scholarly journals CpG methylation at the USF-binding site mediates cell-specific transcription of human ascorbate transporter SVCT2 exon 1a

2011 ◽  
Vol 440 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Huan Qiao ◽  
James M. May
Keyword(s):  
Vitamin C ◽  
Binding Site ◽  
Promoter Activity ◽  
Cpg Methylation ◽  
Nuclear Factor ◽  
Discrete Elements ◽  
Nuclear Factor Y ◽  
Cpg Site ◽  
E Boxes ◽  
Stimulating Factor

SVCT2 (sodium–vitamin C co-transporter 2) is the major transporter mediating vitamin C uptake in most organs. Its expression is driven by two promoters (CpG-poor exon 1a promoter and CpG-rich exon 1b promoter). In the present study, we mapped discrete elements within the proximal CpG-poor promoter responsible for exon 1a transcription. We identified two E boxes for USF (upstream stimulating factor) binding and one Y box for NF-Y (nuclear factor Y) binding. We show further that NF-Y and USF bind to the exon 1a promoter in a co-operative manner, amplifying the binding of each to the promoter, and is absolutely required for the full activity of the exon 1a promoter. The analysis of the CpG site located at the upstream USF-binding site in the promoter showed a strong correlation between expression and demethylation. It was also shown that exon 1a transcription was induced in cell culture treated with the demethylating agent decitabine. The specific methylation of this CpG site impaired both the binding of USF and the formation of the functional NF-Y–USF complex as well as promoter activity, suggesting its importance for cell-specific transcription. Thus CpG methylation at the upstream USF-binding site functions in establishing and maintaining cell-specific transcription from the CpG-poor SVCT2 exon 1a promoter.

A Nuclear Factor Y (NFY) Site Positively Regulates the Human CD34 Stem Cell Gene

Blood ◽  
1999 ◽  
Vol 94 (11) ◽  
pp. 3772-3780 ◽  
Author(s):  
Hanna S. Radomska ◽  
Anne B. Satterthwaite ◽  
Natalie Taranenko ◽  
Sailaja Narravula ◽  
Diane S. Krause ◽  
...  
Keyword(s):  
Binding Site ◽  
Promoter Activity ◽  
Cell Types ◽  
Critical Element ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Nuclear Factor Y ◽  
Human Cd34 ◽  
Expression Of Genes ◽  
Ccaat Box

Proper regulation of the human CD34 gene requires a combinatorial action of multiple proximal and long-range, ciselements. This report shows that, like the murine CD34 5′ untranslated region (UTR), the corresponding region of the human CD34 gene is necessary for optimal promoter activity. We localized the most critical element of this region to base pairs +48/+75. Through oligonucleotide competition and antibody supershift experiments in electrophoretic mobility shift assays, we found that this sequence contains a binding site (CCAAT box) for the transcription factor NFY (nuclear factor Y), a factor mediating cell type-specific and cell-cycle regulated expression of genes. Mutating this site led to a 5-fold decrease in CD34 promoter activity in transient transfection experiments. Interestingly, NFY binds adjacently to the earlier identified c-myb binding site. Here we show that both binding sites are important for CD34 promoter function: mutating either site alone decreased CD34 promoter-driven reporter gene activity 4-fold. We also show that the integrity of the c-myb binding site is necessary for stabilization of NFY binding to its site. Such cooperation between c-myb, which is expressed in early hematopoietic cells, and NFY, which is expressed in many cell types, might contribute to specific activation of CD34 in stem cells. The CCAAT box motif was also noted in the 5′ UTR of the murine CD34 gene, however, NFY did not bind to this region. Thus, our results indicate that the functional similarities between the human and murine CD34 5′ UTRs are achieved through different molecular mechanism(s).

A Nuclear Factor Y (NFY) Site Positively Regulates the Human CD34 Stem Cell Gene

Blood ◽  
1999 ◽  
Vol 94 (11) ◽  
pp. 3772-3780 ◽  
Author(s):  
Hanna S. Radomska ◽  
Anne B. Satterthwaite ◽  
Natalie Taranenko ◽  
Sailaja Narravula ◽  
Diane S. Krause ◽  
...  
Keyword(s):  
Binding Site ◽  
Promoter Activity ◽  
Cell Types ◽  
Critical Element ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Nuclear Factor Y ◽  
Human Cd34 ◽  
Expression Of Genes ◽  
Ccaat Box

Abstract Proper regulation of the human CD34 gene requires a combinatorial action of multiple proximal and long-range, ciselements. This report shows that, like the murine CD34 5′ untranslated region (UTR), the corresponding region of the human CD34 gene is necessary for optimal promoter activity. We localized the most critical element of this region to base pairs +48/+75. Through oligonucleotide competition and antibody supershift experiments in electrophoretic mobility shift assays, we found that this sequence contains a binding site (CCAAT box) for the transcription factor NFY (nuclear factor Y), a factor mediating cell type-specific and cell-cycle regulated expression of genes. Mutating this site led to a 5-fold decrease in CD34 promoter activity in transient transfection experiments. Interestingly, NFY binds adjacently to the earlier identified c-myb binding site. Here we show that both binding sites are important for CD34 promoter function: mutating either site alone decreased CD34 promoter-driven reporter gene activity 4-fold. We also show that the integrity of the c-myb binding site is necessary for stabilization of NFY binding to its site. Such cooperation between c-myb, which is expressed in early hematopoietic cells, and NFY, which is expressed in many cell types, might contribute to specific activation of CD34 in stem cells. The CCAAT box motif was also noted in the 5′ UTR of the murine CD34 gene, however, NFY did not bind to this region. Thus, our results indicate that the functional similarities between the human and murine CD34 5′ UTRs are achieved through different molecular mechanism(s).

scholarly journals The nuclear factor YY1 suppresses the human gamma interferon promoter through two mechanisms: inhibition of AP1 binding and activation of a silencer element.

1996 ◽  
Vol 16 (9) ◽  
pp. 4744-4753 ◽  
Author(s):  
J Ye ◽  
M Cippitelli ◽  
L Dorman ◽  
J R Ortaldo ◽  
H A Young
Keyword(s):  
Dna Binding ◽  
Binding Site ◽  
Dna Sequences ◽  
Promoter Activity ◽  
Cell Activation ◽  
Gamma Interferon ◽  
Nuclear Factor ◽  
Enhancer Activity ◽  
Ifn Gamma ◽  
Silencer Element

Our group has previously reported that the nuclear factor Yin-Yang 1 (YY1), a ubiquitous DNA-binding protein, is able to interact with a silencer element (BE) in the gamma interferon (IFN-gamma) promoter region. In this study, we demonstrated that YY1 can directly inhibit the activity of the IFN-gamma promoter by interacting with multiple sites in the promoter. In cotransfection assays, a YY1 expression vector significantly inhibited IFN-gamma promoter activity. Mutation of the YY1 binding site in the native IFN-gamma promoter was associated with an increase in the IFN-gamma promoter activity. Analysis of the DNA sequences of the IFN-gamma promoter revealed a second functional YY1 binding site (BED) that overlaps with an AP1 binding site. In this element, AP1 enhancer activity was suppressed by YY1. Since the nuclear level of YY1 does not change upon cell activation, our data support a model that the nuclear factor YY1 acts to suppress basal IFN-gamma transcription by interacting with the promoter at multiple DNA binding sites. This repression can occur through two mechanisms: (i) cooperation with an as-yet-unidentified AP2-like repressor protein and (ii) competition for DNA binding with the transactivating factor AP1.

scholarly journals Transactivation of the Parathyroid Hormone Promoter by Specificity Proteins and the Nuclear Factor Y Complex

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3409-3416 ◽  
Author(s):  
Alexander P. Alimov ◽  
Ok-Kyong Park-Sarge ◽  
Kevin D. Sarge ◽  
Hartmut H. Malluche ◽  
Nicholas J. Koszewski
Keyword(s):  
Parathyroid Hormone ◽  
Binding Site ◽  
Gene Transcription ◽  
Nuclear Factor ◽  
Nuclear Factor Y ◽  
Specificity Protein 1 ◽  
Nuclear Extracts ◽  
Promoter Construct ◽  
Helical Turn ◽  
Specificity Protein

Abstract We previously identified a highly conserved specificity protein 1 (Sp1) DNA element in mammalian PTH promoters that acted as an enhancer of gene transcription and bound Sp1 and Sp3 proteins present in parathyroid gland nuclear extracts. More recently, a nuclear factor (NF)-Y element (NF-Yprox) was also described by our group, which was located approximately 30 bp downstream from the Sp1 site in the human PTH (hPTH) promoter and by itself acted as a weak enhancer of gene transcription. We now report that Sp proteins and NF-Y can synergistically enhance transcription of a minimal hPTH promoter construct. Positioning of the Sp1 DNA element appears to be critical for this synergism because deviations of one half of a helical turn caused an approximate 60% decrease in transactivation. Finally, examination of the bovine PTH (bPTH) promoter also revealed Sp1/NF-Y synergism, in conjunction with the identification of an analogous NF-Y binding site similarly positioned downstream from the bPTH Sp1 element. In summary, synergistic transactivation of the hPTH and bPTH promoters is observed by Sp proteins and the NF-Y complex. The conservation of this transactivation in the human and bovine promoters suggests that this may be a principle means of enhancing PTH gene transcription.

Nuclear factor Y regulates ancient budgerigar hepadnavirus core promoter activity

2016 ◽  
Vol 478 (2) ◽  
pp. 825-830 ◽  
Author(s):  
Zhongliang Shen ◽  
Yanfeng Liu ◽  
Mengjun Luo ◽  
Wei Wang ◽  
Jing Liu ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Core Promoter ◽  
Nuclear Factor ◽  
Nuclear Factor Y ◽  
Core Promoter Activity

scholarly journals Characterization of the human topoisomerase IIβ (TOP2B) promoter activity: essential roles of the nuclear factor-Y (NF-Y)- and specificity protein-1 (Sp1)-binding sites

2002 ◽  
Vol 368 (3) ◽  
pp. 741-751 ◽  
Author(s):  
Chun-Nam LOK ◽  
Alexander J. LANG ◽  
Shelagh E.L. MIRSKI ◽  
Susan P.C. COLE
Keyword(s):  
Binding Sites ◽  
Promoter Activity ◽  
Luciferase Reporter ◽  
Cancer Drug ◽  
Resting Cells ◽  
Nuclear Factor ◽  
Nuclear Factor Y ◽  
Specificity Protein 1 ◽  
Topo Ii ◽  
Specificity Protein

Eukaryotic topoisomerase II (topo II) catalyses topological genomic changes essential for chromosome segregation, chromatin reorganization, DNA replication and transcription. Mammalian topo II exists as two isoforms, designated α and β. Human topo IIα is an important cancer drug target, and an established determinant of drug sensitivity and resistance. Human topo IIβ is also the target of anticancer drugs but its role in drug resistance is less clear. The two human topo II proteins are encoded by the TOP2A and TOP2B genes, respectively, which despite their highly conserved structural organization, are subject to distinctly different modes of regulation. In the present study, we have cloned and characterized the human TOP2B promoter containing a 1.3kb fragment of the 5′-flanking and untranslated region (-1067 to +193). We found that the promoter activity of this TOP2B fragment was constant throughout the cell cycle, in contrast to the activity of the proximal promoter of TOP2A which was low in resting cells and enhanced during proliferation. Analyses of 5′-serially and internally deleted luciferase reporter constructs revealed that 80% of the TOP2B promoter activity could be attributed to the region between −533 and −481. Mutational analyses of putative regulatory elements indicated that two inverted CCAAT boxes (ICBs) within this region were essential for TOP2B promoter activity and gel mobility-shift assays indicated these sites bound the transcription factor nuclear factor-Y (NF-Y). Co-transfection experiments using a dominant-negative form of subunit A of NF-Y suggested that TOP2B promoter activity required direct interaction of NF-Y with the ICBs. In addition, a specificity protein-1 (Sp1)-binding GC box located just upstream of the ICBs was shown to contribute to TOP2B promoter activity in a synergistic manner with the ICBs. Our results suggest that the binding sites for NF-Y and Sp1 are critical for TOP2B transcription.

Nuclear factor Y (NF-Y) regulates the proximal promoter activity of the mouse collagen α1(XI) gene (Col11a1) in chondrocytes

2013 ◽  
Vol 50 (4) ◽  
pp. 358-366 ◽  
Author(s):  
Mariko Hida ◽  
Ryoji Hamanaka ◽  
Osamu Okamoto ◽  
Kouhei Yamashita ◽  
Takako Sasaki ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Proximal Promoter ◽  
Nuclear Factor ◽  
Nuclear Factor Y
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