scholarly journals Expression of the Ligand-Binding Domain-Containing Region of Retinoic Acid Receptors .ALPHA., .BETA. and .GAMMA. in Escherichia coli and Evaluation of Ligand-Binding Selectivity.

1993 ◽  
Vol 16 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Hiroshi FUKASAWA ◽  
Toru IIJIMA ◽  
Hiroyuki KAGECHIKA ◽  
Yuichi HASHIMOTO ◽  
Koichi SHUDO
Keyword(s):  
Escherichia Coli ◽  
Retinoic Acid ◽  
Ligand Binding ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Retinoic Acid Receptors ◽  
Binding Selectivity ◽  
Alpha Beta

Expression of human all-trans-retinoic acid receptor β and its ligand-binding domain in Escherichia coli

1995 ◽  
Vol 308 (1) ◽  
pp. 353-359 ◽  
Author(s):  
M Berggren Söderlund ◽  
G Johannesson ◽  
G Fex
Keyword(s):  
Escherichia Coli ◽  
Retinoic Acid ◽  
Ligand Binding ◽  
Retinoic Acid Receptor ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Acid Receptor ◽  
Recombinant Receptors ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid

all-trans-Retinoic acid, one of the hormonally active derivatives of vitamin A, occurs physiologically in plasma at a concentration below 10 nmol/l. The methods currently used for its quantification are based on HPLC, need about 1 ml of serum, are relatively laborious and thus not well suited for mass analysis. The affinity and specificity of retinoic acid receptors for all-trans-retinoic acid encouraged us to express both the entire human retinoic acid receptor beta (RAR-beta) and two versions of its retinoic acid-binding domain in Escherichia coli in the hope that these recombinant proteins might be used as binders in a ligand-binding assay for all-trans-retinoic acid. The recombinant receptors, the whole receptor [RAR-beta-(V7-Q448)], corresponding to domains A-F, and the ligand-binding domain [RAR-beta-(E149-Q448)], corresponding to domains D-F, were expressed in the vector pET 3d/BL21 (DE3) as inclusion bodies, solubilized with guanidinium chloride, renatured and purified by ion-exchange chromatography. RAR-beta-(P193-Q448), corresponding to domains E-F, was expressed in the vector pET 3d/BL21(DE3)pLysS, and purified by reversed-phase chromatography. Under non-denaturing conditions, the expressed whole receptor [RAR-beta-(V7-Q448)] and the D-F construct (RAR-beta-(E149-Q448)] behaved chromatographically as monomeric proteins whereas the E-F construct [RAR-beta-(P193-Q448)] had a strong tendency to aggregate. RAR-beta-(V7-Q448) and RAR-beta-(E149-Q448) had similar Kd values for all-trans-retinoic acid (1.4 and 0.6 nmol/l respectively) whereas RAR-beta-(P193-Q448) bound all-trans-retinoic acid less avidly (Kd 9.6 nmol/l). 9-cis-Retinoic acid bound to RAR-beta-(E149-Q448) and RAR-beta-(V7-Q448) as avidly as all-trans-retinoic acid. Competition experiments showed weak or no binding of 4-oxo-all-trans-retinoic acid, 4-oxo-13-cis-retinoic acid, 13-cis-retinoic acid, acitretin and retinol by RAR-beta-(E149-Q448).

scholarly journals Novel Mechanism of Nuclear Receptor Corepressor Interaction Dictated by Activation Function 2 Helix Determinants

2002 ◽  
Vol 22 (19) ◽  
pp. 6831-6841 ◽  
Author(s):  
Anna N. Moraitis ◽  
Vincent Giguère ◽  
Catherine C. Thompson
Keyword(s):  
Retinoic Acid ◽  
Thyroid Hormone ◽  
Ligand Binding ◽  
Nuclear Receptor ◽  
Thyroid Hormone Receptor ◽  
Activation Function ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Cerebellar Development ◽  
Nuclear Receptor Corepressor

ABSTRACT Transcriptional regulation by nuclear receptors is controlled by the concerted action of coactivator and corepressor proteins. The product of the thyroid hormone-regulated mammalian gene hairless (Hr) was recently shown to function as a thyroid hormone receptor corepressor. Here we report that Hr acts as a potent repressor of transcriptional activation by RORα, an orphan nuclear receptor essential for cerebellar development. In contrast to other corepressor-nuclear receptor interactions, Hr binding to RORα is mediated by two LXXLL-containing motifs, a mechanism associated with coactivator interaction. Mutagenesis of conserved amino acids in the ligand binding domain indicates that RORα activity is ligand-dependent, suggesting that corepressor activity is maintained in the presence of ligand. Despite similar recognition helices shared with coactivators, Hr does not compete for the same molecular determinants at the surface of the RORα ligand binding domain, indicating that Hr-mediated repression is not simply through displacement of coactivators. Remarkably, the specificity of Hr corepressor action can be transferred to a retinoic acid receptor by exchanging the activation function 2 (AF-2) helix. Repression of the chimeric receptor is observed in the presence of retinoic acid, demonstrating that in this context, Hr is indeed a ligand-oblivious nuclear receptor corepressor. These results suggest a novel molecular mechanism for corepressor action and demonstrate that the AF-2 helix can play a dynamic role in controlling corepressor as well as coactivator interactions. The interaction of Hr with RORα provides direct evidence for the convergence of thyroid hormone and RORα-mediated pathways in cerebellar development.

scholarly journals Location of Two Photoaffinity-Labeled Sites on the Ligand-Binding Domain of Retinoic Acid Receptor .ALPHA..

1996 ◽  
Vol 19 (5) ◽  
pp. 659-664 ◽  
Author(s):  
Toru SASAKI ◽  
Rumiko SHIMAZAWA ◽  
Takayuki SAWADA ◽  
Toru IIJIMA ◽  
Hiroshi FUKASAWA ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Ligand Binding ◽  
Retinoic Acid Receptor ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Retinoic Acid Receptor Alpha ◽  
Acid Receptor ◽  
Receptor Alpha
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