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Cai J, Hu F, Yang M, Wu R, Liu X. Genome-wide identification of HDAC members and function analysis of PnHDT1/2 in salt stress response in Phyla nodiflora (L.) Greene. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 208:108442. [PMID: 38382345 DOI: 10.1016/j.plaphy.2024.108442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/28/2024] [Accepted: 02/15/2024] [Indexed: 02/23/2024]
Abstract
Reversible histone acetylation and deacetylation play an essential role in regulating chromatin structure and gene expression. Histone deacetylases (HDACs) catalyze the removal of acetyl groups from lysine residues of core histones, resulting in closed chromatin structure and transcription repression. Although the HDCAs have been extensively studied in model plants, the HDAC members have not been identified in Phyla nodiflora (L.) Greene (P. nodiflora), a salt-tolerant plant species. Here, 17 PnHDAC genes were identified in the genome of P. nodiflora. Phylogenetic analysis displayed that the PnHDACs were classified into three groups, the RPD3/HDA1-group (11 members), the SIR2-group (2 members) and the plant-specific HD2-group (4 members). Transcription analysis displayed that the gene expression patterns of PnHDACs were affected by salt stress in P. nodiflora seedlings. PnHDT1 and PnHDT2, two HD2-type HDAC proteins were found to be subcellular localized in the nucleolus. Furthermore, overexpressing PnHDT1 and PnHDT2 in Arabidopsis decreased the sensitivity to plant hormone abscisic acid whereas reduced the tolerance to salt stress during seed germination and seedling stages. Overall, our work identified the PnHDAC gene family for the first time in P. nodiflora and revealed an involvement of PnHDT1 and PnHDT2 in salt stress tolerance, which may contribute to uncover the mechanism of P. nodiflora in adaption to salt environments.
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Affiliation(s)
- Jiajia Cai
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
| | - Feng Hu
- Department of Landscape and Tourism Planning and Design, Guangzhou Urban Planning and Design Survey Research Institute, Guangzhou, 510650, China
| | - Min Yang
- Department of Landscape and Tourism Planning and Design, Guangzhou Urban Planning and Design Survey Research Institute, Guangzhou, 510650, China
| | - Ronghua Wu
- Department of Landscape and Tourism Planning and Design, Guangzhou Urban Planning and Design Survey Research Institute, Guangzhou, 510650, China
| | - Xuncheng Liu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
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2
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Felício D, du Mérac TR, Amorim A, Martins S. Functional implications of paralog genes in polyglutamine spinocerebellar ataxias. Hum Genet 2023; 142:1651-1676. [PMID: 37845370 PMCID: PMC10676324 DOI: 10.1007/s00439-023-02607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/22/2023] [Indexed: 10/18/2023]
Abstract
Polyglutamine (polyQ) spinocerebellar ataxias (SCAs) comprise a group of autosomal dominant neurodegenerative disorders caused by (CAG/CAA)n expansions. The elongated stretches of adjacent glutamines alter the conformation of the native proteins inducing neurotoxicity, and subsequent motor and neurological symptoms. Although the etiology and neuropathology of most polyQ SCAs have been extensively studied, only a limited selection of therapies is available. Previous studies on SCA1 demonstrated that ATXN1L, a human duplicated gene of the disease-associated ATXN1, alleviated neuropathology in mice models. Other SCA-associated genes have paralogs (i.e., copies at different chromosomal locations derived from duplication of the parental gene), but their functional relevance and potential role in disease pathogenesis remain unexplored. Here, we review the protein homology, expression pattern, and molecular functions of paralogs in seven polyQ dominant ataxias-SCA1, SCA2, MJD/SCA3, SCA6, SCA7, SCA17, and DRPLA. Besides ATXN1L, we highlight ATXN2L, ATXN3L, CACNA1B, ATXN7L1, ATXN7L2, TBPL2, and RERE as promising functional candidates to play a role in the neuropathology of the respective SCA, along with the parental gene. Although most of these duplicates lack the (CAG/CAA)n region, if functionally redundant, they may compensate for a partial loss-of-function or dysfunction of the wild-type genes in SCAs. We aim to draw attention to the hypothesis that paralogs of disease-associated genes may underlie the complex neuropathology of dominant ataxias and potentiate new therapeutic strategies.
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Affiliation(s)
- Daniela Felício
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Instituto Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313, Porto, Portugal
| | - Tanguy Rubat du Mérac
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Faculty of Science, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - António Amorim
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal
| | - Sandra Martins
- Instituto de Investigação e Inovação em Saúde (i3S), 4200-135, Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), 4200-135, Porto, Portugal.
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3
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Szatkownik A, Zea DJ, Richard H, Laine E. Building alternative splicing and evolution-aware sequence-structure maps for protein repeats. J Struct Biol 2023; 215:107997. [PMID: 37453591 DOI: 10.1016/j.jsb.2023.107997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/15/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023]
Abstract
Alternative splicing of repeats in proteins provides a mechanism for rewiring and fine-tuning protein interaction networks. In this work, we developed a robust and versatile method, ASPRING, to identify alternatively spliced protein repeats from gene annotations. ASPRING leverages evolutionary meaningful alternative splicing-aware hierarchical graphs to provide maps between protein repeats sequences and 3D structures. We re-think the definition of repeats by explicitly accounting for transcript diversity across several genes/species. Using a stringent sequence-based similarity criterion, we detected over 5,000 evolutionary conserved repeats by screening virtually all human protein-coding genes and their orthologs across a dozen species. Through a joint analysis of their sequences and structures, we extracted specificity-determining sequence signatures and assessed their implication in experimentally resolved and modelled protein interactions. Our findings demonstrate the widespread alternative usage of protein repeats in modulating protein interactions and open avenues for targeting repeat-mediated interactions.
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Affiliation(s)
- Antoine Szatkownik
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France; Bioinformatics Unit, Genome Competence Center (MF1), Robert Koch Institute, 13353 Berlin, Germany
| | - Diego Javier Zea
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Hugues Richard
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France; Bioinformatics Unit, Genome Competence Center (MF1), Robert Koch Institute, 13353 Berlin, Germany.
| | - Elodie Laine
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France.
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4
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Martinez-Gomez L, Cerdán-Vélez D, Abascal F, Tress ML. Origins and Evolution of Human Tandem Duplicated Exon Substitution Events. Genome Biol Evol 2022; 14:6809199. [PMID: 36346145 PMCID: PMC9741552 DOI: 10.1093/gbe/evac162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/25/2022] [Accepted: 10/29/2022] [Indexed: 11/10/2022] Open
Abstract
The mutually exclusive splicing of tandem duplicated exons produces protein isoforms that are identical save for a homologous region that allows for the fine tuning of protein function. Tandem duplicated exon substitution events are rare, yet highly important alternative splicing events. Most events are ancient, their isoforms are highly expressed, and they have significantly more pathogenic mutations than other splice events. Here, we analyzed the physicochemical properties and functional roles of the homologous polypeptide regions produced by the 236 tandem duplicated exon substitutions annotated in the human gene set. We find that the most important structural and functional residues in these homologous regions are maintained, and that most changes are conservative rather than drastic. Three quarters of the isoforms produced from tandem duplicated exon substitution events are tissue-specific, particularly in nervous and cardiac tissues, and tandem duplicated exon substitution events are enriched in functional terms related to structures in the brain and skeletal muscle. We find considerable evidence for the convergent evolution of tandem duplicated exon substitution events in vertebrates, arthropods, and nematodes. Twelve human gene families have orthologues with tandem duplicated exon substitution events in both Drosophila melanogaster and Caenorhabditis elegans. Six of these gene families are ion transporters, suggesting that tandem exon duplication in genes that control the flow of ions into the cell has an adaptive benefit. The ancient origins, the strong indications of tissue-specific functions, and the evidence of convergent evolution suggest that these events may have played important roles in the evolution of animal tissues and organs.
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Affiliation(s)
- Laura Martinez-Gomez
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain
| | - Daniel Cerdán-Vélez
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain
| | - Federico Abascal
- Somatic Evolution Group, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
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5
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Zea DJ, Laskina S, Baudin A, Richard H, Laine E. Assessing conservation of alternative splicing with evolutionary splicing graphs. Genome Res 2021; 31:1462-1473. [PMID: 34266979 PMCID: PMC8327911 DOI: 10.1101/gr.274696.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 06/11/2021] [Indexed: 12/29/2022]
Abstract
Understanding how protein function has evolved and diversified is of great importance for human genetics and medicine. Here, we tackle the problem of describing the whole transcript variability observed in several species by generalizing the definition of splicing graph. We provide a practical solution to construct parsimonious evolutionary splicing graphs where each node is a minimal transcript building block defined across species. We show a clear link between the functional relevance, tissue regulation, and conservation of alternative transcripts on a set of 50 genes. By scaling up to the whole human protein-coding genome, we identify a few thousand genes where alternative splicing modulates the number and composition of pseudorepeats. We have implemented our approach in ThorAxe, an efficient, versatile, robust, and freely available computational tool.
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Affiliation(s)
- Diego Javier Zea
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Sofya Laskina
- Bioinformatics Unit (MF1), Department for Methods Development and Research Infrastructure, Robert Koch Institute, 13353 Berlin, Germany
| | - Alexis Baudin
- Sorbonne Université, CNRS, LIP6, F-75005 Paris, France
| | - Hugues Richard
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
- Bioinformatics Unit (MF1), Department for Methods Development and Research Infrastructure, Robert Koch Institute, 13353 Berlin, Germany
| | - Elodie Laine
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
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6
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Martinez Gomez L, Pozo F, Walsh TA, Abascal F, Tress ML. The clinical importance of tandem exon duplication-derived substitutions. Nucleic Acids Res 2021; 49:8232-8246. [PMID: 34302486 PMCID: PMC8373072 DOI: 10.1093/nar/gkab623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/21/2021] [Indexed: 01/04/2023] Open
Abstract
Most coding genes in the human genome are annotated with multiple alternative transcripts. However, clear evidence for the functional relevance of the protein isoforms produced by these alternative transcripts is often hard to find. Alternative isoforms generated from tandem exon duplication-derived substitutions are an exception. These splice events are rare, but have important functional consequences. Here, we have catalogued the 236 tandem exon duplication-derived substitutions annotated in the GENCODE human reference set. We find that more than 90% of the events have a last common ancestor in teleost fish, so are at least 425 million years old, and twenty-one can be traced back to the Bilateria clade. Alternative isoforms generated from tandem exon duplication-derived substitutions also have significantly more clinical impact than other alternative isoforms. Tandem exon duplication-derived substitutions have >25 times as many pathogenic and likely pathogenic mutations as other alternative events. Tandem exon duplication-derived substitutions appear to have vital functional roles in the cell and may have played a prominent part in metazoan evolution.
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Affiliation(s)
- Laura Martinez Gomez
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain
| | - Fernando Pozo
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain
| | - Thomas A Walsh
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain.,Eukaryotic Annotation Team, EMBL-EBI, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA. UK
| | - Federico Abascal
- Somatic Evolution Group, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Michael L Tress
- Bioinformatics Unit, Spanish National Cancer Research Centre (CNIO), C. Melchor Fernandez Almagro, 3, 28029 Madrid, Spain
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7
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Wang Y, Guo B. The divergence of alternative splicing between ohnologs in teleost fishes. BMC Ecol Evol 2021; 21:98. [PMID: 34034651 PMCID: PMC8146666 DOI: 10.1186/s12862-021-01833-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 05/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Gene duplication and alternative splicing (AS) are two distinct mechanisms generating new materials for genetic innovations. The evolutionary link between gene duplication and AS is still controversial, due to utilizing duplicates from inconsistent ages of duplication events in earlier studies. With the aid of RNA-seq data, we explored evolutionary scenario of AS divergence between duplicates with ohnologs that resulted from the teleost genome duplication event in zebrafish, medaka, and stickleback. RESULTS Ohnologs in zebrafish have fewer AS forms compared to their singleton orthologs, supporting the function-sharing model of AS divergence between duplicates. Ohnologs in stickleback have more AS forms compared to their singleton orthologs, which supports the accelerated model of AS divergence between duplicates. The evolution of AS in ohnologs in medaka supports a combined scenario of the function-sharing and the accelerated model of AS divergence between duplicates. We also found a small number of ohnolog pairs in each of the three teleosts showed significantly asymmetric AS divergence. For example, the well-known ovary-factor gene cyp19a1a has no AS form but its ohnolog cyp19a1b has multiple AS forms in medaka, suggesting that functional divergence between duplicates might have result from AS divergence. CONCLUSIONS We found that a combined scenario of function-sharing and accelerated models for AS evolution in ohnologs in teleosts and rule out the independent model that assumes a lack of correlation between gene duplication and AS. Our study thus provided insights into the link between gene duplication and AS in general and ohnolog divergence in teleosts from AS perspective in particular.
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Affiliation(s)
- Yuwei Wang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Baocheng Guo
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650201, China.
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8
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Královičová J, Borovská I, Pengelly R, Lee E, Abaffy P, Šindelka R, Grutzner F, Vořechovský I. Restriction of an intron size en route to endothermy. Nucleic Acids Res 2021; 49:2460-2487. [PMID: 33550394 PMCID: PMC7969005 DOI: 10.1093/nar/gkab046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 01/11/2021] [Accepted: 01/15/2021] [Indexed: 11/15/2022] Open
Abstract
Ca2+-insensitive and -sensitive E1 subunits of the 2-oxoglutarate dehydrogenase complex (OGDHC) regulate tissue-specific NADH and ATP supply by mutually exclusive OGDH exons 4a and 4b. Here we show that their splicing is enforced by distant lariat branch points (dBPs) located near the 5' splice site of the intervening intron. dBPs restrict the intron length and prevent transposon insertions, which can introduce or eliminate dBP competitors. The size restriction was imposed by a single dominant dBP in anamniotes that expanded into a conserved constellation of four dBP adenines in amniotes. The amniote clusters exhibit taxon-specific usage of individual dBPs, reflecting accessibility of their extended motifs within a stable RNA hairpin rather than U2 snRNA:dBP base-pairing. The dBP expansion took place in early terrestrial species and was followed by a uridine enrichment of large downstream polypyrimidine tracts in mammals. The dBP-protected megatracts permit reciprocal regulation of exon 4a and 4b by uridine-binding proteins, including TIA-1/TIAR and PUF60, which promote U1 and U2 snRNP recruitment to the 5' splice site and BP, respectively, but do not significantly alter the relative dBP usage. We further show that codons for residues critically contributing to protein binding sites for Ca2+ and other divalent metals confer the exon inclusion order that mirrors the Irving-Williams affinity series, linking the evolution of auxiliary splicing motifs in exons to metallome constraints. Finally, we hypothesize that the dBP-driven selection for Ca2+-dependent ATP provision by E1 facilitated evolution of endothermy by optimizing the aerobic scope in target tissues.
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Affiliation(s)
- Jana Královičová
- University of Southampton, Faculty of Medicine, HDH, Southampton SO16 6YD, UK
- Slovak Academy of Sciences, Centre for Biosciences, 840 05 Bratislava, Slovak Republic
| | - Ivana Borovská
- Slovak Academy of Sciences, Centre for Biosciences, 840 05 Bratislava, Slovak Republic
| | - Reuben Pengelly
- University of Southampton, Faculty of Medicine, HDH, Southampton SO16 6YD, UK
| | - Eunice Lee
- School of Biological Sciences, University of Adelaide, Adelaide 5005, SA, Australia
| | - Pavel Abaffy
- Czech Academy of Sciences, Institute of Biotechnology, 25250 Vestec, Czech Republic
| | - Radek Šindelka
- Czech Academy of Sciences, Institute of Biotechnology, 25250 Vestec, Czech Republic
| | - Frank Grutzner
- School of Biological Sciences, University of Adelaide, Adelaide 5005, SA, Australia
| | - Igor Vořechovský
- University of Southampton, Faculty of Medicine, HDH, Southampton SO16 6YD, UK
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Lam SD, Babu MM, Lees J, Orengo CA. Biological impact of mutually exclusive exon switching. PLoS Comput Biol 2021; 17:e1008708. [PMID: 33651795 PMCID: PMC7954323 DOI: 10.1371/journal.pcbi.1008708] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 03/12/2021] [Accepted: 01/14/2021] [Indexed: 12/27/2022] Open
Abstract
Alternative splicing can expand the diversity of proteomes. Homologous mutually exclusive exons (MXEs) originate from the same ancestral exon and result in polypeptides with similar structural properties but altered sequence. Why would some genes switch homologous exons and what are their biological impact? Here, we analyse the extent of sequence, structural and functional variability in MXEs and report the first large scale, structure-based analysis of the biological impact of MXE events from different genomes. MXE-specific residues tend to map to single domains, are highly enriched in surface exposed residues and cluster at or near protein functional sites. Thus, MXE events are likely to maintain the protein fold, but alter specificity and selectivity of protein function. This comprehensive resource of MXE events and their annotations is available at: http://gene3d.biochem.ucl.ac.uk/mxemod/. These findings highlight how small, but significant changes at critical positions on a protein surface are exploited in evolution to alter function.
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Affiliation(s)
- Su Datt Lam
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
- * E-mail: (SDL); (JL); (CO)
| | - M. Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jonathan Lees
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom
- * E-mail: (SDL); (JL); (CO)
| | - Christine A. Orengo
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- * E-mail: (SDL); (JL); (CO)
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10
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Zhang Y, Rahmani RS, Yang X, Chen J, Shi T. Integrative expression network analysis of microRNA and gene isoforms in sacred lotus. BMC Genomics 2020; 21:429. [PMID: 32586276 PMCID: PMC7315500 DOI: 10.1186/s12864-020-06853-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 06/19/2020] [Indexed: 01/29/2023] Open
Abstract
Background Gene expression is complex and regulated by multiple molecular mechanisms, such as miRNA-mediated gene inhibition and alternative-splicing of pre-mRNAs. However, the coordination of interaction between miRNAs with different splicing isoforms, and the change of splicing isoform in response to different cellular environments are largely unexplored in plants. In this study, we analyzed the miRNA and mRNA transcriptome from lotus (Nelumbo nucifera), an economically important flowering plant. Results Through RNA-seq analyses on miRNAs and their target genes (isoforms) among six lotus tissues, expression of most miRNAs seem to be negatively correlated with their targets and tend to be tissue-specific. Further, our results showed that preferential interactions between miRNAs and hub gene isoforms in one coexpression module which is highly correlated with leaf. Intriguingly, for many genes, their corresponding isoforms were assigned to different co-expressed modules, and they exhibited more divergent mRNA structures including presence and absence of miRNA binding sites, suggesting functional divergence for many isoforms is escalated by both structural and expression divergence. Further detailed functional enrichment analysis of miRNA targets revealed that miRNAs are involved in the regulation of lotus growth and development by regulating plant hormone-related pathway genes. Conclusions Taken together, our comprehensive analyses of miRNA and mRNA transcriptome elucidate the coordination of interaction between miRNAs and different splicing isoforms, and highlight the functional divergence of many transcript isoforms from the same locus in lotus.
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Affiliation(s)
- Yue Zhang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.,Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Razgar Seyed Rahmani
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Xingyu Yang
- Wuhan Institute of Landscape Architecture, Wuhan, China
| | - Jinming Chen
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China. .,Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China.
| | - Tao Shi
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China. .,Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan, 430074, China.
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11
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Ait-Hamlat A, Zea DJ, Labeeuw A, Polit L, Richard H, Laine E. Transcripts' Evolutionary History and Structural Dynamics Give Mechanistic Insights into the Functional Diversity of the JNK Family. J Mol Biol 2020; 432:2121-2140. [PMID: 32067951 DOI: 10.1016/j.jmb.2020.01.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/03/2020] [Accepted: 01/28/2020] [Indexed: 12/14/2022]
Abstract
Alternative splicing and alternative initiation/termination transcription sites have the potential to greatly expand the proteome in eukaryotes by producing several transcript isoforms from the same gene. Although these mechanisms are well described at the genomic level, little is known about their contribution to protein evolution and their impact at the protein structure level. Here, we address both issues by reconstructing the evolutionary history of transcripts and by modeling the tertiary structures of the corresponding protein isoforms. We reconstruct phylogenetic forests relating 60 protein-coding transcripts from the c-Jun N-terminal kinase (JNK) family observed in seven species. We identify two alternative splicing events of ancient origin and show that they induce subtle changes in the protein's structural dynamics. We highlight a previously uncharacterized transcript whose predicted structure seems stable in solution. We further demonstrate that orphan transcripts, for which no phylogeny could be reconstructed, display peculiar sequence and structural properties. Our approach is implemented in PhyloSofS (Phylogenies of Splicing Isoforms Structures), a fully automated computational tool freely available at https://github.com/PhyloSofS-Team/PhyloSofS.
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Affiliation(s)
- Adel Ait-Hamlat
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France
| | - Diego Javier Zea
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France
| | - Antoine Labeeuw
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France
| | - Lélia Polit
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France
| | - Hugues Richard
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France.
| | - Elodie Laine
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, 75005, France.
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Ray D, Ray P, Ferrer-Torres D, Wang Z, Nancarrow D, Yoon HW, Martinho MS, Hinton T, Owens S, Thomas D, Jiang H, Lawrence TS, Lin J, Lagisetty K, Chang AC, Beer DG. Isoforms of RNF128 Regulate the Stability of Mutant P53 in Barrett's Esophageal Cells. Gastroenterology 2020; 158:583-597.e1. [PMID: 31715145 PMCID: PMC7429981 DOI: 10.1053/j.gastro.2019.10.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 10/21/2019] [Accepted: 10/30/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND & AIMS Barrett's esophagus (BE) can progress to dysplasia and esophageal adenocarcinoma (EAC), accompanied by mutations in TP53 that increase the stability of its product, p53. We analyzed BE tissues for messenger RNAs (mRNAs) that associate with BE progression and identified one that affects the stabilization of p53. METHODS We obtained 54 BE samples collected from patients with high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC), from 1992 through 2015, and performed RNA sequence analyses, including isoform-specific analyses. We performed reverse-transcription polymerase chain reaction analyses of 166 samples and immunohistochemical analyses of tissue microarrays that contained BE tissues from 100 patients with HGD or EAC and normal esophageal squamous mucosa (controls). Proteins were expressed from transfected plasmids or knocked down with small interfering RNAs in BE cells and analyzed by immunoblots and in immunoprecipitation and ubiquitin ligase assays. Athymic nude mice bearing EAC xenograft tumors (grown from OE-33 cells) were given intraperitoneal injections of simvastatin; tumor growth was monitored and tumors were collected and analyzed by immunoblotting for levels of RNF128, p53, and acetylated p53. RESULTS Progression of BE to HGD or EAC associated with changes in expression of mRNAs that encoded mucins and promoted inflammation and activation of ATM and the DNA damage response. As tissues progressed from BE to HGD to EAC, they increased expression of mRNAs encoding isoform 1 of RNF128 (Iso1) and decreased expression of Iso2 of RNF128. RNF128 is an E3 ubiquitin ligase that targets p53 for degradation. Incubation of BE cells with interferon gamma caused them to increase expression of Iso1 and reduce expression of Iso2. Iso1 was heavily glycosylated with limited ubiquitin ligase activity for p53, resulting in p53 stabilization. Knockdown of Iso1 in BE and EAC cells led to degradation of the mutant form of p53 and reduced clonogenic survival. In contrast, Iso2 was a potent ligase that reduced levels of the mutant form of p53 in BE cells. In BE cells, Iso2 was hypoglycosylated and degraded, via ATM and GSK3β-mediated phosphorylation and activation of the beta-TrCP1-containing SCF ubiquitin ligase complex. Simvastatin, which degrades the mutant form of p53, also degraded RNF128 Iso1 protein in BE cells and slowed growth of EAC xenograft tumors in mice. CONCLUSIONS We found that isoform 2 of RNF128 is decreased in BE cells, resulting in increased levels of mutant p53, whereas isoform 1 of RNF128 is increased in BE cells, further promoting the stabilization of mutant p53.
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Affiliation(s)
- Dipankar Ray
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
| | - Paramita Ray
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Daysha Ferrer-Torres
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Zhuwen Wang
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Derek Nancarrow
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Hee-won Yoon
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - May San Martinho
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Tonaye Hinton
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Scott Owens
- Department of Pathology, University of Michigan, Ann Arbor, Michigan
| | - Dafydd Thomas
- Department of Pathology, University of Michigan, Ann Arbor, Michigan
| | - Hui Jiang
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan
| | | | - Jules Lin
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Kiran Lagisetty
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Andrew C. Chang
- Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
| | - David G. Beer
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan,Department of Surgery, Thoracic Surgery, University of Michigan, Ann Arbor, Michigan
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Zhang D, Yang JF, Gao B, Liu TY, Hao GF, Yang GF, Fu LJ, Chen MX, Zhang J. Identification, evolution and alternative splicing profile analysis of the splicing factor 30 (SPF30) in plant species. PLANTA 2019; 249:1997-2014. [PMID: 30904945 DOI: 10.1007/s00425-019-03146-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 03/19/2019] [Indexed: 06/09/2023]
Abstract
The work offers a comprehensive evaluation on the phylogenetics and conservation of splicing patterns of the plant SPF30 splicing factor gene family. In eukaryotes, one pre-mRNA can generate multiple mRNA transcripts by alternative splicing (AS), which expands transcriptome and proteome diversity. Splicing factor 30 (SPF30), also known as survival motor neuron domain containing protein 1 (SMNDC1), is a spliceosomal protein that plays an essential role in spliceosomal assembly. Although SPF30 genes have been well characterised in human and yeast, little is known about their homologues in plants. Here, we report the genome-wide identification and phylogenetic analysis of SPF30 genes in the plant kingdom. In total, 82 SPF30 genes were found in 64 plant species from algae to land plants. Alternative transcripts were found in many SPF30 genes and splicing profile analysis revealed that the second intron in SPF30 genome is frequently associated with AS events and contributed to the birth of novel exons in a few SPF30 members. In addition, different conserved sequences were observed at these putative splice sites among moss, monocots and dicots, respectively. Our findings will facilitate further functional characterization of plant SPF30 genes as putative splicing factors.
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Affiliation(s)
- Di Zhang
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Jing-Fang Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Bei Gao
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Tie-Yuan Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Ge-Fei Hao
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China
| | - Li-Jun Fu
- Fujian Provincial Key Laboratory of Ecology-Toxicological Effects & Control for Emerging Contaminants, Putian University, Putian, 351100, Fujian, People's Republic of China
| | - Mo-Xian Chen
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong.
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| | - Jianhua Zhang
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
- Department of Biology, Hong Kong Baptist University and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong.
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Hatje K, Rahman RU, Vidal RO, Simm D, Hammesfahr B, Bansal V, Rajput A, Mickael ME, Sun T, Bonn S, Kollmar M. The landscape of human mutually exclusive splicing. Mol Syst Biol 2017; 13:959. [PMID: 29242366 PMCID: PMC5740500 DOI: 10.15252/msb.20177728] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Mutually exclusive splicing of exons is a mechanism of functional gene and protein diversification with pivotal roles in organismal development and diseases such as Timothy syndrome, cardiomyopathy and cancer in humans. In order to obtain a first genomewide estimate of the extent and biological role of mutually exclusive splicing in humans, we predicted and subsequently validated mutually exclusive exons (MXEs) using 515 publically available RNA‐Seq datasets. Here, we provide evidence for the expression of over 855 MXEs, 42% of which represent novel exons, increasing the annotated human mutually exclusive exome more than fivefold. The data provide strong evidence for the existence of large and multi‐cluster MXEs in higher vertebrates and offer new insights into MXE evolution. More than 82% of the MXE clusters are conserved in mammals, and five clusters have homologous clusters in Drosophila. Finally, MXEs are significantly enriched in pathogenic mutations and their spatio‐temporal expression might predict human disease pathology.
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Affiliation(s)
- Klas Hatje
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany
| | - Raza-Ur Rahman
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ramon O Vidal
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany
| | - Dominic Simm
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Theoretical Computer Science and Algorithmic Methods, Institute of Computer Science Georg-August-University, Göttingen, Germany
| | - Björn Hammesfahr
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Vikas Bansal
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ashish Rajput
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Michel Edwar Mickael
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Ting Sun
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany.,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Bonn
- Group of Computational Systems Biology, German Center for Neurodegenerative Diseases, Göttingen, Germany .,Center for Molecular Neurobiology, Institute of Medical Systems Biology University Clinic Hamburg-Eppendorf, Hamburg, Germany.,German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Martin Kollmar
- Group Systems Biology of Motor Proteins Department of NMR-Based Structural Biology Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
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Dennenmoser S, Sedlazeck FJ, Iwaszkiewicz E, Li X, Altmüller J, Nolte AW. Copy number increases of transposable elements and protein-coding genes in an invasive fish of hybrid origin. Mol Ecol 2017; 26:4712-4724. [PMID: 28390096 PMCID: PMC5638112 DOI: 10.1111/mec.14134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/25/2022]
Abstract
Evolutionary dynamics of structural genetic variation in lineages of hybrid origin is not well explored, although structural mutations may increase in controlled hybrid crosses. We therefore tested whether structural variants accumulate in a fish of recent hybrid origin, invasive Cottus, relative to both parental species Cottus rhenanus and Cottus perifretum. Copy-number variation in exons of 10,979 genes was assessed using comparative genome hybridization arrays. Twelve genes showed significantly higher copy numbers in invasive Cottus compared to both parents. This coincided with increased expression for three genes related to vision, detoxification and muscle development, suggesting possible gene dosage effects. Copy number increases of putative transposons were assessed by comparative mapping of genomic DNA reads against a de novo assembly of 1,005 repetitive elements. In contrast to exons, copy number increases of repetitive elements were common (20.7%) in invasive Cottus, whereas decrease was very rare (0.01%). Among the increased repetitive elements, 53.8% occurred at higher numbers in C. perifretum compared to C. rhenanus, while only 1.4% were more abundant in C. rhenanus. This implies a biased mutational process that amplifies genetic material from one ancestor. To assess the frequency of de novo mutations through hybridization, we screened 64 laboratory-bred F2 offspring between the parental species for copy-number changes at five candidate loci. We found no evidence for new structural variants, indicating that they are too rare to be detected given our sampling scheme. Instead, they must have accumulated over more generations than we observed in a controlled cross.
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Affiliation(s)
- Stefan Dennenmoser
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
- Institute for BiologyCarl von Ossietzky University OldenburgOldenburgGermany
| | | | - Elzbieta Iwaszkiewicz
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
| | - Xiang‐Yi Li
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Janine Altmüller
- Cologne Center for Genomics, and Institute of Human GeneticsUniversity of CologneCologneGermany
| | - Arne W. Nolte
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
- Institute for BiologyCarl von Ossietzky University OldenburgOldenburgGermany
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Liavas A, Lignani G, Schorge S. Conservation of alternative splicing in sodium channels reveals evolutionary focus on release from inactivation and structural insights into gating. J Physiol 2017. [PMID: 28621020 PMCID: PMC5811987 DOI: 10.1113/jp274693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Key points Sodium channels are critical for supporting fast action potentials in neurons; even mutations which cause small changes in sodium channel activity can have devastating consequences for the function of the nervous system. Alternative splicing also changes the activity of sodium channels, and while it is highly conserved, it is not known whether the functional role of this splicing is also conserved. Our data reveal that splicing has a highly conserved impact on the availability of sodium channels during trains of rapid stimulations, and suggest that in one mammalian channel, Nav1.1 encoded by SCN1A, the increased availability of one splice variant is detrimental. A model reproducing the effects of splicing on channel behaviour suggests that the voltage sensor in the first domain is a rate limiting step for release of the inactivation domain, and highlights the functional specialization of channel domains.
Abstract Voltage‐gated sodium channels are critical for neuronal activity, and highly intolerant to variation. Even mutations that cause subtle changes in the activity these channels are sufficient to cause devastating inherited neurological diseases, such as epilepsy and pain. However, these channels do vary in healthy tissue. Alternative splicing modifies sodium channels, but the functional relevance and adaptive significance of this splicing remain poorly understood. Here we use a conserved alternate exon encoding part of the first domain of sodium channels to compare how splicing modifies different channels, and to ask whether the functional consequences of this splicing have been preserved in different genes. Although the splicing event is highly conserved, one splice variant has been selectively removed from Nav1.1 in multiple mammalian species, suggesting that the functional variation in Nav1.1 is less well tolerated. We show for three human channels (Nav1.1, Nav1.2 and Nav1.7) that splicing modifies the return from inactivated to deactivated states, and the differences between splice variants are occluded by antiepileptic drugs that bind to and stabilize inactivated states. A model based on structural data can replicate these changes, and indicates that splicing may exploit a distinct role of the first domain to change channel availability, and that the first domain of all three sodium channels plays a role in determining the rate at which the inactivation domain dissociates. Taken together, our data suggest that the stability of inactivated states is under tight evolutionary control, but that in Nav1.1 faster recovery from inactivation is associated with negative selection in mammals. Sodium channels are critical for supporting fast action potentials in neurons; even mutations which cause small changes in sodium channel activity can have devastating consequences for the function of the nervous system. Alternative splicing also changes the activity of sodium channels, and while it is highly conserved, it is not known whether the functional role of this splicing is also conserved. Our data reveal that splicing has a highly conserved impact on the availability of sodium channels during trains of rapid stimulations, and suggest that in one mammalian channel, Nav1.1 encoded by SCN1A, the increased availability of one splice variant is detrimental. A model reproducing the effects of splicing on channel behaviour suggests that the voltage sensor in the first domain is a rate limiting step for release of the inactivation domain, and highlights the functional specialization of channel domains.
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Affiliation(s)
- A Liavas
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - G Lignani
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - S Schorge
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, WC1N 3BG, UK
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17
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Iñiguez LP, Hernández G. The Evolutionary Relationship between Alternative Splicing and Gene Duplication. Front Genet 2017; 8:14. [PMID: 28261262 PMCID: PMC5306129 DOI: 10.3389/fgene.2017.00014] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/02/2017] [Indexed: 01/23/2023] Open
Abstract
The protein diversity that exists today has resulted from various evolutionary processes. It is well known that gene duplication (GD) along with the accumulation of mutations are responsible, among other factors, for an increase in the number of different proteins. The gene structure in eukaryotes requires the removal of non-coding sequences, introns, to produce mature mRNAs. This process, known as cis-splicing, referred to here as splicing, is regulated by several factors which can lead to numerous splicing arrangements, commonly designated as alternative splicing (AS). AS, producing several transcripts isoforms form a single gene, also increases the protein diversity. However, the evolution and manner for increasing protein variation differs between AS and GD. An important question is how are patterns of AS affected after a GD event. Here, we review the current knowledge of AS and GD, focusing on their evolutionary relationship. These two processes are now considered the main contributors to the increasing protein diversity and therefore their relationship is a relevant, yet understudied, area of evolutionary study.
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Affiliation(s)
- Luis P Iñiguez
- Programa de Genómica Funcional de Eucariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, México
| | - Georgina Hernández
- Programa de Genómica Funcional de Eucariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, México
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18
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The ribosome-engaged landscape of alternative splicing. Nat Struct Mol Biol 2016; 23:1117-1123. [PMID: 27820807 DOI: 10.1038/nsmb.3317] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/06/2016] [Indexed: 02/07/2023]
Abstract
High-throughput RNA sequencing (RNA-seq) has revealed an enormous complexity of alternative splicing (AS) across diverse cell and tissue types. However, it is currently unknown to what extent repertoires of splice-variant transcripts are translated into protein products. Here, we surveyed AS events engaged by the ribosome. Notably, at least 75% of human exon-skipping events detected in transcripts with medium-to-high abundance in RNA-seq data were also detected in ribosome profiling data. Furthermore, relatively small subsets of functionally related splice variants are engaged by ribosomes at levels that do not reflect their absolute abundance, thus indicating a role for AS in modulating translational output. This mode of regulation is associated with control of the mammalian cell cycle. Our results thus suggest that a major fraction of splice variants is translated and that specific cellular functions including cell-cycle control are subject to AS-dependent modulation of translation output.
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19
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Kralovicova J, Vorechovsky I. Alternative splicing of U2AF1 reveals a shared repression mechanism for duplicated exons. Nucleic Acids Res 2016; 45:417-434. [PMID: 27566151 PMCID: PMC5224494 DOI: 10.1093/nar/gkw733] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 12/30/2022] Open
Abstract
The auxiliary factor of U2 small nuclear ribonucleoprotein (U2AF) facilitates branch point (BP) recognition and formation of lariat introns. The gene for the 35-kD subunit of U2AF gives rise to two protein isoforms (termed U2AF35a and U2AF35b) that are encoded by alternatively spliced exons 3 and Ab, respectively. The splicing recognition sequences of exon 3 are less favorable than exon Ab, yet U2AF35a expression is higher than U2AF35b across tissues. We show that U2AF35b repression is facilitated by weak, closely spaced BPs next to a long polypyrimidine tract of exon Ab. Each BP lacked canonical uridines at position -2 relative to the BP adenines, with efficient U2 base-pairing interactions predicted only for shifted registers reminiscent of programmed ribosomal frameshifting. The BP cluster was compensated by interactions involving unpaired cytosines in an upstream, EvoFold-predicted stem loop (termed ESL) that binds FUBP1/2. Exon Ab inclusion correlated with predicted free energies of mutant ESLs, suggesting that the ESL operates as a conserved rheostat between long inverted repeats upstream of each exon. The isoform-specific U2AF35 expression was U2AF65-dependent, required interactions between the U2AF-homology motif (UHM) and the α6 helix of U2AF35, and was fine-tuned by exon Ab/3 variants. Finally, we identify tandem homologous exons regulated by U2AF and show that their preferential responses to U2AF65-related proteins and SRSF3 are associated with unpaired pre-mRNA segments upstream of U2AF-repressed 3′ss. These results provide new insights into tissue-specific subfunctionalization of duplicated exons in vertebrate evolution and expand the repertoire of exon repression mechanisms that control alternative splicing.
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Affiliation(s)
- Jana Kralovicova
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Igor Vorechovsky
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
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20
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Wang M, Yue H, Feng K, Deng P, Song W, Nie X. Genome-wide identification, phylogeny and expressional profiles of mitogen activated protein kinase kinase kinase (MAPKKK) gene family in bread wheat (Triticum aestivum L.). BMC Genomics 2016; 17:668. [PMID: 27549916 PMCID: PMC4994377 DOI: 10.1186/s12864-016-2993-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/03/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Mitogen-activated protein kinase kinase kinases (MAPKKKs) are the important components of MAPK cascades, which play the crucial role in plant growth and development as well as in response to diverse stresses. Although this family has been systematically studied in many plant species, little is known about MAPKKK genes in wheat (Triticum aestivum L.), especially those involved in the regulatory network of stress processes. RESULTS In this study, we identified 155 wheat MAPKKK genes through a genome-wide search method based on the latest available wheat genome information, of which 29 belonged to MEKK, 11 to ZIK and 115 to Raf subfamily, respectively. Then, chromosome localization, gene structure and conserved protein motifs and phylogenetic relationship as well as regulatory network of these TaMAPKKKs were systematically investigated and results supported the prediction. Furthermore, a total of 11 homologous groups between A, B and D sub-genome and 24 duplication pairs among them were detected, which contributed to the expansion of wheat MAPKKK gene family. Finally, the expression profiles of these MAPKKKs during development and under different abiotic stresses were investigated using the RNA-seq data. Additionally, 10 tissue-specific and 4 salt-responsive TaMAPKKK genes were selected to validate their expression level through qRT-PCR analysis. CONCLUSIONS This study for the first time reported the genome organization, evolutionary features and expression profiles of the wheat MAPKKK gene family, which laid the foundation for further functional analysis of wheat MAPKKK genes, and contributed to better understanding the roles and regulatory mechanism of MAPKKKs in wheat.
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Affiliation(s)
- Meng Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
| | - Hong Yue
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
| | - Kewei Feng
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
| | - Pingchuan Deng
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
| | - Weining Song
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
- Australia-China Joint Research Centre for Abiotic and Biotic Stress Management in Agriculture, Horticulture and Forestry, Yangling, 712100 Shaanxi China
| | - Xiaojun Nie
- State Key Laboratory of Crop Stress Biology in Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, 3 Taicheng Road, Yangling, 712100 Shaanxi China
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Lees JG, Dawson NL, Sillitoe I, Orengo CA. Functional innovation from changes in protein domains and their combinations. Curr Opin Struct Biol 2016; 38:44-52. [DOI: 10.1016/j.sbi.2016.05.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/17/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
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22
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Piccolo paralogs and orthologs display conserved patterns of alternative splicing within the C2A and C2B domains. Genes Genomics 2016. [DOI: 10.1007/s13258-015-0383-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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The Rho GTPase Family Genes in Bivalvia Genomes: Sequence, Evolution and Expression Analysis. PLoS One 2015; 10:e0143932. [PMID: 26633655 PMCID: PMC4669188 DOI: 10.1371/journal.pone.0143932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 11/11/2015] [Indexed: 01/27/2023] Open
Abstract
Background Rho GTPases are important members of the Ras superfamily, which represents the largest signaling protein family in eukaryotes, and function as key molecular switches in converting and amplifying external signals into cellular responses. Although numerous analyses of Rho family genes have been reported, including their functions and evolution, a systematic analysis of this family has not been performed in Mollusca or in Bivalvia, one of the most important classes of Mollusca. Results In this study, we systematically identified and characterized a total set (Rho, Rac, Mig, Cdc42, Tc10, Rnd, RhoU, RhoBTB and Miro) of thirty Rho GTPase genes in three bivalve species, including nine in the Yesso scallop Patinopecten yessoensis, nine in the Zhikong scallop Chlamys farreri, and twelve in the Pacific oyster Crassostrea gigas. Phylogenetic analysis and interspecies comparison indicated that bivalves might possess the most complete types of Rho genes in invertebrates. A multiple RNA-seq dataset was used to investigate the expression profiles of bivalve Rho genes, revealing that the examined scallops share more similar Rho expression patterns than the oyster, whereas more Rho mRNAs are expressed in C. farreri and C. gigas than in P. yessoensis. Additionally, Rho, Rac and Cdc42 were found to be duplicated in the oyster but not in the scallops. Among the expanded Rho genes of C. gigas, duplication pairs with high synonymous substitution rates (Ks) displayed greater differences in expression. Conclusion A comprehensive analysis of bivalve Rho GTPase family genes was performed in scallop and oyster species, and Rho genes in bivalves exhibit greater conservation than those in any other invertebrate. This is the first study focusing on a genome-wide characterization of Rho GTPase genes in bivalves, and the findings will provide a valuable resource for a better understanding of Rho evolution and Rho GTPase function in Bivalvia.
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Abascal F, Ezkurdia I, Rodriguez-Rivas J, Rodriguez JM, del Pozo A, Vázquez J, Valencia A, Tress ML. Alternatively Spliced Homologous Exons Have Ancient Origins and Are Highly Expressed at the Protein Level. PLoS Comput Biol 2015; 11:e1004325. [PMID: 26061177 PMCID: PMC4465641 DOI: 10.1371/journal.pcbi.1004325] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 05/08/2015] [Indexed: 11/19/2022] Open
Abstract
Alternative splicing of messenger RNA can generate a wide variety of mature RNA transcripts, and these transcripts may produce protein isoforms with diverse cellular functions. While there is much supporting evidence for the expression of alternative transcripts, the same is not true for the alternatively spliced protein products. Large-scale mass spectroscopy experiments have identified evidence of alternative splicing at the protein level, but with conflicting results. Here we carried out a rigorous analysis of the peptide evidence from eight large-scale proteomics experiments to assess the scale of alternative splicing that is detectable by high-resolution mass spectroscopy. We find fewer splice events than would be expected: we identified peptides for almost 64% of human protein coding genes, but detected just 282 splice events. This data suggests that most genes have a single dominant isoform at the protein level. Many of the alternative isoforms that we could identify were only subtly different from the main splice isoform. Very few of the splice events identified at the protein level disrupted functional domains, in stark contrast to the two thirds of splice events annotated in the human genome that would lead to the loss or damage of functional domains. The most striking result was that more than 20% of the splice isoforms we identified were generated by substituting one homologous exon for another. This is significantly more than would be expected from the frequency of these events in the genome. These homologous exon substitution events were remarkably conserved—all the homologous exons we identified evolved over 460 million years ago—and eight of the fourteen tissue-specific splice isoforms we identified were generated from homologous exons. The combination of proteomics evidence, ancient origin and tissue-specific splicing indicates that isoforms generated from homologous exons may have important cellular roles. Alternative splicing is thought to be one means for generating the protein diversity necessary for the whole range of cellular functions. While the presence of alternatively spliced transcripts in the cell has been amply demonstrated, the same cannot be said for alternatively spliced proteins. The quest for alternative protein isoforms has focused primarily on the analysis of peptides from large-scale mass spectroscopy experiments, but evidence for alternative isoforms has been patchy and contradictory. A careful analysis of the peptide evidence is needed to fully understand the scale of alternative splicing detectable at the protein level. Here we analysed peptides from eight large-scale data sets, identifying just 282 splice events among 12,716 genes. This suggests that most genes have a single dominant isoform. Many of the alternative isoforms that we identified were only subtly different from the main splice variant, and one in five was generated by substitution of homologous exons by swapping one related exon for another. Remarkably, the alternative isoforms generated from homologous exons were highly conserved, first appearing 460 million years ago, and several appear to have tissue-specific roles in the brain and heart. Our results suggest that these particular isoforms are likely to have important cellular roles.
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Affiliation(s)
- Federico Abascal
- Structural Biology and Bioinformatics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Iakes Ezkurdia
- Unidad de Proteómica, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Juan Rodriguez-Rivas
- Structural Biology and Bioinformatics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Jose Manuel Rodriguez
- National Bioinformatics Institute (INB), Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Angela del Pozo
- Instituto de Genetica Medica y Molecular, Hospital Universitario La Paz, Madrid, Spain
| | - Jesús Vázquez
- Laboratorio de Proteómica Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares (CNIC) Madrid, Spain
| | - Alfonso Valencia
- Structural Biology and Bioinformatics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- National Bioinformatics Institute (INB), Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- * E-mail: (AV); (MLT)
| | - Michael L. Tress
- Structural Biology and Bioinformatics Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
- * E-mail: (AV); (MLT)
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