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Tan C, Sim D, Zhen Y, Tian H, Koh J, Roca X. PRPF40A induces inclusion of exons in GC-rich regions important for human myeloid cell differentiation. Nucleic Acids Res 2024; 52:8800-8814. [PMID: 38943321 PMCID: PMC11347146 DOI: 10.1093/nar/gkae557] [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: 11/07/2023] [Revised: 06/07/2024] [Accepted: 06/19/2024] [Indexed: 07/01/2024] Open
Abstract
We characterized the regulatory mechanisms and role in human myeloid cell survival and differentiation of PRPF40A, a splicing factor lacking a canonical RNA Binding Domain. Upon PRPF40A knockdown, HL-60 cells displayed increased cell death, decreased proliferation and slight differentiation phenotype with upregulation of immune activation genes. Suggestive of both redundant and specific functions, cell death but not proliferation was rescued by overexpression of its paralog PRPF40B. Transcriptomic analysis revealed the predominant role of PRPF40A as an activator of cassette exon inclusion of functionally relevant splicing events. Mechanistically, the exons exclusively upregulated by PRPF40A are flanked by short and GC-rich introns which tend to localize to nuclear speckles in the nucleus center. These PRPF40A regulatory features are shared with other splicing regulators such as SRRM2, SON, PCBP1/2, and to a lesser extent TRA2B and SRSF2, as a part of a functional network that regulates splicing partly via co-localization in the nucleus.
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Affiliation(s)
- Cheryl Weiqi Tan
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Donald Yuhui Sim
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Yashu Zhen
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Haobo Tian
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Jace Koh
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
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Barraza SJ, Bhattacharyya A, Trotta CR, Woll MG. Targeting strategies for modulating pre-mRNA splicing with small molecules: Recent advances. Drug Discov Today 2023; 28:103431. [PMID: 36356786 DOI: 10.1016/j.drudis.2022.103431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
The concept of using small molecules to therapeutically modulate pre-mRNA splicing was validated with the US Food and Drug Administration (FDA) approval of Evrysdi® (risdiplam) in 2020. Since then, efforts have continued unabated toward the discovery of new splicing-modulating drugs. However, the drug development world has evolved in the 10 years since risdiplam precursors were first identified in high-throughput screening (HTS). Now, new mechanistic insights into RNA-processing pathways and regulatory networks afford increasingly feasible targeted approaches. In this review, organized into classes of biological target, we compile and summarize small molecules discovered, devised, and developed since 2020 to alter pre-mRNA splicing.
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Affiliation(s)
- Scott J Barraza
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, USA.
| | | | | | - Matthew G Woll
- PTC Therapeutics, Inc., 100 Corporate Court, South Plainfield, NJ, USA
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Interplay between A-to-I Editing and Splicing of RNA: A Potential Point of Application for Cancer Therapy. Int J Mol Sci 2022; 23:ijms23095240. [PMID: 35563631 PMCID: PMC9105294 DOI: 10.3390/ijms23095240] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/17/2022] Open
Abstract
Adenosine-to-inosine RNA editing is a system of post-transcriptional modification widely distributed in metazoans which is catalyzed by ADAR enzymes and occurs mostly in double-stranded RNA (dsRNA) before splicing. This type of RNA editing changes the genetic code, as inosine generally pairs with cytosine in contrast to adenosine, and this expectably modulates RNA splicing. We review the interconnections between RNA editing and splicing in the context of human cancer. The editing of transcripts may have various effects on splicing, and resultant alternatively spliced isoforms may be either tumor-suppressive or oncogenic. Dysregulated RNA splicing in cancer often causes the release of excess amounts of dsRNA into cytosol, where specific dsRNA sensors provoke antiviral-like responses, including type I interferon signaling. These responses may arrest cell division, causing apoptosis and, externally, stimulate antitumor immunity. Thus, small-molecule spliceosome inhibitors have been shown to facilitate the antiviral-like signaling and are considered to be potential cancer therapies. In turn, a cytoplasmic isoform of ADAR can deaminate dsRNA in cytosol, thereby decreasing its levels and diminishing antitumor innate immunity. We propose that complete or partial inhibition of ADAR may enhance the proapoptotic and cytotoxic effects of splicing inhibitors and that it may be considered a promising addition to cancer therapies targeting RNA splicing.
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Genome-Wide RNAi Screening Identifies Novel Pathways/Genes Involved in Oxidative Stress and Repurposable Drugs to Preserve Cystic Fibrosis Airway Epithelial Cell Integrity. Antioxidants (Basel) 2021; 10:antiox10121936. [PMID: 34943039 PMCID: PMC8750174 DOI: 10.3390/antiox10121936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/23/2021] [Accepted: 11/27/2021] [Indexed: 12/20/2022] Open
Abstract
Recurrent infection-inflammation cycles in cystic fibrosis (CF) patients generate a highly oxidative environment, leading to progressive destruction of the airway epithelia. The identification of novel modifier genes involved in oxidative stress susceptibility in the CF airways might contribute to devise new therapeutic approaches. We performed an unbiased genome-wide RNAi screen using a randomized siRNA library to identify oxidative stress modulators in CF airway epithelial cells. We monitored changes in cell viability after a lethal dose of hydrogen peroxide. Local similarity and protein-protein interaction network analyses uncovered siRNA target genes/pathways involved in oxidative stress. Further mining against public drug databases allowed identifying and validating commercially available drugs conferring oxidative stress resistance. Accordingly, a catalog of 167 siRNAs able to confer oxidative stress resistance in CF submucosal gland cells targeted 444 host genes and multiple circuitries involved in oxidative stress. The most significant processes were related to alternative splicing and cell communication, motility, and remodeling (impacting cilia structure/function, and cell guidance complexes). Other relevant pathways included DNA repair and PI3K/AKT/mTOR signaling. The mTOR inhibitor everolimus, the α1-adrenergic receptor antagonist doxazosin, and the Syk inhibitor fostamatinib significantly increased the viability of CF submucosal gland cells under strong oxidative stress pressure. Thus, novel therapeutic strategies to preserve airway cell integrity from the harsh oxidative milieu of CF airways could stem from a deep understanding of the complex consequences of oxidative stress at the molecular level, followed by a rational repurposing of existing "protective" drugs. This approach could also prove useful to other respiratory pathologies.
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Ruta V, Pagliarini V, Sette C. Coordination of RNA Processing Regulation by Signal Transduction Pathways. Biomolecules 2021; 11:biom11101475. [PMID: 34680108 PMCID: PMC8533259 DOI: 10.3390/biom11101475] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 02/06/2023] Open
Abstract
Signal transduction pathways transmit the information received from external and internal cues and generate a response that allows the cell to adapt to changes in the surrounding environment. Signaling pathways trigger rapid responses by changing the activity or localization of existing molecules, as well as long-term responses that require the activation of gene expression programs. All steps involved in the regulation of gene expression, from transcription to processing and utilization of new transcripts, are modulated by multiple signal transduction pathways. This review provides a broad overview of the post-translational regulation of factors involved in RNA processing events by signal transduction pathways, with particular focus on the regulation of pre-mRNA splicing, cleavage and polyadenylation. The effects of several post-translational modifications (i.e., sumoylation, ubiquitination, methylation, acetylation and phosphorylation) on the expression, subcellular localization, stability and affinity for RNA and protein partners of many RNA-binding proteins are highlighted. Moreover, examples of how some of the most common signal transduction pathways can modulate biological processes through changes in RNA processing regulation are illustrated. Lastly, we discuss challenges and opportunities of therapeutic approaches that correct RNA processing defects and target signaling molecules.
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Affiliation(s)
- Veronica Ruta
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Laboratory of Neuroembryology, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Correspondence:
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Inoue A. RBM10: Structure, functions, and associated diseases. Gene 2021; 783:145463. [PMID: 33515724 PMCID: PMC10445532 DOI: 10.1016/j.gene.2021.145463] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 12/24/2020] [Accepted: 01/04/2021] [Indexed: 12/22/2022]
Abstract
RBM10 is a nuclear RNA-binding protein (RBP) that regulates the alternative splicing of primary transcripts. Recently, research on RBM10 has become increasingly active owing to its clinical importance, as indicated by studies on RBM0 mutations that cause TARP syndrome, an X-linked congenital pleiotropic developmental anomaly, and various cancers such as lung adenocarcinoma in adults. Herein, the molecular biology of RBM10 and its significance in medicine are reviewed, focusing on the gene and protein structures of RBM10, its cell biology, molecular functions and regulation, relationship with the paralogous protein RBM5, and the mutations of RBM10 and their associated diseases. Finally, the challenges in future studies of RBM10 are discussed in the concluding remarks.
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Affiliation(s)
- Akira Inoue
- Department of Otolaryngology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
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Identification of phenothiazine derivatives as UHM-binding inhibitors of early spliceosome assembly. Nat Commun 2020; 11:5621. [PMID: 33159082 PMCID: PMC7648758 DOI: 10.1038/s41467-020-19514-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/16/2020] [Indexed: 12/31/2022] Open
Abstract
Interactions between U2AF homology motifs (UHMs) and U2AF ligand motifs (ULMs) play a crucial role in early spliceosome assembly in eukaryotic gene regulation. UHM-ULM interactions mediate heterodimerization of the constitutive splicing factors U2AF65 and U2AF35 and between other splicing factors that regulate spliceosome assembly at the 3′ splice site, where UHM domains of alternative splicing factors, such as SPF45 and PUF60, contribute to alternative splicing regulation. Here, we performed high-throughput screening using fluorescence polarization assays with hit validation by NMR and identified phenothiazines as general inhibitors of UHM-ULM interactions. NMR studies show that these compounds occupy the tryptophan binding pocket of UHM domains. Co-crystal structures of the inhibitors with the PUF60 UHM domain and medicinal chemistry provide structure-activity-relationships and reveal functional groups important for binding. These inhibitors inhibit early spliceosome assembly on pre-mRNA substrates in vitro. Our data show that spliceosome assembly can be inhibited by targeting UHM-ULM interactions by small molecules, thus extending the toolkit of splicing modulators for structural and biochemical studies of the spliceosome and splicing regulation. So far only a few compounds have been reported as splicing modulators. Here, the authors combine high-throughput screening, chemical synthesis, NMR, X-ray crystallography with functional studies and develop phenothiazines as inhibitors for the U2AF Homology Motif (UHM) domains of proteins that regulate splicing and show that they inhibit early spliceosome assembly on pre-mRNA substrates in vitro.
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Fan F, Li S, Wen Z, Ye Q, Chen X, Ye Q. Regulation of PGC-1α mediated by acetylation and phosphorylation in MPP+ induced cell model of Parkinson's disease. Aging (Albany NY) 2020; 12:9461-9474. [PMID: 32452827 PMCID: PMC7288924 DOI: 10.18632/aging.103219] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 03/31/2020] [Indexed: 12/21/2022]
Abstract
Background: Parkinson’s disease (PD) is one of the most common neurodegenerative diseases with complex etiology in sporadic cases. Accumulating evidence suggests that oxidative stress and defects in mitochondrial dynamics are associated with the pathogenesis of PD. The oxidative stress and mitochondrial dynamics are regulated strictly by peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α). We investigated whether acetylation and phosphorylation of PGC-1α contribute to protecting neuronal cell against oxidative stress. Results: We found that acetylation and phosphorylation mediated the nuclear translocation of PGC-1α protects against oxidative damage. In contrast to the increased nuclear PGC-1α, the cytosolic PGC-1α was decreased upon inhibition of GCN5 acetyltransferase. Similarly to the inhibition of GCN5 acetyltransferase, the increased nuclear PGC-1α and the decreased cytosolic PGC-1α were observed upon p38MAPK and AMPK activation. Briefly, the significantly increased nuclear PGC-1α is regulated either by inhibiting the acetylation of PGC-1α or by the phosphorylating PGC-1α, which results in a reduction in ROS. Conclusion: PGC-1α protects neuronal cells against MPP+-induced toxicity partially through the acetylation of PGC-1α mediated by GCN5, and mostly through the phosphorylation PGC-1α mediated by p38MAPK or AMPK. Therapeutic reagents activating PGC-1α may be valuable for preventing mitochondrial dysfunction in PD by against oxidative damage. Methods: With established the 1-methyl-4-phenylpyridinium (MPP+)-induced cell model of PD, the effects of MPP+ and experimental reagents on the cell viability was investigated. The expression of PGC-1α, general control of nucleotide synthesis 5 (GCN5), p38 mitogen-activated protein kinase (p38MAPK) and adenosine monophosphate activated protein kinase (AMPK) were detected by Western blotting and quantitative real-time PCR. The level of reactive oxygen species (ROS) was measured by flow cytometry. All statistical analyses were carried out using one-way ANOVA.
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Affiliation(s)
- Fei Fan
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.,Fujian Health College, Fuzhou, Fujian, China.,Institute or Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Songlin Li
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.,Affiliated Sichuan Provincial Rehabilitation Hospital of Chengdu University of TCM, Sichuan Bayi Rehabilitation Center, Chengdu, Sichuan, China
| | - Zhipeng Wen
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.,Affiliated Hospital of Putian University, Putian, Fujian, China
| | - Qiaoyue Ye
- Fuzhou No. 8 High School, Fuzhou, Fujian, China
| | - Xiaochun Chen
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.,Institute or Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
| | - Qinyong Ye
- Department of Neurology, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.,Institute or Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, Fujian, China
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More than a messenger: Alternative splicing as a therapeutic target. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1862:194395. [PMID: 31271898 DOI: 10.1016/j.bbagrm.2019.06.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/30/2022]
Abstract
Alternative splicing of pre-mRNA is an essential post- and co-transcriptional mechanism of gene expression regulation that produces multiple mature mRNA transcripts from a single gene. Genetic mutations that affect splicing underlie numerous devastating diseases. The complexity of splicing regulation allows for multiple therapeutic approaches to correct disease-associated mis-splicing events. In this review, we first highlight recent findings from therapeutic strategies that have used splice switching antisense oligonucleotides and small molecules that bind directly to RNA. Second, we summarize different genetic and chemical approaches to target components of the spliceosome to correct splicing defects in pathological conditions. Finally, we present an overview of compounds that target kinases and accessory pathways that intersect with the splicing machinery. Advancements in the understanding of disease-specific defects caused by mis-regulation of alternative splicing will certainly increase the development of therapeutic options for the clinic. This article is part of a Special Issue entitled: RNA structure and splicing regulation edited by Francisco Baralle, Ravindra Singh and Stefan Stamm.
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Abstract
Nucleolin is an RNA binding protein that is involved in many post-transcriptional regulation steps of messenger RNAs in addition to its nucleolar role in ribosomal RNA transcription and assembly in pre-ribosomes. Acetylated nucleolin was found to be associated with nuclear speckles and to co-localize with the splicing factor SC35. Previous nuclear pull down of nucleolin identified several splicing components and factors involved in RNA polymerase II transcription associated with nucleolin. In this report, we show that these splicing components are specifics of the pre-catalytic A and B spliceosomes, while proteins recruited in the Bact, C and P complexes are absent from the nucleolin interacting proteins. Furthermore, we show that acetylated nucleolin co-localized with P-SF3B1, a marker of co-transcriptional active spliceosomes. P-SF3B1 complexes can be pulled down with nucleolin specific antibodies. Interestingly, the alternative splicing of Fibronectin at the IIICS and EDB sites was affected by nucleolin depletion. These data are consistent with a model where nucleolin could be a factor bridging RNA polymerase II transcription and assembly of pre-catalytic spliceosome similarly to its function in the co-transcriptional maturation of pre-rRNA.
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Zhao S. Alternative splicing, RNA-seq and drug discovery. Drug Discov Today 2019; 24:1258-1267. [PMID: 30953866 DOI: 10.1016/j.drudis.2019.03.030] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/14/2019] [Accepted: 03/28/2019] [Indexed: 12/27/2022]
Abstract
Alternative splicing, hereafter referred to as AS, is an essential component of gene expression regulation that contributes to the diversity of proteomes. Recent developments in RNA sequencing (RNA-seq) technologies, combined with the advent of computational tools, have enabled transcriptome-wide studies of AS at an unprecedented scale and resolution. RNA mis-splicing can cause human disease, and to target alternative splicing has led to the development of novel therapeutics. Splice variants diversify the repertoire of biomarkers and functionally contribute to drug resistance. Our expanding knowledge of AS variation in human populations holds great promise for improving disease diagnoses and ultimately patient care in the era of sequencing and precision medicine.
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Affiliation(s)
- Shanrong Zhao
- Pfizer Worldwide Research and Development, Cambridge, MA 02139, USA.
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12
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Zhou Z, Chen Y, Jin M, He J, Guli A, Yan C, Ding S. Comprehensive Analysis of Lysine Acetylome Reveals a Site-Specific Pattern in Rapamycin-Induced Autophagy. J Proteome Res 2019; 18:865-877. [PMID: 30592415 DOI: 10.1021/acs.jproteome.8b00533] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protein acetylation reportedly acts as a key regulator of autophagy. However, up to now, the relationship between acetylome and autophagy has remained unclear. Here stable isotope labeling of amino acids in cell culture and high-throughput quantitative mass spectrometry were used to perform an acetylome analysis of rapamycin-induced autophagy in vitro. Our data revealed that 2135 sites were quantified on 1081 proteins. During autophagy, 421 sites were significantly regulated on 296 proteins, with 80.8% of sites downregulated and 19.2% upregulated. Motif enrichment analysis revealed five main motifs. Most of the downregulated sites conformed to the classical functional motif of p300/CBP [G-AcK]. Furthermore, acetylation targeted proteins involved mainly in ribosomes, spliceosomes, and AcCoA-related metabolic process. In-depth analysis indicated that most of the acetylation sites were in the critical domain, were functional sites, or could change their enzymatic activity by acetylation, highlighting the importance of site-specific acetylation patterns. Subsequently, we demonstrated that K1549 of p300 was also a functional site that could regulate the autophagic process in vitro. In conclusion, our data reveal a deacetylation-preponderant profile with autophagy. The specificity of the related motifs and the identification of site-specific acetylation patterns will assist searches for potential targets or subsequent mechanism-focused studies to elucidate site-specific protein networks in autophagy.
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Affiliation(s)
- Zhuo Zhou
- The National Education Base for Basic Medical Sciences , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
| | - Yu Chen
- The National Education Base for Basic Medical Sciences , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
| | - Mengqi Jin
- The National Education Base for Basic Medical Sciences , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
| | - Jianqin He
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital , Zhejiang University School of Medicine , 79 Qingchun Road , Hangzhou 310003 , Zhejiang Province , China
| | - Ayiding Guli
- The National Education Base for Basic Medical Sciences , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
| | - Chunlan Yan
- Department of Biophysics, Key Laboratory of Medical Neurobiology, Ministry of Health of China , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
| | - Shiping Ding
- The National Education Base for Basic Medical Sciences , Zhejiang University School of Medicine , 866 Yuhangtang Road , Hangzhou 310058 , Zhejiang Province , China
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Simabuco FM, Pavan ICB, Pestana NF, Carvalho PC, Basei FL, Campos Granato D, Paes Leme AF, Zanchin NIT. Interactome analysis of the human Cap‐specific mRNA (nucleoside‐2′‐O‐)‐methyltransferase 1 (hMTr1) protein. J Cell Biochem 2018; 120:5597-5611. [DOI: 10.1002/jcb.27843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/14/2018] [Indexed: 01/28/2023]
Affiliation(s)
- Fernando Moreira Simabuco
- Laboratório de Espectrometria de Massas, Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais Campinas SP Brazil
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas Limeira SP Brazil
| | | | - Nathalie Fortes Pestana
- Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas Limeira SP Brazil
- Centro Universitário da Fundação Hermínio Ometto‐FHO Araras SP Brazil
| | | | | | - Daniela Campos Granato
- Laboratório de Espectrometria de Massas, Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais Campinas SP Brazil
| | - Adriana Franco Paes Leme
- Laboratório de Espectrometria de Massas, Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais Campinas SP Brazil
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Emerging Roles of Ubiquitin-like Proteins in Pre-mRNA Splicing. Trends Biochem Sci 2018; 43:896-907. [PMID: 30269981 DOI: 10.1016/j.tibs.2018.09.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/31/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022]
Abstract
Ubiquitin-like proteins (UBLs) belong to the protein family whose members share a globular beta-grasp fold structure. The archetypal member, ubiquitin, is known for its function in proteasome-mediated protein degradation. UBLs have been shown to play several crucial roles besides protein turnover, including DNA damage response, cell cycle control, cellular signaling, protein trafficking, and innate immunity activation. In the past few years, accumulating evidence illustrates that four UBLs, namely, ubiquitin, SUMO, Hub1, and Sde2, are involved in eukaryotic pre-mRNA splicing. They modify the spliceosomes and promote splicing by adding new surfaces for intermolecular interactions, thereby refining the outcome of gene expression. In this review article, we highlight recent discoveries with an emphasis on the emerging roles of UBLs in splicing regulation.
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15
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Siriboon C, Li TS, Yu CW, Chern JW, Ju JC. Novel histone deacetylase inhibitors and embryo aggregation enhance cloned embryo development and ES cell derivation in pigs. PLoS One 2018; 13:e0204588. [PMID: 30261020 PMCID: PMC6160101 DOI: 10.1371/journal.pone.0204588] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 09/11/2018] [Indexed: 11/26/2022] Open
Abstract
The histone deacetylase inhibitor (HDACi) has been investigated for treating cancers and many other diseases as well as enhancing the reprogramming efficiency in cloned embryos for decades. In the present study, we investigated the effects of two novel HDAC inhibitors, i.e., HDACi-14 and -79, at the concentrations of 0, 1, 2, or 4 μM on the development of embryos cloned by the oocyte bisection cloning technique (OBCT). Blastocyst rates for the reconstructed embryos reached 60% in the 2 μM HDACi-14-treated groups, which was higher (P < 0.05) compared to the untreated group (36.9%). Similarly, HDACi-79 treatment at 2 and 4 μM also conferred higher (P < 0.05) blastocyst rates than that of the untreated group (79.4, 74.2, and 50.0%, respectively). Both HDACi-14 and -79 treatments had no beneficial effect on total cell numbers and apoptotic indices of cloned embryos (P > 0.05). Histone acetylation profile by both HDACi-14 (2 μM) and -79 (2 μM) treatments demonstrated a drastic increase (P < 0.05) mainly in two-cell stage embryos when compared to the control group. After seeding on the feeder cells, the aggregated cloned blastocysts produced by the HDACi-79 treatment showed a significant increase of primary outgrowths compared to the control group (60.0% vs. 42.9%; P < 0.05). Finally, the cloned embryo-derived ES cell lines from aggregated cloned embryos produced from the HDACi-79-treated, HDACi-14-treated and control groups were established (5, 3, and 2 lines, respectively). In conclusion, the novel histone deacetylation inhibitors improve blastocyst formation and potentially increase the derivation efficiency of ES cell lines from the cloned porcine embryos produced in vitro. Depending on the purposes, some fine-tuning may be required to maximize its beneficial effects of these newly synthesized chemicals.
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Affiliation(s)
- Chawalit Siriboon
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Department of Animal Science, Faculty of Agriculture, Ubon Ratchathani University, Ubon Ratchathani, Thailand
| | - Tzai-Shiuan Li
- Translational Medicine Research Center, China Medical University Hospital, Taichung, Taiwan
| | - Chao-Wu Yu
- School of Pharmacy, National Taiwan University, Taipei, Taiwan
| | - Ji-Wang Chern
- School of Pharmacy, National Taiwan University, Taipei, Taiwan
| | - Jyh-Cherng Ju
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Translational Medicine Research Center, China Medical University Hospital, Taichung, Taiwan
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan
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16
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Scaglione A, Patzig J, Liang J, Frawley R, Bok J, Mela A, Yattah C, Zhang J, Teo SX, Zhou T, Chen S, Bernstein E, Canoll P, Guccione E, Casaccia P. PRMT5-mediated regulation of developmental myelination. Nat Commun 2018; 9:2840. [PMID: 30026560 PMCID: PMC6053423 DOI: 10.1038/s41467-018-04863-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/01/2018] [Indexed: 12/16/2022] Open
Abstract
Oligodendrocytes (OLs) are the myelin-forming cells of the central nervous system. They are derived from differentiation of oligodendrocyte progenitors through a process requiring cell cycle exit and histone modifications. Here we identify the histone arginine methyl-transferase PRMT5, a molecule catalyzing symmetric methylation of histone H4R3, as critical for developmental myelination. PRMT5 pharmacological inhibition, CRISPR/cas9 targeting, or genetic ablation decrease p53-dependent survival and impair differentiation without affecting proliferation. Conditional ablation of Prmt5 in progenitors results in hypomyelination, reduced survival and differentiation. Decreased histone H4R3 symmetric methylation is followed by increased nuclear acetylation of H4K5, and is rescued by pharmacological inhibition of histone acetyltransferases. Data obtained using purified histones further validate the results obtained in mice and in cultured oligodendrocyte progenitors. Together, these results identify PRMT5 as critical for oligodendrocyte differentiation and developmental myelination by modulating the cross-talk between histone arginine methylation and lysine acetylation. Myelin-forming cells derive from oligodendrocyte progenitors. Here the authors identify histone arginine methyl-transferase PRMT5 as critical for developmental myelination by modulating the cross-talk between histone arginine methylation and lysine acetylation, to favor differentiation.
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Affiliation(s)
- Antonella Scaglione
- Neuroscience Initiative at the Advanced Science Research Center of the Graduate Center of The City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA
| | - Julia Patzig
- Neuroscience Initiative at the Advanced Science Research Center of the Graduate Center of The City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA
| | - Jialiang Liang
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA
| | - Rebecca Frawley
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA
| | - Jabez Bok
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos Building #3-06, Singapore, 138673, Singapore
| | - Angeliki Mela
- Department of Pathology and Cell Biology, Columbia University Medical Center, 630 West 168th Street, New York, NY, 10032, USA
| | - Camila Yattah
- Neuroscience Initiative at the Advanced Science Research Center of the Graduate Center of The City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA.,Graduate Program in Biochemistry, The Graduate Center of The City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Jingxian Zhang
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos Building #3-06, Singapore, 138673, Singapore
| | - Shun Xie Teo
- Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos Building #3-06, Singapore, 138673, Singapore
| | - Ting Zhou
- Room A-829, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Shuibing Chen
- Room A-829, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA
| | - Emily Bernstein
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA.,Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Columbia University Medical Center, 630 West 168th Street, New York, NY, 10032, USA
| | - Ernesto Guccione
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA.,Institute of Molecular and Cell Biology (IMCB), A*STAR (Agency for Science, Technology and Research), 61 Biopolis Drive, Proteos Building #3-06, Singapore, 138673, Singapore.,Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, New York, NY, 10029, USA
| | - Patrizia Casaccia
- Neuroscience Initiative at the Advanced Science Research Center of the Graduate Center of The City University of New York, 85 St. Nicholas Terrace, New York, NY, 10031, USA. .,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA. .,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, 10029, USA. .,Graduate Program in Biochemistry, The Graduate Center of The City University of New York, 365 5th Avenue, New York, NY, 10016, USA.
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17
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Khoury G, Mota TM, Li S, Tumpach C, Lee MY, Jacobson J, Harty L, Anderson JL, Lewin SR, Purcell DFJ. HIV latency reversing agents act through Tat post translational modifications. Retrovirology 2018; 15:36. [PMID: 29751762 PMCID: PMC5948896 DOI: 10.1186/s12977-018-0421-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 05/05/2018] [Indexed: 12/18/2022] Open
Abstract
Background Different classes of latency reversing agents (LRAs) are being evaluated to measure their effects in reactivating HIV replication from latently infected cells. A limited number of studies have demonstrated additive effects of LRAs with the viral protein Tat in initiating transcription, but less is known about how LRAs interact with Tat, particularly through basic residues that may be post-translationally modified to alter the behaviour of Tat for processive transcription and co-transcriptional RNA processing. Results Here we show that various lysine and arginine mutations reduce the capacity of Tat to induce both transcription and mRNA splicing. The lysine 28 and lysine 50 residues of Tat, or the acetylation and methylation modifications of these basic amino acids, were essential for Tat transcriptional control, and also for the proviral expression effects elicited by histone deacetylase inhibitors (HDACi) or the bromodomain inhibitor JQ1. We also found that JQ1 was the only LRA tested that could induce HIV mRNA splicing in the absence of Tat, or rescue splicing for Tat lysine mutants in a BRD4-dependent manner. Conclusions Our data provide evidence that Tat activities in both co-transcriptional RNA processing together with transcriptional initiation and processivity are crucial during reactivation of latent HIV infection. The HDACi and JQ1 LRAs act with Tat to increase transcription, but JQ1 also enables post-transcriptional mRNA splicing. Tat residues K28 and K50, or their modifications through acetylation or methylation, are critical for LRAs that function in conjunction with Tat. Electronic supplementary material The online version of this article (10.1186/s12977-018-0421-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Georges Khoury
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Talia M Mota
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia.,The Peter Doherty Institute for Infection and Immunity, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Shuang Li
- School of Life Sciences, Peking University, Beijing, China
| | - Carolin Tumpach
- The Peter Doherty Institute for Infection and Immunity, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Michelle Y Lee
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Jonathan Jacobson
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Leigh Harty
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Jenny L Anderson
- The Peter Doherty Institute for Infection and Immunity, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Sharon R Lewin
- The Peter Doherty Institute for Infection and Immunity, Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia.,Department of Infectious Diseases, Alfred Health and Monash University, Melbourne, Australia
| | - Damian F J Purcell
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia.
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18
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Pozzi B, Mammi P, Bragado L, Giono LE, Srebrow A. When SUMO met splicing. RNA Biol 2018; 15:689-695. [PMID: 29741121 PMCID: PMC6152442 DOI: 10.1080/15476286.2018.1457936] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/22/2018] [Accepted: 03/20/2018] [Indexed: 12/12/2022] Open
Abstract
Spliceosomal proteins have been revealed as SUMO conjugation targets. Moreover, we have reported that many of these are in a SUMO-conjugated form when bound to a pre-mRNA substrate during a splicing reaction. We demonstrated that SUMOylation of Prp3 (PRPF3), a component of the U4/U6 di-snRNP, is required for U4/U6•U5 tri-snRNP formation and/or recruitment to active spliceosomes. Expanding upon our previous results, we have shown that the splicing factor SRSF1 stimulates SUMO conjugation to several spliceosomal proteins. Given the relevance of the splicing process, as well as the complex and dynamic nature of its governing machinery, the spliceosome, the molecular mechanisms that modulate its function represent an attractive topic of research. We posit that SUMO conjugation could represent a way of modulating spliceosome assembly and thus, splicing efficiency. How cycles of SUMOylation/de-SUMOylation of spliceosomal proteins become integrated throughout the highly choreographed spliceosomal cycle awaits further investigation.
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Affiliation(s)
- Berta Pozzi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Pablo Mammi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Laureano Bragado
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Luciana E. Giono
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Anabella Srebrow
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
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19
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Mishra SK, Thakran P. Intron specificity in pre-mRNA splicing. Curr Genet 2018; 64:777-784. [PMID: 29299619 DOI: 10.1007/s00294-017-0802-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 02/06/2023]
Abstract
The occurrence of spliceosomal introns in eukaryotic genomes is highly diverse and ranges from few introns in an organism to multiple introns per gene. Introns vary with respect to their lengths, strengths of splicing signals, and position in resident genes. Higher intronic density and diversity in genetically complex organisms relies on increased efficiency and accuracy of spliceosomes for pre-mRNA splicing. Since intron diversity is critical for functions in RNA stability, regulation of gene expression and alternative splicing, RNA-binding proteins, spliceosomal regulatory factors and post-translational modifications of splicing factors ought to make the splicing process intron-specific. We recently reported function and regulation of a ubiquitin fold harboring splicing regulator, Sde2, which following activation by ubiquitin-specific proteases facilitates excision of selected introns from a subset of multi-intronic genes in Schizosaccharomyces pombe (Thakran et al. EMBO J, https://doi.org/10.15252/embj.201796751 , 2017). By reviewing our findings with understandings of intron functions and regulated splicing processes, we propose possible functions and mechanism of intron-specific pre-mRNA splicing and suggest that this process is crucial to highlight importance of introns in eukaryotic genomes.
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Affiliation(s)
- Shravan Kumar Mishra
- Max Planck, DST Partner Group, Centre for Protein Science Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Punjab, 140306, India.
| | - Poonam Thakran
- Max Planck, DST Partner Group, Centre for Protein Science Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Punjab, 140306, India
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20
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Pirnie SP, Osman A, Zhu Y, Carmichael GG. An Ultraconserved Element (UCE) controls homeostatic splicing of ARGLU1 mRNA. Nucleic Acids Res 2017; 45:3473-3486. [PMID: 27899669 PMCID: PMC5389617 DOI: 10.1093/nar/gkw1140] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 10/31/2016] [Indexed: 11/13/2022] Open
Abstract
Arginine and Glutamate-Rich protein 1 (ARGLU1) is a protein whose function is poorly understood, but may act in both transcription and pre-mRNA splicing. We demonstrate that the ARGLU1 gene expresses at least three distinct RNA splice isoforms – a fully spliced isoform coding for the protein, an isoform containing a retained intron that is detained in the nucleus, and an isoform containing an alternative exon that targets the transcript for nonsense mediated decay. Furthermore, ARGLU1 contains a long, highly evolutionarily conserved sequence known as an Ultraconserved Element (UCE) that is within the retained intron and overlaps the alternative exon. Manipulation of the UCE, in a reporter minigene or via random mutations in the genomic context using CRISPR/Cas9, changed the splicing pattern. Further, overexpression of the ARGLU1 protein shifted the splicing of endogenous ARGLU1 mRNA, resulting in an increase in the retained intron isoform and nonsense mediated decay susceptible isoform and a decrease in the fully spliced isoform. Taken together with data showing that functional protein knockout shifts splicing toward the fully spliced isoform, our data are consistent with a model in which unproductive splicing complexes assembled at the alternative exon lead to inefficient splicing and intron retention.
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Affiliation(s)
- Stephan P Pirnie
- Department of Genetics and Genome Sciences, UCONN Health Center, 400 Farmington Avenue, Farmington, CT 06030, USA
| | - Ahmad Osman
- Department of Genetics and Genome Sciences, UCONN Health Center, 400 Farmington Avenue, Farmington, CT 06030, USA
| | - Yinzhou Zhu
- Department of Genetics and Genome Sciences, UCONN Health Center, 400 Farmington Avenue, Farmington, CT 06030, USA
| | - Gordon G Carmichael
- Department of Genetics and Genome Sciences, UCONN Health Center, 400 Farmington Avenue, Farmington, CT 06030, USA
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21
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Linking functions: an additional role for an intrinsically disordered linker domain in the transcriptional coactivator CBP. Sci Rep 2017; 7:4676. [PMID: 28680062 PMCID: PMC5498717 DOI: 10.1038/s41598-017-04611-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/17/2017] [Indexed: 12/25/2022] Open
Abstract
The multi-domain transcriptional coactivators CBP/p300 integrate a multitude of signaling inputs, interacting with more than 400 proteins via one or more of their globular domains. While CBP/p300 function is typically considered in terms of these structured domains, about half of the protein consists of intrinsically disordered regions (IDRs) of varying length. However, these IDRs have only been thought of as linkers that allow flexible spatial arrangement of the structured domains, but recent studies have shown that similar IDRs mediate specific and critical interactions in other proteins. To examine the roles of IDRs in CBP, we performed yeast-two-hybrid screenings of placenta and lung cancer cDNA libraries, which demonstrated that the long IDR linking the KIX domain and bromodomain of CBP (termed ID3) can potentially bind to several proteins. The RNA-binding Zinc-finger protein 106 (ZFP106) detected in both libraries was identified as a novel substrate for CBP-mediated acetylation. Nuclear magnetic resonance (NMR) spectroscopy combined with cross-linking experiments and competition-binding assays showed that the fully disordered isolated ID3 transiently interacts with an IDR of ZFP106 in a fashion that disorder of both regions is maintained. These findings demonstrate that beside the linking function, ID3 can also interact with acetylation substrates of CBP.
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22
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Gallego-Paez LM, Bordone MC, Leote AC, Saraiva-Agostinho N, Ascensão-Ferreira M, Barbosa-Morais NL. Alternative splicing: the pledge, the turn, and the prestige : The key role of alternative splicing in human biological systems. Hum Genet 2017; 136:1015-1042. [PMID: 28374191 PMCID: PMC5602094 DOI: 10.1007/s00439-017-1790-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/25/2017] [Indexed: 02/06/2023]
Abstract
Alternative pre-mRNA splicing is a tightly controlled process conducted by the spliceosome, with the assistance of several regulators, resulting in the expression of different transcript isoforms from the same gene and increasing both transcriptome and proteome complexity. The differences between alternative isoforms may be subtle but enough to change the function or localization of the translated proteins. A fine control of the isoform balance is, therefore, needed throughout developmental stages and adult tissues or physiological conditions and it does not come as a surprise that several diseases are caused by its deregulation. In this review, we aim to bring the splicing machinery on stage and raise the curtain on its mechanisms and regulation throughout several systems and tissues of the human body, from neurodevelopment to the interactions with the human microbiome. We discuss, on one hand, the essential role of alternative splicing in assuring tissue function, diversity, and swiftness of response in these systems or tissues, and on the other hand, what goes wrong when its regulatory mechanisms fail. We also focus on the possibilities that splicing modulation therapies open for the future of personalized medicine, along with the leading techniques in this field. The final act of the spliceosome, however, is yet to be fully revealed, as more knowledge is needed regarding the complex regulatory network that coordinates alternative splicing and how its dysfunction leads to disease.
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Affiliation(s)
- L M Gallego-Paez
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M C Bordone
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - A C Leote
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N Saraiva-Agostinho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - M Ascensão-Ferreira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - N L Barbosa-Morais
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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23
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Sidarovich A, Will CL, Anokhina MM, Ceballos J, Sievers S, Agafonov DE, Samatov T, Bao P, Kastner B, Urlaub H, Waldmann H, Lührmann R. Identification of a small molecule inhibitor that stalls splicing at an early step of spliceosome activation. eLife 2017; 6. [PMID: 28300534 PMCID: PMC5354520 DOI: 10.7554/elife.23533] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/26/2017] [Indexed: 11/13/2022] Open
Abstract
Small molecule inhibitors of pre-mRNA splicing are important tools for identifying new spliceosome assembly intermediates, allowing a finer dissection of spliceosome dynamics and function. Here, we identified a small molecule that inhibits human pre-mRNA splicing at an intermediate stage during conversion of pre-catalytic spliceosomal B complexes into activated Bact complexes. Characterization of the stalled complexes (designated B028) revealed that U4/U6 snRNP proteins are released during activation before the U6 Lsm and B-specific proteins, and before recruitment and/or stable incorporation of Prp19/CDC5L complex and other Bact complex proteins. The U2/U6 RNA network in B028 complexes differs from that of the Bact complex, consistent with the idea that the catalytic RNA core forms stepwise during the B to Bact transition and is likely stabilized by the Prp19/CDC5L complex and related proteins. Taken together, our data provide new insights into the RNP rearrangements and extensive exchange of proteins that occurs during spliceosome activation. DOI:http://dx.doi.org/10.7554/eLife.23533.001
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Affiliation(s)
- Anzhalika Sidarovich
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Cindy L Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Maria M Anokhina
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Javier Ceballos
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Sonja Sievers
- Compound Management and Screening Center, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Dmitry E Agafonov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Timur Samatov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Penghui Bao
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Berthold Kastner
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytics Group, Institute for Clinical Chemistry Göttingen, University Medical Center, Göttingen, Germany
| | - Herbert Waldmann
- Department of Chemical Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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24
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Agafonov DE, van Santen M, Kastner B, Dube P, Will CL, Urlaub H, Lührmann R. ATPγS stalls splicing after B complex formation but prior to spliceosome activation. RNA (NEW YORK, N.Y.) 2016; 22:1329-1337. [PMID: 27411562 PMCID: PMC4986889 DOI: 10.1261/rna.057810.116] [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] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 06/28/2016] [Indexed: 06/06/2023]
Abstract
The ATP analog ATPγS inhibits pre-mRNA splicing in vitro, but there have been conflicting reports as to which step of splicing is inhibited by this small molecule and its inhibitory mechanism remains unclear. Here we have dissected the effect of ATPγS on pre-mRNA splicing in vitro. Addition of ATPγS to splicing extracts depleted of ATP inhibited both catalytic steps of splicing. At ATPγS concentrations ≥0.5 mM, precatalytic B complexes accumulate, demonstrating a block prior to or during the spliceosome activation stage. Affinity purification of the ATPγS-stalled B complexes (B(ATPγS)) and subsequent characterization of their abundant protein components by 2D gel electrophoresis revealed that B(ATPγS) complexes are compositionally more homogeneous than B complexes previously isolated in the presence of ATP. In particular, they contain little or no Prp19/CDC5L complex proteins, indicating that these proteins are recruited after assembly of the precatalytic spliceosome. Under the electron microscope, B(ATPγS) complexes exhibit a morphology highly similar to B complexes, indicating that the ATPγS-induced block in the transformation of the B to B(act) complex is not due to a major structural defect. Likely mechanisms whereby ATPγS blocks spliceosome assembly at the activation stage, including inhibition of the RNA helicase Brr2, are discussed. Given their more homogeneous composition, B complexes stalled by ATPγS may prove highly useful for both functional and structural analyses of the precatalytic spliceosome and its conversion into an activated B(act) spliceosomal complex.
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Affiliation(s)
- Dmitry E Agafonov
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Marieke van Santen
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Berthold Kastner
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Prakash Dube
- 3D Electron Cryomicroscopy Group, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Cindy L Will
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, D-37075 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, MPI for Biophysical Chemistry, D-37077 Göttingen, Germany
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25
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Effenberger KA, Urabe VK, Jurica MS. Modulating splicing with small molecular inhibitors of the spliceosome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27440103 DOI: 10.1002/wrna.1381] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 06/06/2016] [Accepted: 06/28/2016] [Indexed: 12/23/2022]
Abstract
Small molecule inhibitors that target components of the spliceosome have great potential as tools to probe splicing mechanism and dissect splicing regulatory networks in cells. These compounds also hold promise as drug leads for diseases in which splicing regulation plays a critical role, including many cancers. Because the spliceosome is a complicated and dynamic macromolecular machine comprised of many RNA and protein components, a variety of compounds that interfere with different aspects of spliceosome assembly is needed to probe its function. By screening chemical libraries with high-throughput splicing assays, several labs have added to the collection of splicing inhibitors, although the mechanistic insight into splicing yielded from the initial compound hits is somewhat limited so far. In contrast, SF3B1 inhibitors stand out as a great example of what can be accomplished with small molecule tools. This group of compounds were first discovered as natural products that are cytotoxic to cancer cells, and then later shown to target the core spliceosome protein SF3B1. The inhibitors have since been used to uncover details of SF3B1 mechanism in the spliceosome and its impact on gene expression in cells. Continuing structure activity relationship analysis of the compounds is also making progress in identifying chemical features key to their function, which is critical in understanding the mechanism of SF3B1 inhibition. The knowledge is also important for the design of analogs with new and useful features for both splicing researchers and clinicians hoping to exploit splicing as pressure point to target in cancer therapy. WIREs RNA 2017, 8:e1381. doi: 10.1002/wrna.1381 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Kerstin A Effenberger
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA.,Center for Molecular Biology of RNA, University of California, Santa Cruz, CA, USA
| | - Veronica K Urabe
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA.,Center for Molecular Biology of RNA, University of California, Santa Cruz, CA, USA
| | - Melissa S Jurica
- Department of Molecular Cell and Developmental Biology, University of California, Santa Cruz, CA, USA.,Center for Molecular Biology of RNA, University of California, Santa Cruz, CA, USA
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26
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Sorum AW, Shrimp JH, Roberts AM, Montgomery DC, Tiwari NK, Lal-Nag M, Simeonov A, Jadhav A, Meier JL. Microfluidic Mobility Shift Profiling of Lysine Acetyltransferases Enables Screening and Mechanistic Analysis of Cellular Acetylation Inhibitors. ACS Chem Biol 2016; 11:734-41. [PMID: 26428393 DOI: 10.1021/acschembio.5b00709] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Lysine acetyltransferases (KATs) are critical regulators of signaling in many diseases, including cancer. A major challenge in establishing the targetable functions of KATs in disease is a lack of well-characterized, cell-active KAT inhibitors. To confront this challenge, here we report a microfluidic mobility shift platform for the discovery and characterization of small molecule KAT inhibitors. Novel fluorescent peptide substrates were developed for four well-known KAT enzymes (p300, Crebbp, Morf, and Gcn5). Enzyme-catalyzed acetylation alters the electrophoretic mobility of these peptides in a microfluidic chip, allowing facile and direct monitoring of KAT activity. A pilot screen was used to demonstrate the utility of microfluidic mobility shift profiling to identify known and novel modulators of KAT activity. Real-time kinetic monitoring of KAT activity revealed that garcinol, a natural product KAT inhibitor used in cellular studies, exhibits time-dependent and detergent-sensitive inhibition, consistent with an aggregation-based mechanism. In contrast, the cell-permeable bisubstrate inhibitor Tat-CoA exhibited potent and time-independent KAT inhibition, highlighting its potential utility as a cellular inhibitor of KAT activity. These studies define microfluidic mobility shift profiling as a powerful platform for the discovery and characterization of small molecule inhibitors of KAT activity, and provide mechanistic insights potentially important for the application of KAT inhibitors in cellular contexts.
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Affiliation(s)
- Alexander W. Sorum
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Jonathan H. Shrimp
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Allison M. Roberts
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - David C. Montgomery
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Neil K. Tiwari
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Madhu Lal-Nag
- Division
of Preclinical Innovation, National Center for Advancing Translational
Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Anton Simeonov
- Division
of Preclinical Innovation, National Center for Advancing Translational
Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Ajit Jadhav
- Division
of Preclinical Innovation, National Center for Advancing Translational
Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Jordan L. Meier
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
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Cyclin-Dependent Kinase CRK9, Required for Spliced Leader trans Splicing of Pre-mRNA in Trypanosomes, Functions in a Complex with a New L-Type Cyclin and a Kinetoplastid-Specific Protein. PLoS Pathog 2016; 12:e1005498. [PMID: 26954683 PMCID: PMC4783070 DOI: 10.1371/journal.ppat.1005498] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 02/18/2016] [Indexed: 01/08/2023] Open
Abstract
In eukaryotes, cyclin-dependent kinases (CDKs) control the cell cycle and critical steps in gene expression. The lethal parasite Trypanosoma brucei, member of the phylogenetic order Kinetoplastida, possesses eleven CDKs which, due to high sequence divergence, were generically termed CDC2-related kinases (CRKs). While several CRKs have been implied in the cell cycle, CRK9 was the first trypanosome CDK shown to control the unusual mode of gene expression found in kinetoplastids. In these organisms, protein-coding genes are arranged in tandem arrays which are transcribed polycistronically. Individual mRNAs are processed from precursor RNA by spliced leader (SL) trans splicing and polyadenylation. CRK9 ablation was lethal in cultured trypanosomes, causing a block of trans splicing before the first transesterification step. Additionally, CRK9 silencing led to dephosphorylation of RNA polymerase II and to hypomethylation of the SL cap structure. Here, we tandem affinity-purified CRK9 and, among potential CRK9 substrates and modifying enzymes, discovered an unusual tripartite complex comprising CRK9, a new L-type cyclin (CYC12) and a protein, termed CRK9-associated protein (CRK9AP), that is only conserved among kinetoplastids. Silencing of either CYC12 or CRK9AP reproduced the effects of depleting CRK9, identifying these proteins as functional partners of CRK9 in vivo. While mammalian cyclin L binds to CDK11, the CRK9 complex deviates substantially from that of CDK11, requiring CRK9AP for efficient CRK9 complex formation and autophosphorylation in vitro. Interference with this unusual CDK rescued mice from lethal trypanosome infections, validating CRK9 as a potential chemotherapeutic target.
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28
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Small Molecule Modulators of Pre-mRNA Splicing in Cancer Therapy. Trends Mol Med 2015; 22:28-37. [PMID: 26700537 DOI: 10.1016/j.molmed.2015.11.005] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 12/24/2022]
Abstract
Pre-mRNA splicing is a fundamental process in mammalian gene expression and alternative RNA splicing plays a considerable role in generating protein diversity. RNA splicing events are also key to the pathology of numerous diseases, particularly cancers. Some tumors are molecularly addicted to specific RNA splicing isoforms making interference with pre-mRNA processing a viable therapeutic strategy. Several RNA splicing modulators have recently been characterized, some showing promise in preclinical studies. While the targets of most splicing modulators are constitutive RNA processing components, possibly leading to undesirable side effects, selectivity for individual splicing events has been observed. Given the high prevalence of splicing defects in cancer, small molecule modulators of RNA processing represent a potentially promising novel therapeutic strategy in cancer treatment. Here, we review their reported effects, mechanisms, and limitations.
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Giguère SSB, Guise AJ, Jean Beltran PM, Joshi PM, Greco TM, Quach OL, Kong J, Cristea IM. The Proteomic Profile of Deleted in Breast Cancer 1 (DBC1) Interactions Points to a Multifaceted Regulation of Gene Expression. Mol Cell Proteomics 2015; 15:791-809. [PMID: 26657080 DOI: 10.1074/mcp.m115.054619] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 01/01/2023] Open
Abstract
Deleted in breast cancer 1 (DBC1) has emerged as an important regulator of multiple cellular processes, ranging from gene expression to cell cycle progression. DBC1 has been linked to tumorigenesis both as an inhibitor of histone deacetylases, HDAC3 and sirtuin 1, and as a transcriptional cofactor for nuclear hormone receptors. However, despite mounting interest in DBC1, relatively little is known about the range of its interacting partners and the scope of its functions. Here, we carried out a functional proteomics-based investigation of DBC1 interactions in two relevant cell types, T cells and kidney cells. Microscopy, molecular biology, biochemistry, and mass spectrometry studies allowed us to assess DBC1 mRNA and protein levels, localization, phosphorylation status, and protein interaction networks. The comparison of DBC1 interactions in these cell types revealed conserved regulatory roles for DBC1 in gene expression, chromatin organization and modification, and cell cycle progression. Interestingly, we observe previously unrecognized DBC1 interactions with proteins encoded by cancer-associated genes. Among these interactions are five components of the SWI/SNF complex, the most frequently mutated chromatin remodeling complex in human cancers. Additionally, we identified a DBC1 interaction with TBL1XR1, a component of the NCoR complex, which we validated by reciprocal isolation. Strikingly, we discovered that DBC1 associates with proteins that regulate the circadian cycle, including DDX5, DHX9, and SFPQ. We validated this interaction by colocalization and reciprocal isolation. Functional assessment of this association demonstrated that DBC1 protein levels are important for regulating CLOCK and BMAL1 protein oscillations in synchronized T cells. Our results suggest that DBC1 is integral to the maintenance of the circadian molecular clock. Furthermore, the identified interactions provide a valuable resource for the exploration of pathways involved in DBC1-associated tumorigenesis.
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Affiliation(s)
- Sophie S B Giguère
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Amanda J Guise
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Pierre M Jean Beltran
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Preeti M Joshi
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Todd M Greco
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Olivia L Quach
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Jeffery Kong
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Ileana M Cristea
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
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30
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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.
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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.
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31
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Day CR, Chen H, Coulon A, Meier JL, Larson DR. High-throughput single-molecule screen for small-molecule perturbation of splicing and transcription kinetics. Methods 2015; 96:59-68. [PMID: 26655523 DOI: 10.1016/j.ymeth.2015.11.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/23/2015] [Accepted: 11/27/2015] [Indexed: 12/27/2022] Open
Abstract
In eukaryotes, mRNA synthesis is catalyzed by RNA polymerase II and involves several distinct steps, including transcript initiation, elongation, cleavage, and transcript release. Splicing of RNA can occur during (co-transcriptional) or after (post-transcriptional) RNA synthesis. Thus, RNA synthesis and processing occurs through the concerted activity of dozens of enzymes, each of which is potentially susceptible to perturbation by small molecules. However, there are few, if any, high-throughput screening strategies for identifying drugs which perturb a specific step in RNA synthesis and processing. Here we have developed a high-throughput fluorescence microscopy approach in single cells to screen for inhibitors of specific enzymatic steps in RNA synthesis and processing. By utilizing the high affinity interaction between bacteriophage capsid proteins (MS2, PP7) and RNA stem loops, we are able to fluorescently label the intron and exon of a β-globin reporter gene in human cells. This approach allows one to measure the kinetics of transcription, splicing and release in both fixed and living cells using a tractable, genetically encoded assay in a stable cell line. We tested this reagent in a targeted screen of molecules that target chromatin readers and writers and identified three compounds that slow transcription elongation without changing transcription initiation.
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Affiliation(s)
- Christopher R Day
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Huimin Chen
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Antoine Coulon
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Jordan L Meier
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States.
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32
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Becerra S, Andrés-León E, Prieto-Sánchez S, Hernández-Munain C, Suñé C. Prp40 and early events in splice site definition. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 7:17-32. [PMID: 26494226 DOI: 10.1002/wrna.1312] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/18/2015] [Accepted: 09/22/2015] [Indexed: 12/14/2022]
Abstract
The alternative splicing (AS) of precursor messenger RNA (pre-mRNA) is a tightly regulated process through which introns are removed to leave the resulting exons in the mRNA appropriately aligned and ligated. The AS of pre-mRNA is a key mechanism for increasing the complexity of proteins encoded in the genome. In humans, more than 90% of genes undergo AS, underscoring the importance of this process in RNA biogenesis. As such, AS misregulation underlies multiple human diseases. The splicing reaction is catalyzed by the spliceosome, a highly dynamic complex that assembles at or near the intron/exon boundaries and undergoes sequential conformational and compositional changes during splicing. The initial recognition of splice sites defines the exons that are going to be removed, which is a critical step in the highly regulated splicing process. Although the available lines of evidence are increasing, the molecular mechanisms governing AS, including the initial interactions occurring at intron/exon boundaries, and the factors that modulate these critical connections by functioning as a scaffold for active-site RNAs or proteins, remain poorly understood. In this review, we summarize the major hallmarks of the initial steps in the splicing process and the role of auxiliary factors that contribute to the assembly of the spliceosomal complex. We also discuss the role of the essential yeast Prp40 protein and its mammalian homologs in the specificity of this pre-mRNA processing event. In addition, we provide the first exhaustive phylogenetic analysis of the molecular evolution of Prp40 family members. WIREs RNA 2016, 7:17-32. doi: 10.1002/wrna.1312 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Soraya Becerra
- Department of Molecular Biology, Instituto de Parasitología y Biomedicina "López Neyra", Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada 18016, Spain
| | - Eduardo Andrés-León
- Bioinformatics Unit, Instituto de Parasitología y Biomedicina "López Neyra", Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada 18016, Spain
| | - Silvia Prieto-Sánchez
- Department of Molecular Biology, Instituto de Parasitología y Biomedicina "López Neyra", Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada 18016, Spain
| | - Cristina Hernández-Munain
- Department of Cell Biology and Immunology, Instituto de Parasitología y Biomedicina "López Neyra", Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada 18016, Spain
| | - Carlos Suñé
- Department of Molecular Biology, Instituto de Parasitología y Biomedicina "López Neyra", Consejo Superior de Investigaciones Científicas (IPBLN-CSIC), PTS Granada 18016, Spain
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33
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Barjaktarovic Z, Kempf SJ, Sriharshan A, Merl-Pham J, Atkinson MJ, Tapio S. Ionizing radiation induces immediate protein acetylation changes in human cardiac microvascular endothelial cells. JOURNAL OF RADIATION RESEARCH 2015; 56:623-32. [PMID: 25840449 PMCID: PMC4497387 DOI: 10.1093/jrr/rrv014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/21/2015] [Accepted: 02/16/2015] [Indexed: 05/20/2023]
Abstract
Reversible lysine acetylation is a highly regulated post-translational protein modification that is known to regulate several signaling pathways. However, little is known about the radiation-induced changes in the acetylome. In this study, we analyzed the acute post-translational acetylation changes in primary human cardiac microvascular endothelial cells 4 h after a gamma radiation dose of 2 Gy. The acetylated peptides were enriched using anti-acetyl conjugated agarose beads. A total of 54 proteins were found to be altered in their acetylation status, 23 of which were deacetylated and 31 acetylated. Pathway analyses showed three protein categories particularly affected by radiation-induced changes in the acetylation status: the proteins involved in the translation process, the proteins of stress response, and mitochondrial proteins. The activation of the canonical and non-canonical Wnt signaling pathways affecting actin cytoskeleton signaling and cell cycle progression was predicted. The protein expression levels of two nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases, sirtuin 1 and sirtuin 3, were significantly but transiently upregulated 4 but not 24 h after irradiation. The status of the p53 protein, a target of sirtuin 1, was found to be rapidly stabilized by acetylation after radiation exposure. These findings indicate that post-translational modification of proteins by acetylation and deacetylation is essentially affecting the radiation response of the endothelium.
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Affiliation(s)
- Zarko Barjaktarovic
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | - Stefan J Kempf
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | | | - Juliane Merl-Pham
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | - Michael J Atkinson
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
| | - Soile Tapio
- Helmholtz Zentrum München, Ingolstädter Landstraße 1, Neuherberg 85764, Germany
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34
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Koumbadinga GA, Mahmood N, Lei L, Kan Y, Cao W, Lobo VG, Yao X, Zhang S, Xie J. Increased stability of heterogeneous ribonucleoproteins by a deacetylase inhibitor. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:1095-103. [PMID: 25959059 DOI: 10.1016/j.bbagrm.2015.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/27/2015] [Accepted: 05/01/2015] [Indexed: 11/15/2022]
Abstract
Splicing factors are often influenced by various signaling pathways, contributing to the dynamic changes of protein isoforms in cells. Heterogeneous ribonucleoproteins (hnRNPs) regulate many steps of RNA metabolism including pre-mRNA splicing but their control by cell signaling particularly through acetylation and ubiquitination pathways remains largely unknown. Here we show that TSA, a deacetylase inhibitor, reduced the ratio of Bcl-x splice variants Bcl-xL/xS in MDA-MB-231 breast cancer cells. This TSA effect was independent of TGFβ1; however, only in the presence of TGFβ1 was TSA able to change the splicing regulators hnRNP F/H by slightly reducing their mRNA transcripts but strongly preventing protein degradation. The latter was also efficiently prevented by lactacystin, a proteasome inhibitor, suggesting their protein stability control by both acetylation and ubiquitination pathways. Three lysines K87, K98 and K224 of hnRNP F are potential targets of the mutually exclusive acetylation or ubiquitination (K(Ac/Ub)) in the protein modification database PhosphoSitePlus. Mutating each of them but not a control non-K(Ac/Ub) (K68) specifically abolished the TSA enhancement of protein stability. Moreover, mutating K98 (K98R) and K224 (K224R) also abolished the TSA regulation of alternative splicing of a Bcl-x mini-gene. Furthermore, about 86% (30 of 35) of the multi-functional hnRNP proteins in the database contain lysines that are potential sites for acetylation/ubiquitination. We demonstrate that the degradation of three of them (A1, I and L) are also prevented by TSA. Thus, the deacetylase inhibitor TSA enhances hnRNP F stability through the K(Ac/Ub) lysines, with some of them essential for its regulation of alternative splicing. Such a regulation of protein stability is perhaps common for a group of hnRNPs and RNA metabolism.
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Affiliation(s)
- Geremy A Koumbadinga
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Niaz Mahmood
- Biochemistry & Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Lei Lei
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Yunchao Kan
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; Nanyang Normal University, Nanyang, Henan, PR China
| | - Wenguang Cao
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Vincent G Lobo
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Xiaojian Yao
- Department of Medical Microbiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Shetuan Zhang
- Department of Biomedical and Molecular Sciences, Queens University, Kingston, ON, Canada
| | - Jiuyong Xie
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; Biochemistry & Medical Genetics, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
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35
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Nancy MM, Nora RM, Rebeca MC. Peptidic tools applied to redirect alternative splicing events. Peptides 2015; 67:1-11. [PMID: 25748022 DOI: 10.1016/j.peptides.2015.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 02/05/2015] [Accepted: 02/26/2015] [Indexed: 01/25/2023]
Abstract
Peptides are versatile and attractive biomolecules that can be applied to modulate genetic mechanisms like alternative splicing. In this process, a single transcript yields different mature RNAs leading to the production of protein isoforms with diverse or even antagonistic functions. During splicing events, errors can be caused either by mutations present in the genome or by defects or imbalances in regulatory protein factors. In any case, defects in alternative splicing have been related to several genetic diseases including muscular dystrophy, Alzheimer's disease and cancer from almost every origin. One of the most effective approaches to redirect alternative splicing events has been to attach cell-penetrating peptides to oligonucleotides that can modulate a single splicing event and restore correct gene expression. Here, we summarize how natural existing and bioengineered peptides have been applied over the last few years to regulate alternative splicing and genetic expression. Under different genetic and cellular backgrounds, peptides have been shown to function as potent vehicles for splice correction, and their therapeutic benefits have reached clinical trials and patenting stages, emphasizing the use of regulatory peptides as an exciting therapeutic tool for the treatment of different genetic diseases.
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Affiliation(s)
- Martínez-Montiel Nancy
- Laboratorio de Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Mexico
| | - Rosas-Murrieta Nora
- Laboratorio de Bioquímica y Biología Molecular, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Mexico
| | - Martínez-Contreras Rebeca
- Laboratorio de Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Mexico.
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36
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Kfir N, Lev-Maor G, Glaich O, Alajem A, Datta A, Sze S, Meshorer E, Ast G. SF3B1 Association with Chromatin Determines Splicing Outcomes. Cell Rep 2015; 11:618-29. [DOI: 10.1016/j.celrep.2015.03.048] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 02/25/2015] [Accepted: 03/22/2015] [Indexed: 01/08/2023] Open
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37
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Chakrabarty K, Defrenza I, Denora N, Drioli S, Forzato C, Franco M, Lentini G, Nitti P, Pitacco G. Enzymatic resolution of α-methyleneparaconic acids and evaluation of their biological activity. Chirality 2015; 27:239-46. [PMID: 25581906 DOI: 10.1002/chir.22419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/31/2014] [Accepted: 11/18/2014] [Indexed: 12/12/2022]
Abstract
Both enantiomers of three biologically relevant paraconic acids-MB-3, methylenolactocin, and C75-were obtained with enantioselectivities up to 99% by kinetic enzymatic resolutions. Good enantiomeric excesses were obtained for MB-3 and methylenolactocin, using α-chymotrypsin and aminoacylase as enantiocomplementary enzymes, while C75 was resolved with aminoacylase. They all were evaluated for their antiproliferative, antibacterial, and antifungal activities, showing weak effects and practically no difference between enantiomers in each case. At high concentrations (16-64 µg/mL), (-)- C75 acted as an antimicrobial agent against Gram-positive bacteria.
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38
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Pawellek A, McElroy S, Samatov T, Mitchell L, Woodland A, Ryder U, Gray D, Lührmann R, Lamond AI. Identification of small molecule inhibitors of pre-mRNA splicing. J Biol Chem 2014; 289:34683-98. [PMID: 25281741 PMCID: PMC4263873 DOI: 10.1074/jbc.m114.590976] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/02/2014] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic pre-mRNA splicing is an essential step in gene expression for all genes that contain introns. In contrast to transcription and translation, few well characterized chemical inhibitors are available with which to dissect the splicing process, particularly in cells. Therefore, the identification of specific small molecules that either inhibit or modify pre-mRNA splicing would be valuable for research and potentially also for therapeutic applications. We have screened a highly curated library of 71,504 drug-like small molecules using a high throughput in vitro splicing assay. This identified 10 new compounds that both inhibit pre-mRNA splicing in vitro and modify splicing of endogenous pre-mRNA in cells. One of these splicing modulators, DDD00107587 (termed "madrasin," i.e. 2-((7methoxy-4-methylquinazolin-2-yl)amino)-5,6-dimethylpyrimidin-4(3H)-one RNAsplicing inhibitor), was studied in more detail. Madrasin interferes with the early stages of spliceosome assembly and stalls spliceosome assembly at the A complex. Madrasin is cytotoxic at higher concentrations, although at lower concentrations it induces cell cycle arrest, promotes a specific reorganization of subnuclear protein localization, and modulates splicing of multiple pre-mRNAs in both HeLa and HEK293 cells.
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Affiliation(s)
| | - Stuart McElroy
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Timur Samatov
- the Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Lee Mitchell
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Andrew Woodland
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Ursula Ryder
- From the Centre of Gene Regulation and Expression and
| | - David Gray
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Reinhard Lührmann
- the Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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Naryshkin NA, Weetall M, Dakka A, Narasimhan J, Zhao X, Feng Z, Ling KKY, Karp GM, Qi H, Woll MG, Chen G, Zhang N, Gabbeta V, Vazirani P, Bhattacharyya A, Furia B, Risher N, Sheedy J, Kong R, Ma J, Turpoff A, Lee CS, Zhang X, Moon YC, Trifillis P, Welch EM, Colacino JM, Babiak J, Almstead NG, Peltz SW, Eng LA, Chen KS, Mull JL, Lynes MS, Rubin LL, Fontoura P, Santarelli L, Haehnke D, McCarthy KD, Schmucki R, Ebeling M, Sivaramakrishnan M, Ko CP, Paushkin SV, Ratni H, Gerlach I, Ghosh A, Metzger F. Motor neuron disease. SMN2 splicing modifiers improve motor function and longevity in mice with spinal muscular atrophy. Science 2014; 345:688-93. [PMID: 25104390 DOI: 10.1126/science.1250127] [Citation(s) in RCA: 359] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Spinal muscular atrophy (SMA) is a genetic disease caused by mutation or deletion of the survival of motor neuron 1 (SMN1) gene. A paralogous gene in humans, SMN2, produces low, insufficient levels of functional SMN protein due to alternative splicing that truncates the transcript. The decreased levels of SMN protein lead to progressive neuromuscular degeneration and high rates of mortality. Through chemical screening and optimization, we identified orally available small molecules that shift the balance of SMN2 splicing toward the production of full-length SMN2 messenger RNA with high selectivity. Administration of these compounds to Δ7 mice, a model of severe SMA, led to an increase in SMN protein levels, improvement of motor function, and protection of the neuromuscular circuit. These compounds also extended the life span of the mice. Selective SMN2 splicing modifiers may have therapeutic potential for patients with SMA.
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Affiliation(s)
| | - Marla Weetall
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Amal Dakka
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jana Narasimhan
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Xin Zhao
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Zhihua Feng
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Karen K Y Ling
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Gary M Karp
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Hongyan Qi
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Matthew G Woll
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Guangming Chen
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Nanjing Zhang
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Priya Vazirani
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Bansri Furia
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Nicole Risher
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Josephine Sheedy
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Ronald Kong
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Jiyuan Ma
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Anthony Turpoff
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Chang-Sun Lee
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Xiaoyan Zhang
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Young-Choon Moon
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | | | - Ellen M Welch
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Joseph M Colacino
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - John Babiak
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Neil G Almstead
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA
| | - Stuart W Peltz
- PTC Therapeutics, 100 Corporate Court, South Plainfield, NJ 07080, USA.
| | - Loren A Eng
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Karen S Chen
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Jesse L Mull
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Maureen S Lynes
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Lee L Rubin
- Department of Stem Cell and Regenerative Biology and the Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA
| | - Paulo Fontoura
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Luca Santarelli
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Daniel Haehnke
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | | | - Roland Schmucki
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Martin Ebeling
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Manaswini Sivaramakrishnan
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Chien-Ping Ko
- Section of Neurobiology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Sergey V Paushkin
- SMA Foundation, 888 Seventh Avenue, Suite 400, New York, NY 10019, USA
| | - Hasane Ratni
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Irene Gerlach
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Anirvan Ghosh
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Friedrich Metzger
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland.
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40
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Galat A, Thai R. Rapamycin-binding FKBP25 associates with diverse proteins that form large intracellular entities. Biochem Biophys Res Commun 2014; 450:1255-60. [DOI: 10.1016/j.bbrc.2014.06.105] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/22/2014] [Indexed: 11/25/2022]
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41
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Maita H, Tomita K, Ariga H. A split luciferase-based reporter for detection of a cellular macromolecular complex. Anal Biochem 2014; 452:1-9. [PMID: 24503441 DOI: 10.1016/j.ab.2014.01.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 01/21/2014] [Accepted: 01/24/2014] [Indexed: 11/16/2022]
Abstract
The spliceosome is a highly dynamic macromolecular ribonucleoprotein (RNP) machine that catalyzes pre-mRNA splicing by assembling U1, U2, U4, U5, and U6 small nuclear RNPs (snRNPs). To process large numbers of introns with a limited number of snRNPs, synthesis and recycling of snRNPs must be maintained within an appropriate range to avoid their shortage. However, the mechanism that maintains cellular snRNP levels is unknown. Molecules that modulate cellular snRNP levels may help to define this mechanism but are not available. Therefore, the goal of the current study was to develop a reporter for snRNP levels using split luciferase based on proteomic analysis of snRNPs. We constructed an expression library of a luciferase fragment fused to core components of U5 snRNP and used it to isolate pre-mRNA processing factor 6 (PRPF6) and small nuclear ribonucleoprotein 40 kDa (U5-40K) that specifically reconstitute luciferase activity in the U5 snRNP complex. Here we show that this reporter detects the effects of small molecules on the levels of the U5 snRNP reporter protein complex. Our approach provides an alternative assay to discover small molecules targeting a macromolecular complex when the structure of the complex is not precisely identified.
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Affiliation(s)
- Hiroshi Maita
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan.
| | - Kenji Tomita
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan
| | - Hiroyoshi Ariga
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan
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42
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Inoue A, Yamamoto N, Kimura M, Nishio K, Yamane H, Nakajima K. RBM10 regulates alternative splicing. FEBS Lett 2014; 588:942-7. [PMID: 24530524 DOI: 10.1016/j.febslet.2014.01.052] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 12/02/2013] [Accepted: 01/23/2014] [Indexed: 12/30/2022]
Abstract
RBM10, originally called S1-1, is a nuclear RNA-binding protein with domains characteristic of RNA processing proteins. It has been reported that RBM10 constitutes spliceosome complexes and that RBM5, a close homologue of RBM10, regulates alternative splicing of apoptosis-related genes, Fas and cFLIP. In this study, we examined whether RBM10 has a regulatory function in splicing similar to RBM5, and determined that it indeed regulates alternative splicing of Fas and Bcl-x genes. RBM10 promotes exon skipping of Fas pre-mRNA as well as selection of an internal 5'-splice site in Bcl-x pre-mRNA. We propose a consensus RBM10-binding sequence at 5'-splice sites of target exons and a mechanistic model of RBM10 action in the alternative splicing.
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Affiliation(s)
- Akira Inoue
- Department of Immunology, Osaka City University Graduate School of Medicine, Japan; Department of Otolaryngology, Osaka City University Graduate School of Medicine, Japan.
| | - Naoki Yamamoto
- Department of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Japan
| | - Masatsugu Kimura
- Department of Radioisotope Center, Osaka City University Graduate School of Medicine, Japan
| | - Koji Nishio
- Department of Anatomy and Cell Biology, Graduate School of Medicine, Nagoya University, Japan
| | - Hideo Yamane
- Department of Otolaryngology, Osaka City University Graduate School of Medicine, Japan
| | - Koichi Nakajima
- Department of Immunology, Osaka City University Graduate School of Medicine, Japan
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43
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Klironomos FD, de Meaux J, Berg J. Can we always sweep the details of RNA-processing under the carpet? Phys Biol 2013; 10:056007. [PMID: 24091933 DOI: 10.1088/1478-3975/10/5/056007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
RNA molecules follow a succession of enzyme-mediated processing steps from transcription to maturation. The participating enzymes, for example the spliceosome for mRNAs and Drosha and Dicer for microRNAs, are also produced in the cell and their copy-numbers fluctuate over time. Enzyme copy-number changes affect the processing rate of the substrate molecules; high enzyme numbers increase the processing rate, while low enzyme numbers decrease it. We study different RNA-processing cascades where enzyme copy-numbers are either fixed or fluctuate. We find that for the fixed enzyme copy-numbers, the substrates at steady-state are Poisson-distributed, and the whole RNA cascade dynamics can be understood as a single birth-death process of the mature RNA product. In this case, solely fluctuations in the timing of RNA processing lead to variation in the number of RNA molecules. However, we show analytically and numerically that when enzyme copy-numbers fluctuate, the strength of RNA fluctuations increases linearly with the RNA transcription rate. This linear effect becomes stronger as the speed of enzyme dynamics decreases relative to the speed of RNA dynamics. Interestingly, we find that under certain conditions, the RNA cascade can reduce the strength of fluctuations in the expression level of the mature RNA product. Finally, by investigating the effects of processing polymorphisms, we show that it is possible for the effects of transcriptional polymorphisms to be enhanced, reduced or even reversed. Our results provide a framework to understand the dynamics of RNA processing.
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44
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Isaji Y, Murata M, Takaguchi N, Mukai T, Tajima Y, Imai H, Yamada M. Valproic acid treatment from the 4-cell stage improves Oct4 expression and nuclear distribution of histone H3K27me3 in mouse cloned blastocysts. J Reprod Dev 2013; 59:196-204. [PMID: 23337102 PMCID: PMC3934201 DOI: 10.1262/jrd.2012-156] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We examined effects of treatment with valproic acid (0, 0.2, 1 or 2 mM, VPA), an
inhibitor of class I and IIa histone deacetylases (HDACs), of mouse somatic cell nuclear
transfer (SCNT) embryos for 24 h from 48 h (4-cell stage), 24 h (2-cell stage) or
immediately after oocyte activation on blastocyst formation rates and qualities of the
resultant blastocysts. Blastocyst formation rates (33.4–37.0%) were not improved by VPA
treatments compared with the untreated control (35.1–36.4%). However, immunofluorescence
staining revealed that Oct4 expression levels, evaluated from percentages of embryos
expressing Oct4 strongly and having more than 10 Oct4-positive cells, in blastocysts from
SCNT embryos treated with 1 mM VPA for 24 h from the 4-cell stage (VPA-4C) were highest
among all the groups and that the proportion of cells with a normal nuclear distribution
of histone H3 trimethylated at lysine 27 (H3K27me3), a marker of the state of X-chromosome
inactivation, significantly increased in the VPA-4C group (36.6%) compared with the
control group (12.4%, P<0.05). Treatments with scriptaid and sodium butyrate,
inhibitors of class I and IIa/b HDACs, for 24 h from the 4-cell stage also had beneficial
effects on SCNT blastocysts. These findings indicate that treatment with 1 mM VPA from the
4-cell stage improves the Oct4 expression and nuclear distribution of H3K27me3 in mouse
SCNT blastocysts and suggest that the inhibition of class I and IIa HDACs from the 4-cell
stage plays an important role in these effects.
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Affiliation(s)
- Yuuki Isaji
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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45
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Khan DH, Jahan S, Davie JR. Pre-mRNA splicing: role of epigenetics and implications in disease. Adv Biol Regul 2012; 52:377-388. [PMID: 22884031 DOI: 10.1016/j.jbior.2012.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 04/23/2012] [Indexed: 06/01/2023]
Abstract
Epigenetics refer to a variety of processes that have long-term effects on gene expression programs without changes in DNA sequence. Key players in epigenetic control are histone modifications and DNA methylation which, in concert with chromatin remodeling complexes, nuclear architecture and microRNAs, define the chromatin structure of a gene and its transcriptional activity. There is a growing awareness that histone modifications and chromatin organization influence pre-mRNA splicing. Further there is emerging evidence that pre-mRNA splicing itself influences chromatin organization. In the mammalian genome around 95% of multi-exon genes generate alternatively spliced transcripts, the products of which create proteins with different functions. It is now established that several human diseases are a direct consequence of aberrant splicing events. In this review we present the interplay between epigenetic mechanisms and splicing regulation, as well as discuss recent studies on the role of histone deacetylases in splicing activities.
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Affiliation(s)
- Dilshad H Khan
- Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, R3E 3P4 Canada
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Patil V, Canzoneri JC, Samatov TR, Lührmann R, Oyelere AK. Molecular architecture of zinc chelating small molecules that inhibit spliceosome assembly at an early stage. RNA (NEW YORK, N.Y.) 2012; 18:1605-11. [PMID: 22832025 PMCID: PMC3425776 DOI: 10.1261/rna.034819.112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The removal of intervening sequences (introns) from a primary RNA transcript is catalyzed by the spliceosome, a large ribonucleoprotein complex. At the start of each splicing cycle, the spliceosome assembles anew in a sequentially ordered manner on the pre-mRNA intron to be removed. We describe here the identification of a series of naphthalen-2-yl hydroxamate compounds that inhibit pre-mRNA splicing in vitro with mid- to high-micromolar values of IC(50). These hydroxamates stall spliceosome assembly at the A complex stage. A structure-activity analysis of lead compounds revealed three pharmacophores that are essential for splicing inhibition. Specifically, a hydroxamate as a zinc-binding group and a 6-methoxynaphthalene cap group are both critical, and a linker chain comprising eight to nine methylene groups is also important, for the specific binding to the docking site of a target protein molecule and precise positioning of the zinc binding group. As we found no correlation between the inhibition patterns of known histone deacetylases on the one hand and pre-mRNA splicing on the other, we conclude that these compounds may function through the inhibition of the activities of other, at present, unknown spliceosome-associated zinc metalloprotein(s).
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Affiliation(s)
- Vishal Patil
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | - Josh C. Canzoneri
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | - Timur R. Samatov
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
- Corresponding authorsE-mail E-mail
| | - Adegboyega K. Oyelere
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
- Corresponding authorsE-mail E-mail
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47
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Jiang QT, Liu T, Ma J, Wei YM, Lu ZX, Lan XJ, Dai SF, Zheng YL. Characterization of barley Prp1 gene and its expression during seed development and under abiotic stress. Genetica 2012; 139:1283-92. [PMID: 22290495 DOI: 10.1007/s10709-012-9630-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/13/2012] [Indexed: 11/30/2022]
Abstract
The pre-mRNA processing (Prp1) gene encodes a spliceosomal protein. It was firstly identified in fission yeast and plays a regular role during spliceosome activation and cell cycle. Plant Prp1 genes have only been identified from rice, Sorghum and Arabidopsis thaliana. In this study, we reported the identification and isolation of a novel Prp1 gene from barley, and further explored its expressional pattern by using real-time quantitative RTPCR, promoter prediction and analysis of microarray data. The putative barley Prp1 protein has a similar primary structure features to those of other known Prp1 protein in this family. The results of amino acid comparison indicated that Prp1 protein of barley and other plant species has a highly conserved 30 termnal region while their 50 sequences greatly varied. The results of expressional analysis revealed that the expression level of barley Prp1 gene is always stable in different vegetative tissues, except it is up-regulated at the mid- and late stages of seed development or under the condition of cold stress. This kind of expressional pattern for barley Prp1 is also supported by our results of comparison of microarray data from barley, rice and Arabidopsis. For the molecular mechanism of its expressional pattern, we conclude that the expression of Prp1 gene may be up-regulated by the increase of pre-mRNAs and not be constitutive or ubiquitous.
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Affiliation(s)
- Qian-Tao Jiang
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China
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48
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Abstract
Proper splicing of pre-mRNA is required for protein synthesis and therefore is a fundamental cellular function. The discovery of a variety of somatic spliceosomal mutations in haematological malignancies, including myeloid neoplasms and chronic lymphocytic leukaemia has pointed to a new leukaemogenic pathway involving spliceosomal dysfunction. Theoretically, spliceosomal mutations can lead to activation of incorrect splice sites, intron retention or aberrant alternative splicing occurring in patterns generated by mutations of individual spliceosomal proteins. Such events can produce a defective balance between protein isoforms leading to functional consequences including defective regulation of proliferation and differentiation. The observed pattern of occurrence of highly specific missense mutations, coupled with the lack of nonsense mutations and deletions, implies a gain-of-function or better gain-of-dysfunction mechanism. Incorrect splicing of downstream genes, such as tumour suppressor genes, may result in haploinsufficient expression through nonsense-mediated mRNA decay. Thus, spliceosomal mutations may, depending on the pattern of affected proteins, lead to similar functional effects on tumour suppressor genes as chromosomal deletions, epigenetic silencing or inactivating/hypomorphic mutations. The prognostic value of the most common mutations and their phenotypic association in the clinical setting is currently under investigation. It is likely that spliceosomal mutations may indicate sensitivity to spliceosome inhibitors applied in the form of a synthetic lethal approach. This review discusses the most current aspects of spliceosomal research in the context of haematological malignancies.
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Affiliation(s)
- Jaroslaw P Maciejewski
- Department of Translational Hematology and Oncology Research, Taussig Cancer Center, Cleveland, OH, USA
| | - Richard A Padgett
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
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49
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Alternative splicing interference by xenobiotics. Toxicology 2012; 296:1-12. [DOI: 10.1016/j.tox.2012.01.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/21/2012] [Accepted: 01/23/2012] [Indexed: 12/21/2022]
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50
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Hodson MJ, Hudson AJ, Cherny D, Eperon IC. The transition in spliceosome assembly from complex E to complex A purges surplus U1 snRNPs from alternative splice sites. Nucleic Acids Res 2012; 40:6850-62. [PMID: 22505580 PMCID: PMC3413131 DOI: 10.1093/nar/gks322] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Spliceosomes are assembled in stages. The first stage forms complex E, which is characterized by the presence of U1 snRNPs base-paired to the 5′ splice site, components recognizing the 3′ splice site and proteins thought to connect them. The splice sites are held in close proximity and the pre-mRNA is committed to splicing. Despite this, the sites for splicing appear not to be fixed until the next complex (A) forms. We have investigated the reasons why 5′ splice sites are not fixed in complex E, using single molecule methods to determine the stoichiometry of U1 snRNPs bound to pre-mRNA with one or two strong 5′ splice sites. In complex E most transcripts with two alternative 5′ splice sites were bound by two U1 snRNPs. However, the surplus U1 snRNPs were displaced during complex A formation in an ATP-dependent process requiring an intact 3′ splice site. This process leaves only one U1 snRNP per complex A, regardless of the number of potential sites. We propose a mechanism for selection of the 5′ splice site. Our results show that constitutive splicing components need not be present in a fixed stoichiometry in a splicing complex.
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Affiliation(s)
- Mark J Hodson
- Department of Biochemistry, University of Leicester, Leicester LE1 9HN, UK
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