Kidney-specific expression of human organic cation transporter 2 (OCT2/SLC22A2) is regulated by DNA methylation

2008 ◽  
Vol 295 (1) ◽  
pp. F165-F170 ◽  
Author(s):  
Masayo Aoki ◽  
Tomohiro Terada ◽  
Moto Kajiwara ◽  
Ken Ogasawara ◽  
Iwao Ikai ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Promoter Region ◽  
Organic Cation ◽  
Methylation Status ◽  
Organic Cation Transporter ◽  
Proximal Promoter ◽  
Specific Expression ◽  
Proximal Promoter Region ◽  
E Box ◽  
Organic Cation Transporter 2

Human organic cation transporter 2 (OCT2/SLC22A2), which is specifically expressed in the kidney, plays critical roles in the renal secretion of cationic compounds. Tissue expression and membrane localization of OCT2 are closely related to the tissue distribution, pharmacological effects, and/or adverse effects of its substrate drugs. However, the molecular mechanisms underlying the kidney-specific expression of OCT2 have not been elucidated. In the present study, therefore, we examined the contribution of DNA methylation of the promoter region for the OCT2 gene to its tissue-specific expression using human tissue samples. In vivo methylation status of the proximal promoter region of OCT2 and that of OCT1, a liver-specific organic cation transporter, were investigated by bisulfite sequencing using human genomic DNA extracted from the kidney and liver. All CpG sites in the OCT2 proximal promoter were hypermethylated in the liver, while hypomethylated in the kidney. On the other hand, the promoter region of OCT1 was hypermethylated in both the kidney and liver. The level of methylation of the OCT2 promoter was especially low at the CpG site in the E-box, the binding site of the basal transcription factor upstream stimulating factor (USF) 1. In vitro methylation of the OCT2 proximal promoter dramatically reduced the transcriptional activity, and an electrophoretic mobility shift assay showed that methylation at the E-box inhibited the binding of USF1. These results indicate that kidney-specific expression of human OCT2 is regulated by methylation of the proximal promoter region, interfering with the transactivation by USF1.

scholarly journals GC- and E-box Motifs as Regulatory Elements in the Proximal Promoter Region of the Neuronal Nicotinic Receptor α7 Subunit Gene

1998 ◽  
Vol 273 (32) ◽  
pp. 20021-20028 ◽  
Author(s):  
Carmen Carrasco-Serrano ◽  
Antonio Campos-Caro ◽  
Salvador Viniegra ◽  
Juan J. Ballesta ◽  
Manuel Criado
Keyword(s):  
Nicotinic Receptor ◽  
Promoter Region ◽  
Regulatory Elements ◽  
Proximal Promoter ◽  
Subunit Gene ◽  
Proximal Promoter Region ◽  
Neuronal Nicotinic Receptor ◽  
E Box ◽  
Α7 Subunit

scholarly journals Deoxyribonucleic Acid Methylation Controls Cell Type-Specific Expression of Steroidogenic Factor 1

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5599-5609 ◽  
Author(s):  
Erling A. Hoivik ◽  
Linda Aumo ◽  
Reidun Aesoy ◽  
Haldis Lillefosse ◽  
Aurélia E. Lewis ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Rna Polymerase Ii ◽  
Methylation Status ◽  
Endocrine System ◽  
Methylation Pattern ◽  
Proximal Promoter ◽  
Specific Expression ◽  
Steroidogenic Factor 1 ◽  
In Cells

Steroidogenic factor 1 (SF1) is expressed in a time- and cell-specific manner in the endocrine system. In this study we present evidence to support that methylation of CpG sites located in the proximal promoter of the gene encoding SF1 contributes to the restricted expression pattern of this nuclear receptor. DNA methylation analyses revealed a nearly perfect correlation between the methylation status of the proximal promoter and protein expression, such that it was hypomethylated in cells that express SF1 but hypermethylated in nonexpressing cells. Moreover, in vitro methylation of this region completely repressed reporter gene activity in transfected steroidogenic cells. Bisulfite sequencing of DNA from embryonic tissue demonstrated that the proximal promoter was unmethylated in the developing testis and ovary, whereas it was hypermethylated in tissues that do not express SF1. Together these results indicate that the DNA methylation pattern is established early in the embryo and stably inherited thereafter throughout development to confine SF1 expression to the appropriate tissues. Chromatin immunoprecipitation analyses revealed that the transcriptional activator upstream stimulatory factor 2 and RNA polymerase II were specifically recruited to this DNA region in cells in which the proximal promoter is hypomethylated, providing functional support for the fact that lack of methylation corresponds to a transcriptionally active gene. In conclusion, we identified a region within the SF1/Sf1 gene that epigenetically directs cell-specific expression of SF1.

scholarly journals Regulation of human prohormone convertase 2 promoter activity by the transcription factor EGR-1

1997 ◽  
Vol 328 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Erik JANSEN ◽  
A. Y. Torik AYOUBI ◽  
M. P. Sandra MEULEMANS ◽  
Wim J. M. VAN DE VEN
Keyword(s):  
Transcription Factor ◽  
Promoter Region ◽  
Promoter Activity ◽  
Secretory Pathway ◽  
Tata Box ◽  
Proximal Promoter ◽  
Prohormone Convertase ◽  
Specific Expression ◽  
Proximal Promoter Region ◽  
Prohormone Convertase 2

Prohormone convertases are involved in the tissue-specific endoproteolytic processing of prohormones and neuropeptide precursors within the secretory pathway. In the present study, we have isolated genomic clones comprising the 5ʹ-terminal region of the human prohormone convertase 2 (PC2) gene and established characteristics of the PC2 promoter region. The proximal promoter region is very G+C-rich and does not contain a canonical TATA box or a CAAT box. Transient expression assays with a set of human PC2 gene fragments containing progressive 5ʹ deletions demonstrate that the proximal promoter region is capable of directing high levels of neuroendocrine-specific expression of reporter gene constructs. In addition, we show that the transcription factor EGR-1 interacts with two distinct elements within the proximal human PC2 promoter region. Transfection experiments also demonstrate that EGR-1 is able to enhance PC2 promoter activity.

Regulation of basal core promoter activity of human organic cation transporter 1 (OCT1/SLC22A1)

2008 ◽  
Vol 295 (6) ◽  
pp. G1211-G1216 ◽  
Author(s):  
Moto Kajiwara ◽  
Tomohiro Terada ◽  
Jun-ichi Asaka ◽  
Masayo Aoki ◽  
Toshiya Katsura ◽  
...  
Keyword(s):  
Promoter Region ◽  
Promoter Activity ◽  
Organic Cation ◽  
Core Promoter ◽  
Organic Cation Transporter ◽  
Luciferase Assay ◽  
Basal Core Promoter ◽  
Human Liver Cell ◽  
E Box ◽  
Organic Cation Transporter 1

Human organic cation transporter 1 (OCT1/SLC22A1) plays important roles in the hepatic uptake of cationic drugs. The functional characteristics of this transporter have been well evaluated, but molecular information regarding transcriptional regulation is limited. In the present study, therefore, we examined the gene regulation of OCT1 gene focusing on basal core expression. An ∼2.5-kb fragment of the OCT1 promoter region was isolated, and promoter activity was measured by luciferase assay in the human liver cell lines Huh7 and HepG2. Deletion analysis suggested that the region spanning −141/−69 was essential for the basal core transcriptional activity and that this region contained the sequence of a cognate E-box (CACGTG). The E-box is known to be bound by the basal transcription factors, upstream stimulating factors (USFs), and the functional involvements of USF1 and USF2 were confirmed by a transactivation effect, a mutational analysis of the E-box, and an electrophoretic mobility shift assay. The transactivation effect of USFs on the OCT1 promoter was further stimulated by hepatocyte nuclear factor 4α, a liver-enriched transcription factor. There were no polymorphisms in the proximal promoter region (about 400 bp) of OCT1 gene ( n = 109). These findings indicated that both USF1 and USF2 bind to an E-box sequence located in the OCT1 core promoter region and are required for the basal gene expression of this transporter.

Proximal promoter region is sufficient to regulate tissue-specific expression of UDP-galactose: Ceramide galactosyltransferase gene

1998 ◽  
Vol 52 (6) ◽  
pp. 757-765 ◽  
Author(s):  
Tomoko Yonemasu ◽  
Kensuke Nakahira ◽  
Syunichiro Okumura ◽  
Tetsushi Kagawa ◽  
Araceli Espinosa de los Monteros ◽  
...  
Keyword(s):  
Promoter Region ◽  
Proximal Promoter ◽  
Specific Expression ◽  
Tissue Specific ◽  
Proximal Promoter Region ◽  
Tissue Specific Expression

Epigenetic changes in hypothalamic appetite regulatory genes may underlie the developmental programming for obesity in rat neonates subjected to a high-carbohydrate dietary modification

2013 ◽  
Vol 4 (6) ◽  
pp. 479-490 ◽  
Author(s):  
S. Mahmood ◽  
D. J. Smiraglia ◽  
M. Srinivasan ◽  
M. S. Patel
Keyword(s):  
Promoter Region ◽  
Molecular Mechanisms ◽  
Methylation Status ◽  
Proximal Promoter ◽  
Milk Formula ◽  
Proximal Promoter Region ◽  
Cpg Dinucleotides ◽  
High Carbohydrate ◽  
Histone 3 ◽  
Altered Gene

Earlier, we showed that rearing of newborn rats on a high-carbohydrate (HC) milk formula resulted in the onset of hyperinsulinemia, its persistence in the post-weaning period and adult-onset obesity. DNA methylation of CpG dinucleotides in the proximal promoter region and modifications in the N-terminal tail of histone 3 associated with the neuropeptide Y (Npy) and pro-opiomelanocortin (Pomc) genes were investigated to decipher the molecular mechanisms supporting the development of obesity in HC females. Although there were no differences in the methylation status of CpG dinucleotides in the proximal promoter region of the Pomc gene, altered methylation of specific CpG dinucleotides proximal to the transcription start site was observed for the Npy gene in the hypothalami of 16- and 100-day-old HC rats compared with their methylation status in mother-fed (MF) rats. Investigation of histone tail modifications on hypothalamic chromatin extracts from 16-day-old rats indicated decreased acetylation of lysine 9 in histone 3 (H3K9) for the Pomc gene and increased acetylation for the same residue for the Npy gene, without changes in histone methylation (H3K9) in both genes in HC rats. These findings are consistent with the changes in the levels of Npy and Pomc mRNAs in the hypothalami of HC rats compared with MF animals. Our results suggest that epigenetic modifications could contribute to the altered gene expression of the Npy and Pomc genes in the hypothalami of HC rats and could be a mechanism leading to hyperphagia and the development of obesity in adult female HC rats.

scholarly journals Correlation of methylation status in MTHFR promoter region with recurrent pregnancy loss

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Mai Mahmoud Shaker ◽  
Taghreed Abdelmoniem shalabi ◽  
Khalda said Amr
Keyword(s):  
Dna Methylation ◽  
Dna Sequences ◽  
Promoter Region ◽  
Pregnancy Loss ◽  
Recurrent Pregnancy Loss ◽  
Methylation Status ◽  
Control Group ◽  
Case Group ◽  
Methyl Radical ◽  
Fertile Women

Abstract Background DNA methylation is an epigenetic process for modifying transcription factors in various genes. Methylenetetrahydrofolate reductase (MTHFR) stimulates synthesis of methyl radical in the homocysteine cycle and delivers methyl groups needed in DNA methylation. Furthermore, numerous studies have linked gene polymorphisms of this enzyme with a larger risk of recurrent pregnancy loss (RPL), yet scarce information is available concerning the association between epigenetic deviations in this gene and RPL. Hypermethylation at precise DNA sequences can function as biomarkers for a diversity of diseases. We aimed by this study to evaluate the methylation status of the promoter region of MTHFR gene in women with RPL compared to healthy fertile women. It is a case–control study. Hundred RPL patients and hundred healthy fertile women with no history of RPL as controls were recruited. MTHFR C677T was assessed by polymerase chain reaction-restriction fragment length polymorphism (RFLP). Quantitative evaluation of DNA methylation was performed by high-resolution melt analysis by real-time PCR. Results The median of percentage of MTHFR promoter methylation in RPL cases was 6.45 [0.74–100] vs. controls was 4.50 [0.60–91.7], P value < 0.001. In the case group, 57 hypermethylated and 43 normo-methylated among RPL patients vs. 40 hypermethylated and 60 normo-methylated among controls, P< 0.005. Frequency of T allele in C677T MTHFR gene among RPL patients was 29% vs. 23% among the control group; C allele vs. T allele: odds ratio (OR) = 1.367 (95% confidence interval (CI) 0.725–2.581). Conclusion Findings suggested a significant association between hypermethylation of the MTHFR promoter region in RPL patients compared to healthy fertile women.

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