Transcriptional Regulation of the Human Cholecystokinin Gene: Composite Action of Upstream Stimulatory Factor, Sp1, and Members of the CREB/ATF-AP-1 Family of Transcription Factors

Abstract Hepcidin is the presumed negative regulator of systemic iron levels; its expression is induced in iron overload, infection, and inflammation, and by cytokines, but is suppressed in hypoxia and anemia. Although the gene is exquisitely sensitive to changes in iron status in vivo, its mRNA is devoid of prototypical iron-response elements, and it is therefore not obvious how it may be regulated by iron flux. The multiplicity of effectors of its expression also suggests that the transcriptional circuitry controlling the gene may be very complex indeed. In delineating enhancer elements within both the human and mouse hepcidin gene promoters, we show here that members of the basic helix-loop-helix leucine zipper (bHLH-ZIP) family of transcriptional regulators control hepcidin expression. The upstream stimulatory factor 2 (USF2), previously linked to hepcidin through gene ablation in inbred mice, appears to exert a polar or cis-acting effect, while USF1 may act in trans to control hepcidin expression. In mice, we found variation in expression of both hepcidin genes, driven by these transcription factors. In addition, c-Myc and Max synergize to control the expression of this hormone, supporting previous findings for the role of this couple in regulating iron metabolism. Transcriptional activation by both USF1/USF2 and c-Myc/Max heterodimers occurs through E-boxes within the promoter. Site-directed mutagenesis of these elements rendered the promoter unresponsive to USF1/USF2 or c-Myc/Max. Dominant-negative mutants of USF1 and USF2 reciprocally attenuated promoter transactivation by both wild-type USF1 and USF2. Promoter occupancy by the transcription factors was confirmed by DNA-binding and chromatin immunoprecipitation assays. Taken together, it would appear that synergy between these members of the bHLH-ZIP family of transcriptional regulators may subserve an important role in iron metabolism as well as other pathways in which hepcidin may be involved.

Download Full-text

Upstream stimulatory factors stimulate transcription through E-box motifs in the PF4 gene in megakaryocytes

Blood ◽

10.1182/blood-2003-09-3107 ◽

2004 ◽

Vol 104 (7) ◽

pp. 2027-2034 ◽

Cited By ~ 16

Author(s):

Yoshiaki Okada ◽

Eri Matsuura ◽

Zenzaburo Tozuka ◽

Ryohei Nagai ◽

Ayako Watanabe ◽

...

Keyword(s):

Transcription Factors ◽

Regulatory Element ◽

The Novel ◽

Upstream Stimulatory Factor ◽

Platelet Factor ◽

Cd34 Cells ◽

E Box ◽

Hel Cells ◽

B Cell Leukemia ◽

Stimulatory Factor

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.

Download Full-text

Orphan Receptor Chicken Ovalbumin Upstream Promoter Transcription Factors Inhibit Steroid Factor-1, Upstream Stimulatory Factor, and Activator Protein-1 Activation of Ovine Follicle-Stimulating Hormone Receptor Expression via Composite cis-Elements1

Biology of Reproduction ◽

10.1095/biolreprod66.6.1656 ◽

2002 ◽

Vol 66 (6) ◽

pp. 1656-1666 ◽

Cited By ~ 25

Author(s):

Weirong Xing ◽

Natalia Danilovich ◽

M. Ram Sairam

Keyword(s):

Transcription Factors ◽

Follicle Stimulating Hormone ◽

Receptor Expression ◽

Orphan Receptor ◽

Activator Protein 1 ◽

Upstream Stimulatory Factor ◽

Upstream Promoter ◽

Hormone Receptor Expression ◽

Stimulatory Factor ◽

Chicken Ovalbumin

Download Full-text

The role of upstream stimulatory factor 1 in the transcriptional regulation of the human TBX21 promoter mediated by the T-1514C polymorphism associated with systemic lupus erythematosus

Immunogenetics ◽

10.1007/s00251-011-0597-6 ◽

2012 ◽

Vol 64 (5) ◽

pp. 361-370 ◽

Cited By ~ 7

Author(s):

Junggang Li ◽

Jirong Li ◽

Yi You ◽

Song Chen

Keyword(s):

Systemic Lupus Erythematosus ◽

Transcriptional Regulation ◽

Lupus Erythematosus ◽

Upstream Stimulatory Factor ◽

Systemic Lupus ◽

Upstream Stimulatory Factor 1 ◽

Stimulatory Factor

Download Full-text

Synergistic role of specificity proteins and upstream stimulatory factor 1 in transactivation of the mouse carboxylesterase 2/microsomal acylcarnitine hydrolase gene promoter

Biochemical Journal ◽

10.1042/bj20040765 ◽

2004 ◽

Vol 384 (1) ◽

pp. 101-110 ◽

Cited By ~ 28

Author(s):

Tomomi FURIHATA ◽

Masakiyo HOSOKAWA ◽

Tetsuo SATOH ◽

Kan CHIBA

Keyword(s):

Transcription Factors ◽

Molecular Mechanisms ◽

Expression Profiles ◽

Gene Promoter ◽

Nuclear Factor Κb ◽

Tissue Expression ◽

Upstream Stimulatory Factor ◽

Specificity Protein ◽

Upstream Stimulatory Factor 1 ◽

Stimulatory Factor

Mouse carboxylesterase 2 (mCES2), a microsomal acylcarnitine hydrolase, is thought to play some important roles in fatty acid (ester) metabolism, and it is therefore thought that the level of transcription of the mCES2 gene is under tight control. Examination of the tissue expression profiles revealed that mCES2 is expressed in the liver, kidney, small intestine, brain, thymus, lung, adipose tissue and testis. When the mCES2 promoter was cloned and characterized, it was revealed that Sp1 (specificity protein 1) and Sp3 could bind to a GC box, that USF (upstream stimulatory factor) 1 could bind to an E (enhancer) box, and that Sp1 could bind to an NFκB (nuclear factor κB) element in the mCES2 promoter. Co-transfection assays showed that all of these transcription factors contributed synergistically to transactivation of the mCES2 promoter. Taken together, our results indicate that Sp1, Sp3 and USF1 are indispensable factors for transactivation of the mCES2 gene promoter. To our knowledge, this is the first study in which transcription factors that interact with a CES2 family gene have been identified. The results of the present study have provided some clues for understanding the molecular mechanisms regulating mCES2 gene expression, and should be useful for studies aimed at elucidation of physiological functions of mCES2.

Download Full-text

Transcription factors acting on the promoter of the rat fatty acid synthase gene

Biochemical Society Transactions ◽

10.1042/bst0301070 ◽

2002 ◽

Vol 30 (6) ◽

pp. 1070-1072 ◽

Cited By ~ 24

Author(s):

M. Schweizer ◽

K. Roder ◽

L. Zhang ◽

S. S. Wolf

Keyword(s):

Transcription Factors ◽

Fatty Acid ◽

Binding Sites ◽

Fatty Acid Synthase ◽

Regulatory Element ◽

Upstream Stimulatory Factor ◽

Element Binding Protein ◽

Sterol Regulatory Element ◽

Responsive Element ◽

Stimulatory Factor

Fatty acid synthase (FAS), one of the main lipogenic enzymes, converts dietary calories into a storage form of energy. The transcription factors, stimulatory proteins 1 and 3 (Sp1 and Sp3), nuclear factor Y (NF-Y), upstream stimulatory factor (USF) and sterol regulatory element binding protein-1 (SREBP-1) have cognate binding sites on the promoter of the FAS gene. It was shown that Sp1 and NF-Y interact co-operatively at the diet-induced DNase I-hypersensitive site at position —500. Adjacent binding sites for NF-Y and Sp1 have also been found between —71 and —52, and —91 and —83. cAMP regulation is mediated via the inverted CAAT element (ICE) at —99 to —92, which binds NF-Y. The FAS insulin-responsive element 3 (FIRE3)-binding site at —71 to —52 is capable of binding NF-Y, USF and SREBP-1, and is required for the sterol response in conjunction with the co-activator NF-Y around —100. Surprisingly, both FIRE3 and ICE are also necessary for the response to retinoic acid that plays a role in development and is an essential component of the diet.

Download Full-text

Role of upstream stimulatory factor 2 in glutamate dehydrogenase gene transcription

Journal of Molecular Endocrinology ◽

10.1530/jme-17-0142 ◽

2018 ◽

Vol 60 (3) ◽

pp. 247-259 ◽

Cited By ~ 3

Author(s):

Carlos Gaspar ◽

Jonás I Silva-Marrero ◽

María C Salgado ◽

Isabel V Baanante ◽

Isidoro Metón

Keyword(s):

Transcriptional Regulation ◽

Tissue Distribution ◽

Glutamate Dehydrogenase ◽

Sea Bream ◽

Mrna Levels ◽

Nutritional Regulation ◽

Upstream Stimulatory Factor ◽

Hepatic Expression ◽

Stimulatory Factor

Glutamate dehydrogenase (Gdh) plays a central role in ammonia detoxification by catalysing reversible oxidative deamination of l-glutamate into α-ketoglutarate using NAD+ or NADP+ as cofactor. To gain insight into transcriptional regulation of glud, the gene that codes for Gdh, we isolated and characterised the 5′ flanking region of glud from gilthead sea bream (Sparus aurata). In addition, tissue distribution, the effect of starvation as well as short- and long-term refeeding on Gdh mRNA levels in the liver of S. aurata were also addressed. 5′-Deletion analysis of glud promoter in transiently transfected HepG2 cells, electrophoretic mobility shift assays, chromatin immunoprecipitation (ChIP) and site-directed mutagenesis allowed us to identify upstream stimulatory factor 2 (Usf2) as a novel factor involved in the transcriptional regulation of glud. Analysis of tissue distribution of Gdh and Usf2 mRNA levels by reverse transcriptase-coupled quantitative real-time PCR (RT-qPCR) showed that Gdh is mainly expressed in the liver of S. aurata, while Usf2 displayed ubiquitous distribution. RT-qPCR and ChIP assays revealed that long-term starvation down-regulated the hepatic expression of Gdh and Usf2 to similar levels and reduced Usf2 binding to glud promoter, while refeeding resulted in a slow but gradual restoration of both Gdh and Usf2 mRNA abundance. Herein, we demonstrate that Usf2 transactivates S. aurata glud by binding to an E-box located in the proximal region of glud promoter. In addition, our findings provide evidence for a new regulatory mechanism involving Usf2 as a key factor in the nutritional regulation of glud transcription in the fish liver.

Download Full-text