Interaction of upstream stimulatory factor proteins with an E-box located within the human CYP1A2 5′-flanking gene contributes to basal transcriptional gene activation

2003 ◽  
Vol 65 (7) ◽  
pp. 1087-1096 ◽  
George V. Pickwell ◽  
Hsueh Shih ◽  
Linda C. Quattrochi
Endocrinology ◽  
2012 ◽  
Vol 153 (1) ◽  
pp. 492-500 ◽  
Naotetsu Kanamoto ◽  
Tetsuya Tagami ◽  
Yoriko Ueda-Sakane ◽  
Masakatsu Sone ◽  
Masako Miura ◽  

Type 1 iodothyronine deiodinase (D1), a selenoenzyme that catalyzes the bioactivation of thyroid hormone, is expressed mainly in the liver. Its expression and activity are modulated by several factors, but the precise mechanism of its transcriptional regulation remains unclear. In the present study, we have analyzed the promoter of human D1 gene (hDIO1) to identify factors that prevalently increase D1 activity in the human liver. Deletion and mutation analyses demonstrated that a forkhead box (FOX)A binding site and an E-box site within the region between nucleotides −187 and −132 are important for hDIO1 promoter activity in the liver. EMSA demonstrated that FOXA1 and FOXA2 specifically bind to the FOXA binding site and that upstream stimulatory factor (USF) specifically binds to the E-box element. Overexpression of FOXA2 decreased hDIO1 promoter activity, and short interfering RNA-mediated knockdown of FOXA2 increased the expression of hDIO1 mRNA. In contrast, overexpression of USF1/2 increased hDIO1 promoter activity. Short interfering RNA-mediated knockdown of FOXA1 decreased the expression of hDIO1 mRNA, but knockdown of both FOXA1 and FOXA2 restored it. The response of the hDIO1 promoter to USF was greatly attenuated in the absence of FOXA1. Taken together, these results indicate that a balance of FOXA1 and FOXA2 expression modulates hDIO1 expression in the liver.

2003 ◽  
Vol 369 (3) ◽  
pp. 549-561 ◽  
Judy M. COULSON ◽  
Jodie L. EDGSON ◽  
Robert MULGREW ◽  
John P. QUINN ◽  

We have described previously a complex E-box enhancer (-147) of the vasopressin promoter in small-cell lung cancer (SCLC) extracts [Coulson, Fiskerstrand, Woll and Quinn, (1999) Biochem. J. 344, 961—970]. Upstream stimulatory factor (USF) heterodimers were one of the complexes binding to this site in vitro. We now report that USF overexpression in non-SCLC (NSCLC) cells can functionally activate vasopressin promoter-driven reporters that are otherwise inactive in this type of lung cancer cell. Site-directed mutagenesis and electrophoretic mobility-shift analysis demonstrate that although the −147 E-box contributes, none of the previously predicted E-boxes (-147, −135, −34) wholly account for this USF-mediated activation in NSCLC. 5′ Deletion showed the key promoter region as −52 to +42; however, USF-2 binding was not reliant on the −34 E-box, but on a novel adjacent CACGGG non-canonical E-box at −42 (motif E). This mediated USF binding in both SCLC and USF-2-transfected NSCLC cells. Mutation of motif E or the non-canonical TATA box abolished activity, implying both are required for transcriptional initiation on overexpression of USF-2. Co-transfected dominant negative USF confirmed that binding was required through motif E for function, but that the classical activation domain of USF was not essential. USF-2 bound motif E with 10-fold lower affinity than the −147 E-box. In NSCLC, endogenous USF-2 expression is low, and this basal level appears to be insufficient to activate transcription of arginine vasopressin (AVP). In summary, we have demonstrated a novel mechanism for USF activation, which contributes to differential vasopressin expression in lung cancer.

2001 ◽  
Vol 357 (1) ◽  
pp. 97-105 ◽  
Yubin GE ◽  
Mark A. KONRAD ◽  
Larry H. MATHERLY ◽  
Jeffrey W. TAUB

Cystathionine β-synthase (CBS) catalyses the condensation of serine and homocysteine to form cystathionine, an intermediate step in the synthesis of cysteine. Human CBS encodes five distinct 5′ non-coding exons, the most frequent termed CBS −1a and CBS −1b, each transcribed from its own unique GC-rich TATA-less promoter. The minimal transcriptional region (−3792 to −3667) of the CBS −1b promoter was defined by 5′- and 3′-deletions, and transient transfections of reporter gene constructs in HepG2 cells, characterized by CBS transcription exclusively from the −1b promoter. Included in this 125bp region are 3 GC-boxes (termed GC-a, GC-b and GC-c), an inverted CAAT-box and an E-box. By gel-shift and supershift assays, binding of specificity protein (Sp)1 and Sp3 to the GC-box elements, upstream stimulatory factor 1 (USF-1) to the E-box, and both nuclear factor (NF)-Y and an NF-1-like factor to the CAAT box could be demonstrated. By transient trans fections and reporter gene assays in HepG2 and Drosophila SL2 cells, a functional interplay was indicated between NF-Y binding to the CAAT-box, or between USF-1 binding to the E-box, and Sp1/Sp3 binding to the GC-box elements. In SL2 cells, NF-Y and Sp1/Sp3 were synergistic. Furthermore, both Sp1 and the long Sp3 isoform transactivated the CBS −1b minimal promoter; however, the short Sp3 isoforms were potent repressors. These results may explain the cell- or tissue-specific regulation of CBS transcription, and clarify the bases for alterations in CBS gene expression in human disease and Down's syndrome.

Endocrinology ◽  
2009 ◽  
Vol 150 (8) ◽  
pp. 3783-3791 ◽  
Pushpa Viswanathan ◽  
Michelle A. Wood ◽  
William H. Walker

FSH acts through the FSH receptor (FSHR) to modulate cell processes that are required to support developing spermatozoa. Within the testis, only Sertoli cells possess receptors for FSH and are the major targets for this regulator of spermatogenesis. FSH stimulation of Sertoli cells for 24–48 h is known to induce Fshr mRNA expression through an E-box motif (CACGTG) located 25 bp upstream of the transcription start site. In contrast, FSH stimulation for 8 h inhibits Fshr transcription. DNA-protein binding studies performed using nuclear extracts from Sertoli cells show that protein binding to the Fshr promoter E-box was reduced 68% after 6 h of FSH stimulation but increased 191% over basal levels after 48 h of stimulation. The proteins binding to the Fshr E-box were identified as upstream stimulatory factor (USF)-1 and -2. FSH stimulation transiently decreased USF1 levels and increased the expression of the inhibitor of DNA binding/differentiation (ID)-2 repressor protein with the same kinetics as the decreased USF/E-box interactions. Overexpression of ID2 resulted in a dose-dependent decrease in USF-driven Fshr promoter activity in the MSC-1 Sertoli cell line, and ID2 inhibited USF binding to the Fshr E-box. Together, these studies suggest that stimulation of Sertoli cells with FSH transiently decreases expression of the USF1 activator and induces accumulation of the ID2 repressor, to block USF binding to the Fshr promoter and delay activation of Fshr transcription. This FSH-regulated mechanism may explain the cyclical changes in Fshr expression that occurs in Sertoli cells in vivo.

Blood ◽  
2004 ◽  
Vol 104 (7) ◽  
pp. 2027-2034 ◽  
Yoshiaki Okada ◽  
Eri Matsuura ◽  
Zenzaburo Tozuka ◽  
Ryohei Nagai ◽  
Ayako Watanabe ◽  

Abstract Platelet factor 4 (PF4) is expressed during megakaryocytic differentiation. We previously demonstrated that the homeodomain proteins (myeloid ecotropic integra tion site 1 [MEIS1], Pbx-regulating protein 1 [PREP1], and pre-B-cell leukemia transcription factors [PBXs]) bind to the novel regulatory element tandem repeat of MEIS1 binding element [TME] and transactivate the rat PF4 promoter. In the present study, we investigated and identified other TME binding proteins in megakaryocytic HEL cells using mass spectrometry. Among identified proteins, we focused on upstream stimulatory factor (USF1) and USF2 and investigated their effects on the PF4 promoter. USF1 and 2 bound to the E-box motif in the TME and strongly transactivated the PF4 promoter. Furthermore, physiologic bindings of USF1 and 2 to the TME in rat megakaryocytes were demonstrated by the chromatin immunoprecipitation (ChIP) assay. Interestingly, the E-box motif in the TME was conserved in TME-like sequences of both the human and mouse PF4 promoters. USF1 and 2 also bound to the human TME-like sequence and transactivated the human PF4 promoter. Expressions of USF1 and 2 were detected by reverse-transcriptase–polymerase chain reaction (RT-PCR) in the human megakaryocytes derived from CD34+ cells. Thus, these studies demonstrate that the novel TME binding transcription factors, USF1 and 2, transactivate rat and human PF4 promoters and may play an important role in megakaryocytic gene expression.

2001 ◽  
Vol 359 (2) ◽  
pp. 273-284 ◽  
Maureen T. TRAVERS ◽  
Amanda J. VALLANCE ◽  
Helen T. GOURLAY ◽  
Clare A. GILL ◽  
Izabella KLEIN ◽  

Acetyl-CoA carboxylase-α (ACC-α) plays a central role in co-ordinating de novo fatty acid synthesis in animal tissues. We have characterized the regulatory region of the ovine ACC-α gene. Three promoters, PI, PII and PIII, are dispersed throughout 50kb of genomic DNA. Expression from PI is limited to adipose tissue and liver. Sequence comparison of the proximal promoters of ovine and mouse PIs demonstrates high nucleotide identity and that they are characterized by a TATA box at −29, C/EBP (CCAAT enhancer-binding protein)-binding motifs and multiple E-box motifs. A 4.3kb ovine PI-luciferase reporter construct is insulin-responsive when transfected into differentiated ovine adipocytes, whereas when this construct is transfected into ovine preadipocytes and HepG2 cells the construct is inactive and is not inducible by insulin. By contrast, transfection of a construct corresponding to 132bp of the proximal promoter linked to a luciferase reporter is active and inducible by insulin in all three cell systems. Insulin signalling to the −132bp construct in differentiated ovine adipocytes involves, in part, an E-box motif at −114. Upstream stimulatory factor (USF)-1 and USF-2, but not sterol regulatory element-binding protein 1 (SREBP-1), are major components of protein complexes that bind this E-box motif. Activation of the 4.3kb PI construct in differentiated ovine adipocytes is associated with endogenous expression of PI transcripts throughout differentiation; PI transcripts are not detectable by RNase-protection assay in ovine preadipocytes, HepG2 cells or 3T3-F442A adipocytes. These data indicate the presence of repressor motifs in PI that are required to be de-repressed during adipocyte differentiation to allow induction of the promoter by insulin.

2003 ◽  
Vol 284 (6) ◽  
pp. L1027-L1036 ◽  
Erwei Gao ◽  
Ying Wang ◽  
Joseph L. Alcorn ◽  
Carole R. Mendelson

Expression of the pulmonary surfactant protein A ( SP-A) gene is lung specific, developmentally regulated, and enhanced by hormones and factors that increase cAMP. We previously identified two E-box-like enhancers termed distal binding element (DBE) and proximal binding element (PBE) in the 5′-flanking region of the rabbit (r) SP-A gene that are essential for cAMP induction of rSP-A promoter activity (Gao E, Alcorn JL, and Mendelson CR. J Biol Chem 268: 19697–19709, 1993). We also found that DBE and PBE serve as binding sites for the basic helix-loop-helix-leucine zipper transcription factor, upstream stimulatory factor-1 (USF1) (Gao E, Wang Y, Alcorn JL, and Mendelson CR. J Biol Chem 272: 23398–23406, 1997). In the present study, PBE was used to screen a rabbit fetal lung cDNA expression library; a cDNA insert encoding the structurally related rabbit upstream stimulatory factor-2 (rUSF2) was isolated. The levels of rUSF2 mRNA reach peak levels in fetal rabbit lung at 28 days of gestation, in concert with the time of maximal induction of SP-A gene transcription. In yeast two-hybrid analysis, rUSF2 was found to preferentially form heterodimers, compared with homodimers, with rUSF1. Binding complexes of nuclear proteins isolated from fetal rabbit lung type II cells with the DBE and PBE were supershifted by anti-rUSF2 antibodies. Binding activity was enriched in nuclear proteins from type II cells compared with fibroblasts. Overexpression of rUSF2 in transfected lung A549 cells increased rSP-A promoter activity and acted synergistically with rUSF1. We suggest that heterodimers of USF2 and USF1 bound to two E-box elements in the SP-A gene 5′-flanking region serve a key role in developmental and hormonal regulation of SP-A gene expression in pulmonary type II cells.

2012 ◽  
Vol 446 (1) ◽  
pp. 89-98 ◽  
Bohao Chen ◽  
Rona Hsu ◽  
Zhenping Li ◽  
Paul C. Kogut ◽  
Qingxia Du ◽  

Silencing of GATA5 gene expression as a result of promoter hypermethylation has been observed in lung, gastrointestinal and ovarian cancers. However, the regulation of GATA5 gene expression has been poorly understood. In the present study, we have demonstrated that an E (enhancer)-box in the GATA5 promoter (bp −118 to −113 in mice; bp −164 to −159 in humans) positively regulates GATA5 transcription by binding USF1 (upstream stimulatory factor 1). Using site-directed mutagenesis, EMSA (electrophoretic mobility-shift analysis) and affinity chromatography, we found that USF1 specifically binds to the E-box sequence (5′-CACGTG-3′), but not to a mutated E-box. CpG methylation of this E-box significantly diminished its binding of transcription factors. Mutation of the E-box within a GATA5 promoter fragment significantly decreased promoter activity in a luciferase reporter assay. Chromatin immunoprecipitation identified that USF1 physiologically interacts with the GATA5 promoter E-box in mouse intestinal mucosa, which has the highest GATA5 gene expression in mouse. Co-transfection with a USF1 expression plasmid significantly increased GATA5 promoter-driven luciferase transcription. Furthermore, real-time and RT (reverse transcription)–PCR analyses confirmed that overexpression of USF1 activates endogenous GATA5 gene expression in human bronchial epithelial cells. The present study provides the first evidence that USF1 activates GATA5 gene expression through the E-box motif and suggests a potential mechanism (disruption of the E-box) by which GATA5 promoter methylation reduces GATA5 expression in cancer.

Sign in / Sign up

Export Citation Format

Share Document