scholarly journals Identification of a retinoic acid response element upstream of the murine Hox-4.2 gene.

1993 ◽  
Vol 13 (1) ◽  
pp. 257-265 ◽  
Author(s):  
H Pöpperl ◽  
M S Featherstone
Keyword(s):  
Retinoic Acid ◽  
Hox Genes ◽  
Regulatory Element ◽  
Consensus Sequence ◽  
Regulatory Region ◽  
Dominant Negative ◽  
Luciferase Reporter ◽  
Response Element ◽  
Retinoic Acid Response Element ◽  
Ec Cells

Hox genes play an important role in the process of vertebrate pattern formation, and their expression is intricately regulated both temporally and spatially. All-trans-retinoic acid (RA), a physiologically active metabolite of vitamin A, affects the expression of a large number of Hox genes in vitro and in vivo. However, the regulatory mechanisms underlying the RA response of these genes have not been extensively studied, and no response element for RA receptors (RARs) has been characterized in a Hox regulatory region. The expression of murine Hox-4.2 and its human homolog, HOX4B, is increased in embryonal carcinoma (EC) cell lines upon RA treatment (M. S. Featherstone, A. Baron, S. J. Gaunt, M.-G. Mattei, and D. Duboule, Proc. Natl. Acad. Sci. USA 85:4760-4764, 1988; A. Simeone, D. Acampora, V. Nigro, A. Faiella, M. D'Esposito, A. Stornaiuolo, F. Mavilio, and E. Boncinelli, Mech. Dev. 33:215-228, 1991). Using transient expression assays, we showed that luciferase reporter gene constructs carrying genomic sequences located upstream of Hox-4.2 responded to RA in murine P19 EC cells. A 402-bp NcoI fragment was necessary for the RA responsiveness of reporter constructs. This fragment contained a regulatory element, 5'-AGGTGA(N)5AGGTCA-3', that closely resembles the consensus sequence for an RA response element. The Hox-4.2 RA response element was critical for the RA induction and specifically bound RARs. In addition, the response to RA could be inhibited by expressing a dominant negative form of RAR alpha in transfected P19 EC cells. These results suggested that Hox-4.2 is a target for RAR-mediated regulation by RA.

Identification of a retinoic acid response element upstream of the murine Hox-4.2 gene

1993 ◽  
Vol 13 (1) ◽  
pp. 257-265 ◽  
Author(s):  
H Pöpperl ◽  
M S Featherstone
Keyword(s):  
Retinoic Acid ◽  
Hox Genes ◽  
Regulatory Element ◽  
Consensus Sequence ◽  
Regulatory Region ◽  
Dominant Negative ◽  
Luciferase Reporter ◽  
Response Element ◽  
Retinoic Acid Response Element ◽  
Ec Cells

Hox genes play an important role in the process of vertebrate pattern formation, and their expression is intricately regulated both temporally and spatially. All-trans-retinoic acid (RA), a physiologically active metabolite of vitamin A, affects the expression of a large number of Hox genes in vitro and in vivo. However, the regulatory mechanisms underlying the RA response of these genes have not been extensively studied, and no response element for RA receptors (RARs) has been characterized in a Hox regulatory region. The expression of murine Hox-4.2 and its human homolog, HOX4B, is increased in embryonal carcinoma (EC) cell lines upon RA treatment (M. S. Featherstone, A. Baron, S. J. Gaunt, M.-G. Mattei, and D. Duboule, Proc. Natl. Acad. Sci. USA 85:4760-4764, 1988; A. Simeone, D. Acampora, V. Nigro, A. Faiella, M. D'Esposito, A. Stornaiuolo, F. Mavilio, and E. Boncinelli, Mech. Dev. 33:215-228, 1991). Using transient expression assays, we showed that luciferase reporter gene constructs carrying genomic sequences located upstream of Hox-4.2 responded to RA in murine P19 EC cells. A 402-bp NcoI fragment was necessary for the RA responsiveness of reporter constructs. This fragment contained a regulatory element, 5'-AGGTGA(N)5AGGTCA-3', that closely resembles the consensus sequence for an RA response element. The Hox-4.2 RA response element was critical for the RA induction and specifically bound RARs. In addition, the response to RA could be inhibited by expressing a dominant negative form of RAR alpha in transfected P19 EC cells. These results suggested that Hox-4.2 is a target for RAR-mediated regulation by RA.

Expression of the murine Hoxa4 gene requires both autoregulation and a conserved retinoic acid response element

Development ◽  
1998 ◽  
Vol 125 (11) ◽  
pp. 1991-1998 ◽  
Author(s):  
A.I. Packer ◽  
D.A. Crotty ◽  
V.A. Elwell ◽  
D.J. Wolgemuth
Keyword(s):  
Retinoic Acid ◽  
Reporter Gene ◽  
Neural Tube ◽  
Hox Genes ◽  
Regulatory Region ◽  
Ectopic Expression ◽  
Response Element ◽  
Retinoic Acid Response Element ◽  
Transgenic Embryos

Analysis of the regulatory regions of the Hox genes has revealed a complex array of positive and negative cis-acting elements that control the spatial and temporal pattern of expression of these genes during embryogenesis. In this study we show that normal expression of the murine Hoxa4 gene during development requires both autoregulatory and retinoic acid-dependent modes of regulation. When introduced into a Hoxa4 null background, expression of a lacZ reporter gene driven by the Hoxa4 regulatory region (Hoxa4/lacZ) is either abolished or significantly reduced in all tissues at E10. 5-E12.5. Thus, the observed autoregulation of the Drosophila Deformed gene is conserved in a mouse homolog in vivo, and is reflected in a widespread requirement for positive feedback to maintain Hoxa4 expression. We also identify three potential retinoic acid response elements in the Hoxa4 5′ flanking region, one of which is identical to a well-characterized element flanking the Hoxd4 gene. Administration of retinoic acid to Hoxa4/lacZ transgenic embryos resulted in stage-dependent ectopic expression of the reporter gene in the neural tube and hindbrain. When administered to Hoxa4 null embryos, however, persistent ectopic expression was not observed, suggesting that autoregulation is required for maintenance of the retinoic acid-induced expression. Finally, mutation of the consensus retinoic acid response element eliminated the response of the reporter gene to exogenous retinoic acid, and abolished all embryonic expression in untreated embryos, with the exception of the neural tube and prevertebrae. These data add to the evidence that Hox gene expression is regulated, in part, by endogenous retinoids and autoregulatory loops.

scholarly journals A novel retinoic acid-response element requires an enhancer element mediator for transcriptional activation

2004 ◽  
Vol 383 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Laura R. HARRIS ◽  
Olli-Pekka KAMARAINEN ◽  
Minna SEVAKIVI ◽  
Gwen C. MILLER ◽  
James W. CLARKE ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Regulatory Element ◽  
Regulatory Region ◽  
Mobility Shift ◽  
Experimental Conditions ◽  
Response Element ◽  
Enhancer Element ◽  
Retinoic Acid Response Element

The Col11a2 gene codes for α2(XI), a subunit of type XI collagen that is a critical component of the cartilage extracellular matrix. The 5′ regulatory region of Col11a2 was subjected to deletional analysis to detect any regulatory element in addition to the two known chondrocyte-specific enhancer elements B/C and D/E. Deletion of the region from −342 to −242 bp reduced transcriptional activity to less than 50% of wild-type, but the sequence showed no independent ability to increase transcription from a minimal promoter. When cloned downstream of the D/E enhancer, however, a subsection of the sequence nearly doubled transcriptional activity and produced an additional 3-fold activation in response to RA (retinoic acid). A 6-bp direct repeat, separated by 4 bp (a DR-4 element) near the 5′-end of this region, was found to be essential for its activity, and was further shown to bind the RA X receptor β in electrophoretic mobility-shift assays. The present study has revealed a novel RA-response element in Col11a2 that does not interact directly with the promoter, but instead requires the D/E enhancer to mediate transcriptional activation. Proteins bound at the enhancer, therefore, would be expected to affect the transcriptional response to RA. Such a system of regulation, particularly if found to be operating in other cartilage genes, could explain the conflicting responses RA produces in chondrocytes under different experimental conditions.

scholarly journals Regulation of GLUT4 gene expression by SREBP-1c in adipocytes

2006 ◽  
Vol 399 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Seung-Soon Im ◽  
Sool-Ki Kwon ◽  
Seung-Youn Kang ◽  
Tae-Hyun Kim ◽  
Ha-Il Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Glucose Transporter ◽  
Regulatory Element ◽  
Diabetic Rats ◽  
Dominant Negative ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Response Element ◽  
Glut4 Gene Expression

Expression of the GLUT4 (glucose transporter type 4 isoform) gene in adipocytes is subject to hormonal or metabolic control. In the present study, we have characterized an adipose tissue transcription factor that is influenced by fasting/refeeding regimens and insulin. Northern blotting showed that refeeding increased GLUT4 mRNA levels for 24 h in adipose tissue. Consistent with an increased GLUT4 gene expression, the mRNA levels of SREBP (sterol-regulatory-element-binding protein)-1c in adipose tissue were also increased by refeeding. In streptozotocin-induced diabetic rats, insulin treatment increased the mRNA levels of GLUT4 in adipose tissue. Serial deletion, luciferase reporter assays and electrophoretic mobility-shift assay studies indicated that the putative sterol response element is located in the region between bases −109 and −100 of the human GLUT4 promoter. Transduction of the SREBP-1c dominant negative form to differentiated 3T3-L1 adipocytes caused a reduction in the mRNA levels of GLUT4, suggesting that SREBP-1c mediates the transcription of GLUT4. In vivo chromatin immunoprecipitation revealed that refeeding increased the binding of SREBP-1 to the putative sterol-response element in the GLUT4. Furthermore, treating streptozotocin-induced diabetic rats with insulin restored SREBP-1 binding. In addition, we have identified an Sp1 binding site adjacent to the functional sterol-response element in the GLUT4 promoter. The Sp1 site appears to play an additive role in SREBP-1c mediated GLUT4 gene upregulation. These results suggest that upregulation of GLUT4 gene transcription might be directly mediated by SREBP-1c in adipose tissue.

Inhibition of retinoic acid-inducible transcription by COUP-TFI in human salivary gland adenocarcinoma cell line HSG

1999 ◽  
Vol 77 (6) ◽  
pp. 515-526 ◽  
Author(s):  
Seiko Kyakumoto ◽  
Minoru Ota ◽  
Nobuko Sato
Keyword(s):  
Transcription Factor ◽  
Salivary Gland ◽  
Retinoic Acid ◽  
Reporter Gene ◽  
Luciferase Activity ◽  
Transcription Activation ◽  
Luciferase Reporter ◽  
Response Element ◽  
Human Salivary Gland ◽  
Retinoic Acid Response Element

Human salivary gland adenocarcinoma cells (HSG) express nuclear receptors, all-trans-retinoic acid (at-RA) receptors (RARs), and retinoid X/9-cis-retinoic acid (9-c-RA) receptors (RXRs). In order to investigate whether the endogenous RARs or RXRs of HSG cells can induce transcription activation, the thymidine kinase promoter (TK)-driven luciferase reporter gene containing the retinoic acid response element (RARE), of RARβ, βRARE2-TK-Luc, was transfected into HSG cells and ligand-dependent transcription activation was examined. Luciferase activity of cell lysate increased by the treatment with either at-RA or 9-c-RA. Co-transfection of RARα and (or) RXRα-expression plasmids with the reporter gene enhanced the luciferase activity, suggesting that endogenous RARs and RXRs work as ligand-dependent transfactors in HSG cells. Reverse transcriptase - polymerase chain reaction analysis revealed that HSG cells express chicken ovalbumin upstream promoter - transcription factor I (COUP-TFI). Co-transfection of COUP-TFI-expression plasmid suppressed the at-RA-induced transcription activation of the reporter gene. Similar results were shown using a chromatin-integrated reporter gene system, using a stably transfected β-RARE2-TK-β-galactosidase (β-Gal) reporter gene. The at-RA-dependent increase in the β-Gal expression was completely inhibited by COUP-TFI. The transfection of antisense oligonucleotide of COUP-TFI squelched the RA-dependent growth inhibition induced by RAR-RXR heterodimers. Conclusively, RARs and RXRs of HSG cells are functional and play roles as transactivators in at-RA-sensitive processes such as the proliferation or differentiation of cells. COUP-TFI very likely regulates these processes by repressing the functions of these transactivators.Key words: retinoic acid receptor, retinoid X receptor, COUP-transcription factor (COUP-TF), retinoic acid response element.

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