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Wills MF, Alejo CB, Hundt N, Hudson AJ, Eperon IC. FluoroTensor: Identification and tracking of colocalised molecules and their stoichiometries in multi-colour single molecule imaging via deep learning. Comput Struct Biotechnol J 2024; 23:918-928. [PMID: 38375530 PMCID: PMC10875188 DOI: 10.1016/j.csbj.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 02/21/2024] Open
Abstract
The identification of photobleaching steps in single molecule fluorescence imaging is a well-established procedure for analysing the stoichiometries of molecular complexes. Nonetheless, the method is challenging with protein fluorophores because of the high levels of noise, rapid bleaching and highly variable signal intensities, all of which complicate methods based on statistical analyses of intensities to identify bleaching steps. It has recently been shown that deep learning by convolutional neural networks can yield an accurate analysis with a relatively short computational time. We describe here an improved use of such an approach that detects bleaching events even in the first time point of observation, and we have included this within an integrated software package incorporating fluorescence spot detection, colocalisation, tracking, FRET and photobleaching step analyses of single molecules or complexes. This package, known as FluoroTensor, is written in Python with a self-explanatory user interface.
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Affiliation(s)
- Max F.K. Wills
- Institute for Structural and Chemical Biology, University of Leicester, UK
- Department of Molecular and Cell Biology, University of Leicester, UK
| | - Carlos Bueno Alejo
- Institute for Structural and Chemical Biology, University of Leicester, UK
- Department of Chemistry, University of Leicester, UK
| | - Nikolas Hundt
- Department of Cellular Physiology, Ludwig-Maximilians-Universität München, Germany
| | - Andrew J. Hudson
- Institute for Structural and Chemical Biology, University of Leicester, UK
- Department of Chemistry, University of Leicester, UK
| | - Ian C. Eperon
- Institute for Structural and Chemical Biology, University of Leicester, UK
- Department of Molecular and Cell Biology, University of Leicester, UK
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2
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Flemr M, Schwaiger M, Hess D, Iesmantavicius V, Ahel J, Tuck AC, Mohn F, Bühler M. Mouse nuclear RNAi-defective 2 promotes splicing of weak 5' splice sites. RNA (NEW YORK, N.Y.) 2023; 29:1140-1165. [PMID: 37137667 PMCID: PMC10351895 DOI: 10.1261/rna.079465.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023]
Abstract
Removal of introns during pre-mRNA splicing, which is central to gene expression, initiates by base pairing of U1 snRNA with a 5' splice site (5'SS). In mammals, many introns contain weak 5'SSs that are not efficiently recognized by the canonical U1 snRNP, suggesting alternative mechanisms exist. Here, we develop a cross-linking immunoprecipitation coupled to a high-throughput sequencing method, BCLIP-seq, to identify NRDE2 (nuclear RNAi-defective 2), and CCDC174 (coiled-coil domain-containing 174) as novel RNA-binding proteins in mouse ES cells that associate with U1 snRNA and 5'SSs. Both proteins bind directly to U1 snRNA independently of canonical U1 snRNP-specific proteins, and they are required for the selection and effective processing of weak 5'SSs. Our results reveal that mammalian cells use noncanonical splicing factors bound directly to U1 snRNA to effectively select suboptimal 5'SS sequences in hundreds of genes, promoting proper splice site choice, and accurate pre-mRNA splicing.
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Affiliation(s)
- Matyas Flemr
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Michaela Schwaiger
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
- Swiss Institute of Bioinformatics, 4058 Basel, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | | | - Josip Ahel
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Alex Charles Tuck
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Fabio Mohn
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Marc Bühler
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
- University of Basel, 4003 Basel, Switzerland
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3
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lncRNA ZFAS1 Promotes HMGCR mRNA Stabilization via Binding U2AF2 to Modulate Pancreatic Carcinoma Lipometabolism. J Immunol Res 2022; 2022:4163198. [PMID: 35846429 PMCID: PMC9286883 DOI: 10.1155/2022/4163198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022] Open
Abstract
Being one of the most lethal malignant tumors worldwide, pancreatic carcinoma (PC) shows strong invasiveness and high mortality. In tumorigenesis and progression, the role played by long-chain noncoding RNAs (lncRNAs) cannot be ignored. This article mainly probes into the function of lncRNA ZFAS1 in PC. ZFAS1 expression in PC and normal counterparts retrieved from the Genotype-Tissue Expression (GTEx) project and The Cancer Genome Atlas (TCGA) database was analysed by GEPIA2. Its expression profile in clinical specimens and human PC cell strains was quantified using qRT-PCR. Measurements of BxPC-3 cell multiplication and invasiveness employed CCK-8, plate clone formation test, and Transwell chamber assay. ZFAS1's impact on lipid content in BxPC-3 cells was detected. RNA pulldown and RIP assays analyzed the interaction of ZFAS1 with U2AF2 and HMGCR in BxPC-3 cells. Finally, the impacts of U2AF2 and HMGCR on the biological behavior of BxPC-3 were observed. ZFAS1 was kept at a high level in PC tissues versus the normal counterparts. ZFAS1 gene knockout remarkably suppressed PC cell multiplication and invasiveness and decreased the contents of free fatty acids, total cholesterol, triglycerides, and phospholipids. Mechanistically, ZFAS1 stabilized HMGCR mRNA through U2AF2, thus increasing HMGCR expression and promoting PC lipid accumulation. Meanwhile, reduced PC cell viability and invasiveness were observed after downregulating U2AF2 and HMGCR. As an oncogene of PC, ZFAS1 can modulate lipometabolism and stabilize HMGCR mRNA expression by binding with U2AF2 in PC, which is a candidate target for PC diagnosis and treatment.
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4
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Mol AA, Vogel M, Suess B. Inducible nuclear import by TetR aptamer-controlled 3' splice site selection. RNA (NEW YORK, N.Y.) 2021; 27:234-241. [PMID: 33148600 PMCID: PMC7812871 DOI: 10.1261/rna.077453.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Correct cellular localization is essential for the function of many eukaryotic proteins and hence cell physiology. Here, we present a synthetic genetic device that allows the control of nuclear and cytosolic localization based on controlled alternative splicing in human cells. The device is based on the fact that an alternative 3' splice site is located within a TetR aptamer that in turn is positioned between the branch point and the canonical splice site. The novel splice site is only recognized when the TetR repressor is bound. Addition of doxycycline prevents TetR aptamer binding and leads to recognition of the canonical 3' splice site. It is thus possible to produce two independent splice isoforms. Since the terminal loop of the aptamer may be replaced with any sequence of choice, one of the two isoforms may be extended by the respective sequence of choice depending on the presence of doxycycline. In a proof-of-concept study, we fused a nuclear localization sequence to a cytosolic target protein, thus directing the protein into the nucleus. However, the system is not limited to the control of nuclear localization. In principle, any target sequence can be integrated into the aptamer, allowing not only the production of a variety of different isoforms on demand, but also to study the function of mislocalized proteins. Moreover, it also provides a valuable tool for investigating the mechanism of alternative splicing in human cells.
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Affiliation(s)
- Adam A Mol
- Department of Biology, Technical University of Darmstadt, D-64287 Darmstadt, Germany
| | - Marc Vogel
- Department of Biology, Technical University of Darmstadt, D-64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technical University of Darmstadt, D-64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, D-64287 Darmstadt, Germany
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5
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Parra M, Zhang W, Vu J, DeWitt M, Conboy JG. Antisense targeting of decoy exons can reduce intron retention and increase protein expression in human erythroblasts. RNA (NEW YORK, N.Y.) 2020; 26:996-1005. [PMID: 32312846 PMCID: PMC7373989 DOI: 10.1261/rna.075028.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/10/2020] [Indexed: 06/11/2023]
Abstract
The decoy exon model has been proposed to regulate a subset of intron retention (IR) events involving predominantly larger introns (>1 kb). Splicing reporter studies have shown that decoy splice sites are essential for activity, suggesting that decoys act by engaging intron-terminal splice sites and competing with cross-intron interactions required for intron excision. The decoy model predicts that antisense oligonucleotides may be able to block decoy splice sites in endogenous pre-mRNA, thereby reducing IR and increasing productive gene expression. Indeed, we now demonstrate that targeting a decoy 5' splice site in the O-GlcNAc transferase (OGT) gene reduced IR from ∼80% to ∼20% in primary human erythroblasts, accompanied by increases in spliced OGT RNA and OGT protein expression. The remaining OGT IR was refractory to antisense treatment and might be mediated by independent mechanism(s). In contrast, other retained introns were strongly dependent on decoy function, since antisense targeting of decoy 5' splice sites greatly reduced (SNRNP70) or nearly eliminated (SF3B1) IR in two widely expressed splicing factors, and also greatly reduced IR in transcripts encoding the erythroid-specific structural protein, α-spectrin (SPTA1). These results show that modulating decoy exon function can dramatically alter IR and suggest that dynamic regulation of decoy exons could be a mechanism to fine-tune gene expression post-transcriptionally in many cell types.
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Affiliation(s)
- Marilyn Parra
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Weiguo Zhang
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jonathan Vu
- Innovative Genomics Institute, University of California, Berkeley, California, USA
| | - Mark DeWitt
- Innovative Genomics Institute, University of California, Berkeley, California, USA
| | - John G Conboy
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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6
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Wimmer K, Schamschula E, Wernstedt A, Traunfellner P, Amberger A, Zschocke J, Kroisel P, Chen Y, Callens T, Messiaen L. AG-exclusion zone revisited: Lessons to learn from 91 intronic NF1 3' splice site mutations outside the canonical AG-dinucleotides. Hum Mutat 2020; 41:1145-1156. [PMID: 32126153 PMCID: PMC7317903 DOI: 10.1002/humu.24005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/26/2020] [Accepted: 02/24/2020] [Indexed: 12/17/2022]
Abstract
Uncovering frequent motives of action by which variants impair 3′ splice site (3′ss) recognition and selection is essential to improve our understanding of this complex process. Through several mini‐gene experiments, we demonstrate that the pyrimidine (Y) to purine (R) transversion NM_000267.3(NF1):c.1722‐11T>G, although expected to weaken the polypyrimidine tract, causes exon skipping primarily by introducing a novel AG in the AG‐exclusion zone (AGEZ) between the authentic 3′ss AG and the branch point. Evaluation of 90 additional noncanonical intronic NF1 3′ss mutations confirmed that 63% of all mutations and 89% (49/55) of the single‐nucleotide variants upstream of positions ‐3 interrupt the AGEZ. Of these AGEZ‐interrupting mutations, 24/49 lead to exon skipping suggesting that absence of AG in this region is necessary for accurate 3′ss selection already in the initial steps of splicing. The analysis of 91 noncanonical NF1 3′ss mutations also shows that 90% either introduce a novel AG in the AGEZ, cause a Y>R transversion at position ‐3 or remove ≥2 Ys in the AGEZ. We confirm in a validation cohort that these three motives distinguish spliceogenic from splice‐neutral variants with 85% accuracy and, therefore, are generally applicable to select among variants of unknown significance those likely to affect splicing.
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Affiliation(s)
- Katharina Wimmer
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Esther Schamschula
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Annekatrin Wernstedt
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Pia Traunfellner
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Albert Amberger
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Johannes Zschocke
- Institute of Human Genetics, Department of Genetics and Pharmacology, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Kroisel
- Diagnostic & Research Institute of Human Genetics, Diagnostic & Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | - Yunjia Chen
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tom Callens
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Ludwine Messiaen
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
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7
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Esfahani MS, Lee LJ, Jeon YJ, Flynn RA, Stehr H, Hui AB, Ishisoko N, Kildebeck E, Newman AM, Bratman SV, Porteus MH, Chang HY, Alizadeh AA, Diehn M. Functional significance of U2AF1 S34F mutations in lung adenocarcinomas. Nat Commun 2019; 10:5712. [PMID: 31836708 PMCID: PMC6911043 DOI: 10.1038/s41467-019-13392-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/07/2019] [Indexed: 12/23/2022] Open
Abstract
The functional role of U2AF1 mutations in lung adenocarcinomas (LUADs) remains incompletely understood. Here, we report a significant co-occurrence of U2AF1 S34F mutations with ROS1 translocations in LUADs. To characterize this interaction, we profiled effects of S34F on the transcriptome-wide distribution of RNA binding and alternative splicing in cells harboring the ROS1 translocation. Compared to its wild-type counterpart, U2AF1 S34F preferentially binds and modulates splicing of introns containing CAG trinucleotides at their 3' splice junctions. The presence of S34F caused a shift in cross-linking at 3' splice sites, which was significantly associated with alternative splicing of skipped exons. U2AF1 S34F induced expression of genes involved in the epithelial-mesenchymal transition (EMT) and increased tumor cell invasion. Finally, S34F increased splicing of the long over the short SLC34A2-ROS1 isoform, which was also associated with enhanced invasiveness. Taken together, our results suggest a mechanistic interaction between mutant U2AF1 and ROS1 in LUAD.
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Affiliation(s)
- Mohammad S Esfahani
- Stanford Cancer Institute, Stanford University, Stanford, USA
- Division of Oncology, Department of Medicine, Stanford University, Stanford, USA
- Department of Radiation Oncology, Stanford University, Stanford, USA
| | - Luke J Lee
- Stanford Cancer Institute, Stanford University, Stanford, USA
| | - Young-Jun Jeon
- Stanford Cancer Institute, Stanford University, Stanford, USA
- Department of Radiation Oncology, Stanford University, Stanford, USA
| | - Ryan A Flynn
- Department of Chemistry, Stanford University, Stanford, USA
| | - Henning Stehr
- Stanford Cancer Institute, Stanford University, Stanford, USA
- Department of Pathology, Stanford University, Stanford, CA, USA
| | - Angela B Hui
- Stanford Cancer Institute, Stanford University, Stanford, USA
- Department of Radiation Oncology, Stanford University, Stanford, USA
| | - Noriko Ishisoko
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Eric Kildebeck
- Department of Pediatrics, Stanford University, Stanford, USA
| | - Aaron M Newman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, USA
- Department of Biomedical Data Science, Stanford University, Stanford, USA
| | - Scott V Bratman
- Department of Radiation Oncology, Stanford University, Stanford, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, USA
- Department of Radiation Oncology, University of Toronto, Toronto, CA, USA
| | | | - Howard Y Chang
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
- Division of Hematology, Department of Medicine, Stanford University, Stanford, USA
| | - Ash A Alizadeh
- Stanford Cancer Institute, Stanford University, Stanford, USA.
- Division of Oncology, Department of Medicine, Stanford University, Stanford, USA.
- Division of Hematology, Department of Medicine, Stanford University, Stanford, USA.
| | - Maximilian Diehn
- Stanford Cancer Institute, Stanford University, Stanford, USA.
- Department of Radiation Oncology, Stanford University, Stanford, USA.
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, USA.
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8
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Lemaire S, Fontrodona N, Aubé F, Claude JB, Polvèche H, Modolo L, Bourgeois CF, Mortreux F, Auboeuf D. Characterizing the interplay between gene nucleotide composition bias and splicing. Genome Biol 2019; 20:259. [PMID: 31783898 PMCID: PMC6883713 DOI: 10.1186/s13059-019-1869-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 10/28/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Nucleotide composition bias plays an important role in the 1D and 3D organization of the human genome. Here, we investigate the potential interplay between nucleotide composition bias and the regulation of exon recognition during splicing. RESULTS By analyzing dozens of RNA-seq datasets, we identify two groups of splicing factors that activate either about 3200 GC-rich exons or about 4000 AT-rich exons. We show that splicing factor-dependent GC-rich exons have predicted RNA secondary structures at 5' ss and are dependent on U1 snRNP-associated proteins. In contrast, splicing factor-dependent AT-rich exons have a large number of decoy branch points, SF1- or U2AF2-binding sites and are dependent on U2 snRNP-associated proteins. Nucleotide composition bias also influences local chromatin organization, with consequences for exon recognition during splicing. Interestingly, the GC content of exons correlates with that of their hosting genes, isochores, and topologically associated domains. CONCLUSIONS We propose that regional nucleotide composition bias over several dozens of kilobase pairs leaves a local footprint at the exon level and induces constraints during splicing that can be alleviated by local chromatin organization at the DNA level and recruitment of specific splicing factors at the RNA level. Therefore, nucleotide composition bias establishes a direct link between genome organization and local regulatory processes, like alternative splicing.
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Affiliation(s)
- Sébastien Lemaire
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Nicolas Fontrodona
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Fabien Aubé
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Jean-Baptiste Claude
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | | | - Laurent Modolo
- LBMC Biocomputing Center, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Cyril F Bourgeois
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Franck Mortreux
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France
| | - Didier Auboeuf
- Laboratory of Biology and Modelling of the Cell, Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, 46 Allée d'Italie Site Jacques Monod, F-69007, Lyon, France.
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9
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Cho HM, Park SJ, Choe SH, Lee JR, Kim SU, Jin YB, Kim JS, Lee SR, Kim YH, Huh JW. Cooperative evolution of two different TEs results in lineage-specific novel transcripts in the BLOC1S2 gene. BMC Evol Biol 2019; 19:196. [PMID: 31666001 PMCID: PMC6822395 DOI: 10.1186/s12862-019-1530-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 10/18/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The BLOC1S2 gene encodes the multifunctional protein BLOS2, a shared subunit of two lysosomal trafficking complexes: i) biogenesis of lysosome-related organelles complex-1 and i) BLOC-1-related complex. In our previous study, we identified an intriguing unreported transcript of the BLOC1S2 gene that has a novel exon derived from two transposable elements (TEs), MIR and AluSp. To investigate the evolutionary footprint and molecular mechanism of action of this transcript, we performed PCR and RT-PCR experiments and sequencing analyses using genomic DNA and RNA samples from humans and various non-human primates. RESULTS The results showed that the MIR element had integrated into the genome of our common ancestor, specifically in the BLOC1S2 gene region, before the radiation of all primate lineages and that the AluSp element had integrated into the genome of our common ancestor, fortunately in the middle of the MIR sequences, after the divergence of Old World monkeys and New World monkeys. The combined MIR and AluSp sequences provide a 3' splice site (AG) and 5' splice site (GT), respectively, and generate the Old World monkey-specific transcripts. Moreover, branch point sequences for the intron removal process are provided by the MIR and AluSp combination. CONCLUSIONS We show for the first time that sequential integration into the same location and sequence divergence events of two different TEs generated lineage-specific transcripts through sequence collaboration during primate evolution.
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Affiliation(s)
- Hyeon-Mu Cho
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea
| | - Sang-Je Park
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Se-Hee Choe
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea
| | - Ja-Rang Lee
- Primate Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, 56216, Korea
| | - Sun-Uk Kim
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea.,Futuristic Animal Resource and Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Yeung-Bae Jin
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea
| | - Ji-Su Kim
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea.,Primate Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, 56216, Korea
| | - Sang-Rae Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea.,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea
| | - Young-Hyun Kim
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea. .,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea.
| | - Jae-Won Huh
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, 28116, Korea. .,Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science & Technology (UST), Daejeon, 34113, Korea.
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10
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Jobbins AM, Reichenbach LF, Lucas CM, Hudson AJ, Burley GA, Eperon IC. The mechanisms of a mammalian splicing enhancer. Nucleic Acids Res 2019; 46:2145-2158. [PMID: 29394380 PMCID: PMC5861446 DOI: 10.1093/nar/gky056] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/19/2018] [Indexed: 12/21/2022] Open
Abstract
Exonic splicing enhancer (ESE) sequences are bound by serine & arginine-rich (SR) proteins, which in turn enhance the recruitment of splicing factors. It was inferred from measurements of splicing around twenty years ago that Drosophila doublesex ESEs are bound stably by SR proteins, and that the bound proteins interact directly but with low probability with their targets. However, it has not been possible with conventional methods to demonstrate whether mammalian ESEs behave likewise. Using single molecule multi-colour colocalization methods to study SRSF1-dependent ESEs, we have found that that the proportion of RNA molecules bound by SRSF1 increases with the number of ESE repeats, but only a single molecule of SRSF1 is bound. We conclude that initial interactions between SRSF1 and an ESE are weak and transient, and that these limit the activity of a mammalian ESE. We tested whether the activation step involves the propagation of proteins along the RNA or direct interactions with 3' splice site components by inserting hexaethylene glycol or abasic RNA between the ESE and the target 3' splice site. These insertions did not block activation, and we conclude that the activation step involves direct interactions. These results support a model in which regulatory proteins bind transiently and in dynamic competition, with the result that each ESE in an exon contributes independently to the probability that an activator protein is bound and in close proximity to a splice site.
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Affiliation(s)
- Andrew M Jobbins
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, UK
| | | | - Christian M Lucas
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, UK
| | - Andrew J Hudson
- Leicester Institute of Structural & Chemical Biology and Department of Chemistry, University of Leicester, UK
| | - Glenn A Burley
- Department of Pure and Applied Chemistry, University of Strathclyde, UK
| | - Ian C Eperon
- Leicester Institute of Structural & Chemical Biology and Department of Molecular & Cell Biology, University of Leicester, UK
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11
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Abstract
Proteins and RNA are often found in ribonucleoprotein particles (RNPs), where they function in cellular processes to synthesize proteins (the ribosome), chemically modify RNAs (small nucleolar RNPs), splice pre-mRNAs (the spliceosome), and, on a larger scale, sequester RNAs, degrade them, or process them (P bodies, Cajal bodies, and nucleoli). Each RNA–protein interaction is a story in itself, as both molecules can change conformation, compete for binding sites, and regulate cellular functions. Recent studies of Xist long non-coding RNP, the U4/5/6 tri-small nuclear RNP complex, and an activated state of a spliceosome reveal new features of RNA interactions with proteins, and, although their stories are incomplete, they are already fascinating.
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Affiliation(s)
- Kathleen B Hall
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, 63110, USA
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