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Zhang R, Lang Y, Shi X, Zhang Y, Liu X, Pan F, Qiao D, Teng X, Shao L. Three exonic variants in the COL4A5 gene alter RNA splicing in a minigene assay. Mol Genet Genomic Med 2024; 12:e2395. [PMID: 38400605 PMCID: PMC10891438 DOI: 10.1002/mgg3.2395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 01/22/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND X-linked Alport syndrome (XLAS) is an inherited renal disease caused by rare variants of COL4A5 on chromosome Xq22. Many studies have indicated that single nucleotide variants (SNVs) in exons can disrupt normal splicing process of the pre-mRNA by altering various splicing regulatory signals. The male patients with XLAS have a strong genotype-phenotype correlation. Confirming the effect of variants on splicing can help to predict kidney prognosis. This study aimed to investigate whether single nucleotide substitutions, located within three bases at the 5' end of the exons or internal position of the exons in COL4A5 gene, cause aberrant splicing process. METHODS We analyzed 401 SNVs previously presumed missense and nonsense variants in COL4A5 gene by bioinformatics programs and identified candidate variants that may affect the splicing of pre-mRNA via minigene assays. RESULTS Our study indicated three of eight candidate variants induced complete or partial exon skipping. Variants c.2678G>C and c.2918G>A probably disturb classic splice sites leading to corresponding exon skipping. Variant c.3700C>T may disrupt splicing enhancer motifs accompanying with generation of splicing silencer sequences resulting in the skipping of exon 41. CONCLUSION Our study revealed that two missense variants positioned the first nucleotides of the 5' end of COL4A5 exons and one internal exonic nonsense variant caused aberrant splicing. Importantly, this study emphasized the necessity of assessing the effects of SNVs at the mRNA level.
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Affiliation(s)
- Ran Zhang
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Yanhua Lang
- Department of Materialsthe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xiaomeng Shi
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Yiyin Zhang
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xuyan Liu
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Fengjiao Pan
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Dan Qiao
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Xin Teng
- Department of Ultrasoundthe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
| | - Leping Shao
- Department of Nephrologythe Affiliated Qingdao Municipal Hospital of Qingdao UniversityQingdaoChina
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Mura-Escorche G, Perdomo-Ramírez A, Ramos-Trujillo E, Trujillo-Frías CJ, Claverie-Martín F. Characterization of pre-mRNA Splicing Defects Caused by CLCN5 and OCRL Mutations and Identification of Novel Variants Associated with Dent Disease. Biomedicines 2023; 11:3082. [PMID: 38002082 PMCID: PMC10669864 DOI: 10.3390/biomedicines11113082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/08/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Dent disease (DD) is an X-linked renal tubulopathy characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and progressive renal failure. Two-thirds of cases are associated with inactivating variants in the CLCN5 gene (Dent disease 1, DD1) and a few present variants in the OCRL gene (Dent disease 2, DD2). The aim of the present study was to test the effect on the pre-mRNA splicing process of DD variants, described here or in the literature, and describe the clinical and genotypic features of thirteen unrelated patients with suspected DD. All patients presented tubular proteinuria, ten presented hypercalciuria and five had nephrolithiasis or nephrocalcinosis. CLCN5 and OCRL genes were analyzed by Sanger sequencing. Nine patients showed variants in CLCN5 and four in OCRL; eight of these were new. Bioinformatics tools were used to select fifteen variants with a potential effect on pre-mRNA splicing from our patients' group and from the literature, and were experimentally tested using minigene assays. Results showed that three exonic missense mutations and two intronic variants affect the mRNA splicing process. Our findings widen the genotypic spectrum of DD and provide insight into the impact of variants causing DD.
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Affiliation(s)
- Glorián Mura-Escorche
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
- Departamento de Medicina Interna, Dermatología y Psiquiatría, Facultad de Medicina, Universidad de la Laguna, 38071 Santa Cruz de Tenerife, Spain
| | - Ana Perdomo-Ramírez
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
- Departamento de Medicina Física y Farmacología, Facultad de Medicina, Universidad de la Laguna, 38071 Santa Cruz de Tenerife, Spain
| | - Carmen Jane Trujillo-Frías
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
| | - Félix Claverie-Martín
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
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Liu X, Shi X, Xin Q, Liu Z, Pan F, Qiao D, Chen M, Zhang Y, Guo W, Li C, Zhang Y, Shao L, Zhang R. Identified eleven exon variants in PKD1 and PKD2 genes that altered RNA splicing by minigene assay. BMC Genomics 2023; 24:407. [PMID: 37468838 PMCID: PMC10354997 DOI: 10.1186/s12864-023-09444-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 06/11/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND Autosomal dominant polycystic kidney disease (ADPKD) is a common monogenic multisystem disease caused primarily by mutations in the PKD1 gene or PKD2 gene. There is increasing evidence that some of these variants, which are described as missense, synonymous or nonsense mutations in the literature or databases, may be deleterious by affecting the pre-mRNA splicing process. RESULTS This study aimed to determine the effect of these PKD1 and PKD2 variants on exon splicing combined with predictive bioinformatics tools and minigene assay. As a result, among the 19 candidate single nucleotide alterations, 11 variants distributed in PKD1 (c.7866C > A, c.7960A > G, c.7979A > T, c.7987C > T, c.11248C > G, c.11251C > T, c.11257C > G, c.11257C > T, c.11346C > T, and c.11393C > G) and PKD2 (c.1480G > T) were identified to result in exon skipping. CONCLUSIONS We confirmed that 11 variants in the gene of PKD1 and PKD2 affect normal splicing by interfering the recognition of classical splicing sites or by disrupting exon splicing enhancers and generating exon splicing silencers. This is the most comprehensive study to date on pre-mRNA splicing of exonic variants in ADPKD-associated disease-causing genes in consideration of the increasing number of identified variants in PKD1 and PKD2 gene in recent years. These results emphasize the significance of assessing the effect of exon single nucleotide variants in ADPKD at the mRNA level.
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Affiliation(s)
- Xuyan Liu
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Xiaomeng Shi
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Qing Xin
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Zhiying Liu
- Renal Division, Peking University First Hospital, Beijing, China
| | - Fengjiao Pan
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Dan Qiao
- Department of Nephrology, Dalian Medical University, Dalian, China
| | - Mengke Chen
- Department of Nephrology, Shandong First Medical University, Taian, China
| | - Yiyin Zhang
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Wencong Guo
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Changying Li
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China
| | - Yan Zhang
- Department of Nephrology, Weifang Medical University, Weifang, China
| | - Leping Shao
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China.
| | - Ruixiao Zhang
- Department of Emergency, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao, 266071, China.
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Hort Y, Sullivan P, Wedd L, Fowles L, Stevanovski I, Deveson I, Simons C, Mallett A, Patel C, Furlong T, Cowley MJ, Shine J, Mallawaarachchi A. Atypical splicing variants in PKD1 explain most undiagnosed typical familial ADPKD. NPJ Genom Med 2023; 8:16. [PMID: 37419908 DOI: 10.1038/s41525-023-00362-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 06/26/2023] [Indexed: 07/09/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of kidney failure and is primarily associated with PKD1 or PKD2. Approximately 10% of patients remain undiagnosed after standard genetic testing. We aimed to utilise short and long-read genome sequencing and RNA studies to investigate undiagnosed families. Patients with typical ADPKD phenotype and undiagnosed after genetic diagnostics were recruited. Probands underwent short-read genome sequencing, PKD1 and PKD2 coding and non-coding analyses and then genome-wide analysis. Targeted RNA studies investigated variants suspected to impact splicing. Those undiagnosed then underwent Oxford Nanopore Technologies long-read genome sequencing. From over 172 probands, 9 met inclusion criteria and consented. A genetic diagnosis was made in 8 of 9 (89%) families undiagnosed on prior genetic testing. Six had variants impacting splicing, five in non-coding regions of PKD1. Short-read genome sequencing identified novel branchpoint, AG-exclusion zone and missense variants generating cryptic splice sites and a deletion causing critical intron shortening. Long-read sequencing confirmed the diagnosis in one family. Most undiagnosed families with typical ADPKD have splice-impacting variants in PKD1. We describe a pragmatic method for diagnostic laboratories to assess PKD1 and PKD2 non-coding regions and validate suspected splicing variants through targeted RNA studies.
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Affiliation(s)
- Yvonne Hort
- Molecular Genetics of Inherited Kidney Disorders Laboratory, Garvan Institute of Medical Research, Sydney, Australia
| | - Patricia Sullivan
- Children's Cancer Institute, Lowy Cancer Centre, UNSW Sydney, Kensington, NSW, Australia
- School of Clinical Medicine, UNSW Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - Laura Wedd
- Molecular Genetics of Inherited Kidney Disorders Laboratory, Garvan Institute of Medical Research, Sydney, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and UNSW Sydney, Sydney, NSW, Australia
| | - Lindsay Fowles
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Igor Stevanovski
- Genomic Technologies, Garvan Institute of Medical Research, Sydney, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and Murdoch Children's Research Institute, Sydney, Australia
| | - Ira Deveson
- Genomic Technologies, Garvan Institute of Medical Research, Sydney, Australia
- Centre for Population Genomics, Garvan Institute of Medical Research and Murdoch Children's Research Institute, Sydney, Australia
| | - Cas Simons
- Centre for Population Genomics, Garvan Institute of Medical Research and UNSW Sydney, Sydney, NSW, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Andrew Mallett
- Department of Renal Medicine, Townsville University Hospital, Townsville, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- College of Medicine and Dentistry, James Cook University, Townsville, QLD, Australia
| | - Chirag Patel
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, QLD, Australia
| | - Timothy Furlong
- Molecular Genetics of Inherited Kidney Disorders Laboratory, Garvan Institute of Medical Research, Sydney, Australia
| | - Mark J Cowley
- Children's Cancer Institute, Lowy Cancer Centre, UNSW Sydney, Kensington, NSW, Australia
- School of Clinical Medicine, UNSW Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - John Shine
- Molecular Genetics of Inherited Kidney Disorders Laboratory, Garvan Institute of Medical Research, Sydney, Australia
| | - Amali Mallawaarachchi
- Molecular Genetics of Inherited Kidney Disorders Laboratory, Garvan Institute of Medical Research, Sydney, Australia.
- Clinical Genetics Service, Institute of Precision Medicine and Bioinformatics, Royal Prince Alfred Hospital, Sydney, Australia.
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Xin Q, Liu Q, Liu Z, Shi X, Liu X, Zhang R, Hong Y, Zhao X, Shao L. Twelve exonic variants in the SLC12A1 and CLCNKB genes alter RNA splicing in a minigene assay. Front Genet 2022; 13:961384. [PMID: 36092934 PMCID: PMC9452827 DOI: 10.3389/fgene.2022.961384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Bartter syndrome (BS) is a rare renal tubular disease caused by gene variants in SLC12A1, KCNJ1, CLCNKA, CLCNKB, BSND or MAGED2 genes. There is growing evidence that many exonic mutations can affect the pre-mRNA normal splicing and induce exon skipping by altering various splicing regulatory signals. Therefore, the aim of this study was to gain new insights into the consequences of exonic mutations associated with BS on pre-mRNA splicing.Methods: We analyzed all the missense, nonsense and synonymous variants described in six pathogenic genes by bioinformatics programs and identified candidate mutations that may promote exon skipping through a minigene system.Results: Results of the study showed that 12 of 14 candidate variants distributed in SLC12A1 (c.728G>A, C.735C>G, c.904C>T, c.905G>A, c.1304C>T, c.1493C>T, c.2221A>T) and CLCNKB (c.226C>T, c.228A>C, c.229G>A, c.229G>C, c.1979C>A) were identified to induce splicing alterations. These variants may not only disrupt exonic splicing enhancers (ESEs) but also generate new exonic splicing silencers (ESSs), or disturb the classic splicing sites.Conclusion: To our knowledge, this is a comprehensive study regarding alterations in pre-mRNA of exonic variants in BS pathogenic genes. Our results reinforce the necessity of assessing the consequences of exonic variants at the mRNA level.
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Affiliation(s)
- Qing Xin
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Qihua Liu
- Department of Material Supply Management, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Zhiying Liu
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xuyan Liu
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yefeng Hong
- Department of Cardiology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiangzhong Zhao
- Medical Research Center, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Xiangzhong Zhao, ; Leping Shao,
| | - Leping Shao
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
- *Correspondence: Xiangzhong Zhao, ; Leping Shao,
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Sarkar A, Panati K, Narala VR. Code inside the codon: The role of synonymous mutations in regulating splicing machinery and its impact on disease. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2022; 790:108444. [PMID: 36307006 DOI: 10.1016/j.mrrev.2022.108444] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 10/10/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
In eukaryotes, precise pre-mRNA processing, including alternative splicing, is essential to carry out the intricate protein translation process. Both point mutations (that alter the translated protein sequence) and synonymous mutations (that do not alter the translated protein sequence) are capable of affecting the splicing process. Synonymous mutations are known to affect gene expression via altering mRNA stability, mRNA secondary structure, splicing processes, and translational kinetics. In higher eukaryotes, precise splicing is regulated by three weakly conserved cis-elements, 5' and 3' splice sites and the branch site. Many other cis-acting elements (exonic/intronic splicing enhancers and silencers) and trans-acting splicing factors (serine and arginine-rich proteins and heterogeneous nuclear ribonucleoproteins) have also been found to enhance or suppress the splicing process. The appearance of synonymous mutations in cis-acting elements can alter the splicing process by changing the binding pattern of splicing factors to exonic splicing enhancers or silencer motifs. This results in exon skipping, intron retention, and various other forms of alternative splicing, eventually leading to the emergence of a wide range of diseases. The focus of this review is to elucidate the role of synonymous mutations and their impact on abnormal splicing mechanisms. Further, this study highlights the function of synonymous mutation in mediating abnormal splicing in cancer and development of X-linked, and autosomal inherited diseases.
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Affiliation(s)
- Avik Sarkar
- Department of Zoology, Vidyasagar University, Midnapore, West Bengal 721102, India
| | - Kalpana Panati
- Department of Biotechnology, Government College for Men, Kadapa 516004, India
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A Custom Target Next-Generation Sequencing 70-Gene Panel and Replication Study to Identify Genetic Markers of Diabetic Kidney Disease. Genes (Basel) 2021; 12:genes12121992. [PMID: 34946941 PMCID: PMC8702126 DOI: 10.3390/genes12121992] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/09/2021] [Accepted: 12/12/2021] [Indexed: 01/16/2023] Open
Abstract
Diabetic kidney disease (DKD) has been pointed out as a prominent cause of chronic and end-stage renal disease (ESRD). There is a genetic predisposition to DKD, although clinically relevant loci are yet to be identified. We utilized a custom target next-generation sequencing 70-gene panel to screen a discovery cohort of 150 controls, DKD and DKD-ESRD patients. Relevant SNPs for the susceptibility and clinical evolution of DKD were replicated in an independent validation cohort of 824 controls and patients. A network analysis aiming to assess the impact of variability along specific pathways was also conducted. Forty-eight SNPs displayed significantly different frequencies in the study groups. Of these, 28 with p-values lower than 0.01 were selected for replication. MYH9 rs710181 was inversely associated with the risk of DKD (OR = 0.52 (0.28–0.97), p = 0.033), whilst SOWAHB rs13140552 and CNDP1 rs4891564 were not carried by cases or controls, respectively (p = 0.044 and 0.023). In addition, the RGMA rs1969589 CC genotype was significantly correlated with lower albumin-to-creatinine ratios in the DKD patients (711.8 ± 113.0 vs. 1375.9 ± 474.1 mg/g for TC/TT; mean difference = 823.5 (84.46–1563.0); p = 0.030). No biological pathway stood out as more significantly affected by genetic variability. Our findings reveal new variants that could be useful as biomarkers of DKD onset and/or evolution.
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Roos D, de Boer M. Mutations in cis that affect mRNA synthesis, processing and translation. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166166. [PMID: 33971252 DOI: 10.1016/j.bbadis.2021.166166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022]
Abstract
Genetic mutations that cause hereditary diseases usually affect the composition of the transcribed mRNA and its encoded protein, leading to instability of the mRNA and/or the protein. Sometimes, however, such mutations affect the synthesis, the processing or the translation of the mRNA, with similar disastrous effects. We here present an overview of mRNA synthesis, its posttranscriptional modification and its translation into protein. We then indicate which elements in these processes are known to be affected by pathogenic mutations, but we restrict our review to mutations in cis, in the DNA of the gene that encodes the affected protein. These mutations can be in enhancer or promoter regions of the gene, which act as binding sites for transcription factors involved in pre-mRNA synthesis. We also describe mutations in polyadenylation sequences and in splice site regions, exonic and intronic, involved in intron removal. Finally, we include mutations in the Kozak sequence in mRNA, which is involved in protein synthesis. We provide examples of genetic diseases caused by mutations in these DNA regions and refer to databases to help identify these regions. The over-all knowledge of mRNA synthesis, processing and translation is essential for improvement of the diagnosis of patients with genetic diseases.
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Affiliation(s)
- Dirk Roos
- Sanquin Blood Supply Organization, Dept. of Blood Cell Research, Landsteiner Laboratory, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Amsterdam, the Netherlands.
| | - Martin de Boer
- Sanquin Blood Supply Organization, Dept. of Blood Cell Research, Landsteiner Laboratory, Amsterdam University Medical Centre, location AMC, University of Amsterdam, Amsterdam, the Netherlands
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Li Q, Li J, Yu CP, Chang S, Xie LL, Wang S. Synonymous mutations that regulate translation speed might play a non-negligible role in liver cancer development. BMC Cancer 2021; 21:388. [PMID: 33836673 PMCID: PMC8033552 DOI: 10.1186/s12885-021-08131-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/30/2021] [Indexed: 01/11/2023] Open
Abstract
Background Synonymous mutations do not change the protein sequences. Automatically, they have been regarded as neutral events and are ignored in the mutation-based cancer studies. However, synonymous mutations will change the codon optimality, resulting in altered translational velocity. Methods We fully utilized the transcriptome and translatome of liver cancer and normal tissue from ten patients. We profiled the mutation spectrum and examined the effect of synonymous mutations on translational velocity. Results Synonymous mutations that increase the codon optimality significantly enhanced the translational velocity, and were enriched in oncogenes. Meanwhile, synonymous mutations decreasing codon optimality slowed down translation, and were enriched in tumor suppressor genes. These synonymous mutations significantly contributed to the translational changes in tumor samples compared to normal samples. Conclusions Synonymous mutations might play a role in liver cancer development by altering codon optimality and translational velocity. Synonymous mutations should no longer be ignored in the genome-wide studies.
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Affiliation(s)
- Qun Li
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jian Li
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Chun-Peng Yu
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shuai Chang
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ling-Ling Xie
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Song Wang
- Department of interventional radiology, The Affiliated Hospital of Qingdao University, Qingdao, China.
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Wang S, Wang Y, Wang J, Liu Z, Zhang R, Shi X, Han Y, Guo W, Bottillo I, Shao L. Six Exonic Variants in the SLC5A2 Gene Cause Exon Skipping in a Minigene Assay. Front Genet 2020; 11:585064. [PMID: 33250922 PMCID: PMC7674938 DOI: 10.3389/fgene.2020.585064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/20/2020] [Indexed: 01/16/2023] Open
Abstract
Background Familial renal glucosuria is a rare renal tubular disorder caused by SLC5A2 gene variants. Most of them are exonic variants and have been classified as missense variants. However, there is growing evidence that some of these variants can be detrimental by affecting the pre-mRNA splicing process. Therefore, we hypothesize that a certain proportion of SLC5A2 exonic variants can result in disease via interfering with the normal splicing process of the pre-mRNA. Methods We used bioinformatics programs to analyze 77 previously described presumed SLC5A2 missense variants and identified candidate variants that may alter the splicing of pre-mRNA through minigene assays. Results Our study indicated six of 7 candidate variants induced splicing alterations. Variants c.216C > A, c.294C > A, c.886G > C, c.932A > G and c.962A > G may disrupt splicing enhancer motifs and generate splicing silencer sequences resulting in the skipping of exon 3. Variants c.305C > T and c.1129G > A probably disturb splice sites leading to exon skipping. Conclusion To our knowledge, we report, for the first time, SLC5A2 exonic variants that produce alterations in pre-mRNA. Our research reinforces the importance of assessing the consequences for putative point variants at the mRNA level. Additionally, we propose that minigenes function analysis may be valuable to evaluate the impact of SLC5A2 exonic variants on pre-mRNA splicing without patients’ RNA samples.
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Affiliation(s)
- Sai Wang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China.,Department of Dermatology, Peking University First Hospital, Beijing, China
| | - Yixiu Wang
- Department of Hepatic Surgery, Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jinchao Wang
- Yantai Branch of Wenden Osteopathic Hospital, Yantai, China
| | - Zhiying Liu
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yue Han
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Wencong Guo
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Italy
| | - Leping Shao
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
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11
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Groopman EE, Povysil G, Goldstein DB, Gharavi AG. Rare genetic causes of complex kidney and urological diseases. Nat Rev Nephrol 2020; 16:641-656. [PMID: 32807983 PMCID: PMC7772719 DOI: 10.1038/s41581-020-0325-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2020] [Indexed: 02/08/2023]
Abstract
Although often considered a single-entity, chronic kidney disease (CKD) comprises many pathophysiologically distinct disorders that result in persistently abnormal kidney structure and/or function, and encompass both monogenic and polygenic aetiologies. Rare inherited forms of CKD frequently span diverse phenotypes, reflecting genetic phenomena including pleiotropy, incomplete penetrance and variable expressivity. Use of chromosomal microarray and massively parallel sequencing technologies has revealed that genomic disorders and monogenic aetiologies contribute meaningfully to seemingly complex forms of CKD across different clinically defined subgroups and are characterized by high genetic and phenotypic heterogeneity. Investigations of prevalent genomic disorders in CKD have integrated genetic, bioinformatic and functional studies to pinpoint the genetic drivers underlying their renal and extra-renal manifestations, revealing both monogenic and polygenic mechanisms. Similarly, massively parallel sequencing-based analyses have identified gene- and allele-level variation that contribute to the clinically diverse phenotypes observed for many monogenic forms of nephropathy. Genome-wide sequencing studies suggest that dual genetic diagnoses are found in at least 5% of patients in whom a genetic cause of disease is identified, highlighting the fact that complex phenotypes can also arise from multilocus variation. A multifaceted approach that incorporates genetic and phenotypic data from large, diverse cohorts will help to elucidate the complex relationships between genotype and phenotype for different forms of CKD, supporting personalized medicine for individuals with kidney disease.
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Affiliation(s)
- Emily E Groopman
- Division of Nephrology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Gundula Povysil
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Ali G Gharavi
- Division of Nephrology, Columbia University College of Physicians and Surgeons, New York, NY, USA.
- Institute for Genomic Medicine, Columbia University, New York, NY, USA.
- Center for Precision Medicine and Genomics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA.
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12
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Alvarez MEV, Chivers M, Borovska I, Monger S, Giannoulatou E, Kralovicova J, Vorechovsky I. Transposon clusters as substrates for aberrant splice-site activation. RNA Biol 2020; 18:354-367. [PMID: 32965162 PMCID: PMC7951965 DOI: 10.1080/15476286.2020.1805909] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transposed elements (TEs) have dramatically shaped evolution of the exon-intron structure and significantly contributed to morbidity, but how recent TE invasions into older TEs cooperate in generating new coding sequences is poorly understood. Employing an updated repository of new exon-intron boundaries induced by pathogenic mutations, termed DBASS, here we identify novel TE clusters that facilitated exon selection. To explore the extent to which such TE exons maintain RNA secondary structure of their progenitors, we carried out structural studies with a composite exon that was derived from a long terminal repeat (LTR78) and AluJ and was activated by a C > T mutation optimizing the 5ʹ splice site. Using a combination of SHAPE, DMS and enzymatic probing, we show that the disease-causing mutation disrupted a conserved AluJ stem that evolved from helix 3.3 (or 5b) of 7SL RNA, liberating a primordial GC 5ʹ splice site from the paired conformation for interactions with the spliceosome. The mutation also reduced flexibility of conserved residues in adjacent exon-derived loops of the central Alu hairpin, revealing a cross-talk between traditional and auxilliary splicing motifs that evolved from opposite termini of 7SL RNA and were approximated by Watson-Crick base-pairing already in organisms without spliceosomal introns. We also identify existing Alu exons activated by the same RNA rearrangement. Collectively, these results provide valuable TE exon models for studying formation and kinetics of pre-mRNA building blocks required for splice-site selection and will be useful for fine-tuning auxilliary splicing motifs and exon and intron size constraints that govern aberrant splice-site activation.
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Affiliation(s)
| | - Martin Chivers
- School of Medicine, University of Southampton, Southampton, UK
| | - Ivana Borovska
- Slovak Academy of Sciences, Institute of Molecular Physiology and Genetics, Bratislava, Slovak Republic
| | - Steven Monger
- Computational Genomics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Eleni Giannoulatou
- Computational Genomics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, Australia.,St. Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Jana Kralovicova
- School of Medicine, University of Southampton, Southampton, UK.,Slovak Academy of Sciences, Institute of Molecular Physiology and Genetics, Bratislava, Slovak Republic
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13
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Bitarafan F, Garshasbi M. Molecular genetic analysis of polycystic kidney disease 1 and polycystic kidney disease 2 mutations in pedigrees with autosomal dominant polycystic kidney disease. JOURNAL OF RESEARCH IN MEDICAL SCIENCES : THE OFFICIAL JOURNAL OF ISFAHAN UNIVERSITY OF MEDICAL SCIENCES 2019; 24:44. [PMID: 31160911 PMCID: PMC6540774 DOI: 10.4103/jrms.jrms_835_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/08/2019] [Accepted: 02/25/2019] [Indexed: 11/04/2022]
Abstract
BACKGROUND Dysfunction of polycystin-1 or polycystin-2, the proteins encoded by polycystic kidney disease 1 (PKD1) and PKD2, respectively, are the cause of autosomal dominant PKD (ADPKD). This genetically heterogeneous monogenic disorder is the most common inherited kidney disease. The disease manifests are progressive cyst growth, renal enlargement, and renal failure, due to abnormal proliferation of kidney tubular epithelium. MATERIALS AND METHODS In this study, mutation analysis of PKD1 and PKD2 genes in nine Iranian families was performed using next-generation sequencing. All patients met the diagnostic criteria of ADPKD. RESULTS Mutations were found in all 9 families in PKD1 gene, comprising 2 novel and 7 previously reported mutations. No mutation in PKD2 was identified. CONCLUSION Finding more mutations and expanding the spectrum of PKD1 and PKD2 mutations can increase the diagnostic value of molecular testing in the screening of ADPKD patients.
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Affiliation(s)
- Fatemeh Bitarafan
- Department of Cellular and Molecular Biology, North Tehran Branch, Islamic Azad University, Teheran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran
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14
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Kim JH, Park EY, Chitayat D, Stachura DL, Schaper J, Lindstrom K, Jewett T, Wieczorek D, Draaisma JM, Sinnema M, Hoeberigs C, Hempel M, Bachman KK, Seeley AH, Stone JK, Kong HK, Vukadin L, Richard A, Shinde DN, McWalter K, Si YC, Douglas G, Lim ST, Vissers LELM, Lemaire M, Ahn EYE. SON haploinsufficiency causes impaired pre-mRNA splicing of CAKUT genes and heterogeneous renal phenotypes. Kidney Int 2019; 95:1494-1504. [PMID: 31005274 DOI: 10.1016/j.kint.2019.01.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/10/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022]
Abstract
Although genetic testing is increasingly used in clinical nephrology, a large number of patients with congenital abnormalities of the kidney and urinary tract (CAKUT) remain undiagnosed with current gene panels. Therefore, careful curation of novel genetic findings is key to improving diagnostic yields. We recently described a novel intellectual disability syndrome caused by de novo heterozygous loss-of-function mutations in the gene encoding the splicing factor SON. Here, we show that many of these patients, including two previously unreported, exhibit a wide array of kidney abnormalities. Detailed phenotyping of 14 patients with SON haploinsufficiency identified kidney anomalies in 8 patients, including horseshoe kidney, unilateral renal hypoplasia, and renal cysts. Recurrent urinary tract infections, electrolyte disturbances, and hypertension were also observed in some patients. SON knockdown in kidney cell lines leads to abnormal pre-mRNA splicing, resulting in decreased expression of several established CAKUT genes. Furthermore, these molecular events were observed in patient-derived cells with SON haploinsufficiency. Taken together, our data suggest that the wide spectrum of phenotypes in patients with a pathogenic SON mutation is a consequence of impaired pre-mRNA splicing of several CAKUT genes. We propose that genetic testing panels designed to diagnose children with a kidney phenotype should include the SON gene.
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Affiliation(s)
- Jung-Hyun Kim
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Eun Young Park
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - David Chitayat
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada; The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - David L Stachura
- Department of Biological Sciences, California State University Chico, Chico, California, USA
| | - Jörg Schaper
- Institute of Diagnostic and Interventional Radiology, University of Düsseldorf, Düsseldorf, Germany
| | - Kristin Lindstrom
- Division of Genetics and Metabolism, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Tamison Jewett
- Department of Pediatrics, Section on Medical Genetics, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Dagmar Wieczorek
- Institute of Human Genetics, University Clinic Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany; Institute of Human Genetics, University Clinic Essen, University Duisburg-Essen, Essen, Germany
| | - Jos M Draaisma
- Department of Pediatrics, Radboudumc Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Margje Sinnema
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Christianne Hoeberigs
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | | | - Joshua K Stone
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Hyun Kyung Kong
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Lana Vukadin
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | - Alexander Richard
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA
| | | | | | | | | | - Ssang-Taek Lim
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Lisenka E L M Vissers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Mathieu Lemaire
- Division of Nephrology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada; Cell Biology Program, SickKids Research Institute, University of Toronto, Toronto, Ontario, Canada.
| | - Eun-Young Erin Ahn
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, USA; Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.
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15
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Claverie-Martin F, Trindade A, Garcia-Gonzalez NC, Callejon AC. Novel missense mutation affecting the LIM-A domain of LMX1B in a family with Nail-Patella syndrome. Intractable Rare Dis Res 2019; 8:14-19. [PMID: 30881852 PMCID: PMC6409120 DOI: 10.5582/irdr.2018.01131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Nail-patella syndrome (NPS) is a rare autosomal dominant disease characterized by developmental defects of dorsal limb structures, the kidney, and the eye, that manifest as dysplastic nails, hypoplastic or absent patella, elbow dysplasia, iliac horns, glomerulopathy, and adult-onset glaucoma, respectively. This disorder is inherited in an autosomal dominant mode and is caused by heterozygous loss-of-function mutations in the LMX1B gene, which encodes the LIM homeodomain transcription factor LMX1B. In this study, we report the clinical findings of a Spanish family, from the Canary Islands, with three affected members who displayed varying phenotypes. DNA sequence analysis identified a novel heterozygous missense mutation in LMX1B, c.305A>G, p.(Y102C), that segregated with the disease. The tyrosine residue affected by the mutation is highly conserved in evolution, and is located in the LIM-A domain, next to one of the cysteine residues involved in zinc binding, suggesting that p.(Y102C) affects LMX1B function by disturbing its interactions with other proteins. Our results expand the mutation spectrum of LMX1B and provide insight into the molecular mechanisms of NPS pathology.
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Affiliation(s)
- Felix Claverie-Martin
- Unidad de Investigacion, Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Address correspondence to:Dr. Félix Claverie-Martín, Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain. E-mail:
| | - Amelia Trindade
- Unidad de Investigacion, Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Present address:Departamento de Medicina, Centro de Ciências Biológicas e da Saude (CCBS), Universidade Federal de São Carlos, São Carlos, Brasil
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16
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Understanding human DNA variants affecting pre-mRNA splicing in the NGS era. ADVANCES IN GENETICS 2019; 103:39-90. [PMID: 30904096 DOI: 10.1016/bs.adgen.2018.09.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pre-mRNA splicing, an essential step in eukaryotic gene expression, relies on recognition of short sequences on the primary transcript intron ends and takes place along transcription by RNA polymerase II. Exonic and intronic auxiliary elements may modify the strength of exon definition and intron recognition. Splicing DNA variants (SV) have been associated with human genetic diseases at canonical intron sites, as well as exonic substitutions putatively classified as nonsense, missense or synonymous variants. Their effects on mRNA may be modulated by cryptic splice sites associated to the SV allele, comprehending exon skipping or shortening, and partial or complete intron retention. As splicing mRNA outputs result from combinatorial effects of both intrinsic and extrinsic factors, in vitro functional assays supported by computational analyses are recommended to assist SV pathogenicity assessment for human Mendelian inheritance diseases. The increasing use of next-generating sequencing (NGS) targeting full genomic gene sequence has raised awareness of the relevance of deep intronic SV in genetic diseases and inclusion of pseudo-exons into mRNA. Finally, we take advantage of recent advances in sequencing and computational technologies to analyze alternative splicing in cancer. We explore the Catalog of Somatic Mutations in Cancer (COSMIC) to describe the proportion of splice-site mutations in cis and trans regulatory elements. Genomic data from large cohorts of different cancer types are increasingly available, in addition to repositories of normal and somatic genetic variations. These are likely to bring new insights to understanding the genetic control of alternative splicing by mapping splicing quantitative trait loci in tumors.
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17
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Perdomo-Ramirez A, de Armas-Ortiz M, Ramos-Trujillo E, Suarez-Artiles L, Claverie-Martin F. Exonic CLDN16 mutations associated with familial hypomagnesemia with hypercalciuria and nephrocalcinosis can induce deleterious mRNA alterations. BMC MEDICAL GENETICS 2019; 20:6. [PMID: 30621608 PMCID: PMC6325764 DOI: 10.1186/s12881-018-0713-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/30/2018] [Indexed: 02/04/2023]
Abstract
BACKGROUND Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis type 1 is an autosomal recessive disease characterized by excessive renal magnesium and calcium excretion, bilateral nephrocalcinosis, and progressive chronic renal failure. This rare disease is caused by mutations in CLDN16 that encodes claudin-16, a tight-junction protein involved in paracellular reabsorption of magnesium and calcium in the renal tubule. Most of these variants are located in exons and have been classified as missense mutations. The functional consequences of some of these claudin-16 mutant proteins have been analysed after heterologous expression showing indeed a significant loss of function compared to the wild-type claudin-16. We hypothesize that a number of CLDN16 exonic mutations can be responsible for the disease phenotype by disrupting the pre-mRNA splicing process. METHODS We selected 12 previously described presumed CLDN16 missense mutations and analysed their potential effect on pre-mRNA splicing using a minigene assay. RESULTS Our results indicate that five of these mutations induce significant splicing alterations. Mutations c.453G > T and c.446G > T seem to inactivate exonic splicing enhancers and promote the use of an internal cryptic acceptor splice site resulting in inclusion of a truncated exon 3 in the mature mRNA. Mutation c.571G > A affects an exonic splicing enhancer resulting in partial skipping of exon 3. Mutations c.593G > C and c.593G > A disturb the acceptor splice site of intron 3 and cause complete exon 4 skipping. CONCLUSIONS To our knowledge, this is the first report of CLDN16 exonic mutations producing alterations in splicing. We suggest that in the absence of patients RNA samples, splicing functional assays with minigenes could be valuable for evaluating the effect of exonic CLDN16 mutations on pre-mRNA splicing.
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Affiliation(s)
- Ana Perdomo-Ramirez
- Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
| | - Marian de Armas-Ortiz
- Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
| | - Lorena Suarez-Artiles
- Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
| | - Felix Claverie-Martin
- Unidad de Investigación, Hospital Nuestra Señora de Candelaria, Carretera del Rosario 145, 38010 Santa Cruz de Tenerife, Spain
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18
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Splicing Analysis of Exonic OCRL Mutations Causing Lowe Syndrome or Dent-2 Disease. Genes (Basel) 2018; 9:genes9010015. [PMID: 29300302 PMCID: PMC5793168 DOI: 10.3390/genes9010015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/11/2017] [Accepted: 12/27/2017] [Indexed: 01/12/2023] Open
Abstract
Mutations in the OCRL gene are associated with both Lowe syndrome and Dent-2 disease. Patients with Lowe syndrome present congenital cataracts, mental disabilities and a renal proximal tubulopathy, whereas patients with Dent-2 disease exhibit similar proximal tubule dysfunction but only mild, or no additional clinical defects. It is not yet understood why some OCRL mutations cause the phenotype of Lowe syndrome, while others develop the milder phenotype of Dent-2 disease. Our goal was to gain new insights into the consequences of OCRL exonic mutations on pre-mRNA splicing. Using predictive bioinformatics tools, we selected thirteen missense mutations and one synonymous mutation based on their potential effects on splicing regulatory elements or splice sites. These mutations were analyzed in a minigene splicing assay. Results of the RNA analysis showed that three presumed missense mutations caused alterations in pre-mRNA splicing. Mutation c.741G>T; p.(Trp247Cys) generated splicing silencer sequences and disrupted splicing enhancer motifs that resulted in skipping of exon 9, while mutations c.2581G>A; p.(Ala861Thr) and c.2581G>C; p.(Ala861Pro) abolished a 5′ splice site leading to skipping of exon 23. Mutation c.741G>T represents the first OCRL exonic variant outside the conserved splice site dinucleotides that results in alteration of pre-mRNA splicing. Our results highlight the importance of evaluating the effects of OCRL exonic mutations at the mRNA level.
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19
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de Boer M, van Leeuwen K, Geissler J, van Alphen F, de Vries E, van der Kuip M, Terheggen SW, Janssen H, van den Berg TK, Meijer AB, Roos D, Kuijpers TW. Hermansky-Pudlak syndrome type 2: Aberrant pre-mRNA splicing and mislocalization of granule proteins in neutrophils. Hum Mutat 2017; 38:1402-1411. [DOI: 10.1002/humu.23271] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 05/25/2017] [Accepted: 05/29/2017] [Indexed: 02/03/2023]
Affiliation(s)
- Martin de Boer
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Karin van Leeuwen
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Judy Geissler
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Floris van Alphen
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Esther de Vries
- Department of Pediatrics; Jeroen Bosch Hospital; ‘s-Hertogenbosch; The Netherlands & Tranzo; Tilburg University; Tilburg The Netherlands
| | - Martijn van der Kuip
- Department of Pediatric Infectious Diseases and Immunology; VU University Medical Center, Amsterdam, The Netherlands
| | - Suzanne W.J. Terheggen
- Department of Pediatrics; Erasmus University Medical Center (EMC); Rotterdam The Netherlands
| | - Hans Janssen
- Division of Cell Biology; The Netherlands Cancer Institute; Amsterdam The Netherlands
| | - Timo K. van den Berg
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Alexander B. Meijer
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Dirk Roos
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
| | - Taco W. Kuijpers
- Sanquin Research; and Landsteiner Laboratory; Academic Medical Center (AMC); University of Amsterdam; Amsterdam The Netherlands
- Department of Pediatric Hematology; Immunology and Infectious Diseases; Academic Medical Center; Emma Children's Hospital; Amsterdam The Netherlands
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20
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Jacobson GN, Clark PL. Quality over quantity: optimizing co-translational protein folding with non-'optimal' synonymous codons. Curr Opin Struct Biol 2016; 38:102-10. [PMID: 27318814 PMCID: PMC5010456 DOI: 10.1016/j.sbi.2016.06.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/28/2022]
Abstract
Protein folding occurs on a time scale similar to peptide bond formation by the ribosome, which has long sparked speculation that altering translation rate could alter the folding mechanism or even the final folded structure of a protein in vivo. Recent results have provided strong support for this model: synonymous substitutions to codons with different usage frequency, which are often translated at different rates, have been shown to significantly alter the co-translational folding mechanism of some proteins, leading to altered cell function. Here we review recent progress towards understanding the connections between synonymous codon usage, translation rate and co-translational protein folding mechanisms.
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Affiliation(s)
- Giselle N Jacobson
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Patricia L Clark
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA; Department of Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
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21
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Gonzalez-Paredes FJ, Ramos-Trujillo E, Claverie-Martin F. Three exonic mutations in polycystic kidney disease-2 gene (PKD2) alter splicing of its pre-mRNA in a minigene system. Gene 2016; 578:117-23. [DOI: 10.1016/j.gene.2015.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/05/2015] [Accepted: 12/07/2015] [Indexed: 11/25/2022]
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22
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Claverie-Martin F, Gonzalez-Paredes FJ, Ramos-Trujillo E. Splicing defects caused by exonic mutations in PKD1 as a new mechanism of pathogenesis in autosomal dominant polycystic kidney disease. RNA Biol 2016; 12:369-74. [PMID: 25757501 DOI: 10.1080/15476286.2015.1014291] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The correct splicing of precursor-mRNA depends on the actual splice sites plus exonic and intronic regulatory elements recognized by the splicing machinery. Surprisingly, an increasing number of examples reveal that exonic mutations disrupt the binding of splicing factors to these sequences or generate new splice sites or regulatory elements, causing disease. This contradicts the general assumption that missense mutations disrupt protein function and that synonymous mutations are merely polymorphisms. Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder caused mainly by mutations in the PKD1 gene. Recently, we analyzed a substantial number of PKD1 missense or synonymous mutations to further characterize their consequences on pre-mRNA splicing. Our results showed that one missense and 2 synonymous mutations induce significant defects in pre-mRNA splicing. Thus, it appears that aberrant splicing as a result of exonic mutations is a previously unrecognized cause of ADPKD.
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Affiliation(s)
- Felix Claverie-Martin
- a Unidad de Investigacion; Hospital Nuestra Señora de Candelaria ; Santa Cruz de Tenerife , Spain
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23
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Decoding mechanisms by which silent codon changes influence protein biogenesis and function. Int J Biochem Cell Biol 2015; 64:58-74. [PMID: 25817479 DOI: 10.1016/j.biocel.2015.03.011] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/02/2015] [Accepted: 03/14/2015] [Indexed: 02/07/2023]
Abstract
SCOPE Synonymous codon usage has been a focus of investigation since the discovery of the genetic code and its redundancy. The occurrences of synonymous codons vary between species and within genes of the same genome, known as codon usage bias. Today, bioinformatics and experimental data allow us to compose a global view of the mechanisms by which the redundancy of the genetic code contributes to the complexity of biological systems from affecting survival in prokaryotes, to fine tuning the structure and function of proteins in higher eukaryotes. Studies analyzing the consequences of synonymous codon changes in different organisms have revealed that they impact nucleic acid stability, protein levels, structure and function without altering amino acid sequence. As such, synonymous mutations inevitably contribute to the pathogenesis of complex human diseases. Yet, fundamental questions remain unresolved regarding the impact of silent mutations in human disorders. In the present review we describe developments in this area concentrating on mechanisms by which synonymous mutations may affect protein function and human health. PURPOSE This synopsis illustrates the significance of synonymous mutations in disease pathogenesis. We review the different steps of gene expression affected by silent mutations, and assess the benefits and possible harmful effects of codon optimization applied in the development of therapeutic biologics. PHYSIOLOGICAL AND MEDICAL RELEVANCE Understanding mechanisms by which synonymous mutations contribute to complex diseases such as cancer, neurodegeneration and genetic disorders, including the limitations of codon-optimized biologics, provides insight concerning interpretation of silent variants and future molecular therapies.
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Abstract
Owing to the degeneracy of the genetic code, a protein sequence can be encoded by many different synonymous mRNA coding sequences. Synonymous codon usage was once thought to be functionally neutral, but evidence now indicates it is shaped by evolutionary selection and affects other aspects of protein biogenesis beyond specifying the amino acid sequence of the protein. Synonymous rare codons, once thought to have only negative impacts on the speed and accuracy of translation, are now known to play an important role in diverse functions, including regulation of cotranslational folding, covalent modifications, secretion, and expression level. Mutations altering synonymous codon usage are linked to human diseases. However, much remains unknown about the molecular mechanisms connecting synonymous codon usage to efficient protein biogenesis and proper cell physiology. Here we review recent literature on the functional effects of codon usage, including bioinformatics approaches aimed at identifying general roles for synonymous codon usage.
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