Y, Yang M, Liao DJ. New methods as alternative or corrective measures for the pitfalls and artifacts of reverse transcription and polymerase chain reactions (RT-PCR) in cloning chimeric or antisense-accompanied RNA. RNA Biol 2013; 10:958-67. [PMID: 23618925 PMCID: PMC4111735 DOI: 10.4161/rna.24570] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We established new methods for cloning cDNA ends that start with reverse transcription (RT) and soon proceed with the synthesis of the second cDNA strand, avoiding manipulations of fragile RNA. Our 3′-end cloning method does not involve poly-dT primers and polymerase chain reactions (PCR), is low in efficiency but high in fidelity and can clone those RNAs without a poly-A tail. We also established a cDNA protection assay to supersede RNA protection assay. The protected cDNA can be amplified, cloned and sequenced, enhancing sensitivity and fidelity. We report that RT product using gene-specific primer (GSP) cannot be gene- or strand-specific because RNA sample contains endogenous random primers (ERP). The gene-specificity may be improved by adding a linker sequence at the 5′-end of the GSP to prime RT and using the linker as a primer in the ensuing PCR. The strand-specificity may be improved by using strand-specific DNA oligos in our protection assay. The CDK4 mRNA and TSPAN31 mRNA are transcribed from the opposite DNA strands and overlap at their 3′ ends. Using this relationship as a model, we found that the overlapped sequence might serve as a primer with its antisense as the template to create a wrong-template extension in RT or PCR. We infer that two unrelated RNAs or cDNAs overlapping at the 5′- or 3′-end might create a spurious chimera in this way, and many chimeras with a homologous sequence may be such artifacts. The ERP and overlapping antisense together set complex pitfalls, which one should be aware of.
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Affiliation(s)
- Chengfu Yuan
- Hormel Institute, University of Minnesota, Austin, MN, USA
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