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Fernández-Pérez J, Nantón A, Méndez J. Sequence characterization of the 5S ribosomal DNA and the internal transcribed spacer (ITS) region in four European Donax species (Bivalvia: Donacidae). BMC Genet 2018; 19:97. [PMID: 30367592 PMCID: PMC6204057 DOI: 10.1186/s12863-018-0684-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 10/11/2018] [Indexed: 01/04/2023] Open
Abstract
Background The whole repeat unit of 5S rDNA and the internal transcribed spacer (ITS) of four European Donax species were analysed. After amplifying, cloning and sequencing several 5S and ITS units, their basic features and their variation were described. The phylogenetic usefulness of 5S and ITS sequences in the inference of evolutionary relationships among these wedge clams was also investigated. Results The length of the 5S repeat presented little variation among species, except D. trunculus that differed from the rest of the Donax species in 170–210 bp. The deduced coding region covered 120 bp, and showed recognizable internal control regions (ICRs) involved in the transcription. The length of non-transcribed spacer region (NTS) ranged from 157 bp to 165 bp in Donax trunculus and from 335 bp to 367 bp in the other three species. The conservation degree of transcriptional regulatory regions was analysed revealing a conserved TATA-like box in the upstream region. Regarding ITS sequences, the four Donax species showed slight size differences among clones due to the variation occurring in the ITS1 and ITS2, except Donax variegatus did not display size differences in the ITS2. The total length of the ITS sequence ranged between 814 and 1014 bp. Resulting phylogenetic trees display that the two ribosomal DNA regions provide well-resolved phylogenies where the four European Donax species form a single clade receiving high support in nodes. The topology obtained with 5S sequences was in agreement with Donax evolutionary relationships inferred from several sequences of different nature in previous studies. Conclusions This is not only a basic research work, where new data and new knowledge is provided about Donax species, but also have allowed the authentication of these wedge clams and offers future applications to provide other genetic resources. Electronic supplementary material The online version of this article (10.1186/s12863-018-0684-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jenyfer Fernández-Pérez
- Grupo Xenomar, Departamento de Bioloxía, Facultade de Ciencias and Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, Campus de A Zapateira, 15071, A Coruña, Spain.
| | - Ana Nantón
- Grupo Xenomar, Departamento de Bioloxía, Facultade de Ciencias and Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, Campus de A Zapateira, 15071, A Coruña, Spain
| | - Josefina Méndez
- Grupo Xenomar, Departamento de Bioloxía, Facultade de Ciencias and Centro de Investigaciones Científicas Avanzadas (CICA), Universidade da Coruña, Campus de A Zapateira, 15071, A Coruña, Spain
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2
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Behura SK, Sarro J, Li P, Mysore K, Severson DW, Emrich SJ, Duman-Scheel M. High-throughput cis-regulatory element discovery in the vector mosquito Aedes aegypti. BMC Genomics 2016; 17:341. [PMID: 27161480 PMCID: PMC4862039 DOI: 10.1186/s12864-016-2468-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/12/2016] [Indexed: 12/15/2022] Open
Abstract
Background Despite substantial progress in mosquito genomic and genetic research, few cis-regulatory elements (CREs), DNA sequences that control gene expression, have been identified in mosquitoes or other non-model insects. Formaldehyde-assisted isolation of regulatory elements paired with DNA sequencing, FAIRE-seq, is emerging as a powerful new high-throughput tool for global CRE discovery. FAIRE results in the preferential recovery of open chromatin DNA fragments that are not bound by nucleosomes, an evolutionarily conserved indicator of regulatory activity, which are then sequenced. Despite the power of the approach, FAIRE-seq has not yet been applied to the study of non-model insects. In this investigation, we utilized FAIRE-seq to profile open chromatin and identify likely regulatory elements throughout the genome of the human disease vector mosquito Aedes aegypti. We then assessed genetic variation in the regulatory elements of dengue virus susceptible (Moyo-S) and refractory (Moyo-R) mosquito strains. Results Analysis of sequence data obtained through next generation sequencing of FAIRE DNA isolated from A. aegypti embryos revealed >121,000 FAIRE peaks (FPs), many of which clustered in the 1 kb 5’ upstream flanking regions of genes known to be expressed at this stage. As expected, known transcription factor consensus binding sites were enriched in the FPs, and of these FoxA1, Hunchback, Gfi, Klf4, MYB/ph3 and Sox9 are most predominant. All of the elements tested in vivo were confirmed to drive gene expression in transgenic Drosophila reporter assays. Of the >13,000 single nucleotide polymorphisms (SNPs) recently identified in dengue virus-susceptible and refractory mosquito strains, 3365 were found to map to FPs. Conclusion FAIRE-seq analysis of open chromatin in A. aegypti permitted genome-wide discovery of CREs. The results of this investigation indicate that FAIRE-seq is a powerful tool for identification of regulatory DNA in the genomes of non-model organisms, including human disease vector mosquitoes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2468-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Susanta K Behura
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Joseph Sarro
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Ave., South Bend, IN, 46617, USA
| | - Ping Li
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Ave., South Bend, IN, 46617, USA
| | - Keshava Mysore
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Ave., South Bend, IN, 46617, USA
| | - David W Severson
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Ave., South Bend, IN, 46617, USA
| | - Scott J Emrich
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA. .,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA. .,Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA.
| | - Molly Duman-Scheel
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA. .,Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA. .,Department of Medical and Molecular Genetics, Indiana University School of Medicine, 1234 Notre Dame Ave., South Bend, IN, 46617, USA.
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3
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Systematic analysis and evolution of 5S ribosomal DNA in metazoans. Heredity (Edinb) 2013; 111:410-21. [PMID: 23838690 DOI: 10.1038/hdy.2013.63] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 04/09/2013] [Accepted: 05/17/2013] [Indexed: 11/08/2022] Open
Abstract
Several studies on 5S ribosomal DNA (5S rDNA) have been focused on a subset of the following features in mostly one organism: number of copies, pseudogenes, secondary structure, promoter and terminator characteristics, genomic arrangements, types of non-transcribed spacers and evolution. In this work, we systematically analyzed 5S rDNA sequence diversity in available metazoan genomes, and showed organism-specific and evolutionary-conserved features. Putatively functional sequences (12,766) from 97 organisms allowed us to identify general features of this multigene family in animals. Interestingly, we show that each mammal species has a highly conserved (housekeeping) 5S rRNA type and many variable ones. The genomic organization of 5S rDNA is still under debate. Here, we report the occurrence of several paralog 5S rRNA sequences in 58 of the examined species, and a flexible genome organization of 5S rDNA in animals. We found heterogeneous 5S rDNA clusters in several species, supporting the hypothesis of an exchange of 5S rDNA from one locus to another. A rather high degree of variation of upstream, internal and downstream putative regulatory regions appears to characterize metazoan 5S rDNA. We systematically studied the internal promoters and described three different types of termination signals, as well as variable distances between the coding region and the typical termination signal. Finally, we present a statistical method for detection of linkage among noncoding RNA (ncRNA) gene families. This method showed no evolutionary-conserved linkage among 5S rDNAs and any other ncRNA genes within Metazoa, even though we found 5S rDNA to be linked to various ncRNAs in several clades.
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Perina A, Seoane D, González-Tizón AM, Rodríguez-Fariña F, Martínez-Lage A. Molecular organization and phylogenetic analysis of 5S rDNA in crustaceans of the genus Pollicipes reveal birth-and-death evolution and strong purifying selection. BMC Evol Biol 2011; 11:304. [PMID: 22004418 PMCID: PMC3215682 DOI: 10.1186/1471-2148-11-304] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 10/17/2011] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The 5S ribosomal DNA (5S rDNA) is organized in tandem arrays with repeat units that consist of a transcribing region (5S) and a variable nontranscribed spacer (NTS), in higher eukaryotes. Until recently the 5S rDNA was thought to be subject to concerted evolution, however, in several taxa, sequence divergence levels between the 5S and the NTS were found higher than expected under this model. So, many studies have shown that birth-and-death processes and selection can drive the evolution of 5S rDNA. In analyses of 5S rDNA evolution is found several 5S rDNA types in the genome, with low levels of nucleotide variation in the 5S and a spacer region highly divergent. Molecular organization and nucleotide sequence of the 5S ribosomal DNA multigene family (5S rDNA) were investigated in three Pollicipes species in an evolutionary context. RESULTS The nucleotide sequence variation revealed that several 5S rDNA variants occur in Pollicipes genomes. They are clustered in up to seven different types based on differences in their nontranscribed spacers (NTS). Five different units of 5S rDNA were characterized in P. pollicipes and two different units in P. elegans and P. polymerus. Analysis of these sequences showed that identical types were shared among species and that two pseudogenes were present. We predicted the secondary structure and characterized the upstream and downstream conserved elements. Phylogenetic analysis showed an among-species clustering pattern of 5S rDNA types. CONCLUSIONS These results suggest that the evolution of Pollicipes 5S rDNA is driven by birth-and-death processes with strong purifying selection.
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Affiliation(s)
- Alejandra Perina
- Department of Cell and Molecular Biology, Evolutionary Biology Group, Universidade da Coruña, A Fraga 10, E-15008 A Coruña, Spain
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5
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Vierna J, Jensen KT, Martínez-Lage A, González-Tizón AM. The linked units of 5S rDNA and U1 snDNA of razor shells (Mollusca: Bivalvia: Pharidae). Heredity (Edinb) 2011; 107:127-42. [PMID: 21364693 DOI: 10.1038/hdy.2010.174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The linkage between 5S ribosomal DNA and other multigene families has been detected in many eukaryote lineages, but whether it provides any selective advantage remains unclear. In this work, we report the occurrence of linked units of 5S ribosomal DNA (5S rDNA) and U1 small nuclear DNA (U1 snDNA) in 10 razor shell species (Mollusca: Bivalvia: Pharidae) from four different genera. We obtained several clones containing partial or complete repeats of both multigene families in which both types of genes displayed the same orientation. We provide a comprehensive collection of razor shell 5S rDNA clones, both with linked and nonlinked organisation, and the first bivalve U1 snDNA sequences. We predicted the secondary structures and characterised the upstream and downstream conserved elements, including a region at -25 nucleotides from both 5S rDNA and U1 snDNA transcription start sites. The analysis of 5S rDNA showed that some nontranscribed spacers (NTSs) are more closely related to NTSs from other species (and genera) than to NTSs from the species they were retrieved from, suggesting birth-and-death evolution and ancestral polymorphism. Nucleotide conservation within the functional regions suggests the involvement of purifying selection, unequal crossing-overs and gene conversions. Taking into account this and other studies, we discuss the possible mechanisms by which both multigene families could have become linked in the Pharidae lineage. The reason why 5S rDNA is often found linked to other multigene families seems to be the result of stochastic processes within genomes in which its high copy number is determinant.
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Affiliation(s)
- J Vierna
- Department of Molecular and Cell Biology, Evolutionary Biology Group (GIBE), Universidade da Coruña, La Coruña, Spain.
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6
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Freire R, Arias A, Insua AM, Méndez J, Eirín-López JM. Evolutionary dynamics of the 5S rDNA gene family in the mussel Mytilus: mixed effects of birth-and-death and concerted evolution. J Mol Evol 2010; 70:413-26. [PMID: 20386892 DOI: 10.1007/s00239-010-9341-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 03/30/2010] [Indexed: 11/24/2022]
Abstract
In higher eukaryotes, the gene family encoding the 5S ribosomal RNA (5S rRNA) has been used (together with histones) to showcase the archetypal example of a gene family subject to concerted evolution. However, recent studies have revealed conspicuous features challenging the predictions of this model, including heterogeneity of repeat units, the presence of functional 5S gene variants as well as the existence of 5S rDNA divergent pseudogenes lacking traces of homogenization. In the present work, we have broadened the scope in the evolutionary study of ribosomal gene families by studying the 5S rRNA family in mussels, a model organism which stands out among other animals due to the heterogeneity it displays regarding sequence and organization. To this end, 48 previously unknown 5S rDNA units (coding and spacer regions) were sequenced in five mussel species, leading to the characterization of two new types of units (referred to here as small-beta 5S rDNA and gamma-5S rDNA) coexisting in the genome with alpha and beta rDNA units. The intense genetic dynamics of this family is further supported by the first description of an association between gamma-5S rDNA units and tRNA genes. Molecular evolutionary and phylogenetic analyses revealed an extensive lack of homology among spacer sequences belonging to different rDNA types, suggesting the presence of independent evolutionary pathways leading to their differentiation. Overall, our results suggest that the long-term evolution of the 5S rRNA gene family in mussels is most likely mediated by a mixed mechanism involving the generation of genetic diversity through birth-and-death, followed by a process of local homogenization resulting from concerted evolution in order to maintain the genetic identities of the different 5S units, probably after their transposition to independent chromosomal locations.
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Affiliation(s)
- Ruth Freire
- XENOMAR Group, Departamento de Biología Celular y Molecular, Facultade de Ciencias, Universidade da Coruña, Campus de A Zapateira s/n, A Coruña, Spain
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7
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Abstract
In Drosophila virilis, the three clusters of 5S rRNA genes on chromosome 5 comprise two different gene families (B and C), which differ profoundly in the organization of their spacer sequences. While C-type genes, which are found in two of the clusters, exhibit a true repetitive character, the B-type genes of the third cluster are each embedded in completely different genomic environments. Southern blots of genomic DNA of different D. virilis subspecies, D. hydei and D. melanogaster probed with 5S rRNA gene spacer and coding sequences demonstrate the specificity of C-type sequences for the D. virilis species group. The comparative analysis of flanking sequences of 5S rRNA genes of D. virilis, members of the D. melanogaster species subgroup and of the blowfly Calliphora erythrocephala reveals the existence of conserved sequence motifs both in the 5' upstream and 3' downstream flanking regions. Their possible roles in the control of expression and processing of the 5S rRNA precursor molecule are discussed.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Southern
- Chromosome Mapping
- Cloning, Molecular
- Conserved Sequence
- DNA, Recombinant
- Diptera/genetics
- Drosophila/genetics
- Drosophila melanogaster/genetics
- Evolution, Molecular
- In Situ Hybridization
- Models, Genetic
- Molecular Sequence Data
- Multigene Family
- Nucleic Acid Conformation
- Nucleic Acid Hybridization
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/ultrastructure
- Sequence Analysis, DNA
- Species Specificity
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Affiliation(s)
- H Kress
- Institut für Biologie-Genetik, Freie Universität Berlin, Germany.
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8
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Cloix C, Tutois S, Yukawa Y, Mathieu O, Cuvillier C, Espagnol MC, Picard G, Tourmente S. Analysis of the 5S RNA pool in Arabidopsis thaliana: RNAs are heterogeneous and only two of the genomic 5S loci produce mature 5S RNA. Genome Res 2002; 12:132-44. [PMID: 11779838 PMCID: PMC155267 DOI: 10.1101/gr.181301] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2001] [Accepted: 10/26/2001] [Indexed: 11/25/2022]
Abstract
One major 5S RNA, 120 bases long, was revealed by an analysis of mature 5S RNA from tissues, developmental stages, and polysomes in Arabidopsis thaliana. Minor 5S RNA were also found, varying from the major one by one or two base substitutions; 5S rDNA units from each 5S array of the Arabidopsis genome were isolated by PCR using CIC yeast artificial chromosomes (YACs) mapped on the different loci. By using a comparison of the 5S DNA and RNA sequences, we could show that both major and minor 5S transcripts come from only two of the genomic 5S loci: chromosome 4 and chromosome 5 major block. Other 5S loci are either not transcribed or produce rapidly degraded 5S transcripts. Analysis of the 5'- and 3'-DNA flanking sequence has permitted the definition of specific signatures for each 5S rDNA array.
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Affiliation(s)
- Catherine Cloix
- U.M.R. 6547 BIOMOVE, Université Blaise Pascal, 24 Avenue des Landais, 63177 Aubière Cedex, France
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9
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Abstract
The task of transcribing nuclear genes is shared between three RNA polymerases in eukaryotes: RNA polymerase (pol) I synthesizes the large rRNA, pol II synthesizes mRNA and pol III synthesizes tRNA and 5S rRNA. Although pol II has received most attention, pol I and pol III are together responsible for the bulk of transcriptional activity. This survey will summarise what is known about the process of transcription by pol I and pol III, how it happens and the proteins involved. Attention will be drawn to the similarities between the three nuclear RNA polymerase systems and also to their differences.
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Affiliation(s)
- M R Paule
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA.
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10
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Cronn RC, Zhao X, Paterson AH, Wendel JF. Polymorphism and concerted evolution in a tandemly repeated gene family: 5S ribosomal DNA in diploid and allopolyploid cottons. J Mol Evol 1996; 42:685-705. [PMID: 8662014 DOI: 10.1007/bf02338802] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
5S RNA genes and their nontranscribed spacers are tandemly repeated in plant genomes at one or more chromosomal loci. To facilitate an understanding of the forces that govern 5S rDNA evolution, copy-number estimation and DNA sequencing were conducted for a phylogenetically well-characterized set of 16 diploid species of cotton (Gossypium) and 4 species representing allopolyploid derivatives of the diploids. Copy number varies over twentyfold in the genus, from approximately 1,000 to 20,000 copies/2C genome. When superimposed on the organismal phylogeny, these data reveal examples of both array expansion and contraction. Across species, a mean of 12% of nucleotide positions are polymorphic within individual arrays, for both gene and spacer sequences. This shows, in conjunction with phylogenetic evidence for ancestral polymorphisms that survive speciation events, that intralocus concerted evolutionary forces are relatively weak and that the rate of interrepeat homogenization is approximately equal to the rate of speciation. Evidence presented also shows that duplicated 5S rDNA arrays in allopolyploids have retained their subgenomic identity since polyploid formation, thereby indicating that interlocus concerted evolution has not been an important factor in the evolution of these arrays. A descriptive model, one which incorporates the opposing forces of mutation and homogenization within a selective framework, is outlined to account for the empirical data presented. Weak homogenizing forces allow equivalent levels of sequence polymorphism to accumulate in the 5S gene and spacer sequences, but fixation of mutations is nearly prohibited in the 5S gene. As a consequence, fixed interspecific differences are statistically underrepresented for 5S genes. This result explains the apparent paradox that despite similar levels of gene and spacer diversity, phylogenetic analysis of spacer sequences yields highly resolved trees, whereas analyses based on 5S gene sequences do not.
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MESH Headings
- Base Sequence
- DNA, Plant/genetics
- DNA, Ribosomal/genetics
- Diploidy
- Evolution, Molecular
- Genes, Plant
- Gossypium/genetics
- Molecular Sequence Data
- Phylogeny
- Polymorphism, Genetic
- Polyploidy
- RNA, Plant/genetics
- RNA, Ribosomal, 5S/genetics
- Repetitive Sequences, Nucleic Acid
- Sequence Alignment
- Sequence Homology, Nucleic Acid
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Affiliation(s)
- R C Cronn
- Department of Botany, Iowa State University, Ames, IA 50011, USA
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11
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Wang HD, Yuh CH, Dang CV, Johnson DL. The hepatitis B virus X protein increases the cellular level of TATA-binding protein, which mediates transactivation of RNA polymerase III genes. Mol Cell Biol 1995; 15:6720-8. [PMID: 8524237 PMCID: PMC230925 DOI: 10.1128/mcb.15.12.6720] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The hepatitis B virus X gene product transactivates a variety of cellular and viral genes. The mechanism for X induction of RNA polymerase (pol) III genes was investigated. By using Drosophila S-2 cells stably transformed with the X gene, the transient expression of a tRNA gene is enhanced. Comparing the transcriptional activities of extracts derived from these cells, all three types of RNA pol III promoters are stimulated by X. Interestingly, both S-2 and rat 1A cells stably transformed with the X gene produce increased cellular levels of the TATA-binding protein (TBP). By using various kinase inhibitors, it was found that the X-mediated increases in both transcription and TBP are dependent upon protein kinase C activation. Since TBP is a subunit of TFIIIB, the activity of this component fractionated from extracts derived from control and X-transformed cells was analyzed. These studies reveal that TFIIIB activity is substantially more limiting in control cells and that TFIIIB isolated from X-transformed cells has increased activity in reconstitution assays compared with TFIIIB isolated from control cells. Conversely, comparison of TFIIIC from control and X-transformed cell extracts revealed that there is relatively little change in its ability either to reconstitute transcription or to bind to DNA and that there is no change in the catalytic activity of RNA pol III. Studies were performed to determine whether directly increasing cellular TBP alone could enhance RNA pol III gene transcription. Transient expression of a TBP cDNA in rat 1A cells was capable of stimulating transcription activity from the resultant extracts in vitro. Together, these results demonstrate that one mechanism by which X mediates transactivation of RNA poll III genes is by increasing limiting TBP via the activation of cellular signaling pathways. The discovery that X increases cellular TBP, the universal transcription factor, provides a novel mechanism for the function of a viral transactivator protein and may explain the ability of X to produce such large and diverse effects on cellular gene expression.
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Affiliation(s)
- H D Wang
- Department of Molecular Pharmacology, School of Pharmacy, University of Southern California, Los Angeles 90033, USA
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12
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Arkhipova IR. Complex patterns of transcription of a Drosophila retrotransposon in vivo and in vitro by RNA polymerases II and III. Nucleic Acids Res 1995; 23:4480-7. [PMID: 7501473 PMCID: PMC307407 DOI: 10.1093/nar/23.21.4480] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The mdg1 retrovirus-like retrotransposon of Drosophila melanogaster was found to possess a complex promoter which can be transcribed by both RNA polymerases II and III (pol II and pol III). Pol III transcription, which is not typical of protein-coding genes, is driven by the sequences located in the long terminal repeat (LTR) of mdg1, predominantly within the transcribed region and is initiated 10 bp upstream from the regular pol II RNA start site. The pol III RNA start site is observed not only in in vitro transcription reactions, but also in total RNA isolated from tissue culture cells, larvae, pupae and adult flies. A possible role of pol III transcription in mechanisms controlling the expression of full-length mdg1-encoded transcripts in the developing fly, which are apparently relaxed in cell culture, is discussed.
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Affiliation(s)
- I R Arkhipova
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138-2092, USA
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13
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Päques F, Samson ML, Jordan P, Wegnez M. Structural evolution of the Drosophila 5S ribosomal genes. J Mol Evol 1995; 41:615-21. [PMID: 7490776 DOI: 10.1007/bf00175820] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We compare the 5S gene structure from nine Drosophila species. New sequence data (5S genes of D. melanogaster, D. mauritiana, D. sechellia, D. yakuba, D. erecta, D. orena, and D. takahashii) and already-published data (5S genes of D. melanogaster, D. simulans, and D. teissieri) are used in these comparisons. We show that four regions within the Drosophila 5S genes display distinct rates of evolution: the coding region (120 bp), the 5'-flanking region (54-55 bp), the 3'-flanking region (21-22 bp), and the internal spacer (149-206 bp). Intra- and interspecific heterogeneity is due mainly to insertions and deletions of 6-17-bp oligomers. These small rearrangements could be generated by fork slippages during replication and could produce rapid sequence divergence in a limited number of steps.
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MESH Headings
- Animals
- Base Sequence
- Cloning, Molecular
- Conserved Sequence
- DNA, Ribosomal
- Drosophila/genetics
- Evolution, Molecular
- Genes, Insect
- Molecular Sequence Data
- Polymorphism, Genetic
- RNA, Ribosomal, 5S/genetics
- Repetitive Sequences, Nucleic Acid
- Sequence Analysis, DNA
- Sequence Deletion
- Sequence Homology, Nucleic Acid
- Species Specificity
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Affiliation(s)
- F Päques
- Labotoire d'Embryologie Moléculaire, Unité de Recherche Associée 1134, Centre National de la Recherche Scientifique, Université Paris XI, Orsay, France
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14
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Smith TP, Young LS, Bender LB, Sprague KU. Silkworm TFIIIA requires additional class III factors for commitment to transcription complex assembly on a 5S RNA gene. Nucleic Acids Res 1995; 23:1244-51. [PMID: 7739903 PMCID: PMC306838 DOI: 10.1093/nar/23.7.1244] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We find striking similarities in promoter structure and requirements for template commitment on 5S RNA and tRNA genes from silkworms. The promoters are nearly the same size (approximately 160 bp) and include flanking as well as internal sequences. To analyze the factor requirements for 5S RNA transcription complex assembly in a completely homologous system, we have isolated a silkworm fraction that is highly enriched for the 5S RNA-specific transcription factor, TFIIIA. Using this fraction, together with the other silkworm fractions, TFIIIB, TFIIIC, TFIIID and RNA polymerase III, we demonstrate that the requirements for 5S RNA transcription complex assembly are very similar to those previously established for a tRNA(C)(Ala) gene. Specifically, no individual factor fraction is sufficient for commitment of silkworm 5S RNA genes to transcription complex assembly. Rather, combinations of at least three factor fractions are required. Our observation that more than one subset of factors is competent for commitment suggests that silkworm 5S RNA genes further resemble tRNA(C)(Ala) genes in their ability to use multiple pathways for transcription complex formation.
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Affiliation(s)
- T P Smith
- Institute of Molecular Biology, University of Oregon, Eugene 97403, USA
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15
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Lee Y, Erkine AM, Van Ryk DI, Nazar RN. In vivo analyses of the internal control region in the 5S rRNA gene from Saccharomyces cerevisiae. Nucleic Acids Res 1995; 23:634-40. [PMID: 7899084 PMCID: PMC306731 DOI: 10.1093/nar/23.4.634] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The internal control region of the Saccharomyces cerevisiae 5S rRNA gene has been characterized in vivo by genomic DNase I footprinting and by mutational analyses using base substitutions, deletions or insertions. A high copy shuttle vector was used to efficiently express mutant 5S rRNA genes in vivo and isotope labelling kinetics were used to distinguish impeded gene expression from nascent RNA degradation. In contrast to mutational studies in reconstituted systems, the analyses describe promoter elements which closely resemble the three distinct sequence elements that have been observed in Xenopus laevis 5S rRNA. The results indicate a more highly conserved structure than previously reported with reconstituted systems and suggest that the saturated conditions which are used in reconstitution studies mask sequence dependence which may be physiologically significant. Footprint analyses support the extended region of protein interaction which has recently been observed in some reconstituted systems, but mutational analyses indicate that these interactions are not sequence specific. Periodicity in the footprint provides further detail regarding the in vivo topology of the interacting protein.
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Affiliation(s)
- Y Lee
- Department of Molecular Biology and Genetics, University of Guelph, Ontario, Canada
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16
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Nielsen JN, Hallenberg C, Frederiksen S, Sørensen PD, Lomholt B. Transcription of human 5S rRNA genes is influenced by an upstream DNA sequence. Nucleic Acids Res 1993; 21:3631-6. [PMID: 8367278 PMCID: PMC309857 DOI: 10.1093/nar/21.16.3631] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Six human 5S rRNA genes and gene variants and one pseudogene have been sequenced. The six genes/variants were transcribed in a HeLa cell extract with about equal efficiency. Three genes contain the Sp1 binding sequence GGGCGG in position -43 to -38 and three genes contain the Sp1 like sequence GGGCCG in this position. The six genes contain furthermore one Sp1 binding site in a position about -245 and one ATF recognition site in a position about -202. A 12 bp sequence (GGCTCTTGGGGC) found in position -32 to -21 strongly influenced the transcriptional efficiency in vitro. This 12-mer, designated the D box, has also been found upstream a 5S rRNA gene from hamster and mouse. Removal of the Sp1 binding sites had no effect on the transcription in vitro whereas the transcriptional efficiency decreased to 10% if the D box was removed from the human 5S rRNA gene.
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Affiliation(s)
- J N Nielsen
- Department of Medical Biochemistry and Genetics, Panum Institute, University of Copenhagen, Denmark
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17
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Abstract
The human 5S rRNA genes are found in clusters of tandem repeated units. We have cloned and partially characterized six restriction fragments from two clusters of 2.3 kb and 1.6 kb repeats, respectively. Four fragments from the cluster of 2.3 kb repeats contain a 5S rRNA gene and one fragment contains a gene variant with an additional nucleotide in the internal control region. A fragment from the 1.6 kb cluster contains a gene and is highly homologous to the 2.3 kb repeats, except for a large deletion in the 3'-flanking region starting 12 bp downstream of the gene. The number of genes and closely related gene variants is found to be 300-400 per haploid human genome. 100-150 of these are found in 2.3 kb repeats and 5-10 are found in 1.6 kb repeats. The total number of 5S rRNA sequences, including pseudogenes, is 1700-2000 per haploid genome. The genes and the gene variant are transcribed equally efficient in a HeLa cell extract. If 5'-flanking sequences, including a GC-motif in the -40 region, are removed from the genes, transcription is reduced with a factor 10 or more, suggesting that sequences upstream of the coding region are important for the level of transcription.
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Affiliation(s)
- P D Sørensen
- Department of Biochemistry B, University of Copenhagen, Denmark
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18
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Struksnes K, Forus A, Gabrielsen OS, Oyen TB. Yeast TFIIIA + TFIIIC/tau-factor, but not yeast TFIIIA alone, interacts with the Xenopus 5S rRNA gene. Nucleic Acids Res 1991; 19:565-71. [PMID: 2011529 PMCID: PMC333649 DOI: 10.1093/nar/19.3.565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The successful use of mixed heterologous in vitro transcription systems has suggested that the species specificity of RNA polymerase III transcription is low. To see if this extends to lower eukaryotic class III transcription factors, we compared the interactions of the two yeast assembly factors, TFIIIA and TFIIIC/tau factor, with a homologous yeast 5S rRNA gene and a heterologous Xenopus laevis somatic 5S rRNA gene. Transcription assays showed that the Xenopus gene was transcriptionally inactive in a crude cell-free yeast extract that actively transcribes the homologous gene. However, the Xenopus gene was still able to compete for limiting transcription factors. Electrophoretic DNA binding assays revealed that while TFIIIA bound avidly to the yeast gene (generating the 'A-complex'), it had no affinity for the Xenopus 5S rRNA gene. Nevertheless, a complex of both TFIIIA and TFIIIC/tau factor (the 'AC-complex') was formed on the two genes with similar affinity, although only the complex assembled on the homologous gene was able to activate transcription. Thus enough sequence information is present on the heterologous gene to direct transcription factor assembly, but not to activate transcription. Like its counterpart in Xenopus, the yeast TFIIIA appears to be a zinc binding protein that is inactivated by EDTA and 1,10-phenanthroline, and reactivated in the presence of zinc ions. Bound to the 5S rRNA gene, TFIIIA is however significantly more resistant to inactivation by chelators than in its free state. The AC-complex differs from the A-complex by being less affected by chelators, and by being more sensitive to the dissociating effect of single-stranded DNA.
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Affiliation(s)
- K Struksnes
- Department of Biochemistry, University of Oslo, Norway
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19
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Human transcription factor TFIIIC2 specifically interacts with a unique sequence in the Xenopus laevis 5S rRNA gene. Mol Cell Biol 1990. [PMID: 2601702 DOI: 10.1128/mcb.9.11.4941] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription factor TFIIIC2 derived from human cells is required for tRNA-type gene transcription and binds with high affinity to the essential B-box promoter element of tRNA-type genes. Although 5S rRNA genes contain no homology with the tRNA-type gene B box, we show that TFIIIC2 is also required for Xenopus laevis 5S rRNA gene transcription. TFIIIC2 protected an approximately 30-base-pair (-10 to +18) region of a Xenopus 5S rRNA gene from DNase I digestion. This region, which spanned the transcription start site, included sequences that are highly conserved among eucaryotic 5S rRNA genes and have no homology with the B-box sequence of tRNA genes. Mutation of the TFIIIC2-binding site reduced transcription of the 5S rRNA gene by a factor of 10 in HeLa cell extracts. Methylation of C residues within the TFIIIC2-binding site interfered with binding of TFIIIC2. These results suggest a role of the TFIIIC2-binding sequence in 5S rRNA gene transcription. In addition, the 5S rRNA gene binding site and the tRNA-type gene B-box sequence did not compete with each other for binding to TFIIIC2 any better than did an unrelated DNA sequence, indicating that TFIIIC2 interacts with 5S rRNA genes and tRNA-type genes through separate DNA-binding domains or polypeptides.
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20
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Genomic footprinting of a yeast tRNA gene reveals stable complexes over the 5'-flanking region. Mol Cell Biol 1989. [PMID: 2677668 DOI: 10.1128/mcb.9.8.3244] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have shown by genomic footprinting that the 5'-flanking region of the Saccharomyces cerevisiae tRNASUP53 gene is protected from DNase I digestion. The protected region has a 5' boundary at -40 (relative to the transcription initiation site) and extends into the coding region of the gene, with a 3' boundary at approximately +15. Although the DNase I protection over this region was much greater than at the A- and B-box internal promoters, point mutations within the A or B box that reduced transcription in vitro eliminated the upstream DNase I protection. This implies that formation of a stable complex over the 5'-flanking region is dependent on interaction of the gene with transcription factor IIIC but that stability of the complex may not require continued interaction with this factor. The DNase I protection under varied growth conditions further suggested that the upstream complex is composed of two or more components. The region over the transcription initiation site (approximately +15 to -10) was less protected in stationary-phase cultures, whereas the more upstream region (approximately -10 to -40) was protected in both exponential- and stationary-phase cultures.
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21
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Fradkin LG, Yoshinaga SK, Berk AJ, Dasgupta A. Human transcription factor TFIIIC2 specifically interacts with a unique sequence in the Xenopus laevis 5S rRNA gene. Mol Cell Biol 1989; 9:4941-50. [PMID: 2601702 PMCID: PMC363645 DOI: 10.1128/mcb.9.11.4941-4950.1989] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Transcription factor TFIIIC2 derived from human cells is required for tRNA-type gene transcription and binds with high affinity to the essential B-box promoter element of tRNA-type genes. Although 5S rRNA genes contain no homology with the tRNA-type gene B box, we show that TFIIIC2 is also required for Xenopus laevis 5S rRNA gene transcription. TFIIIC2 protected an approximately 30-base-pair (-10 to +18) region of a Xenopus 5S rRNA gene from DNase I digestion. This region, which spanned the transcription start site, included sequences that are highly conserved among eucaryotic 5S rRNA genes and have no homology with the B-box sequence of tRNA genes. Mutation of the TFIIIC2-binding site reduced transcription of the 5S rRNA gene by a factor of 10 in HeLa cell extracts. Methylation of C residues within the TFIIIC2-binding site interfered with binding of TFIIIC2. These results suggest a role of the TFIIIC2-binding sequence in 5S rRNA gene transcription. In addition, the 5S rRNA gene binding site and the tRNA-type gene B-box sequence did not compete with each other for binding to TFIIIC2 any better than did an unrelated DNA sequence, indicating that TFIIIC2 interacts with 5S rRNA genes and tRNA-type genes through separate DNA-binding domains or polypeptides.
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Affiliation(s)
- L G Fradkin
- Department of Microbiology and Immunology, School of Medicine, University of California, Los Angeles 90024-1747
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22
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Cruces J, Díaz-Guerra M, Gil I, Renart J. The 5S rRNA-histone repeat in the crustacean Artemia: structure, polymorphism and variation of the 5S rRNA segment in different populations. Nucleic Acids Res 1989; 17:6283-97. [PMID: 2570403 PMCID: PMC318278 DOI: 10.1093/nar/17.15.6283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
5S rRNA genes are linked to the histone genes in the 13 populations of the crustacean Artemia that we have studied. In all cases, two types of repeat units are found. Southern blot analysis of all populations shows that they can be grouped into three classes: a) American bisexuals; b) Eurasian bisexuals, and c) parthenogenetic organisms (all from Eurasia). Restriction analysis of a bisexual population from San Francisco Bay shows that the two repeat units are of 9.0 and 8.5 kb (with minor heterogeneities of restriction sites). In parthenogenetic organisms, the two repeat units are of approximately 12 kb. Sequencing data from the region of the 5S rRNA from the San Francisco Bay population, shows that in both types of units, the single 5S rRNA gene (315 bp in length), is located 430 bp downstream the 3' regulatory sequences of the H2A gene, the last gene in the histone cluster. We have isolated three clones that contain 5S rRNA sequences. Two of them (one from an American bisexual and the other from a parthenogenetic population) contain histone and 5S rRNA genes, both with the same transcriptional polarity. The third clone, lacking histone genes, is likely to be an orphon derived from the parthenogenetic population.
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Affiliation(s)
- J Cruces
- Instituto de Investigaciones Biomédicas del CSIC, Madrid, Spain
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23
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Huibregtse JM, Engelke DR. Genomic footprinting of a yeast tRNA gene reveals stable complexes over the 5'-flanking region. Mol Cell Biol 1989; 9:3244-52. [PMID: 2677668 PMCID: PMC362368 DOI: 10.1128/mcb.9.8.3244-3252.1989] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We have shown by genomic footprinting that the 5'-flanking region of the Saccharomyces cerevisiae tRNASUP53 gene is protected from DNase I digestion. The protected region has a 5' boundary at -40 (relative to the transcription initiation site) and extends into the coding region of the gene, with a 3' boundary at approximately +15. Although the DNase I protection over this region was much greater than at the A- and B-box internal promoters, point mutations within the A or B box that reduced transcription in vitro eliminated the upstream DNase I protection. This implies that formation of a stable complex over the 5'-flanking region is dependent on interaction of the gene with transcription factor IIIC but that stability of the complex may not require continued interaction with this factor. The DNase I protection under varied growth conditions further suggested that the upstream complex is composed of two or more components. The region over the transcription initiation site (approximately +15 to -10) was less protected in stationary-phase cultures, whereas the more upstream region (approximately -10 to -40) was protected in both exponential- and stationary-phase cultures.
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Affiliation(s)
- J M Huibregtse
- Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-0606
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24
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Nietfeld W, Digweed M, Mentzel H, Meyerhof W, Köster M, Knöchel W, Erdmann VA, Pieler T. Oocyte and somatic 5S ribosomal RNA and 5S RNA encoding genes in Xenopus tropicalis. Nucleic Acids Res 1988; 16:8803-15. [PMID: 3174434 PMCID: PMC338636 DOI: 10.1093/nar/16.18.8803] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have investigated the structure of oocyte and somatic 5S ribosomal RNA and of 5S RNA encoding genes in Xenopus tropicalis. The sequences of the two 5S RNA families differ in four positions, but only one of these substitutions, a C to U transition in position 79 within the internal control region of the corresponding 5S RNA encoding genes, is a distinguishing characteristic of all Xenopus somatic and oocyte 5S RNAs characterized to date, including those from Xenopus laevis and Xenopus borealis. 5S RNA genes in Xenopus tropicalis are organized in clusters of multiple repeats of a 264 base pair unit; the structural and functional organization of the Xenopus tropicalis oocyte 5S gene is similar to the somatic but distinct from the oocyte 5S DNA in Xenopus laevis and Xenopus borealis. A comparative sequence analysis reveals the presence of a strictly conserved pentamer motif AAAGT in the 5'-flanking region of Xenopus 5S genes which we demonstrate in a separate communication to serve as a binding signal for an upstream stimulatory factor.
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Affiliation(s)
- W Nietfeld
- Max-Planck-Institut für Molekulare Genetik, Otto-Warburg-Laboratorium, Berlin, FRG
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