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Chen JL, Leeder WM, Morais P, Adachi H, Yu YT. Pseudouridylation-mediated gene expression modulation. Biochem J 2024; 481:1-16. [PMID: 38174858 DOI: 10.1042/bcj20230096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
RNA-guided pseudouridylation, a widespread post-transcriptional RNA modification, has recently gained recognition for its role in cellular processes such as pre-mRNA splicing and the modulation of premature termination codon (PTC) readthrough. This review provides insights into its mechanisms, functions, and potential therapeutic applications. It examines the mechanisms governing RNA-guided pseudouridylation, emphasizing the roles of guide RNAs and pseudouridine synthases in catalyzing uridine-to-pseudouridine conversion. A key focus is the impact of RNA-guided pseudouridylation of U2 small nuclear RNA on pre-mRNA splicing, encompassing its influence on branch site recognition and spliceosome assembly. Additionally, the review discusses the emerging role of RNA-guided pseudouridylation in regulating PTC readthrough, impacting translation termination and genetic disorders. Finally, it explores the therapeutic potential of pseudouridine modifications, offering insights into potential treatments for genetic diseases and cancer and the development of mRNA vaccine.
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Affiliation(s)
- Jonathan L Chen
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
| | | | | | - Hironori Adachi
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
| | - Yi-Tao Yu
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY, U.S.A
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2
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Al-Ali AK, Al-Rubaish AM, Alali RA, Almansori MS, Al-Jumaan MA, Alshehri AM, Al-Madan MS, Vatte C, Cherlin T, Young S, Verma SS, Morahan G, Koeleman BPC, Keating BJ. Uncovering myocardial infarction genetic signatures using GWAS exploration in Saudi and European cohorts. Sci Rep 2023; 13:21866. [PMID: 38072966 PMCID: PMC10711020 DOI: 10.1038/s41598-023-49105-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/04/2023] [Indexed: 12/18/2023] Open
Abstract
Genome-wide association studies (GWAS) have yielded significant insights into the genetic architecture of myocardial infarction (MI), although studies in non-European populations are still lacking. Saudi Arabian cohorts offer an opportunity to discover novel genetic variants impacting disease risk due to a high rate of consanguinity. Genome-wide genotyping (GWG), imputation and GWAS followed by meta-analysis were performed based on two independent Saudi Arabian studies comprising 3950 MI patients and 2324 non-MI controls. Meta-analyses were then performed with these two Saudi MI studies and the CardioGRAMplusC4D and UK BioBank GWAS as controls. Meta-analyses of the two Saudi MI studies resulted in 17 SNPs with genome-wide significance. Meta-analyses of all 4 studies revealed 66 loci with genome-wide significance levels of p < 5 × 10-8. All of these variants, except rs2764203, have previously been reported as MI-associated loci or to have high linkage disequilibrium with known loci. One SNP association in Shisa family member 5 (SHISA5) (rs11707229) was evident at a much higher frequency in the Saudi MI populations (> 12% MAF). In conclusion, our results replicated many MI associations, whereas in Saudi-only GWAS (meta-analyses), several new loci were implicated that require future validation and functional analyses.
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Affiliation(s)
- Amein K Al-Ali
- Department of Clinical Biochemistry, College of Medicine, Imam Abdulrahman bin Faisal University, 3144, Dammam, Saudi Arabia.
| | - Abdullah M Al-Rubaish
- Department of Internal Medicine, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
| | - Rudaynah A Alali
- Department of Internal Medicine, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
| | - Mohammed S Almansori
- Department of Internal Medicine, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
| | - Mohammed A Al-Jumaan
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
- Department of Emergency Medicine, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
| | - Abdullah M Alshehri
- Department of Internal Medicine, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
| | - Mohammed S Al-Madan
- College of Medicine, Imam Abdulrahman bin Faisal University, 31441, Dammam, Saudi Arabia
- Department of Pediatrics, King Fahd Hospital of the University, 34445, Al-Khobar, Saudi Arabia
| | - ChittiBabu Vatte
- Department of Clinical Biochemistry, College of Medicine, Imam Abdulrahman bin Faisal University, 3144, Dammam, Saudi Arabia
| | - Tess Cherlin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sylvia Young
- Centre for Diabetes Research, Harry Perkins Institute of Medical Research, University of Western Australia, Nedlands, 6009, Australia
| | - Shefali S Verma
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grant Morahan
- Centre for Diabetes Research, Harry Perkins Institute of Medical Research, University of Western Australia, Nedlands, 6009, Australia
| | - Bobby P C Koeleman
- Department of Genetics, University Medical Center Utrecht, Utrecht, 85500/3508 GA, The Netherlands
| | - Brendan J Keating
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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3
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Cai J, Zhou M, Xu J. N6-methyladenosine (m6A) RNA methylation regulator SNRPC is a prognostic biomarker and is correlated with immunotherapy in hepatocellular carcinoma. World J Surg Oncol 2021; 19:241. [PMID: 34389000 PMCID: PMC8364031 DOI: 10.1186/s12957-021-02354-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 08/01/2021] [Indexed: 12/26/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, and due to its complex pathogenic factors, its prognosis is poor. N6-methyladenosine (m6A) RNA methylation plays an important role in the tumorigenesis, progression, and prognosis of many tumors. The m6A RNA methylation regulator small nuclear ribonucleoprotein polypeptide C (SNRPC), which encodes one of the specific protein components of the U1 small nuclear ribonucleoprotein (snRNP) particle, has been proven to be related to the prognosis of patients with HCC. However, the effect of SNRPC on the tumor microenvironment and immunotherapy in HCC remains unclear. Case presentation The HCC RNA-seq profiles in The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases, including 421 LIHC and 440 LIRI-JP samples, respectively, were used in this study. Both the expression of SNRPC in HCC was upregulated in the TCGA and ICGC databases compared to normal tissues. Next, the expression of SNRPC was validated as a risk factor for prognosis by Kaplan-Meier analysis and employed to establish a nomogram with T pathologic stage. By gene set variation (GSVA) analysis and gene set enrichment (GSEA) analysis, we found that SNRPC was mainly related to protein metabolism and the immune process. Furthermore, the estimation of stromal and immune cells in malignant tumor tissues using expression (ESTIMATE), microenvironment cell population counter (MCP-counter), and single sample GSEA (ssGSEA) algorithms revealed that the high-SNRPC group had a lower stromal score, lower abundance of endothelial cells and fibroblasts, and lower immune infiltration. Ultimately, a tumor immune dysfunction and exclusion (TIDE) analysis revealed that patients in the low-SNRPC group may be more sensitive to immune checkpoint inhibitor therapy. Conclusion SNRPC could serve as a promising prognostic and immunotherapeutic marker in HCC and might contribute to new directions and strategies for HCC treatment.
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Affiliation(s)
- Jihao Cai
- The Second Clinical Medical College of Nanchang University, Nanchang, China.
| | - Minglei Zhou
- School of Computer Science and Technology of Shandong University of Technology, Zibo, China
| | - Jianxin Xu
- The Second Clinical Medical College of Nanchang University, Nanchang, China
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4
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Zhang Y, Qiu J, Zuo D, Yuan Y, Qiu Y, Qiao L, He W, Li B, Yuan Y. SNRPC promotes hepatocellular carcinoma cell motility by inducing epithelial-mesenchymal transition. FEBS Open Bio 2021; 11:1757-1770. [PMID: 33934562 PMCID: PMC8167856 DOI: 10.1002/2211-5463.13175] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/15/2021] [Accepted: 04/23/2021] [Indexed: 12/18/2022] Open
Abstract
The therapeutic outcome of hepatocellular carcinoma (HCC) remains unsatisfactory because of poor response and acquired drug resistance. To better elucidate the molecular mechanisms of HCC, here we used three Gene Expression Omnibus datasets to identify potential oncogenes, and thereby identified small nuclear ribonucleoprotein polypeptide C (SNRPC). We report that SNRPC is highly up‐regulated in HCC tissues as determined using immunohistochemistry assays of samples from a cohort of 224 patients with HCC, and overexpression of SNRPC was correlated with multiple tumors, advanced stage, and poor outcome. Kaplan–Meier analysis confirmed that patients with high SNRPC expression exhibited shorter survival in four independent HCC cohorts (all P < 0.05). Furthermore, SNRPC mutations are significantly more frequent in HCC tissues than in normal liver tissues and are an early event in the development of HCC. Functional network analysis suggested that SNRPC is linked to the regulation of ribosome, spliceosome, and proteasome signaling. Subsequently, gain‐ and loss‐of‐function assays showed that SNRPC promotes the motility and epithelial–mesenchymal transition of HCC cells in vitro. SNRPC expression was negatively correlated with the infiltration of CD4+ T cells, macrophage cells, and neutrophil cells (all P < 0.05), as determined by analyzing the TIMER (Tumor IMmune Estimation Resource) database. In conclusion, our findings suggest that SNRPC has a potential role in epithelial–mesenchymal transition and motility in HCC.
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Affiliation(s)
- Yuanping Zhang
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Jiliang Qiu
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Dinglan Zuo
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yichuan Yuan
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yuxiong Qiu
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Liang Qiao
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Wei He
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Binkui Li
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yunfei Yuan
- Department of Liver Surgery, Sun Yat-sen University Cancer Center, Guangzhou, China.,State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.,Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
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5
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Nguyen H, Das U, Wang B, Xie J. The matrices and constraints of GT/AG splice sites of more than 1000 species/lineages. Gene 2018; 660:92-101. [PMID: 29588184 DOI: 10.1016/j.gene.2018.03.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 03/08/2018] [Accepted: 03/12/2018] [Indexed: 12/11/2022]
Abstract
To provide a resource for the splice sites (SS) of different species, we calculated the matrices of nucleotide compositions of about 38 million splice sites from >1000 species/lineages. The matrices are enriched of aGGTAAGT (5'SS) or (Y)6N(C/t)AG(g/a)t (3'SS) overall; however, they are quite diverse among hundreds of species. The diverse matrices remain prominent even under sequence selection pressures, suggesting the existence of diverse constraints as well as U snRNAs and other spliceosomal factors and/or their interactions with the splice sites. Using an algorithm to measure and compare the splice site constraints across all species, we demonstrate their distinct differences quantitatively. As an example of the resource's application to answering specific questions, we confirm that high constraints of particular positions are significantly associated with transcriptome-wide, increased occurrences of alternative splicing when uncommon nucleotides are present. More interestingly, the abundance of alternative splicing in 16 species correlates with the average constraint index of splice sites in a bell curve. This resource will allow users to assess specific sequences/splice sites against the consensus of every Ensembl-annotated species, and to explore the evolutionary changes or relationship to alternative splicing and transcriptome diversity. Web-search or update features are also included.
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Affiliation(s)
- Hai Nguyen
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - Urmi Das
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Benjamin Wang
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; University of Illinois Urbana-Champaign, IL, USA
| | - Jiuyong Xie
- Department of Physiology & Pathophysiology, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
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6
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Tan J, Ho JXJ, Zhong Z, Luo S, Chen G, Roca X. Noncanonical registers and base pairs in human 5' splice-site selection. Nucleic Acids Res 2016; 44:3908-21. [PMID: 26969736 PMCID: PMC4856993 DOI: 10.1093/nar/gkw163] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/27/2022] Open
Abstract
Accurate recognition of splice sites is essential for pre-messenger RNA splicing. Mammalian 5' splice sites are mainly recognized by canonical base-pairing to the 5' end of U1 small nuclear RNA, yet we described multiple noncanonical base-pairing registers by shifting base-pair positions or allowing one-nucleotide bulges. By systematic mutational and suppressor U1 analyses, we prove three registers involving asymmetric loops and show that two-nucleotide bulges but not longer can form in this context. Importantly, we established that a noncanonical uridine-pseudouridine interaction in the 5' splice site/U1 helix contributes to the recognition of certain 5' splice sites. Thermal melting experiments support the formation of noncanonical registers and uridine-pseudouridine interactions. Overall, we experimentally validated or discarded the majority of predicted noncanonical registers, to derive a list of 5' splice sites using such alternative mechanisms that is much different from the original. This study allows not only the mechanistic understanding of the recognition of a wide diversity of mammalian 5' splice sites, but also the future development of better splice-site scoring methods that reliably predict the effects of disease-causing mutations at these sequences.
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Affiliation(s)
- Jiazi Tan
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Jia Xin Jessie Ho
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Zhensheng Zhong
- Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Shufang Luo
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Gang Chen
- Division of Chemistry & Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
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7
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Konarska MM, Vilardell J, Query CC. Repositioning of the Reaction Intermediate within the Catalytic Center of the Spliceosome. Mol Cell 2006; 21:543-53. [PMID: 16483935 DOI: 10.1016/j.molcel.2006.01.017] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 12/02/2005] [Accepted: 01/05/2006] [Indexed: 11/21/2022]
Abstract
Conformational change within the spliceosome is required between the first catalytic step of pre-mRNA splicing, when the branch site attacks the 5' splice site (SS), and the second step, when the 5' exon attacks the 3'SS. Little is known, however, about repositioning of the reaction substrates during this transition. Whereas the 5'SS is positioned for the first step by pairing with the invariant U6 snRNA-ACAGAG site, we demonstrate that this pairing interaction must be disrupted to allow transition to the second step. We propose that removal of the branch structure from the catalytic center is in competition with binding of the 3'SS substrate for the second step. Changes in the relative occupancy of first and second step substrates at the catalytic center alter efficiency of the two steps of splicing, allowing use of suboptimal intron sequences and thereby altering substrate selectivity.
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8
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Konarska MM, Query CC. Insights into the mechanisms of splicing: more lessons from the ribosome. Genes Dev 2005; 19:2255-60. [PMID: 16204176 DOI: 10.1101/gad.1363105] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Giles KE, Beemon KL. Retroviral splicing suppressor sequesters a 3' splice site in a 50S aberrant splicing complex. Mol Cell Biol 2005; 25:4397-405. [PMID: 15899846 PMCID: PMC1140646 DOI: 10.1128/mcb.25.11.4397-4405.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Retroviral replication requires both spliced and unspliced mRNAs. Splicing suppression of avian retroviral RNA depends in part upon a cis-acting element within the gag gene called the negative regulator of splicing (NRS). The NRS, linked to a downstream intron and exon (NRS-Ad3'), was not capable of splicing in vitro. However, a double-point mutation in the NRS pseudo-5' splice site sequence converted it into a functional 5' splice site. The wild-type (WT) NRS-Ad3' transcript assembled an approximately 50S spliceosome-like complex in vitro; its sedimentation rate was similar to that of a functional spliceosome formed on the mutant NRS-Ad3' RNA. The five major spliceosomal snRNPs were observed in both complexes by affinity selection. In addition, U11 snRNP was present only in the WT NRS-Ad3' complex. Addition of heparin to these complexes destabilized the WT NRS-Ad3' complex; it was incapable of forming a B complex on a native gel. Furthermore, the U5 snRNP protein, hPrp8, did not cross-link to the NRS pseudo-5' splice site, suggesting that the tri-snRNP complex was not properly associated with it. We propose that this aberrant, stalled spliceosome, containing U1, U2, and U11 snRNPs and a loosely associated tri-snRNP, sequesters the 3' splice site and prevents its interaction with the authentic 5' splice site upstream of the NRS.
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Affiliation(s)
- Keith E Giles
- Department of Biology, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
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Roca X, Sachidanandam R, Krainer AR. Determinants of the inherent strength of human 5' splice sites. RNA (NEW YORK, N.Y.) 2005; 11:683-98. [PMID: 15840817 PMCID: PMC1370755 DOI: 10.1261/rna.2040605] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Accepted: 02/09/2005] [Indexed: 05/24/2023]
Abstract
We previously showed that the authentic 5' splice site (5'ss) of the first exon in the human beta-globin gene is intrinsically stronger than a cryptic 5'ss located 16 nucleotides upstream. Here we examined by mutational analysis the contribution of individual 5'ss nucleotides to discrimination between these two 5'ss. Based on the in vitro splicing efficiencies of a panel of 26 wild-type and mutant substrates in two separate 5'ss competition assays, we established a hierarchy of 5'ss and grouped them into three functional subclasses: strong, intermediate, and weak. Competition between two 5'ss from different subclasses always resulted in selection of the 5'ss that belongs to the stronger subclass. Moreover, each subclass has different characteristic features. Strong and intermediate 5'ss can be distinguished by their predicted free energy of base-pairing to the U1 snRNA 5' terminus (DeltaG). Whereas the extent of splicing via the strong 5'ss correlates well with the DeltaG, this is not the case for competition between intermediate 5'ss. Weak 5'ss were used only when the competing authentic 5'ss was inactivated by mutation. These results indicate that extensive complementarity to U1 snRNA exerts a dominant effect for 5'ss selection, but in the case of competing 5'ss with similarly modest complementarity to U1, the role of other 5'ss features is more prominent. This study reveals the importance of additional submotifs present in certain 5'ss sequences, whose characterization will be critical for understanding 5'ss selection in human genes.
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Affiliation(s)
- Xavier Roca
- Cold Spring Harbor Laboratory, PO Box 100, Cold Spring Harbor, NY 11724, USA
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11
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Abstract
Alternative splicing creates transcriptome diversification, possibly leading to speciation. A large fraction of the protein-coding genes of multicellular organisms are alternatively spliced, although no regulated splicing has been detected in unicellular eukaryotes such as yeasts. A comparative analysis of unicellular and multicellular eukaryotic 5' splice sites has revealed important differences - the plasticity of the 5' splice sites of multicellular eukaryotes means that these sites can be used in both constitutive and alternative splicing, and for the regulation of the inclusion/skipping ratio in alternative splicing. So, alternative splicing might have originated as a result of relaxation of the 5' splice site recognition in organisms that originally could support only constitutive splicing.
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Affiliation(s)
- Gil Ast
- Department of Human Genetics and Molecular Medicine, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.
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12
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Sorek R, Lev-Maor G, Reznik M, Dagan T, Belinky F, Graur D, Ast G. Minimal conditions for exonization of intronic sequences: 5' splice site formation in alu exons. Mol Cell 2004; 14:221-31. [PMID: 15099521 DOI: 10.1016/s1097-2765(04)00181-9] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 03/17/2004] [Accepted: 03/23/2004] [Indexed: 02/05/2023]
Abstract
Alu exonization, which is an evolutionary pathway that creates primate-specific transcriptomic diversity, is a powerful tool for studying alternative-splicing regulation. Through bioinformatic analyses combined with experimental methodology, we identified the mutational changes needed to create functional 5' splice sites in Alu. We revealed a complex mechanism by which the sequence composition of the 5' splice site and its base pairing with the small nuclear RNA U1 govern alternative splicing. We show that in Alu-derived GC introns the strength of the base pairing between U1 snRNA and the 5' splice site controls the skipping/inclusion ratio of alternative splicing. Based on these findings, we identified 7810 Alus within the human genome that are prone to exonization. Mutations in these Alus may cause genetic disorders or contribute to human-specific protein diversity.
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Affiliation(s)
- Rotem Sorek
- Department of Human Genetics and Molecular Medicine, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel
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13
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Current awareness on yeast. Yeast 2002; 19:1183-90. [PMID: 12371408 DOI: 10.1002/yea.828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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