1
|
Du Y, Cao L, Wang S, Guo L, Tan L, Liu H, Feng Y, Wu W. Differences in alternative splicing and their potential underlying factors between animals and plants. J Adv Res 2024; 64:83-98. [PMID: 37981087 DOI: 10.1016/j.jare.2023.11.017] [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: 05/07/2023] [Revised: 08/16/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023] Open
Abstract
BACKGROUND Alternative splicing (AS), a posttranscriptional process, contributes to the complexity of transcripts from a limited number of genes in a genome, and AS is considered a great source of genetic and phenotypic diversity in eukaryotes. In animals, AS is tightly regulated during the processes of cell growth and differentiation, and its dysregulation is involved in many diseases, including cancers. Likewise, in plants, AS occurs in all stages of plant growth and development, and it seems to play important roles in the rapid reprogramming of genes in response to environmental stressors. To date, the prevalence and functional roles of AS have been extensively reviewed in animals and plants. However, AS differences between animals and plants, especially their underlying molecular mechanisms and impact factors, are anecdotal and rarely reviewed. AIM OF REVIEW This review aims to broaden our understanding of AS roles in a variety of biological processes and provide insights into the underlying mechanisms and impact factors likely leading to AS differences between animals and plants. KEY SCIENTIFIC CONCEPTS OF REVIEW We briefly summarize the roles of AS regulation in physiological and biochemical activities in animals and plants. Then, we underline the differences in the process of AS between plants and animals and especially analyze the potential impact factors, such as gene exon/intron architecture, 5'/3' untranslated regions (UTRs), spliceosome components, chromatin dynamics and transcription speeds, splicing factors [serine/arginine-rich (SR) proteins and heterogeneous nuclear ribonucleoproteins (hnRNPs)], noncoding RNAs, and environmental stimuli, which might lead to the differences. Moreover, we compare the nonsense-mediated mRNA decay (NMD)-mediated turnover of the transcripts with a premature termination codon (PTC) in animals and plants. Finally, we summarize the current AS knowledge published in animals versus plants and discuss the potential development of disease therapies and superior crops in the future.
Collapse
Affiliation(s)
- Yunfei Du
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Lu Cao
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Shuo Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Liangyu Guo
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Lingling Tan
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Hua Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China
| | - Ying Feng
- Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health (SINH), Chinese Academy of Sciences (CAS), Shanghai 200032, China.
| | - Wenwu Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, 311300, Hangzhou, China.
| |
Collapse
|
2
|
Sybilska E, Collin A, Sadat Haddadi B, Mur LAJ, Beckmann M, Guo W, Simpson CG, Daszkowska-Golec A. The cap-binding complex modulates ABA-responsive transcript splicing during germination in barley (Hordeum vulgare). Sci Rep 2024; 14:18278. [PMID: 39107424 PMCID: PMC11303550 DOI: 10.1038/s41598-024-69373-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
To decipher the molecular bases governing seed germination, this study presents the pivotal role of the cap-binding complex (CBC), comprising CBP20 and CBP80, in modulating the inhibitory effects of abscisic acid (ABA) in barley. Using both single and double barley mutants in genes encoding the CBC, we revealed that the double mutant hvcbp20.ab/hvcbp80.b displays ABA insensitivity, in stark contrast to the hypersensitivity observed in single mutants during germination. Our comprehensive transcriptome and metabolome analysis not only identified significant alterations in gene expression and splicing patterns but also underscored the regulatory nexus among CBC, ABA, and brassinosteroid (BR) signaling pathways.
Collapse
Affiliation(s)
- Ewa Sybilska
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28, 40-032, Katowice, Poland
| | - Anna Collin
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28, 40-032, Katowice, Poland
| | | | - Luis A J Mur
- Department of Life Science, Aberystwyth University, Aberystwyth, UK
| | - Manfred Beckmann
- Department of Life Science, Aberystwyth University, Aberystwyth, UK
| | - Wenbin Guo
- Information and Computational Sciences, James Hutton Institute, Dundee, DD2 5DA, Scotland, UK
| | - Craig G Simpson
- Cell and Molecular Sciences, James Hutton Institute, Dundee, DD2 5DA, Scotland, UK
| | - Agata Daszkowska-Golec
- Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28, 40-032, Katowice, Poland.
| |
Collapse
|
3
|
Warden CD, Wu X. Critical Differential Expression Assessment for Individual Bulk RNA-Seq Projects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.579728. [PMID: 38405814 PMCID: PMC10888899 DOI: 10.1101/2024.02.10.579728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Finding the right balance of quality and quantity can be important, and it is essential that project quality does not drop below the level where important main conclusions are missed or misstated. We use knock-out and over-expression studies as a simplification to test recovery of a known causal gene in RNA-Seq cell line experiments. When single-end RNA-Seq reads are aligned with STAR and quantified with htseq-count, we found potential value in testing the use of the Generalized Linear Model (GLM) implementation of edgeR with robust dispersion estimation more frequently for either single-variate or multi-variate 2-group comparisons (with the possibility of defining criteria less stringent than |fold-change| > 1.5 and FDR < 0.05). When considering a limited number of patient sample comparisons with larger sample size, there might be some decreased variability between methods (except for DESeq1). However, at the same time, the ranking of the gene identified using immunohistochemistry (for ER/PR/HER2 in breast cancer samples from The Cancer Genome Atlas) showed as possible shift in performance compared to the cell line comparisons, potentially highlighting utility for standard statistical tests and/or limma-based analysis with larger sample sizes. If this continues to be true in additional studies and comparisons, then that could be consistent with the possibility that it may be important to allocate time for potential methods troubleshooting for genomics projects. Analysis of public data presented in this study does not consider all experimental designs, and presentation of downstream analysis is limited. So, any estimate from this simplification would be an underestimation of the true need for some methods testing for every project. Additionally, this set of independent cell line experiments has a limitation in being able to determine the frequency of missing a highly important gene if the problem is rare (such as 10% or lower). For example, if there was an assumption that only one method can be tested for "initial" analysis, then it is not completely clear to the extent that using edgeR-robust might perform better than DESeq2 in the cell line experiments. Importantly, we do not wish to cause undue concern, and we believe that it should often be possible to define a gene expression differential expression workflow that is suitable for some purposes for many samples. Nevertheless, at the same time, we provide a variety of measures that we believe emphasize the need to critically assess every individual project and maximize confidence in published results.
Collapse
Affiliation(s)
- Charles D Warden
- Integrative Genomics Core, Department of Molecular and Cellular Biology, City of Hope National Medical Center, Duarte, CA
| | - Xiwei Wu
- Integrative Genomics Core, Department of Molecular and Cellular Biology, City of Hope National Medical Center, Duarte, CA
| |
Collapse
|
4
|
Bakhtiar D, Vondraskova K, Pengelly RJ, Chivers M, Kralovicova J, Vorechovsky I. Exonic splicing code and coordination of divalent metals in proteins. Nucleic Acids Res 2024; 52:1090-1106. [PMID: 38055834 PMCID: PMC10853796 DOI: 10.1093/nar/gkad1161] [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: 06/16/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/08/2023] Open
Abstract
Exonic sequences contain both protein-coding and RNA splicing information but the interplay of the protein and splicing code is complex and poorly understood. Here, we have studied traditional and auxiliary splicing codes of human exons that encode residues coordinating two essential divalent metals at the opposite ends of the Irving-Williams series, a universal order of relative stabilities of metal-organic complexes. We show that exons encoding Zn2+-coordinating amino acids are supported much less by the auxiliary splicing motifs than exons coordinating Ca2+. The handicap of the former is compensated by stronger splice sites and uridine-richer polypyrimidine tracts, except for position -3 relative to 3' splice junctions. However, both Ca2+ and Zn2+ exons exhibit close-to-constitutive splicing in multiple tissues, consistent with their critical importance for metalloprotein function and a relatively small fraction of expendable, alternatively spliced exons. These results indicate that constraints imposed by metal coordination spheres on RNA splicing have been efficiently overcome by the plasticity of exon-intron architecture to ensure adequate metalloprotein expression.
Collapse
Affiliation(s)
- Dara Bakhtiar
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Katarina Vondraskova
- Slovak Academy of Sciences, Centre of Biosciences, 840 05 Bratislava, Slovak Republic
| | - Reuben J Pengelly
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Martin Chivers
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Jana Kralovicova
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
- Slovak Academy of Sciences, Centre of Biosciences, 840 05 Bratislava, Slovak Republic
| | - Igor Vorechovsky
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| |
Collapse
|
5
|
Xu N, Ren Y, Bao Y, Shen X, Kang J, Wang N, Wang Z, Han X, Li Z, Zuo J, Wei GH, Wang Z, Zong WX, Liu W, Xie G, Wang Y. PUF60 promotes cell cycle and lung cancer progression by regulating alternative splicing of CDC25C. Cell Rep 2023; 42:113041. [PMID: 37682709 DOI: 10.1016/j.celrep.2023.113041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 06/27/2023] [Accepted: 08/14/2023] [Indexed: 09/10/2023] Open
Abstract
Alternative splicing (AS) has been implicated in cell cycle regulation and cancer, but the underlying mechanisms are poorly understood. The poly(U)-binding splicing factor 60 (PUF60) is essential for embryonic development and is overexpressed in multiple types of cancer. Here, we report that PUF60 promotes mitotic cell cycle and lung cancer progression by controlling AS of the cell division cycle 25C (CDC25C). Systematic analysis of splicing factors deregulated in lung adenocarcinoma (LUAD) identifies that elevated copy number and expression of PUF60 correlate with poor prognosis. PUF60 depletion inhibits LUAD cell-cycle G2/M transition, cell proliferation, and tumor development. Mechanistically, PUF60 knockdown leads to exon skipping enriched in mitotic cell cycle genes, including CDC25C. Exon 3 skipping in the full-length CDC25C results in nonsense-mediated mRNA decay and a decrease of CDC25C protein, thereby inhibiting cell proliferation. This study establishes PUF60 as a cell cycle regulator and an oncogenic splicing factor in lung cancer.
Collapse
Affiliation(s)
- Nan Xu
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yunpeng Ren
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yufang Bao
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Xianfeng Shen
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Jiahui Kang
- Institute of Reproductive Medicine, Medical School, Nantong University, Qixiu Road 19, Nantong 226001, China
| | - Ning Wang
- Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zixian Wang
- MOE Key Laboratory of Metabolism and Molecular Medicine & Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, and Fudan University Shanghai Cancer Center, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinlu Han
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Zhen Li
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Ji Zuo
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Gong-Hong Wei
- MOE Key Laboratory of Metabolism and Molecular Medicine & Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, and Fudan University Shanghai Cancer Center, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zefeng Wang
- Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai 200031, China
| | - Wei-Xing Zong
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers-The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Wen Liu
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Gangcai Xie
- Institute of Reproductive Medicine, Medical School, Nantong University, Qixiu Road 19, Nantong 226001, China.
| | - Yongbo Wang
- Department of Cellular and Genetic Medicine, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; Minhang Hospital & Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China; Shanghai Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.
| |
Collapse
|
6
|
Borovská I, Vořechovský I, Královičová J. Alu RNA fold links splicing with signal recognition particle proteins. Nucleic Acids Res 2023; 51:8199-8216. [PMID: 37309897 PMCID: PMC10450188 DOI: 10.1093/nar/gkad500] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/23/2023] [Accepted: 05/31/2023] [Indexed: 06/14/2023] Open
Abstract
Transcriptomic diversity in primates was considerably expanded by exonizations of intronic Alu elements. To better understand their cellular mechanisms we have used structure-based mutagenesis coupled with functional and proteomic assays to study the impact of successive primate mutations and their combinations on inclusion of a sense-oriented AluJ exon in the human F8 gene. We show that the splicing outcome was better predicted by consecutive RNA conformation changes than by computationally derived splicing regulatory motifs. We also demonstrate an involvement of SRP9/14 (signal recognition particle) heterodimer in splicing regulation of Alu-derived exons. Nucleotide substitutions that accumulated during primate evolution relaxed the conserved left-arm AluJ structure including helix H1 and reduced the capacity of SRP9/14 to stabilize the closed Alu conformation. RNA secondary structure-constrained mutations that promoted open Y-shaped conformations of the Alu made the Alu exon inclusion reliant on DHX9. Finally, we identified additional SRP9/14 sensitive Alu exons and predicted their functional roles in the cell. Together, these results provide unique insights into architectural elements required for sense Alu exonization, identify conserved pre-mRNA structures involved in exon selection and point to a possible chaperone activity of SRP9/14 outside the mammalian signal recognition particle.
Collapse
Affiliation(s)
- Ivana Borovská
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava 840 05, Slovak Republic
| | - Igor Vořechovský
- Faculty of Medicine, University of Southampton, HDH, MP808, Southampton SO16 6YD, United Kingdom
| | - Jana Královičová
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava 840 05, Slovak Republic
- Institute of Zoology, Slovak Academy of Sciences, Bratislava 845 06, Slovak Republic
| |
Collapse
|
7
|
Vester K, Preußner M, Holton N, Feng S, Schultz C, Heyd F, Wahl MC. Recruitment of a splicing factor to the nuclear lamina for its inactivation. Commun Biol 2022; 5:736. [PMID: 35869234 PMCID: PMC9307855 DOI: 10.1038/s42003-022-03689-y] [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: 01/09/2022] [Accepted: 07/08/2022] [Indexed: 11/10/2022] Open
Abstract
Precursor messenger RNA splicing is a highly regulated process, mediated by a complex RNA-protein machinery, the spliceosome, that encompasses several hundred proteins and five small nuclear RNAs in humans. Emerging evidence suggests that the spatial organization of splicing factors and their spatio-temporal dynamics participate in the regulation of splicing. So far, methods to manipulate the spatial distribution of splicing factors in a temporally defined manner in living cells are missing. Here, we describe such an approach that takes advantage of a reversible chemical dimerizer, and outline the requirements for efficient, reversible re-localization of splicing factors to selected sub-nuclear compartments. In a proof-of-principle study, the partial re-localization of the PRPF38A protein to the nuclear lamina in HEK293T cells induced a moderate increase in intron retention. Our approach allows fast and reversible re-localization of splicing factors, has few side effects and can be applied to many splicing factors by fusion of a protein tag through genome engineering. Apart from the systematic analysis of the spatio-temporal aspects of splicing regulation, the approach has a large potential for the fast induction and reversal of splicing switches and can reveal mechanisms of splicing regulation in native nuclear environments. Through the use of a reversible chemical dimerizer, the splicing factor PRPF38A is re-localized to the nuclear lamina, paving the way for a systematic analysis of spatio-temporal splicing regulation.
Collapse
|
8
|
Fennell AP, Baxter AE, Berkovic SF, Ellaway CJ, Forwood C, Hildebrand MS, Kumble S, McKeown C, Mowat D, Poke G, Rajagopalan S, Regan BM, Scheffer IE, Stark Z, Stutterd CA, Tan TY, Wilkins EJ, Yeung A, Hunter MF. The diverse pleiotropic effects of spliceosomal protein PUF60: A case series of Verheij syndrome. Am J Med Genet A 2022; 188:3432-3447. [PMID: 36367278 DOI: 10.1002/ajmg.a.62950] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/17/2022] [Accepted: 06/11/2022] [Indexed: 01/31/2023]
Abstract
Verheij syndrome (VRJS) is a rare craniofacial spliceosomopathy presenting with craniofacial dysmorphism, multiple congenital anomalies and variable neurodevelopmental delay. It is caused by single nucleotide variants (SNVs) in PUF60 or interstitial deletions of the 8q24.3 region. PUF60 encodes a splicing factor which forms part of the spliceosome. To date, 36 patients with a sole diagnosis of VRJS due to disease-causing PUF60 SNVs have been reported in peer-reviewed publications. Although the depth of their phenotyping has varied greatly, they exhibit marked phenotypic heterogeneity. We report 10 additional unrelated patients, including the first described patients of Khmer, Indian, and Vietnamese ethnicities, and the eldest patient to date, with 10 heterozygous PUF60 variants identified through exome sequencing, 8 previously unreported. All patients underwent deep phenotyping identifying variable dysmorphism, growth delay, neurodevelopmental delay, and multiple congenital anomalies, including several unique features. The eldest patient is the only reported individual with a germline variant and neither neurodevelopmental delay nor intellectual disability. In combining these detailed phenotypic data with that of previously reported patients (n = 46), we further refine the known frequencies of features associated with VRJS. These include neurodevelopmental delay/intellectual disability (98%), axial skeletal anomalies (74%), appendicular skeletal anomalies (73%), oral anomalies (68%), short stature (66%), cardiac anomalies (63%), brain malformations (48%), hearing loss (46%), microcephaly (41%), colobomata (38%), and other ocular anomalies (65%). This case series, incorporating three patients from previously unreported ethnic backgrounds, further delineates the broad pleiotropy and mutational spectrum of PUF60 pathogenic variants.
Collapse
Affiliation(s)
- Andrew Paul Fennell
- Monash Genetics, Monash Health, Melbourne, Australia.,Clinical Genetics Service, Austin Health, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | | | - Samuel Frank Berkovic
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Heidelberg, Australia
| | - Carolyn Jane Ellaway
- Paediatrics North, Sydney, Australia.,Genetic Metabolic Disorders Service, The Sydney Children's Hospital Network, Sydney, Australia.,Faculty of Medicine and Health, The University of Sydney, Sydney, Australia.,Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Caitlin Forwood
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Michael Stephen Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Heidelberg, Australia.,Murdoch Children's Research Institute, Melbourne, Australia
| | - Smitha Kumble
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Colina McKeown
- Genetic Health Service New Zealand, Wellington Hospital, Wellington, New Zealand
| | - David Mowat
- Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Sydney, Australia
| | - Gemma Poke
- Genetic Health Service New Zealand, Wellington Hospital, Wellington, New Zealand
| | | | - Brigid M Regan
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Heidelberg, Australia
| | - Ingrid Eileen Scheffer
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Heidelberg, Australia.,Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
| | - Zornitza Stark
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Chloe Alice Stutterd
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Tiong Yang Tan
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Ella Jane Wilkins
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Alison Yeung
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, Australia
| | - Matthew Frank Hunter
- Monash Genetics, Monash Health, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| |
Collapse
|
9
|
Morita T, Hayashi K. Actin-related protein 5 functions as a novel modulator of MyoD and MyoG in skeletal muscle and in rhabdomyosarcoma. eLife 2022; 11:77746. [PMID: 35348112 PMCID: PMC8983046 DOI: 10.7554/elife.77746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Myogenic regulatory factors (MRFs) are pivotal transcription factors in myogenic differentiation. MyoD commits cells to the skeletal muscle lineage by inducing myogenic genes through recruitment of chromatin remodelers to its target loci. This study showed that Actin-related protein 5 (Arp5) acts as an inhibitory regulator of MyoD and MyoG by binding to their cysteine-rich (CR) region, which overlaps with the region essential for their epigenetic functions. Arp5 expression was faint in skeletal muscle tissues. Excessive Arp5 in mouse hind limbs caused skeletal muscle fiber atrophy. Further, Arp5 overexpression in myoblasts inhibited myotube formation by diminishing myogenic gene expression, whereas Arp5 depletion augmented myogenic gene expression. Arp5 disturbed MyoD-mediated chromatin remodeling through competition with the three-amino-acid-loop-extension-class homeodomain transcription factors the Pbx1–Meis1 heterodimer for binding to the CR region. This antimyogenic function was independent of the INO80 chromatin remodeling complex, although Arp5 is an important component of that. In rhabdomyosarcoma (RMS) cells, Arp5 expression was significantly higher than in normal myoblasts and skeletal muscle tissue, probably contributing to MyoD and MyoG activity dysregulation. Arp5 depletion in RMS partially restored myogenic properties while inhibiting tumorigenic properties. Thus, Arp5 is a novel modulator of MRFs in skeletal muscle differentiation.
Collapse
|
10
|
Guo S, Lin S. mRNA alternative polyadenylation (APA) in regulation of gene expression and diseases. Genes Dis 2021; 10:165-174. [PMID: 37013028 PMCID: PMC10066270 DOI: 10.1016/j.gendis.2021.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/26/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
The mRNA polyadenylation plays essential function in regulation of mRNA metabolism. Mis-regulations of mRNA polyadenylation are frequently linked with aberrant gene expression and disease progression. Under the action of polyadenylate polymerase, poly(A) tail is synthesized after the polyadenylation signal (PAS) sites on the mRNAs. Alternative polyadenylation (APA) often occurs in mRNAs with multiple poly(A) sites, producing different 3' ends for transcript variants, and therefore plays important functions in gene expression regulation. In this review, we first summarize the classical process of mRNA 3'-terminal formation and discuss the length control mechanisms of poly(A) in nucleus and cytoplasm. Then we review the research progress on alternative polyadenylation regulation and the APA site selection mechanism. Finally, we summarize the functional roles of APA in the regulation of gene expression and diseases including cancers.
Collapse
Affiliation(s)
- Siyao Guo
- Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, China
| | - Shuibin Lin
- Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, China
- Corresponding author. Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
| |
Collapse
|
11
|
Kobayashi A, Clément MJ, Craveur P, El Hage K, Salone JDM, Bollot G, Pastré D, Maucuer A. Identification of a small molecule splicing inhibitor targeting UHM domains. FEBS J 2021; 289:682-698. [PMID: 34520118 DOI: 10.1111/febs.16199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/10/2021] [Accepted: 09/13/2021] [Indexed: 01/07/2023]
Abstract
Splicing factor mutations are frequent in myeloid neoplasms, blood cancers, and solid tumors. Cancer cells harboring these mutations present a particular vulnerability to drugs that target splicing factors such as SF3b155 or CAPERα. Still, the arsenal of chemical probes that target the spliceosome is very limited. U2AF homology motifs (UHMs) are common protein interaction domains among splicing factors. They present a hydrophobic pocket ideally suited to anchor small molecules with the aim to inhibit protein-protein interaction. Here, we combined a virtual screening of a small molecules database and an in vitro competition assay and identified a small molecule, we named UHMCP1 that prevents the SF3b155/U2AF65 interaction. NMR analyses and molecular dynamics simulations confirmed the binding of this molecule in the hydrophobic pocket of the U2AF65 UHM domain. We further provide evidence that UHMCP1 impacts RNA splicing and cell viability and is therefore an interesting novel compound targeting an UHM domain with potential anticancer properties.
Collapse
Affiliation(s)
- Asaki Kobayashi
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France.,SYNSIGHT, Genopole Entreprises, Evry, France
| | | | | | - Krystel El Hage
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France
| | | | | | - David Pastré
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France
| | - Alexandre Maucuer
- SABNP, Univ Evry, INSERM U1204, Université Paris-Saclay, Evry, France
| |
Collapse
|
12
|
Ngwa CJ, Farrukh A, Pradel G. Zinc finger proteins of Plasmodium falciparum. Cell Microbiol 2021; 23:e13387. [PMID: 34418264 DOI: 10.1111/cmi.13387] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/19/2021] [Accepted: 07/24/2021] [Indexed: 01/14/2023]
Abstract
Zinc finger proteins (ZFPs) are a large diverse family of proteins with one or more zinc finger domains in which zinc is important in stabilising the domain. ZFPs can interact with DNA, RNA, lipids or even other proteins and therefore contribute to diverse cellular processes including transcriptional regulation, ubiquitin-mediated protein degradation, mRNA decay and stability. In this review, we provide the first comprehensive classification of ZFPs of the malaria parasite Plasmodium falciparum and provide a state of knowledge on the main ZFPs in the parasite, which include the C2H2, CCCH, RING finger and the PHD finger proteins. TAKE AWAYS: The Plasmodium falciparum genome encodes 170 putative Zinc finger proteins (ZFPs). The C2H2, CCCH, RING finger and PHD finger subfamilies of ZFPs are most represented. Known ZFP functions include the regulation of mRNA metabolism and proteostasis.
Collapse
Affiliation(s)
- Che Julius Ngwa
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Afia Farrukh
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany
| |
Collapse
|
13
|
Martínez-Valiente C, Garcia-Ruiz C, Rosón B, Liquori A, González-Romero E, Fernández-González R, Gómez-Redondo I, Cervera J, Gutiérrez-Adán A, Sanjuan-Pla A. Aberrant Alternative Splicing in U2af1/Tet2 Double Mutant Mice Contributes to Major Hematological Phenotypes. Int J Mol Sci 2021; 22:6963. [PMID: 34203454 PMCID: PMC8269301 DOI: 10.3390/ijms22136963] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/19/2022] Open
Abstract
Mutations in splicing factors are recurrent somatic alterations identified in myelodysplastic syndromes (MDS) and they frequently coincide with mutations in epigenetic factors. About 25% of patients present concurrent mutations in such pathways, suggesting a cooperative role in the pathogenesis of MDS. We focused on the splicing factor U2AF1 involved in the recognition of the 3' splice site during pre-mRNA splicing. Using a CRISPR/Cas9 system, we created heterozygous mice with a carboxy-terminal truncated U2af1 allele (U2af1mut/+), studied the U2af1mut/+ hematopoietic system, and did not observe any gross differences in both young (12-13 weeks) and old (23 months) U2af1mut/+ mice, except for a reduction in size of approximately 20%. However, hematopoietic stem/progenitor cells lacked reconstitution capacity in transplantation assays and displayed an aberrant RNA splicing by RNA sequencing. We also evaluated U2af1mut/+ in conjunction with Tet2-deficiency. Novel double mutant U2af1mut/+Tet2-/- mice showed increased monogranulocytic precursors. Hematopoietic stem/progenitor cells were also enhanced and presented functional and transcriptomic alterations. Nonetheless, U2af1mut/+Tet2-/- mice did not succumb to MDS disease over a 6-month observation period. Collectively, our data suggest that cooperation between mutant U2af1 and Tet2 loss is not sufficient for MDS initiation in mice.
Collapse
Affiliation(s)
- Cristina Martínez-Valiente
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| | - Cristian Garcia-Ruiz
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| | - Beatriz Rosón
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| | - Alessandro Liquori
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| | - Elisa González-Romero
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| | - Raúl Fernández-González
- Animal Reproduction Department, INIA, Ctra. de La Coruña, km 7.5, 28040 Madrid, Spain; (R.F.-G.); (I.G.-R.); (A.G.-A.)
| | - Isabel Gómez-Redondo
- Animal Reproduction Department, INIA, Ctra. de La Coruña, km 7.5, 28040 Madrid, Spain; (R.F.-G.); (I.G.-R.); (A.G.-A.)
| | - José Cervera
- Hematology Service, Hospital Universitario y Politécnico La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain;
- Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC), Av. Monforte de Lemos, 3-5 Pabellón 11, 28029 Madrid, Spain
- Genetics Unit, Hospital Universitario y Politécnico La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain
| | - Alfonso Gutiérrez-Adán
- Animal Reproduction Department, INIA, Ctra. de La Coruña, km 7.5, 28040 Madrid, Spain; (R.F.-G.); (I.G.-R.); (A.G.-A.)
| | - Alejandra Sanjuan-Pla
- Hematology Research Group, Instituto de Investigación Sanitaria La Fe, Avda. Fernando Abril Martorell 106, 46026 Valencia, Spain; (C.M.-V.); (C.G.-R.); (B.R.); (A.L.); (E.G.-R.)
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Kováčová T, Souček P, Hujová P, Freiberger T, Grodecká L. Splicing Enhancers at Intron-Exon Borders Participate in Acceptor Splice Sites Recognition. Int J Mol Sci 2020; 21:ijms21186553. [PMID: 32911621 PMCID: PMC7554774 DOI: 10.3390/ijms21186553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/05/2020] [Accepted: 09/06/2020] [Indexed: 02/07/2023] Open
Abstract
Acceptor splice site recognition (3′ splice site: 3′ss) is a fundamental step in precursor messenger RNA (pre-mRNA) splicing. Generally, the U2 small nuclear ribonucleoprotein (snRNP) auxiliary factor (U2AF) heterodimer recognizes the 3′ss, of which U2AF35 has a dual function: (i) It binds to the intron–exon border of some 3′ss and (ii) mediates enhancer-binding splicing activators’ interactions with the spliceosome. Alternative mechanisms for 3′ss recognition have been suggested, yet they are still not thoroughly understood. Here, we analyzed 3′ss recognition where the intron–exon border is bound by a ubiquitous splicing regulator SRSF1. Using the minigene analysis of two model exons and their mutants, BRCA2 exon 12 and VARS2 exon 17, we showed that the exon inclusion correlated much better with the predicted SRSF1 affinity than 3′ss quality, which were assessed using the Catalog of Inferred Sequence Binding Preferences of RNA binding proteins (CISBP-RNA) database and maximum entropy algorithm (MaxEnt) predictor and the U2AF35 consensus matrix, respectively. RNA affinity purification proved SRSF1 binding to the model 3′ss. On the other hand, knockdown experiments revealed that U2AF35 also plays a role in these exons’ inclusion. Most probably, both factors stochastically bind the 3′ss, supporting exon recognition, more apparently in VARS2 exon 17. Identifying splicing activators as 3′ss recognition factors is crucial for both a basic understanding of splicing regulation and human genetic diagnostics when assessing variants’ effects on splicing.
Collapse
Affiliation(s)
- Tatiana Kováčová
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, 656 91 Brno, Czech Republic; (T.K.); (P.S.); (P.H.); (T.F.)
- Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Přemysl Souček
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, 656 91 Brno, Czech Republic; (T.K.); (P.S.); (P.H.); (T.F.)
- Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Pavla Hujová
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, 656 91 Brno, Czech Republic; (T.K.); (P.S.); (P.H.); (T.F.)
- Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Tomáš Freiberger
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, 656 91 Brno, Czech Republic; (T.K.); (P.S.); (P.H.); (T.F.)
- Faculty of Medicine, Masaryk University, 625 00 Brno, Czech Republic
| | - Lucie Grodecká
- Molecular Genetics Laboratory, Centre for Cardiovascular Surgery and Transplantation, 656 91 Brno, Czech Republic; (T.K.); (P.S.); (P.H.); (T.F.)
- Correspondence:
| |
Collapse
|
16
|
Warnasooriya C, Feeney CF, Laird KM, Ermolenko DN, Kielkopf CL. A splice site-sensing conformational switch in U2AF2 is modulated by U2AF1 and its recurrent myelodysplasia-associated mutation. Nucleic Acids Res 2020; 48:5695-5709. [PMID: 32343311 PMCID: PMC7261175 DOI: 10.1093/nar/gkaa293] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/09/2020] [Accepted: 04/17/2020] [Indexed: 02/02/2023] Open
Abstract
An essential heterodimer of the U2AF1 and U2AF2 pre-mRNA splicing factors nucleates spliceosome assembly at polypyrimidine (Py) signals preceding the major class of 3′ splice sites. U2AF1 frequently acquires an S34F-encoding mutation among patients with myelodysplastic syndromes (MDS). The influence of the U2AF1 subunit and its S34F mutation on the U2AF2 conformations remains unknown. Here, we employ single molecule Förster resonance energy transfer (FRET) to determine the influence of wild-type or S34F-substituted U2AF1 on the conformational dynamics of U2AF2 and its splice site RNA complexes. In the absence of RNA, the U2AF1 subunit stabilizes a high FRET value, which by structure-guided mutagenesis corresponds to a closed conformation of the tandem U2AF2 RNA recognition motifs (RRMs). When the U2AF heterodimer is bound to a strong, uridine-rich splice site, U2AF2 switches to a lower FRET value characteristic of an open, side-by-side arrangement of the RRMs. Remarkably, the U2AF heterodimer binds weak, uridine-poor Py tracts as a mixture of closed and open U2AF2 conformations, which are modulated by the S34F mutation. Shifts between open and closed U2AF2 may underlie U2AF1-dependent splicing of degenerate Py tracts and contribute to a subset of S34F-dysregulated splicing events in MDS patients.
Collapse
Affiliation(s)
- Chandani Warnasooriya
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Callen F Feeney
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Kholiswa M Laird
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Dmitri N Ermolenko
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Clara L Kielkopf
- Department of Biochemistry and Biophysics and Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| |
Collapse
|
17
|
Kralovicova J, Borovska I, Kubickova M, Lukavsky PJ, Vorechovsky I. Cancer-Associated Substitutions in RNA Recognition Motifs of PUF60 and U2AF65 Reveal Residues Required for Correct Folding and 3' Splice-Site Selection. Cancers (Basel) 2020; 12:cancers12071865. [PMID: 32664474 PMCID: PMC7408900 DOI: 10.3390/cancers12071865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 12/22/2022] Open
Abstract
U2AF65 (U2AF2) and PUF60 (PUF60) are splicing factors important for recruitment of the U2 small nuclear ribonucleoprotein to lariat branch points and selection of 3′ splice sites (3′ss). Both proteins preferentially bind uridine-rich sequences upstream of 3′ss via their RNA recognition motifs (RRMs). Here, we examined 36 RRM substitutions reported in cancer patients to identify variants that alter 3′ss selection, RNA binding and protein properties. Employing PUF60- and U2AF65-dependent 3′ss previously identified by RNA-seq of depleted cells, we found that 43% (10/23) and 15% (2/13) of independent RRM mutations in U2AF65 and PUF60, respectively, conferred splicing defects. At least three RRM mutations increased skipping of internal U2AF2 (~9%, 2/23) or PUF60 (~8%, 1/13) exons, indicating that cancer-associated RRM mutations can have both cis- and trans-acting effects on splicing. We also report residues required for correct folding/stability of each protein and map functional RRM substitutions on to existing high-resolution structures of U2AF65 and PUF60. These results identify new RRM residues critical for 3′ss selection and provide relatively simple tools to detect clonal RRM mutations that enhance the mRNA isoform diversity.
Collapse
Affiliation(s)
- Jana Kralovicova
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK;
- Institute of Molecular Physiology and Genetics, Center of Biosciences, Slovak Academy of Sciences, 840 05 Bratislava, Slovakia;
| | - Ivana Borovska
- Institute of Molecular Physiology and Genetics, Center of Biosciences, Slovak Academy of Sciences, 840 05 Bratislava, Slovakia;
| | - Monika Kubickova
- CEITEC, Masaryk University, 625 00 Brno, Czech Republic; (M.K.); (P.J.L.)
| | - Peter J. Lukavsky
- CEITEC, Masaryk University, 625 00 Brno, Czech Republic; (M.K.); (P.J.L.)
| | - Igor Vorechovsky
- Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK;
- Correspondence: ; Tel.: +44-2381-206425; Fax: +44-2381-204264
| |
Collapse
|
18
|
Chang JW, Yeh HS, Park M, Erber L, Sun J, Cheng S, Bui AM, Fahmi NA, Nasti R, Kuang R, Chen Y, Zhang W, Yong J. mTOR-regulated U2af1 tandem exon splicing specifies transcriptome features for translational control. Nucleic Acids Res 2019; 47:10373-10387. [PMID: 31504847 PMCID: PMC6821156 DOI: 10.1093/nar/gkz761] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/23/2019] [Accepted: 08/23/2019] [Indexed: 01/13/2023] Open
Abstract
U2 auxiliary factor 1 (U2AF1) functions in 3′-splice site selection during pre-mRNA processing. Alternative usage of duplicated tandem exons in U2AF1 produces two isoforms, U2AF1a and U2AF1b, but their functional differences are unappreciated due to their homology. Through integrative approaches of genome editing, customized-transcriptome profiling and crosslinking-mediated interactome analyses, we discovered that the expression of U2AF1 isoforms is controlled by mTOR and they exhibit a distinctive molecular profile for the splice site and protein interactomes. Mechanistic dissection of mutually exclusive alternative splicing events revealed that U2AF1 isoforms’ inherent differential preferences of nucleotide sequences and their stoichiometry determine the 3′-splice site. Importantly, U2AF1a-driven transcriptomes feature alternative splicing events in the 5′-untranslated region (5′-UTR) that are favorable for translation. These findings unveil distinct roles of duplicated tandem exon-derived U2AF1 isoforms in the regulation of the transcriptome and suggest U2AF1a-driven 5′-UTR alternative splicing as a molecular mechanism of mTOR-regulated translational control.
Collapse
Affiliation(s)
- Jae-Woong Chang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Hsin-Sung Yeh
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Meeyeon Park
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Luke Erber
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Jiao Sun
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Sze Cheng
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Alexander M Bui
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Naima Ahmed Fahmi
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Ryan Nasti
- Department of Genetics, Cell and Developmental Biology, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Rui Kuang
- Department of Computer Science and Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Yue Chen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| | - Wei Zhang
- Department of Computer Science, University of Central Florida, Orlando, FL 32816, USA
| | - Jeongsik Yong
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
| |
Collapse
|
19
|
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.
Collapse
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.
| |
Collapse
|
20
|
Tari M, Manceau V, de Matha Salone J, Kobayashi A, Pastré D, Maucuer A. U2AF 65 assemblies drive sequence-specific splice site recognition. EMBO Rep 2019; 20:e47604. [PMID: 31271494 PMCID: PMC6681011 DOI: 10.15252/embr.201847604] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 05/21/2019] [Accepted: 05/28/2019] [Indexed: 02/06/2023] Open
Abstract
The essential splicing factor U2AF65 is known to help anchoring U2 snRNP at the branch site. Its C-terminal UHM domain interacts with ULM motifs of SF3b155, an U2 snRNP protein. Here, we report a cooperative binding of U2AF65 and the related protein CAPERα to the multi-ULM domain of SF3b155. In addition, we show that the RS domain of U2AF65 drives a liquid-liquid phase separation that is amplified by intronic RNA with repeated pyrimidine tracts. In cells, knockdown of either U2AF65 or CAPERα improves the inclusion of cassette exons that are preceded by such repeated pyrimidine-rich motifs. These results support a model in which liquid-like assemblies of U2AF65 and CAPERα on repetitive pyrimidine-rich RNA sequences are driven by their RS domains, and facilitate the recruitment of the multi-ULM domain of SF3b155. We anticipate that posttranslational modifications and proteins recruited in dynamical U2AF65 and CAPERα condensates may further contribute to the complex mechanisms leading to specific splice site choice that occurs in cells.
Collapse
Affiliation(s)
- Manel Tari
- SABNPUniv EvryINSERM U1204Université Paris‐SaclayEvryFrance
| | - Valérie Manceau
- Institut Necker Enfants Malades (INEM)Inserm U1151 – CNRS UMR 8253Université Paris DescartesParisFrance
- Present address:
Faculty of MedicineInstitut Necker Enfants Malades (INEM)Inserm U1151–CNRS UMR 8253University Paris DescartesSorbonne Paris CitéParisFrance
| | | | | | - David Pastré
- SABNPUniv EvryINSERM U1204Université Paris‐SaclayEvryFrance
| | | |
Collapse
|
21
|
Královicová J, Ševcíková I, Stejskalová E, Obuca M, Hiller M, Stanek D, Vorechovský I. PUF60-activated exons uncover altered 3' splice-site selection by germline missense mutations in a single RRM. Nucleic Acids Res 2019; 46:6166-6187. [PMID: 29788428 PMCID: PMC6093180 DOI: 10.1093/nar/gky389] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/01/2018] [Indexed: 12/27/2022] Open
Abstract
PUF60 is a splicing factor that binds uridine (U)-rich tracts and facilitates association of the U2 small nuclear ribonucleoprotein with primary transcripts. PUF60 deficiency (PD) causes a developmental delay coupled with intellectual disability and spinal, cardiac, ocular and renal defects, but PD pathogenesis is not understood. Using RNA-Seq, we identify human PUF60-regulated exons and show that PUF60 preferentially acts as their activator. PUF60-activated internal exons are enriched for Us upstream of their 3′ splice sites (3′ss), are preceded by longer AG dinucleotide exclusion zones and more distant branch sites, with a higher probability of unpaired interactions across a typical branch site location as compared to control exons. In contrast, PUF60-repressed exons show U-depletion with lower estimates of RNA single-strandedness. We also describe PUF60-regulated, alternatively spliced isoforms encoding other U-bound splicing factors, including PUF60 partners, suggesting that they are co-regulated in the cell, and identify PUF60-regulated exons derived from transposed elements. PD-associated amino-acid substitutions, even within a single RNA recognition motif (RRM), altered selection of competing 3′ss and branch points of a PUF60-dependent exon and the 3′ss choice was also influenced by alternative splicing of PUF60. Finally, we propose that differential distribution of RNA processing steps detected in cells lacking PUF60 and the PUF60-paralog RBM39 is due to the RBM39 RS domain interactions. Together, these results provide new insights into regulation of exon usage by the 3′ss organization and reveal that germline mutation heterogeneity in RRMs can enhance phenotypic variability at the level of splice-site and branch-site selection.
Collapse
Affiliation(s)
- Jana Královicová
- University of Southampton Faculty of Medicine, Southampton SO16 6YD, UK.,Slovak Academy of Sciences, Centre for Biosciences, 840 05 Bratislava, Slovak Republic
| | - Ivana Ševcíková
- Slovak Academy of Sciences, Centre for Biosciences, 840 05 Bratislava, Slovak Republic
| | - Eva Stejskalová
- Czech Academy of Sciences, Institute of Molecular Genetics, 142 20 Prague, Czech Republic
| | - Mina Obuca
- Czech Academy of Sciences, Institute of Molecular Genetics, 142 20 Prague, Czech Republic
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics and Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - David Stanek
- Czech Academy of Sciences, Institute of Molecular Genetics, 142 20 Prague, Czech Republic
| | - Igor Vorechovský
- University of Southampton Faculty of Medicine, Southampton SO16 6YD, UK
| |
Collapse
|
22
|
Xiong F, Ren JJ, Yu Q, Wang YY, Lu CC, Kong LJ, Otegui MS, Wang XL. AtU2AF65b functions in abscisic acid mediated flowering via regulating the precursor messenger RNA splicing of ABI5 and FLC in Arabidopsis. THE NEW PHYTOLOGIST 2019; 223:277-292. [PMID: 30790290 DOI: 10.1111/nph.15756] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 02/11/2019] [Indexed: 05/20/2023]
Abstract
In mammalians and yeast, the splicing factor U2AF65/Mud2p functions in precursor messenger RNA (pre-mRNA) processing. Arabidopsis AtU2AF65b encodes a putative U2AF65 but its specific functions in plants are unknown. This paper examines the function of AtU2AF65b as a negative regulator of flowering time in Arabidopsis. We investigated the expression and function of AtU2AF65b in abscisic acid (ABA)-regulated flowering as well as the transcript abundance and pre-mRNA splicing of flowering-related genes in the knock-out mutants of AtU2AF65b. The atu2af65b mutants show early-flowering phenotype under both long-day and short-day conditions. The transcript accumulation of the flowering repressor gene FLOWERING LOCUS C (FLC) is reduced in the shoot apex of atu2af65b, due to both increased intron retention and reduced transcription activation. Reduced transcription of FLC results, at least partially, from the abnormal splicing and reduced transcript abundance of ABSCISIC ACID-INSENSITIVE 5 (ABI5), which encodes an activator of FLC in ABA-regulated flowering signaling. Additionally, the expression of AtU2AF65b is promoted by ABA. Transition to flowering and splicing of FLC and ABI5 in the atu2af65b mutants are compromised during ABA-induced flowering. ABA-responsive AtU2AF65b functions in the pre-mRNA splicing of FLC and ABI5 in shoot apex, whereby AtU2AF65b is involved in ABA-mediated flowering transition in Arabidopsis.
Collapse
Affiliation(s)
- Feng Xiong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Jing-Jing Ren
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Qin Yu
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Yu-Yi Wang
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Chong-Chong Lu
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Lan-Jing Kong
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| | - Marisa S Otegui
- Department of Botany and Genetics, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Xiu-Ling Wang
- National Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, 271018, China
| |
Collapse
|
23
|
Homogentisate 1,2-dioxygenase (HGD) gene variants, their analysis and genotype-phenotype correlations in the largest cohort of patients with AKU. Eur J Hum Genet 2019; 27:888-902. [PMID: 30737480 DOI: 10.1038/s41431-019-0354-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 01/12/2019] [Accepted: 01/24/2019] [Indexed: 11/08/2022] Open
Abstract
Alkaptonuria (AKU) is a rare metabolic disorder caused by a deficient enzyme in the tyrosine degradation pathway, homogentisate 1,2-dioxygenase (HGD). In 172 AKU patients from 39 countries, we identified 28 novel variants of the HGD gene, which include three larger genomic deletions within this gene discovered via self-designed multiplex ligation-dependent probe amplification (MLPA) probes. In addition, using a reporter minigene assay, we provide evidence that three of eight tested variants potentially affecting splicing cause exon skipping or cryptic splice-site activation. Extensive bioinformatics analysis of novel missense variants, and of the entire HGD monomer, confirmed mCSM as an effective computational tool for evaluating possible enzyme inactivation mechanisms. For the first time for AKU, a genotype-phenotype correlation study was performed for the three most frequent HGD variants identified in the Suitability Of Nitisinone in Alkaptonuria 2 (SONIA2) study. We found a small but statistically significant difference in urinary homogentisic acid (HGA) excretion, corrected for dietary protein intake, between variants leading to 1% or >30% residual HGD activity. There was, interestingly, no difference in serum levels or absolute urinary excretion of HGA, or clinical symptoms, indicating that protein intake is more important than differences in HGD variants for the amounts of HGA that accumulate in the body of AKU patients.
Collapse
|
24
|
Wang B, Lo UG, Wu K, Kapur P, Liu X, Huang J, Chen W, Hernandez E, Santoyo J, Ma SH, Pong RC, He D, Cheng YQ, Hsieh JT. Developing new targeting strategy for androgen receptor variants in castration resistant prostate cancer. Int J Cancer 2017; 141:2121-2130. [PMID: 28722220 PMCID: PMC5777133 DOI: 10.1002/ijc.30893] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/09/2017] [Accepted: 07/03/2017] [Indexed: 01/05/2023]
Abstract
The presence of androgen receptor variant 7 (AR-V7) variants becomes a significant hallmark of castration-resistant prostate cancer (CRPC) relapsed from hormonal therapy and is associated with poor survival of CRPC patients because of lacking a ligand-binding domain. Currently, it still lacks an effective agent to target AR-V7 or AR-Vs in general. Here, we showed that a novel class of agents (thailanstatins, TSTs and spliceostatin A analogs) can significantly suppress the expression of AR-V7 mRNA and protein but in a less extent on the full-length AR expression. Mechanistically, TST-D is able to inhibit AR-V7 gene splicing by interfering the interaction between U2AF65 and SAP155 and preventing them from binding to polypyrimidine tract located between the branch point and the 3' splice site. In vivo, TST-D exhibits a potent tumor inhibitory effect on human CRPC xenografts leading to cell apoptosis. The machinery associated with AR gene splicing in CRPC is a potential target for drugs. Based on their potency in the suppression of AR-V7 responsible for the growth/survival of CRPC, TSTs representing a new class of anti-AR-V agents warrant further development into clinical application.
Collapse
Affiliation(s)
- Bin Wang
- Department of Urology, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - U-Ging Lo
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kaijie Wu
- Department of Urology, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Xiangyang Liu
- UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA
| | - Jun Huang
- Department of Urology, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wei Chen
- Department of Urology, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Elizabeth Hernandez
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John Santoyo
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shi-Hong Ma
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rey-Chen Pong
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Dalin He
- Department of Urology, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Yi-Qiang Cheng
- UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA
| | - Jer-Tsong Hsieh
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Graduate Institute of Cancer Biology, China Medical University Hospital, Taichung 40447, Taiwan
| |
Collapse
|
25
|
Chen L, Weinmeister R, Kralovicova J, Eperon LP, Vorechovsky I, Hudson AJ, Eperon IC. Stoichiometries of U2AF35, U2AF65 and U2 snRNP reveal new early spliceosome assembly pathways. Nucleic Acids Res 2017; 45:2051-2067. [PMID: 27683217 PMCID: PMC5389562 DOI: 10.1093/nar/gkw860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/16/2016] [Indexed: 12/24/2022] Open
Abstract
The selection of 3΄ splice sites (3΄ss) is an essential early step in mammalian RNA splicing reactions, but the processes involved are unknown. We have used single molecule methods to test whether the major components implicated in selection, the proteins U2AF35 and U2AF65 and the U2 snRNP, are able to recognize alternative candidate sites or are restricted to one pre-specified site. In the presence of adenosine triphosphate (ATP), all three components bind in a 1:1 stoichiometry with a 3΄ss. Pre-mRNA molecules with two alternative 3΄ss can be bound concurrently by two molecules of U2AF or two U2 snRNPs, so none of the components are restricted. However, concurrent occupancy inhibits splicing. Stoichiometric binding requires conditions consistent with coalescence of the 5΄ and 3΄ sites in a complex (I, initial), but if this cannot form the components show unrestricted and stochastic association. In the absence of ATP, when complex E forms, U2 snRNP association is unrestricted. However, if protein dephosphorylation is prevented, an I-like complex forms with stoichiometric association of U2 snRNPs and the U2 snRNA is base-paired to the pre-mRNA. Complex I differs from complex A in that the formation of complex A is associated with the loss of U2AF65 and 35.
Collapse
Affiliation(s)
- Li Chen
- University of Leicester, Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, Leicester LE1 9HN, UK
| | - Robert Weinmeister
- University of Leicester, Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, Leicester LE1 9HN, UK
| | - Jana Kralovicova
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Lucy P Eperon
- University of Leicester, Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, Leicester LE1 9HN, UK
| | - Igor Vorechovsky
- University of Southampton, Faculty of Medicine, Southampton SO16 6YD, UK
| | - Andrew J Hudson
- University of Leicester, Leicester Institute for Structural and Chemical Biology and Department of Chemistry, Leicester LE1 7RH, UK
| | - Ian C Eperon
- University of Leicester, Leicester Institute for Structural and Chemical Biology and Department of Molecular and Cell Biology, Leicester LE1 9HN, UK
| |
Collapse
|
26
|
Jenkins JL, Kielkopf CL. Splicing Factor Mutations in Myelodysplasias: Insights from Spliceosome Structures. Trends Genet 2017; 33:336-348. [PMID: 28372848 PMCID: PMC5447463 DOI: 10.1016/j.tig.2017.03.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 01/08/2023]
Abstract
Somatic mutations of pre-mRNA splicing factors recur among patients with myelodysplastic syndrome (MDS) and related malignancies. Although these MDS-relevant mutations alter the splicing of a subset of transcripts, the mechanisms by which these single amino acid substitutions change gene expression remain controversial. New structures of spliceosome intermediates and associated protein complexes shed light on the molecular interactions mediated by 'hotspots' of the SF3B1 and U2AF1 pre-mRNA splicing factors. The frequently mutated SF3B1 residues contact the pre-mRNA splice site. Based on structural homology with other spliceosome subunits, and recent findings of altered RNA binding by mutant U2AF1 proteins, we suggest that affected U2AF1 residues also contact pre-mRNA. Altered pre-mRNA recognition emerges as a molecular theme among MDS-relevant mutations of pre-mRNA splicing factors.
Collapse
Affiliation(s)
- Jermaine L Jenkins
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Clara L Kielkopf
- Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
| |
Collapse
|
27
|
Yip BH, Steeples V, Repapi E, Armstrong RN, Llorian M, Roy S, Shaw J, Dolatshad H, Taylor S, Verma A, Bartenstein M, Vyas P, Cross NC, Malcovati L, Cazzola M, Hellström-Lindberg E, Ogawa S, Smith CW, Pellagatti A, Boultwood J. The U2AF1S34F mutation induces lineage-specific splicing alterations in myelodysplastic syndromes. J Clin Invest 2017; 127:2206-2221. [PMID: 28436936 PMCID: PMC5451246 DOI: 10.1172/jci91363] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/21/2017] [Indexed: 12/23/2022] Open
Abstract
Mutations of the splicing factor–encoding gene U2AF1 are frequent in the myelodysplastic syndromes (MDS), a myeloid malignancy, and other cancers. Patients with MDS suffer from peripheral blood cytopenias, including anemia, and an increasing percentage of bone marrow myeloblasts. We studied the impact of the common U2AF1S34F mutation on cellular function and mRNA splicing in the main cell lineages affected in MDS. We demonstrated that U2AF1S34F expression in human hematopoietic progenitors impairs erythroid differentiation and skews granulomonocytic differentiation toward granulocytes. RNA sequencing of erythroid and granulomonocytic colonies revealed that U2AF1S34F induced a higher number of cassette exon splicing events in granulomonocytic cells than in erythroid cells. U2AF1S34F altered mRNA splicing of many transcripts that were expressed in both cell types in a lineage-specific manner. In hematopoietic progenitors, the introduction of isoform changes identified in the U2AF1S34F target genes H2AFY, encoding an H2A histone variant, and STRAP, encoding serine/threonine kinase receptor–associated protein, recapitulated phenotypes associated with U2AF1S34F expression in erythroid and granulomonocytic cells, suggesting a causal link. Furthermore, we showed that isoform modulation of H2AFY and STRAP rescues the erythroid differentiation defect in U2AF1S34F MDS cells, suggesting that splicing modulators could be used therapeutically. These data have critical implications for understanding MDS phenotypic heterogeneity and support the development of therapies targeting splicing abnormalities.
Collapse
Affiliation(s)
- Bon Ham Yip
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Violetta Steeples
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Emmanouela Repapi
- The Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Richard N Armstrong
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Miriam Llorian
- Department of Biochemistry, Downing Site, University of Cambridge, Cambridge, United Kingdom
| | - Swagata Roy
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Jacqueline Shaw
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Hamid Dolatshad
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Stephen Taylor
- The Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Amit Verma
- Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Paresh Vyas
- Medical Research Council, Molecular Hematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, and Department of Hematology, Oxford University Hospital National Health Service Trust, Oxford, United Kingdom
| | - Nicholas Cp Cross
- Faculty of Medicine, University of Southampton, Southampton, and National Genetics Reference Laboratory (Wessex), Salisbury, United Kingdom
| | - Luca Malcovati
- Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Mario Cazzola
- Fondazione IRCCS Policlinico San Matteo and University of Pavia, Pavia, Italy
| | - Eva Hellström-Lindberg
- Center for Hematology and Regenerative Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Kyoto University, Kyoto, Japan
| | - Christopher Wj Smith
- Department of Biochemistry, Downing Site, University of Cambridge, Cambridge, United Kingdom
| | - Andrea Pellagatti
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| | - Jacqueline Boultwood
- Bloodwise Molecular Haematology Unit, Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, and BRC Blood Theme, National Institute for Health Research (NIHR) Oxford Biomedical Centre, Oxford University Hospital, Oxford, United Kingdom
| |
Collapse
|
28
|
Kralovicova J, Moreno PM, Cross NC, Pêgo AP, Vorechovsky I. Antisense Oligonucleotides Modulating Activation of a Nonsense-Mediated RNA Decay Switch Exon in the ATM Gene. Nucleic Acid Ther 2016; 26:392-400. [PMID: 27658045 PMCID: PMC5105335 DOI: 10.1089/nat.2016.0635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/25/2016] [Indexed: 12/28/2022] Open
Abstract
ATM (ataxia-telangiectasia, mutated) is an important cancer susceptibility gene that encodes a key apical kinase in the DNA damage response pathway. ATM mutations in the germ line result in ataxia-telangiectasia (A-T), a rare genetic syndrome associated with hypersensitivity to double-strand DNA breaks and predisposition to lymphoid malignancies. ATM expression is limited by a tightly regulated nonsense-mediated RNA decay (NMD) switch exon (termed NSE) located in intron 28. In this study, we identify antisense oligonucleotides that modulate NSE inclusion in mature transcripts by systematically targeting the entire 3.1-kb-long intron. Their identification was assisted by a segmental deletion analysis of transposed elements, revealing NSE repression upon removal of a distant antisense Alu and NSE activation upon elimination of a long terminal repeat transposon MER51A. Efficient NSE repression was achieved by delivering optimized splice-switching oligonucleotides to embryonic and lymphoblastoid cells using chitosan-based nanoparticles. Together, these results provide a basis for possible sequence-specific radiosensitization of cancer cells, highlight the power of intronic antisense oligonucleotides to modify gene expression, and demonstrate transposon-mediated regulation of NSEs.
Collapse
Affiliation(s)
- Jana Kralovicova
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Pedro M.D. Moreno
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Engenharia Biomédica (INEB), Universidade do Porto, Porto, Portugal
| | - Nicholas C.P. Cross
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Wessex Regional Genetics Laboratory, Salisbury Hospital, Salisbury, United Kingdom
| | - Ana Paula Pêgo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Engenharia Biomédica (INEB), Universidade do Porto, Porto, Portugal
- Faculdade de Engenharia and Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Igor Vorechovsky
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Park SM, Ou J, Chamberlain L, Simone TM, Yang H, Virbasius CM, Ali AM, Zhu LJ, Mukherjee S, Raza A, Green MR. U2AF35(S34F) Promotes Transformation by Directing Aberrant ATG7 Pre-mRNA 3' End Formation. Mol Cell 2016; 62:479-90. [PMID: 27184077 PMCID: PMC5012111 DOI: 10.1016/j.molcel.2016.04.011] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 03/07/2016] [Accepted: 04/08/2016] [Indexed: 10/21/2022]
Abstract
Recurrent mutations in the splicing factor U2AF35 are found in several cancers and myelodysplastic syndrome (MDS). How oncogenic U2AF35 mutants promote transformation remains to be determined. Here we derive cell lines transformed by the oncogenic U2AF35(S34F) mutant and identify aberrantly processed pre-mRNAs by deep sequencing. We find that in U2AF35(S34F)-transformed cells the autophagy-related factor 7 (Atg7) pre-mRNA is abnormally processed, which unexpectedly is not due to altered splicing but rather selection of a distal cleavage and polyadenylation (CP) site. This longer Atg7 mRNA is translated inefficiently, leading to decreased ATG7 levels and an autophagy defect that predisposes cells to secondary mutations, resulting in transformation. MDS and acute myeloid leukemia patient samples harboring U2AF35(S34F) have a similar increased use of the ATG7 distal CP site, and previous studies have shown that mice with hematopoietic cells lacking Atg7 develop an MDS-like syndrome. Collectively, our results reveal a basis for U2AF35(S34F) oncogenic activity.
Collapse
MESH Headings
- Aged
- Aged, 80 and over
- Animals
- Autophagy
- Autophagy-Related Protein 7/genetics
- Autophagy-Related Protein 7/metabolism
- Cell Line, Transformed
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Male
- Mice, Inbred BALB C
- Mice, Nude
- Middle Aged
- Mitochondria/metabolism
- Mitochondria/pathology
- Mutation
- Myelodysplastic Syndromes/genetics
- Myelodysplastic Syndromes/metabolism
- Myelodysplastic Syndromes/pathology
- Polyadenylation
- RNA 3' End Processing
- RNA Interference
- RNA Precursors/genetics
- RNA Precursors/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Splicing Factor U2AF/genetics
- Splicing Factor U2AF/metabolism
- Time Factors
- Transfection
- Tumor Burden
Collapse
Affiliation(s)
- Sung Mi Park
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jianhong Ou
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Lynn Chamberlain
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tessa M Simone
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Huan Yang
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ching-Man Virbasius
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Abdullah M Ali
- Department of Medicine, Division of Hematology and Oncology, Columbia University Medical Center and New York Presbyterian Hospital, New York, NY 10032, USA
| | - Lihua Julie Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Programs in Molecular Medicine and Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Siddhartha Mukherjee
- Department of Medicine, Division of Hematology and Oncology, Columbia University Medical Center and New York Presbyterian Hospital, New York, NY 10032, USA
| | - Azra Raza
- Department of Medicine, Division of Hematology and Oncology, Columbia University Medical Center and New York Presbyterian Hospital, New York, NY 10032, USA.
| | - Michael R Green
- Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA; Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| |
Collapse
|
31
|
Kralovicova J, Knut M, Cross NCP, Vorechovsky I. Exon-centric regulation of ATM expression is population-dependent and amenable to antisense modification by pseudoexon targeting. Sci Rep 2016; 6:18741. [PMID: 26732650 PMCID: PMC4702124 DOI: 10.1038/srep18741] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 11/25/2015] [Indexed: 01/10/2023] Open
Abstract
ATM is an important cancer susceptibility gene that encodes a critical apical kinase of the DNA damage response (DDR) pathway. We show that a key nonsense-mediated RNA decay switch exon (NSE) in ATM is repressed by U2AF, PUF60 and hnRNPA1. The NSE activation was haplotype-specific and was most promoted by cytosine at rs609621 in the NSE 3' splice-site (3'ss), which is predominant in high cancer risk populations. NSE levels were deregulated in leukemias and were influenced by the identity of U2AF35 residue 34. We also identify splice-switching oligonucleotides (SSOs) that exploit competition of adjacent pseudoexons to modulate NSE levels. The U2AF-regulated exon usage in the ATM signalling pathway was centred on the MRN/ATM-CHEK2-CDC25-cdc2/cyclin-B axis and preferentially involved transcripts implicated in cancer-associated gene fusions and chromosomal translocations. These results reveal important links between 3'ss control and ATM-dependent responses to double-strand DNA breaks, demonstrate functional plasticity of intronic variants and illustrate versatility of intronic SSOs that target pseudo-3'ss to modify gene expression.
Collapse
Affiliation(s)
- Jana Kralovicova
- University of Southampton Faculty of Medicine Southampton SO16 6YD United Kingdom
| | - Marcin Knut
- University of Southampton Faculty of Medicine Southampton SO16 6YD United Kingdom
| | - Nicholas C. P. Cross
- University of Southampton Faculty of Medicine Southampton SO16 6YD United Kingdom
- Wessex Regional Genetics Laboratory Salisbury Hospital Salisbury SP2 8BJ United Kingdom
| | - Igor Vorechovsky
- University of Southampton Faculty of Medicine Southampton SO16 6YD United Kingdom
| |
Collapse
|
32
|
Denisov S, Bazykin G, Favorov A, Mironov A, Gelfand M. Correlated Evolution of Nucleotide Positions within Splice Sites in Mammals. PLoS One 2015; 10:e0144388. [PMID: 26642327 PMCID: PMC4671708 DOI: 10.1371/journal.pone.0144388] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 11/17/2015] [Indexed: 12/26/2022] Open
Abstract
Splice sites (SSs)--short nucleotide sequences flanking introns--are under selection for spliceosome binding, and adhere to consensus sequences. However, non-consensus nucleotides, many of which probably reduce SS performance, are frequent. Little is known about the mechanisms maintaining such apparently suboptimal SSs. Here, we study the correlations between strengths of nucleotides occupying different positions of the same SS. Such correlations may arise due to epistatic interactions between positions (i.e., a situation when the fitness effect of a nucleotide in one position depends on the nucleotide in another position), their evolutionary history, or to other reasons. Within both the intronic and the exonic parts of donor SSs, nucleotides that increase (decrease) SS strength tend to co-occur with other nucleotides increasing (respectively, decreasing) it, consistent with positive epistasis. Between the intronic and exonic parts of donor SSs, the correlations of nucleotide strengths tend to be negative, consistent with negative epistasis. In the course of evolution, substitutions at a donor SS tend to decrease the strength of its exonic part, and either increase or do not change the strength of its intronic part. In acceptor SSs, the situation is more complicated; the correlations between adjacent positions appear to be driven mainly by avoidance of the AG dinucleotide which may cause aberrant splicing. In summary, both the content and the evolution of SSs is shaped by a complex network of interdependences between adjacent nucleotides that respond to a range of sometimes conflicting selective constraints.
Collapse
Affiliation(s)
- Stepan Denisov
- A. A. Kharkevich Insitute for Information Transmission Problems RAS, Moscow, Russia
| | - Georgii Bazykin
- A. A. Kharkevich Insitute for Information Transmission Problems RAS, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Alexander Favorov
- Division of Oncology Biostatistics, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, United States of America
- Laboratory of System Biology and Computational Genetics, Department of Computational System Biology, N. I. Vavilov Institute of General Genetics, Moscow, Russia
- Laboratory of Bioinformatics, State Research Institute of Genetics and Selection of Industrial Microorganism (GosNIIGenetika), Moscow, Russia
| | - Andrey Mironov
- A. A. Kharkevich Insitute for Information Transmission Problems RAS, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Mikhail Gelfand
- A. A. Kharkevich Insitute for Information Transmission Problems RAS, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, M. V. Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
33
|
Whisenant TC, Peralta ER, Aarreberg LD, Gao NJ, Head SR, Ordoukhanian P, Williamson JR, Salomon DR. The Activation-Induced Assembly of an RNA/Protein Interactome Centered on the Splicing Factor U2AF2 Regulates Gene Expression in Human CD4 T Cells. PLoS One 2015; 10:e0144409. [PMID: 26641092 PMCID: PMC4671683 DOI: 10.1371/journal.pone.0144409] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/16/2015] [Indexed: 12/22/2022] Open
Abstract
Activation of CD4 T cells is a reaction to challenges such as microbial pathogens, cancer and toxins that defines adaptive immune responses. The roles of T cell receptor crosslinking, intracellular signaling, and transcription factor activation are well described, but the importance of post-transcriptional regulation by RNA-binding proteins (RBPs) has not been considered in depth. We describe a new model expanding and activating primary human CD4 T cells and applied this to characterizing activation-induced assembly of splicing factors centered on U2AF2. We immunoprecipitated U2AF2 to identify what mRNA transcripts were bound as a function of activation by TCR crosslinking and costimulation. In parallel, mass spectrometry revealed the proteins incorporated into the U2AF2-centered RNA/protein interactome. Molecules that retained interaction with the U2AF2 complex after RNAse treatment were designated as "central" interactome members (CIMs). Mass spectrometry also identified a second class of activation-induced proteins, "peripheral" interactome members (PIMs), that bound to the same transcripts but were not in physical association with U2AF2 or its partners. siRNA knockdown of two CIMs and two PIMs caused changes in activation marker expression, cytokine secretion, and gene expression that were unique to each protein and mapped to pathways associated with key aspects of T cell activation. While knocking down the PIM, SYNCRIP, impacts a limited but immunologically important set of U2AF2-bound transcripts, knockdown of U2AF1 significantly impairs assembly of the majority of protein and mRNA components in the activation-induced interactome. These results demonstrated that CIMs and PIMs, either directly or indirectly through RNA, assembled into activation-induced U2AF2 complexes and play roles in post-transcriptional regulation of genes related to cytokine secretion. These data suggest an additional layer of regulation mediated by the activation-induced assembly of RNA splicing interactomes that is important for understanding T cell activation.
Collapse
Affiliation(s)
- Thomas C. Whisenant
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Eigen R. Peralta
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Lauren D. Aarreberg
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Nina J. Gao
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Steven R. Head
- NGS and Microarray Core Facility, The Scripps Research Institute, La Jolla, California, United States of America
| | - Phillip Ordoukhanian
- NGS and Microarray Core Facility, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jamie R. Williamson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Daniel R. Salomon
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
34
|
Sohail M, Xie J. Diverse regulation of 3' splice site usage. Cell Mol Life Sci 2015; 72:4771-93. [PMID: 26370726 PMCID: PMC11113787 DOI: 10.1007/s00018-015-2037-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/12/2015] [Accepted: 09/03/2015] [Indexed: 01/13/2023]
Abstract
The regulation of splice site (SS) usage is important for alternative pre-mRNA splicing and thus proper expression of protein isoforms in cells; its disruption causes diseases. In recent years, an increasing number of novel regulatory elements have been found within or nearby the 3'SS in mammalian genes. The diverse elements recruit a repertoire of trans-acting factors or form secondary structures to regulate 3'SS usage, mostly at the early steps of spliceosome assembly. Their mechanisms of action mainly include: (1) competition between the factors for RNA elements, (2) steric hindrance between the factors, (3) direct interaction between the factors, (4) competition between two splice sites, or (5) local RNA secondary structures or longer range loops, according to the mode of protein/RNA interactions. Beyond the 3'SS, chromatin remodeling/transcription, posttranslational modifications of trans-acting factors and upstream signaling provide further layers of regulation. Evolutionarily, some of the 3'SS elements seem to have emerged in mammalian ancestors. Moreover, other possibilities of regulation such as that by non-coding RNA remain to be explored. It is thus likely that there are more diverse elements/factors and mechanisms that influence the choice of an intron end. The diverse regulation likely contributes to a more complex but refined transcriptome and proteome in mammals.
Collapse
Affiliation(s)
- Muhammad Sohail
- Department of Physiology and Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3E 0J9, Canada
| | - Jiuyong Xie
- Department of Physiology and Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3E 0J9, Canada.
- Department of Biochemistry and Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3E 0J9, Canada.
| |
Collapse
|