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Klaassen K, Stankovic B, Kotur N, Djordjevic M, Zukic B, Nikcevic G, Ugrin M, Spasovski V, Srzentic S, Pavlovic S, Stojiljkovic M. New PAH gene promoter KLF1 and 3'-region C/EBPalpha motifs influence transcription in vitro. J Appl Genet 2016; 58:79-85. [PMID: 27447460 DOI: 10.1007/s13353-016-0359-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/01/2016] [Accepted: 06/30/2016] [Indexed: 11/28/2022]
Abstract
Phenylketonuria (PKU) is a metabolic disease caused by mutations in the phenylalanine hydroxylase (PAH) gene. Although the PAH genotype remains the main determinant of PKU phenotype severity, genotype-phenotype inconsistencies have been reported. In this study, we focused on unanalysed sequences in non-coding PAH gene regions to assess their possible influence on the PKU phenotype. We transiently transfected HepG2 cells with various chloramphenicol acetyl transferase (CAT) reporter constructs which included PAH gene non-coding regions. Selected non-coding regions were indicated by in silico prediction to contain transcription factor binding sites. Furthermore, electrophoretic mobility shift assay (EMSA) and supershift assays were performed to identify which transcriptional factors were engaged in the interaction. We found novel KLF1 motif in the PAH promoter, which decreases CAT activity by 50 % in comparison to basal transcription in vitro. The cytosine at the c.-170 promoter position creates an additional binding site for the protein complex involving KLF1 transcription factor. Moreover, we assessed for the first time the role of a multivariant variable number tandem repeat (VNTR) region located in the 3'-region of the PAH gene. We found that the VNTR3, VNTR7 and VNTR8 constructs had approximately 60 % of CAT activity. The regulation is mediated by the C/EBPalpha transcription factor, present in protein complex binding to VNTR3. Our study highlighted two novel promoter KLF1 and 3'-region C/EBPalpha motifs in the PAH gene which decrease transcription in vitro and, thus, could be considered as PAH expression modifiers. New transcription motifs in non-coding regions will contribute to better understanding of the PKU phenotype complexity and may become important for the optimisation of PKU treatment.
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Affiliation(s)
- Kristel Klaassen
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Biljana Stankovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Nikola Kotur
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Maja Djordjevic
- Mother and Child Health Care Institute of Serbia "Dr Vukan Cupic", School of Medicine, University of Belgrade, Radoja Dakića 6-8, 11070, Belgrade, Serbia
| | - Branka Zukic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Gordana Nikcevic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Milena Ugrin
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Vesna Spasovski
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Sanja Srzentic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Sonja Pavlovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia
| | - Maja Stojiljkovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010, Belgrade, Serbia.
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Tao J, Li N, Jia H, Liu Z, Li X, Song J, Deng Y, Jin X, Zhu J. Correlation between genotype and the tetrahydrobiopterin-responsive phenotype in Chinese patients with phenylketonuria. Pediatr Res 2015; 78:691-9. [PMID: 26322415 PMCID: PMC4700046 DOI: 10.1038/pr.2015.167] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 06/17/2015] [Indexed: 01/30/2023]
Abstract
BACKGROUND A growing body of research has suggested that tetrahydrobiopterin (BH4) responsive phenotype can be predicted by the phenylalanine hydroxylase (PAH) genotype in patients with phenylketonuria (PKU), but data concerning the association between genotype and BH4 responsiveness are scarce in China. METHODS A total of 165 PKU patients from China who had undergone a 24-h loading test with BH4 administration were recruited. Genotyping was performed by the next-generation sequencing (NGS) technique. Using the predicted residual PAH activity, we analyzed the association between genotype and BH4-responsiveness. RESULTS Among the 165 patients, 40 patients (24.24%) responded to BH4. A total of 74 distinct mutations were observed, including 13 novel mutations. The mutation p.R241C was most frequently associated with response. Two known mutations (p.A322T and p.Q419R) and two novel mutations (p.L98V and IVS3-2A>T) were first reported as responsive to BH4. Residual PAH activity of at least 12.5% was needed for responsive genotypes. CONCLUSION Genotype-based predictions of BH4-responsiveness are only for selecting potential responders. Accordingly, it is necessary to test potential responders with a long-term BH4 challenge.
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Affiliation(s)
- Jing Tao
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- West China School of Public Health, Sichuan University, Sichuan, China
| | - Nana Li
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- Laboratory of Molecular Epidemiology for Birth Defects, West China Second University Hospital, Sichuan University, Sichuan, China
| | - Haitao Jia
- BGI-Shenzhen, Shenzhen, Guangdong, China
| | - Zhen Liu
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- Laboratory of Molecular Epidemiology for Birth Defects, West China Second University Hospital, Sichuan University, Sichuan, China
| | - Xiaohong Li
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- Laboratory of Molecular Epidemiology for Birth Defects, West China Second University Hospital, Sichuan University, Sichuan, China
| | | | - Ying Deng
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- Laboratory of Molecular Epidemiology for Birth Defects, West China Second University Hospital, Sichuan University, Sichuan, China
| | - Xi Jin
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
- Laboratory of Molecular Epidemiology for Birth Defects, West China Second University Hospital, Sichuan University, Sichuan, China
| | - Jun Zhu
- National Centre for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Sichuan, China
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Bashyam MD, Chaudhary AK, Kiran M, Nagarajaram HA, Devi RR, Ranganath P, Dalal A, Bashyam L, Gupta N, Kabra M, Muranjan M, Puri RD, Verma IC, Nampoothiri S, Kadandale JS. Splice, insertion-deletion and nonsense mutations that perturb the phenylalanine hydroxylase transcript cause phenylketonuria in India. J Cell Biochem 2013; 115:566-74. [PMID: 24130151 DOI: 10.1002/jcb.24692] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/10/2013] [Indexed: 01/20/2023]
Abstract
Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by mutational inactivation of the phenylalanine hydroxylase (PAH) gene. Missense mutations are the most common PAH mutation type detected in PKU patients worldwide. We performed PAH mutation analysis in 27 suspected Indian PKU families (including 7 from our previous study) followed by structure and function analysis of specific missense and splice/insertion-deletion/nonsense mutations, respectively. Of the 27 families, disease-causing mutations were detected in 25. A total of 20 different mutations were identified of which 7 "unique" mutations accounted for 13 of 25 mutation positive families. The unique mutations detected exclusively in Indian PKU patients included three recurrent mutations detected in three families each. The 20 mutations included only 5 missense mutations in addition to 5 splice, 4 each nonsense and insertion-deletion mutations, a silent variant in coding region and a 3'UTR mutation. One deletion and two nonsense mutations were characterized to confirm significant reduction in mutant transcript levels possibly through activation of nonsense mediated decay. All missense mutations affected conserved amino acid residues and sequence and structure analysis suggested significant perturbations in the enzyme activity of respective mutant proteins. This is probably the first report of identification of a significantly low proportion of missense PAH mutations from PKU families and together with the presence of a high proportion of splice, insertion-deletion, and nonsense mutations, points to a unique PAH mutation profile in Indian PKU patients.
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Affiliation(s)
- Murali D Bashyam
- Laboratory of Molecular Oncology, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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Polak E, Ficek A, Radvanszky J, Soltysova A, Urge O, Cmelova E, Kantarska D, Kadasi L. Phenylalanine hydroxylase deficiency in the Slovak population: genotype-phenotype correlations and genotype-based predictions of BH4-responsiveness. Gene 2013; 526:347-55. [PMID: 23764561 DOI: 10.1016/j.gene.2013.05.057] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 05/08/2013] [Accepted: 05/20/2013] [Indexed: 10/26/2022]
Abstract
We investigated the mutation spectrum of the phenylalanine hydroxylase gene (PAH) in a cohort of patients from 135 Slovak PKU families. Mutational screening of the known coding region, including conventional intron splice sites, was performed using high-resolution melting analysis, with subsequent sequencing analysis of the samples showing deviated melting profiles compared to control samples. The PAH gene was also screened for deletions and duplications using MLPA analysis. Forty-eight different disease causing mutations were identified in our patient group, including 30 missense, 8 splicing, 7 nonsense, 2 large deletions and 1 small deletion with frameshift; giving a detection rate of 97.6%. The most prevalent mutation was the p.R408W, occurring in 47% of all alleles, which concurs with results from neighboring and other Slavic countries. Other frequent mutations were: p.R158Q (5.3%), IVS12+1G>A (5.3%), p.R252W (5.1%), p.R261Q (3.9%) and p.A403V (3.6%). We also identified three novel missense mutations: p.F233I, p.R270I, p.F331S and one novel variant: c.-30A>T in the proximal part of the PAH gene promoter. A spectrum of 84 different genotypes was observed and a genotype based predictions of BH4-responsiveness were assessed. Among all genotypes, 36 were predicted to be BH4-responsive represented by 51 PKU families. In addition, genotype-phenotype correlations were performed.
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Affiliation(s)
- Emil Polak
- Comenius University, Faculty of Natural Sciences, Department of Molecular Biology, Mlynska Dolina, 842 15 Bratislava, Slovak Republic.
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Wan Q, Wang L, Su J, Yang C, Peng L, Chen L. Genetic structure, polymorphism identification of LGP2 gene and their relationship with the resistance/susceptibility to GCRV in grass carp, Ctenopharyngodon idella. Gene 2013; 521:166-75. [DOI: 10.1016/j.gene.2013.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 03/07/2013] [Indexed: 01/31/2023]
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Wan Q, Su J, Chen X, Yang C, Chen L, Yan N, Zhang Y. Genomic sequence comparison, promoter activity, SNP detection of RIG-I gene and association with resistance/susceptibility to grass carp reovirus in grass carp (Ctenopharyngodon idella). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 39:333-342. [PMID: 23276879 DOI: 10.1016/j.dci.2012.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 12/05/2012] [Accepted: 12/05/2012] [Indexed: 06/01/2023]
Abstract
As an intracellular pattern recognition receptor (PRR), retinoic acid-inducible gene-I (RIG-I) is responsible for detection of nucleic acids from pathogens in infected cells and activation of type I interferon (IFN). In the present study, the 5'-flanking region, introns and single nucleotide polymorphisms (SNPs) of CiRIG-I (Ctenopharyngodon idella RIG-I) were identified and characterized. The genomic CiRIG-I was 12810 bp in length, consisted of an 1864 bp 5'-flank region whose promoter activity was confirmed, 15 exons and 14 introns. By pooled DNA sequencing, two SNPs were detected in the 5'-flanking region; 10 SNPs were discovered in introns; and one SNP was found in exons. After a challenge experiment, these SNPs were selected to analyze their association with the resistance/susceptibility of C. idella to grass carp reovirus (GCRV), using case-control study. Chi-square test was employed to assess the association. The result showed that -780 C/T, 4731 C/T, 4945 A/G, 8461 C/T, and haplotype 3428A-3432G were significantly associated with the phenotype (P<0.05). To confirm the correlation, another independent challenge experiment was performed, in which the cumulative mortality of -780 genotype CC, 4731 genotype CC and 4945 genotype AA were significantly lower than that of -780 genotype TT, 4731 genotype TT and 4945 genotype GG, respectively (P<0.05). In addition, the SNP-SNP interaction analysis revealed that there was no significant interaction among those SNPs (P>0.05). These significant SNPs and the haplotype might be potential genetic markers for the molecular selection of C. idella strains that are resistant to GCRV.
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Affiliation(s)
- Quanyuan Wan
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
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Spasovski V, Tosic N, Nikcevic G, Stojiljkovic M, Zukic B, Radmilovic M, Karan-Djurasevic T, Srzentic S, Colovic M, Pavlovic S. The influence of novel transcriptional regulatory element in intron 14 on the expression of Janus kinase 2 gene in myeloproliferative neoplasms. J Appl Genet 2012. [PMID: 23188718 DOI: 10.1007/s13353-012-0125-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The expression of Janus kinase 2 (JAK2) gene is altered in myeloproliferative neoplasms (MPN) and the regulation of transcription could be a mechanism that modulates JAK2 gene expression. We analyzed the transcriptional potential of single-nucleotide polymorphism (SNP) rs12343867 T > C in JAK2 intron 14, tagging 46/1 haplotype, and its influence on JAK2 gene expression. Functional analysis of JAK2 intron 14 was performed using the pBLCAT5 reporter system in K562 cells. Identification of the proteins binding to the intron 14 regulatory element was accomplished by electrophoretic mobility shift assay (EMSA) and supershift assays. Quantification of the expression of JAK2 gene in a cohort of 51 MPN patients and 12 healthy controls was performed by real-time quantitative polymerase chain reaction (RQ-PCR). Functional analysis revealed that the intronic DNA element harboring SNP rs12343867 T > C acts as a transcriptional repressor in vitro. The repressor activity was significantly attenuated by the presence of nucleotide C. Supershift analysis showed the enrolment of transcriptional factor Meis1 in this process. RQ-PCR experiments showed increased JAK2 expression in patients with the JAK2V617F mutation, with a significant difference between essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF) patients. SNP rs12343867 showed no statistically significant influence on the expression of JAK2 gene in MNP patients.
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Affiliation(s)
- Vesna Spasovski
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
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Molecular Genetics and Genotype-Based Estimation of BH4-Responsiveness in Serbian PKU Patients: Spotlight on Phenotypic Implications of p.L48S. JIMD Rep 2012; 9:49-58. [PMID: 23430547 DOI: 10.1007/8904_2012_178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/02/2012] [Accepted: 09/06/2012] [Indexed: 12/31/2022] Open
Abstract
Phenylketonuria (PKU) is caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) enzyme. Here, we report the updated spectrum of PAH mutations in 61 Serbian PKU patients. By using both DGGE/DNA sequencing and PCR-RFLP, we identified 26 disease-causing mutations (detection rate 99%). The most frequent ones were p.L48S (31%), p.R408W (16.4%), p.P281L (6%), p.E390G (5.2%), and p.I306V (5.2%). Homozygosity value indicated high heterogeneity of Serbian population.To overcome possible pitfalls of patients' phenotypic classification, we used two parameters: pretreatment/maximal phenylalanine blood concentration and Phe tolerance. The two phenotypes did not match only for patients with p.L48S. Therefore, we used Mann-Whitney statistical test to compare pretreatment/maximal blood Phe concentration and Phe tolerance detected in patients with p.[L48S];[null] and p.[missense];[null] genotypes. For patients with p.L48S, our results implied that Phe tolerance is a better parameter for phenotypic classification. Also, Fisher's exact test was used to compare p.L48S effect on phenotype of homozygous and functionally hemizygous patients. Our findings showed that effect of p.L48S was altered in functional hemizygotes. Moreover, phenotypic inconsistency found in homozygotes suggested that interallelic complementation and/or additional factors play a role in genotype-phenotype correlation.Since BH4-supplementation therapy is not available in Serbia, we made the first estimation of its potential benefit based on patients' genotypes. In the analyzed cohort, the total frequency of BH4-responsive mutations was 52.6%. Furthermore, we found a significant number of genotypes (26.2% BH4-responsive and 51% probably BH4-responsive) that may respond to BH4 therapy. This led us to a conclusion that BH4-supplementation therapy could bring benefit to Serbian PKU patients.
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