scholarly journals Retinoid receptors cause distortion of the retinoic acid response element in the phosphoenolpyruvate carboxykinase gene promoter

1995 ◽  
Vol 310 (2) ◽  
pp. 483-490 ◽  
Author(s):  
D K Scott ◽  
R K Hall ◽  
D K Granner
Keyword(s):  
Retinoic Acid ◽  
Conformational Changes ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Retinoic Acid Receptor ◽  
Gene Promoter ◽  
Ring Closure ◽  
Retinoid Receptors ◽  
Retinoic Acid Response Element ◽  
Cyclization Kinetics ◽  
Distortion Angle

Functional retinoic acid response elements (RAREs) have been described wherein the direct repeats are separated by 1, 2 or 5 bp (termed DR1, DR2 and DR5 respectively). We have previously shown that retinoic acid receptor/retinoid X receptor (RAR/RXR) binds a DR1 RARE within the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter and is the trans-acting complex that mediates the retinoic acid (RA) response. However, the mechanism of trans-activation is unknown. The consequences of RAR/RXR binding to the PEPCK RARE were examined using a circular permutation analysis as a first step to explore the possible role of DNA conformational changes in the RA response. The RAR/RXR heterodimer produced a distortion angle of 78 degrees. The DNA distortion was shown to be at the centre of the PEPCK RARE; RA did not affect the severity of the distortion angle or the location of the distortion centre. Monomers and homodimers of RAR also distorted the DNA, but to a lesser extent than did RAR/RXR. The results of a phasing analysis demonstrated that RAR/RXR heterodimers did not induce a static DNA bend, in either the presence or the absence of RA. A cyclization kinetics assay was employed to show that RAR/RXR binding affected DNA ring closure in a phase-sensitive, RA-insensitive, manner. Taken together, these observations support the idea that RAR/RXR heterodimers distort the structure of the PEPCK RARE, at least in part, by altering DNA flexibility. The conformational change in the PEPCK RARE upon RAR/RXR binding has implications for how RAR/RXR heterodimers recognize various RARE structures.

scholarly journals Activation of the phosphoenolpyruvate carboxykinase gene retinoic acid response element is dependent on a retinoic acid receptor/coregulator complex.

1992 ◽  
Vol 12 (12) ◽  
pp. 5527-5535 ◽  
Author(s):  
R K Hall ◽  
D K Scott ◽  
E L Noisin ◽  
P C Lucas ◽  
D K Granner
Keyword(s):  
Retinoic Acid ◽  
Transcriptional Control ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Mutational Analysis ◽  
Retinoic Acid Receptor ◽  
Retinoid Receptor ◽  
Response Element ◽  
Acid Receptor ◽  
Receptor Alpha ◽  
Retinoic Acid Response Element

The accessory factor 1 (AF1) element is an upstream transcriptional control region that plays a role in the response of the phosphoenolpyruvate carboxykinase (PEPCK) gene to both glucocorticoids and retinoic acid. We demonstrate here that retinoic acid receptor alpha (RAR alpha) binds to a sequence within the AF1 element, TGACCT (site B), that is a consensus retinoic acid response element (RARE) half-site. A similar DNA sequence, TGGCCG (site C), located 1 bp downstream of site B, is not involved in the binding of RAR alpha monomers or dimers but is required for the constitution of a functional RARE. Site C is also required for the formation of a complex involving RAR alpha and a liver nuclear factor designated CR, for coregulator. Mutational analysis of the AF1 element shows that the RAR alpha/CR complex is the trans-acting unit that mediates the retinoic acid response of the PEPCK gene. Another member of the retinoid receptor family, retinoid X receptor alpha (RXR alpha), can also form a complex with RAR alpha and the AF1 element. Several observations, including the observation that RXR alpha antibody interacts with CR, indicate that RXR alpha and CR are identical or closely related proteins. Through RXR alpha forms a complex with RAR alpha and the AF1 element, we demonstrate that the AF1 element is functionally distinguishable from a retinoid X response element. Taken together, our results show that the AF1 element contains an RARE that mediates a retinoic acid response by binding an RAR alpha/coregulator complex; this coregulator is presumably RXR alpha.

Specificity of a retinoic acid response element in the phosphoenolpyruvate carboxykinase gene promoter: consequences of both retinoic acid and thyroid hormone receptor binding

1991 ◽  
Vol 11 (10) ◽  
pp. 5164-5170
Author(s):  
P C Lucas ◽  
B M Forman ◽  
H H Samuels ◽  
D K Granner
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Thyroid Hormone ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Thyroid Hormone Receptor ◽  
Gene Promoter ◽  
Response Element ◽  
Promoter Sequences ◽  
Retinoic Acid Response Element ◽  
Cat Expression

The ability of a retinoic acid (RA) response element (RARE) in the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter to mediate effects of either RA or thyroid hormone (T3) on gene expression was studied. Fusion gene constructs consisting of PEPCK promoter sequences ligated to the chloramphenicol acetyltransferase (CAT) reporter gene were used for this analysis. While T3 induced CAT expression to a small degree (about twofold) when such constructs were transiently transfected into H4IIE rat hepatoma cells, along with an expression vector encoding the alpha subtype of the T3 receptor (TR), this effect was mediated by promoter sequences distinct from the PEPCK RARE. Although TRs were capable of binding the PEPCK RARE in the form of putative monomers, dimers, and heterodimers with RA receptors (RARs), this element failed to mediate any positive effect of T3 on gene expression. In contrast, the PEPCK RARE mediated six- to eightfold induction of CAT expression by RA. When TRs were coexpressed along with RARs in transfected H4IIE cells, this RA induction was substantially blunted in a T3-independent manner. This inhibitory effect may be due to the binding of nonfunctional TRs or TR-RAR heterodimers to the PEPCK RARE. A model is proposed to explain the previously observed in vivo effects of T3 on PEPCK gene expression.

scholarly journals Specificity of a retinoic acid response element in the phosphoenolpyruvate carboxykinase gene promoter: consequences of both retinoic acid and thyroid hormone receptor binding.

1991 ◽  
Vol 11 (10) ◽  
pp. 5164-5170 ◽  
Author(s):  
P C Lucas ◽  
B M Forman ◽  
H H Samuels ◽  
D K Granner
Keyword(s):  
Gene Expression ◽  
Retinoic Acid ◽  
Thyroid Hormone ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Thyroid Hormone Receptor ◽  
Gene Promoter ◽  
Response Element ◽  
Promoter Sequences ◽  
Retinoic Acid Response Element ◽  
Cat Expression

The ability of a retinoic acid (RA) response element (RARE) in the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter to mediate effects of either RA or thyroid hormone (T3) on gene expression was studied. Fusion gene constructs consisting of PEPCK promoter sequences ligated to the chloramphenicol acetyltransferase (CAT) reporter gene were used for this analysis. While T3 induced CAT expression to a small degree (about twofold) when such constructs were transiently transfected into H4IIE rat hepatoma cells, along with an expression vector encoding the alpha subtype of the T3 receptor (TR), this effect was mediated by promoter sequences distinct from the PEPCK RARE. Although TRs were capable of binding the PEPCK RARE in the form of putative monomers, dimers, and heterodimers with RA receptors (RARs), this element failed to mediate any positive effect of T3 on gene expression. In contrast, the PEPCK RARE mediated six- to eightfold induction of CAT expression by RA. When TRs were coexpressed along with RARs in transfected H4IIE cells, this RA induction was substantially blunted in a T3-independent manner. This inhibitory effect may be due to the binding of nonfunctional TRs or TR-RAR heterodimers to the PEPCK RARE. A model is proposed to explain the previously observed in vivo effects of T3 on PEPCK gene expression.

scholarly journals Activation of the phosphoenolpyruvate carboxykinase gene retinoic acid response element is dependent on a retinoic acid receptor/coregulator complex

1992 ◽  
Vol 12 (12) ◽  
pp. 5527-5535
Author(s):  
R K Hall ◽  
D K Scott ◽  
E L Noisin ◽  
P C Lucas ◽  
D K Granner
Keyword(s):  
Retinoic Acid ◽  
Transcriptional Control ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Mutational Analysis ◽  
Retinoic Acid Receptor ◽  
Retinoid Receptor ◽  
Response Element ◽  
Acid Receptor ◽  
Receptor Alpha ◽  
Retinoic Acid Response Element

The accessory factor 1 (AF1) element is an upstream transcriptional control region that plays a role in the response of the phosphoenolpyruvate carboxykinase (PEPCK) gene to both glucocorticoids and retinoic acid. We demonstrate here that retinoic acid receptor alpha (RAR alpha) binds to a sequence within the AF1 element, TGACCT (site B), that is a consensus retinoic acid response element (RARE) half-site. A similar DNA sequence, TGGCCG (site C), located 1 bp downstream of site B, is not involved in the binding of RAR alpha monomers or dimers but is required for the constitution of a functional RARE. Site C is also required for the formation of a complex involving RAR alpha and a liver nuclear factor designated CR, for coregulator. Mutational analysis of the AF1 element shows that the RAR alpha/CR complex is the trans-acting unit that mediates the retinoic acid response of the PEPCK gene. Another member of the retinoid receptor family, retinoid X receptor alpha (RXR alpha), can also form a complex with RAR alpha and the AF1 element. Several observations, including the observation that RXR alpha antibody interacts with CR, indicate that RXR alpha and CR are identical or closely related proteins. Through RXR alpha forms a complex with RAR alpha and the AF1 element, we demonstrate that the AF1 element is functionally distinguishable from a retinoid X response element. Taken together, our results show that the AF1 element contains an RARE that mediates a retinoic acid response by binding an RAR alpha/coregulator complex; this coregulator is presumably RXR alpha.

scholarly journals Targeted disruption of retinoic acid receptor alpha (RAR alpha) and RAR gamma results in receptor-specific alterations in retinoic acid-mediated differentiation and retinoic acid metabolism.

1995 ◽  
Vol 15 (2) ◽  
pp. 843-851 ◽  
Author(s):  
J F Boylan ◽  
T Lufkin ◽  
C C Achkar ◽  
R Taneja ◽  
P Chambon ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Specific Gene ◽  
Cell Type ◽  
Targeted Disruption ◽  
F9 Cells ◽  
Retinoid Receptors ◽  
Alpha Gene ◽  
Polar Derivatives ◽  
Crabp Ii

F9 embryonic teratocarcinoma stem cells differentiate into an epithelial cell type called extraembryonic endoderm when treated with retinoic acid (RA), a derivative of retinol (vitamin A). This differentiation is presumably mediated through the actions of retinoid receptors, the RARs and RXRs. To delineate the functions of each of the different retinoid receptors in this model system, we have generated F9 cell lines in which both copies of either the RAR alpha gene or the RAR gamma gene are disrupted by homologous recombination. The absence of RAR alpha is associated with a reduction in the RA-induced expression of both the CRABP-II and Hoxb-1 (formerly 2.9) genes. The absence of RAR gamma is associated with a loss of the RA-inducible expression of the Hoxa-1 (formerly Hox-1.6), Hoxa-3 (formerly Hox-1.5), laminin B1, collagen IV (alpha 1), GATA-4, and BMP-2 genes. Furthermore, the loss of RAR gamma is associated with a reduction in the metabolism of all-trans-RA to more polar derivatives, while the loss of RAR alpha is associated with an increase in metabolism of RA relative to wild-type F9 cells. Thus, each of these RARs exhibits some specificity with respect to the regulation of differentiation-specific gene expression. These results provide an explanation for the expression of multiple RAR types within one cell type and suggest that each RAR has specific functions.

Ligand-inducible retinoid X receptor-mediated protein: DNA interactions in the retinoic acid receptor β2 gene promoter in vivo

1998 ◽  
Vol 136 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Masato Ikeda ◽  
Remco A Spanjaard ◽  
Elizabeth W Noordhoek ◽  
Akio Kawaguchi ◽  
Toshimasa Onaya ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Retinoic Acid Receptor ◽  
Gene Promoter ◽  
Retinoid X Receptor ◽  
Dna Interactions ◽  
Acid Receptor ◽  
Protein Dna Interactions ◽  
Retinoic Acid Receptor Β2

scholarly journals Ligand-induced Conformational Changes in the Human Retinoic Acid Receptor γ Detected Using Monoclonal Antibodies

1996 ◽  
Vol 271 (38) ◽  
pp. 22969-22975 ◽  
Author(s):  
Joyce E. Driscoll ◽  
Carrie L. Seachord ◽  
John A. Lupisella ◽  
Richard P. Darveau ◽  
Peter R. Reczek
Keyword(s):  
Monoclonal Antibodies ◽  
Retinoic Acid ◽  
Conformational Changes ◽  
Retinoic Acid Receptor ◽  
Acid Receptor
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