1
|
Dobson-Stone C, Guennewig B, Mundell H, Kwok JB. Detecting and Validating MAPT Mutations in Neurodegeneration Patients and Analysis of Exon Splicing Consequences. Methods Mol Biol 2024; 2754:411-433. [PMID: 38512679 DOI: 10.1007/978-1-0716-3629-9_22] [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] [Indexed: 03/23/2024]
Abstract
Mutation of MAPT has been observed in patients with parkinsonism, progressive supranuclear palsy, and corticobasal degeneration and is a significant cause of frontotemporal dementia. In this chapter, we discuss considerations for next-generation sequencing analysis to identify MAPT mutations in patient genomic DNA and describe the validation of these mutations by Sanger sequencing. One of the most common effects of MAPT mutations is differential splicing of exon 10, which leads to an imbalance in the proportion of 3-repeat and 4-repeat tau isoforms. We describe how to investigate the effect of novel DNA variants on the splicing efficiency of this exon in vitro using the exon-trapping technique, also known as the splicing reporter minigene assay.
Collapse
Affiliation(s)
- Carol Dobson-Stone
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia.
| | - Boris Guennewig
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Hamish Mundell
- New South Wales Brain Tissue Resource Centre, School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - John B Kwok
- Brain and Mind Centre and School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| |
Collapse
|
2
|
Wang X, Zhang H, Huang H, Wang W, Wen Y, Dai Z, Huang S, Zhou J, Zhou Y. Functional and structural analysis of a novel splice site HMBS variant in a Chinese AIP patient. Front Genet 2023; 14:1333111. [PMID: 38192441 PMCID: PMC10773753 DOI: 10.3389/fgene.2023.1333111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 12/07/2023] [Indexed: 01/10/2024] Open
Abstract
Background: Acute intermittent porphyria (AIP) is a rare metabolic disorder that results from mutations in the gene encoding hydroxymethylbilane synthase (HMBS), an enzyme involved in heme biosynthesis. AIP follows an autosomal dominant inheritance pattern, but most carriers are asymptomatic. The clinical manifestations of AIP include acute attacks of abdominal pain and neuropsychiatric disturbances. The pathogenicity of novel HMBS variants identified in Chinese patients has not been well established. Objective: The article aims to identify the pathogenic mutation in an AIP patient and prove its pathogenicity through in vitro experiments. Methods: A 22-year-old female diagnosed with AIP participated in the study. Variant screening of her HMBS gene was carried out through Sanger sequencing. To ascertain the consequences of the newly discovered variant, we conducted in vitro experimentation targeting HMBS gene expression and enzymatic function. Additionally, protein structure analysis was performed. Cycloheximide treatment and UPF1-specific siRNA knockdown were employed to assess the impact of the mutation on the mechanism of non-sense-mediated mRNA decay (NMD). Results: A novel splice site variant in the HMBS gene (c.648_651+1delCCAGG) was detected in the patient, which caused aberrant mRNA splicing. In vitro experiments demonstrated that this variant significantly decreased the expression of HMBS. Further investigation confirmed that this decrease was due to NMD. Additionally, structural analysis indicated that this variant would destabilize the HMBS protein and impair its catalytic activity. To gain a comprehensive understanding of HMBS mutations in the context of AIP, we conducted a literature search on PubMed using the keywords 'HMBS' and 'Acute intermittent porphyria' from 2013 to 2023. This search yielded 19 clinical case reports written in English, which collectively described 220 HMBS gene mutations worldwide. Conclusion: The study identified and proved the pathogenicity of a novel splice site HMBS variant for the first time. Our results elucidated the pathological mechanism by which this mutation causes AIP through reducing HMBS expression and activity. These findings provide theoretical guidance for the diagnosis, treatment and genetic counseling of AIP patients.
Collapse
Affiliation(s)
- Xiaoqing Wang
- Dongguan Hospital, Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Huifen Zhang
- Department of Endocrinology, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Huanhuan Huang
- Dongguan Hospital, Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Wenli Wang
- Dongguan Hospital, Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Yuping Wen
- Dongguan Hospital, Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Zhuojin Dai
- The First Clinical Medical College, Guangdong Medical University, Zhanjiang, Guangdong Province, China
| | - Shuling Huang
- Department of Endocrinology, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Jingyi Zhou
- Dongguan Hospital, Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| | - Yuqing Zhou
- Department of Endocrinology, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong Province, China
| |
Collapse
|
3
|
Orosz G, Szabó L, Bereti S, Zámbó V, Csala M, Kereszturi É. Molecular Basis of Unequal Alternative Splicing of Human SCD5 and Its Alteration by Natural Genetic Variations. Int J Mol Sci 2023; 24:ijms24076517. [PMID: 37047490 PMCID: PMC10095032 DOI: 10.3390/ijms24076517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/22/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
Alternative splicing (AS) is a major means of post-transcriptional control of gene expression, and provides a dynamic versatility of protein isoforms. Cancer-related AS disorders have diagnostic, prognostic and therapeutic values. Changes in the expression and AS of human stearoyl-CoA desaturase-5 (SCD5) are promising specific tumor markers, although the transcript variants (TVs) of the gene have not yet been confirmed. Our in silico, in vitro and in vivo study focuses on the distribution of SCD5 TVs (A and B) in human tissues, the functionality of the relevant splice sites, and their modulation by certain single-nucleotide variations (SNVs). An order of magnitude higher SCD5A expression was found compared with SCD5B. This unequal splicing is attributed to a weaker recognition of the SCD5B-specific splicing acceptor site, based on predictions confirmed by an optimized minigene assay. The pronounced dominance of SCD5A was largely modified (rs1430176385_A, rs1011850309_A) or even inverted (rs1011850309_C) by natural SNVs at the TV-specific splice sites. Our results provide long missing data on the proportion of SCD5 TVs in human tissues and reveal mutation-driven changes in SCD5 AS, potentially affecting tumor-associated reprogramming of lipid metabolism, thus having prognostic significance, which may be utilized for novel and personalized therapeutic approaches.
Collapse
Affiliation(s)
- Gabriella Orosz
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Luca Szabó
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Szanna Bereti
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Veronika Zámbó
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Miklós Csala
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| | - Éva Kereszturi
- Department of Molecular Biology, Semmelweis University, H-1085 Budapest, Hungary
| |
Collapse
|
4
|
Tamayo A, Núñez-Moreno G, Ruiz C, Plaisancie J, Damian A, Moya J, Chassaing N, Calvas P, Ayuso C, Minguez P, Corton M. Minigene Splicing Assays and Long-Read Sequencing to Unravel Pathogenic Deep-Intronic Variants in PAX6 in Congenital Aniridia. Int J Mol Sci 2023; 24:ijms24021562. [PMID: 36675087 PMCID: PMC9863980 DOI: 10.3390/ijms24021562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
PAX6 haploinsufficiency causes aniridia, a congenital eye disorder that involves the iris, and foveal hypoplasia. Comprehensive screening of the PAX6 locus, including the non-coding regions, by next-generation sequencing revealed four deep-intronic variants with potential effects on pre-RNA splicing. Nevertheless, without a functional analysis, their pathogenicity could not be established. We aimed to decipher their impact on the canonical PAX6 splicing using in vitro minigene splicing assays and nanopore-based long-read sequencing. Two multi-exonic PAX6 constructs were generated, and minigene assays were carried out. An aberrant splicing pattern was observed for two variants in intron 6, c.357+136G>A and c.357+334G>A. In both cases, several exonization events, such as pseudoexon inclusions and partial intronic retention, were observed due to the creation or activation of new/cryptic non-canonical splicing sites, including a shared intronic donor site. In contrast, two variants identified in intron 11, c.1032+170A>T and c.1033-275A>C, seemed not to affect splicing processes. We confirmed the high complexity of alternative splicing of PAX6 exon 6, which also involves unreported cryptic intronic sites. Our study highlights the importance of integrating functional studies into diagnostic algorithms to decipher the potential implication of non-coding variants, usually classified as variants of unknown significance, thus allowing variant reclassification to achieve a conclusive genetic diagnosis.
Collapse
Affiliation(s)
- Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871 Alcalá de Henares, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Carolina Ruiz
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Julie Plaisancie
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Alejandra Damian
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Nicolas Chassaing
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Patrick Calvas
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
| |
Collapse
|
5
|
Alfen F, Putscher E, Hecker M, Zettl UK, Hermann A, Lukas J. Abnormal Pre-mRNA Splicing in Exonic Fabry Disease-Causing GLA Mutations. Int J Mol Sci 2022; 23:ijms232315261. [PMID: 36499585 PMCID: PMC9737616 DOI: 10.3390/ijms232315261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
Fabry disease (FD) is a rare X-linked disease due to a multiverse of disrupting mutations within the GLA gene encoding lysosomal α-galactosidase A (AGAL). Absent AGAL activity causes the accumulation of complex glycosphingolipids inside of lysosomes in a variety of cell types and results in a progressive multisystem disease. Known disease-associated point mutations in protein-coding gene regions usually cause translational perturbations and result in premature chain termination, punctual amino acid sequence alterations or overall altered sequence alterations downstream of the mutation site. However, nucleotide exchanges at the border between introns and exons can affect splicing behavior and lead to abnormal pre-mRNA processing. Prediction with the Human Splicing Finder (HSF) revealed an indication of a significant change in splicing-relevant information for some known FD-associated GLA mutations. To experimentally determine the extent of the change, we made use of a minigene reporter assay and verified alternative splicing events for the exonic mutations c.194G>T and c.358C>G, which led to the usage of alternative donor splice sites at exon 1 and exon 2, respectively. In addition, the mutations c.548G>T and c.638A>T led to significant exon 4 skipping. We conclude that splicing phenotype analysis should be employed in the in vitro analysis of exonic GLA gene mutations, since abnormal splicing may result in a reduction of enzyme activity and alter the amenability for treatment with pharmacological chaperone (PC).
Collapse
Affiliation(s)
- Franziska Alfen
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany
| | - Elena Putscher
- Neuroimmunology Section, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
| | - Michael Hecker
- Neuroimmunology Section, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
| | - Uwe Klaus Zettl
- Neuroimmunology Section, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
- Deutsches Zentrum für Neurodegenerative (DZNE) Rostock/Greifswald, 18147 Rostock, Germany
| | - Jan Lukas
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, 18147 Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
- Correspondence:
| |
Collapse
|
6
|
Putscher E, Hecker M, Fitzner B, Boxberger N, Schwartz M, Koczan D, Lorenz P, Zettl UK. Genetic risk variants for multiple sclerosis are linked to differences in alternative pre-mRNA splicing. Front Immunol 2022; 13:931831. [PMID: 36405756 PMCID: PMC9670805 DOI: 10.3389/fimmu.2022.931831] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/12/2022] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system to which a genetic predisposition contributes. Over 200 genetic regions have been associated with increased disease risk, but the disease-causing variants and their functional impact at the molecular level are mostly poorly defined. We hypothesized that single-nucleotide polymorphisms (SNPs) have an impact on pre-mRNA splicing in MS. METHODS Our study focused on 10 bioinformatically prioritized SNP-gene pairs, in which the SNP has a high potential to alter alternative splicing events (ASEs). We tested for differential gene expression and differential alternative splicing in B cells from MS patients and healthy controls. We further examined the impact of the SNP genotypes on ASEs and on splice isoform expression levels. Novel genotype-dependent effects on splicing were verified with splicing reporter minigene assays. RESULTS We were able to confirm previously described findings regarding the relation of MS-associated SNPs with the ASEs of the pre-mRNAs from GSDMB and SP140. We also observed an increased IL7R exon 6 skipping when comparing relapsing and progressive MS patients to healthy subjects. Moreover, we found evidence that the MS risk alleles of the SNPs rs3851808 (EFCAB13), rs1131123 (HLA-C), rs10783847 (TSFM), and rs2014886 (TSFM) may contribute to a differential splicing pattern. Of particular interest is the genotype-dependent exon skipping of TSFM due to the SNP rs2014886. The minor allele T creates a donor splice site, resulting in the expression of the exon 3 and 4 of a short TSFM transcript isoform, whereas in the presence of the MS risk allele C, this donor site is absent, and thus the short transcript isoform is not expressed. CONCLUSION In summary, we found that genetic variants from MS risk loci affect pre-mRNA splicing. Our findings substantiate the role of ASEs with respect to the genetics of MS. Further studies on how disease-causing genetic variants may modify the interactions between splicing regulatory sequence elements and RNA-binding proteins can help to deepen our understanding of the genetic susceptibility to MS.
Collapse
Affiliation(s)
- Elena Putscher
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Michael Hecker
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Brit Fitzner
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Nina Boxberger
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Margit Schwartz
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| | - Dirk Koczan
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Peter Lorenz
- Rostock University Medical Center, Institute of Immunology, Rostock, Germany
| | - Uwe Klaus Zettl
- Rostock University Medical Center, Department of Neurology, Division of Neuroimmunology, Rostock, Germany
| |
Collapse
|
7
|
Fan L, Ji L, Xu Y, Shen G, Tang K, Li Z, Ye S, Shen X. A Novel Mutation c.3392G>T of COL2A1 Causes Spondyloepiphyseal Dysplasia Congenital by Affecting Pre-mRNA Splicing. Front Genet 2022; 13:827560. [PMID: 35692839 PMCID: PMC9174977 DOI: 10.3389/fgene.2022.827560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Spondyloepiphyseal dysplasia congenital (SEDC) is a rare chondrodysplasia caused by dominant pathogenic variants in COL2A1. Here, we detected a novel variant c.3392G > T (NM_001844.4) of COL2A1 in a Chinese family with SEDC by targeted next-generation sequencing. To confirm the pathogenicity of the variant, we generated an appropriate minigene construct based on HeLa and HEK293T cell lines. Splicing assay indicated that the mutated minigene led to aberrant splicing of COL2A1 pre-mRNA and produced an alternatively spliced transcript with a skipping of partial exon 48, which generated a predicted in-frame deletion of 15 amino acids (p. Gly1131_Pro1145del) in the COL2A1 protein. Due to the pathogenicity of the variation, we performed prenatal diagnosis on the proband’s wife, which indicated that the fetus carried the same mutation.
Collapse
Affiliation(s)
- Lihong Fan
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| | - Longfei Ji
- Department of Clinical Laboratory, The First People's Hospital of Huzhou, Huzhou, China
| | - Yuqing Xu
- Department of Reproductive Genetics, Women's Hospital, School of Medicine Zhejiang University, Hangzhou, China
| | - Guosong Shen
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| | - Kefeng Tang
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| | - Zhi Li
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| | - Sisi Ye
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| | - Xueping Shen
- Center of Prenatal Diagnosis, Huzhou Maternity & Child Health Care Hospital, Huzhou, China
| |
Collapse
|
8
|
New Variants of the Cytochrome P450 2R1 ( CYP2R1) Gene in Individuals with Severe Vitamin D-Activating Enzyme 25(OH)D Deficiency. Biomolecules 2021; 11:biom11121867. [PMID: 34944511 PMCID: PMC8699237 DOI: 10.3390/biom11121867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Vitamin D is a fat-soluble cholesterol derivative found in two forms, vitamin D2, and vitamin D3. Cytochrome P450 2R1 (CYP2R1) encoded by the CYP2R1 gene is the major hydroxylase that activates vitamin D by catalyzing the formation of 25-hydroxyvitamin D (25(OH)D). METHODS We collected 89 (100%) subjects, 46 of which (51.69%) had a documented severe deficiency of 25(OH)D (<10 ng/mL) and 43 (48.31%) in the control group with documented optimum levels of 25(OH)D (>30 ng/mL). We performed Sanger sequencing of three selected fragments of the CYP2R1 gene (Ch11: 14878000-14878499; Ch11: 14880058-14880883 and Ch11: 14885321-14886113) that affect the binding of substrates to this enzyme and analyzed the possible involvement of genetic variation in these regions with an increased risk of vitamin D deficiency in healthy Polish individuals. RESULTS Two substitutions were found within the three fragments. Bioinformatic analysis suggested that one of these (NC_000011.10: g.14878291G>A) may influence the structure and function of CYP2R1. CONCLUSIONS Variant NC_000011.10: g.14878291G>A may have a perturbing effect on heme binding in the active site of CYP2R1 and on the function of 25-hydroxylase and probably affects the concentration of 25(OH)D in vivo. We intend to perform functional verification in a larger patient population to confirm and extend these results.
Collapse
|