scholarly journals Transcriptional Repression of the α-Subunit Gene by Androgen Receptor Occurs Independently of DNA Binding but Requires the DNA-Binding and Ligand-Binding Domains of the Receptor

1997 ◽  
Vol 11 (10) ◽  
pp. 1497-1506
Author(s):  
Leslie L. Heckert ◽  
Elizabeth M. Wilson ◽  
John H. Nilson
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Ligand Binding ◽  
Transcriptional Repression ◽  
Regulatory Element ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Subunit Gene ◽  
Α Subunit ◽  
Binding Domains

Abstract The pituitary glycoprotein hormones LH and FSH regulate the reproductive cycle and are sensitive to feedback by gonadal steroids. The common α-subunit shared by these hormones is transcriptionally repressed by androgen receptor (AR) in the presence of its ligand dihydrotestosterone. This identifies at least one mechanism that contributes to AR-dependent suppression of gonadotropin synthesis. Repression of α-subunit transcription by AR requires only the sequences within the first 480 bp of the promoter. While this region contains a high-affinity binding site for AR, this element does not mediate the suppressive effects of androgens. Instead, two other elements within the promoter-regulatory region (α-basal element and cAMP-regulatory element), which are important for expression of theα -subunit gene in gonadotropes, mediate the effects of AR. This suggests that AR inhibits activity of the α-subunit promoter by interfering with the transcriptional properties of the proteins that bind to α-basal element and the cAMP-regulatory elements. Furthermore, transfection analysis of various mutant ARs identified both the DNA-binding and ligand-binding domains of the receptor as critical for repression. Comparisons with the MMTV promoter revealed distinct structural requirements that underlie the transactivation and transrepression properties of AR.

scholarly journals Rhodopsin targeted transcriptional silencing by DNA-binding

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Salvatore Botta ◽  
Elena Marrocco ◽  
Nicola de Prisco ◽  
Fabiola Curion ◽  
Mario Renda ◽  
...  
Keyword(s):  
Dna Binding ◽  
Transcriptional Repression ◽  
Binding Protein ◽  
Regulatory Element ◽  
Transcriptional Silencing ◽  
Dna Binding Protein ◽  
Gain Of Function ◽  
Dna Binding Domains ◽  
Binding Domains

Transcription factors (TFs) operate by the combined activity of their DNA-binding domains (DBDs) and effector domains (EDs) enabling the coordination of gene expression on a genomic scale. Here we show that in vivo delivery of an engineered DNA-binding protein uncoupled from the repressor domain can produce efficient and gene-specific transcriptional silencing. To interfere with RHODOPSIN (RHO) gain-of-function mutations we engineered the ZF6-DNA-binding protein (ZF6-DB) that targets 20 base pairs (bp) of a RHOcis-regulatory element (CRE) and demonstrate Rho specific transcriptional silencing upon adeno-associated viral (AAV) vector-mediated expression in photoreceptors. The data show that the 20 bp-long genomic DNA sequence is necessary for RHO expression and that photoreceptor delivery of the corresponding cognate synthetic trans-acting factor ZF6-DB without the intrinsic transcriptional repression properties of the canonical ED blocks Rho expression with negligible genome-wide transcript perturbations. The data support DNA-binding-mediated silencing as a novel mode to treat gain-of-function mutations.

Differentiation-dependent mechanisms of transcriptional regulation of the catalytic subunit of phosphorylase kinase

2002 ◽  
Vol 362 (2) ◽  
pp. 199-211
Author(s):  
Alison M. O'MAHONY ◽  
Donal A. WALSH
Keyword(s):  
Transcriptional Regulation ◽  
Core Promoter ◽  
Regulatory Element ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Catalytic Subunit ◽  
Luciferase Reporter ◽  
Phosphorylase Kinase ◽  
Subunit Gene ◽  
Reporter System

The amount of phosphorylase kinase in skeletal muscle is exquisitely sensitive to developmental signals such as differentiation and innervation, and is clearly regulated in such a manner so as to always maintain the γ catalytic subunit under the control of its regulatory α, β and γ subunits. To identify how the transcription of the γ subunit is regulated, we have analysed 3.8kb of the upstream regulatory region using a luciferase reporter system. A complex sequence of interdependent regulations is evident. The γ catalytic subunit gene contains two inhibitory controls with very dominant features. Also evident are an array of multiple positive regulatory elements, prominent amongst which are four E-boxes, of which two are downstream, one is upstream and one is in the middle of the CAAT-TATA core promoter. Differentiation-dependent positive regulation arises as a consequence of both E-box regulation and the activation of at least one other regulatory element. The primary mode of transcriptional regulation of the γ catalytic subunit gene appears to occur by the relief of regulation of an otherwise default inhibitory status. It is noteworthy that such a mode of regulation mirrors the regulation of the enzymic activity of many protein kinases, including phosphorylase kinase. With phosphorylase kinase, both its transcriptional regulation as well as the regulation of the protein itself, are primed to maintain the γ catalytic subunit either unexpressed or inactivate respectively, until a positive signal occurs to override an otherwise dominant default inhibitory condition.

scholarly journals Intra-domain communication between the N-terminal and DNA-binding domains of the androgen receptor: modulation of androgen response element DNA binding

2005 ◽  
Vol 34 (3) ◽  
pp. 603-615 ◽  
Author(s):  
Jacqueline Brodie ◽  
Iain J McEwan
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Fluorescence Emission ◽  
Progesterone Receptors ◽  
Fluorescence Emission Spectrum ◽  
Response Element ◽  
Amino Terminal ◽  
Binding Domains ◽  
Receptor Modulation

The androgen receptor (AR) is a ligand-activated transcription factor that recognises and binds to specific DNA response elements upon activation by the steroids testosterone or dihydrotestosterone. In vitro, two types of response element have been characterised - non-selective elements that bind the androgen, glucocorticoid and progesterone receptors, and androgen receptor-selective sequences. In the present study, the allosteric effects of DNA binding on the receptor amino-terminal domain (NTD) were studied. Binding to both types of DNA response element resulted in changes in the intrinsic fluorescence emission spectrum for four tryptophan residues within the AR-NTD and resulted in a more protease-resistant conformation. In binding experiments, it was observed that the presence of the AR-NTD reduced the affinity of receptor polypeptides for binding to both selective and non-selective DNA elements derived from the probasin, PEM and prostatin C3 genes respectively, without significantly altering the protein–base pair contacts. Taken together, these results highlight the role of intra-domain communications between the AR-NTD and the DNA binding domain in receptor structure and function.

A mutant androgen receptor from patients with Reifenstein syndrome: identification of the function of a conserved alanine residue in the D box of steroid receptors

1993 ◽  
Vol 13 (12) ◽  
pp. 7850-7858
Author(s):  
F Kaspar ◽  
H Klocker ◽  
A Denninger ◽  
A C Cato
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Steroid Receptors ◽  
Regulatory Elements ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Wild Type ◽  
Binding Studies ◽  
Mutant Receptor ◽  
Alanine Residue

Reifenstein syndrome is an eponymic term that describes partial androgen-insensitive disorders. Androgen receptor isolated from five patients with this syndrome contains a specific mutation in the DNA binding domain of the receptor. This mutation converts an alanine to a threonine at position 596 next to the zinc catenation site at the second finger. The threonine 596 mutant receptor mediated normal androgen response at promoters with closely positioned multiple regulatory elements for the androgen receptor and other transcription factors. Promoters with single isolated androgen response elements were not transactivated by the mutant receptor. In in vitro receptor-DNA binding studies, interaction with DNA by the mutant receptor was achieved only in the presence of an anti-androgen receptor antibody. Exchanging alanine 596 in the wild-type androgen receptor with serine or valine produced mutants with properties indistinguishable from those of the naturally occurring threonine 596 mutant receptor. These results indicate that an alanine residue at position 596 contributes important structural and functional activities to the androgen receptor. In the androgen receptor from the patients with Reifenstein syndrome, in which this alanine is converted to a threonine, wild-type receptor properties can be restored by exchanging an additional threonine at position 602 to an alanine. An alanine residue at position 596 or 602 in the DNA binding domain of the androgen receptor is therefore important for the full function of this receptor. In all steroid receptors that bind the core sequence AGAACANNNTGTTCT, an alanine residue is also present at a position equivalent to alanine 596 in the androgen receptor.

The androgen receptor ligand-binding domain stabilizes DNA binding in living cells

2004 ◽  
Vol 147 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Pascal Farla ◽  
Remko Hersmus ◽  
Bart Geverts ◽  
Pierre O. Mari ◽  
Alex L. Nigg ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Ligand Binding ◽  
Living Cells ◽  
Binding Domain ◽  
Ligand Binding Domain ◽  
Receptor Ligand

scholarly journals A Pair of Highly Conserved Two-Component Systems Participates in the Regulation of the Hypervariable FIR Proteins in Different Legionella Species

2007 ◽  
Vol 189 (9) ◽  
pp. 3382-3391 ◽  
Author(s):  
Michal Feldman ◽  
Gil Segal
Keyword(s):  
Binding Site ◽  
Legionella Pneumophila ◽  
Response Regulator ◽  
Regulatory Element ◽  
Expression System ◽  
Regulatory Region ◽  
Regulatory Elements ◽  
Mobility Shift ◽  
Type Iv ◽  
Essential Components

ABSTRACT Legionella pneumophila and other pathogenic Legionella species multiply inside protozoa and human macrophages by using the Icm/Dot type IV secretion system. The IcmQ protein, which possesses pore-forming activity, and IcmR, which functions as its chaperone, are two essential components of this system. It was previously shown that in 29 Legionella species, a large hypervariable-gene family (fir genes) is located upstream from a conserved icmQ gene, but although nonhomologous, the FIR proteins were found to function similarly together with their corresponding IcmQ proteins. Alignment of the regulatory regions of 29 fir genes revealed that they can be divided into three regulatory groups; the first group contains a binding site for the CpxR response regulator, which was previously shown to regulate the L. pneumophila fir gene (icmR); the second group, which includes most of the fir genes, contains the CpxR binding site and an additional regulatory element that was identified here as a PmrA binding site; and the third group contains only the PmrA binding site. Analysis of the regulatory region of two fir genes, which included substitutions in the CpxR and PmrA consensus sequences, a controlled expression system, as well as examination of direct binding with mobility shift assays, revealed that both CpxR and PmrA positively regulate the expression of the fir genes that contain both regulatory elements. The change in the regulation of the fir genes that occurred during the course of evolution might be required for the adaptation of the different Legionella species to their specific environmental hosts.

Characterization of Tissue-Specific HIF-1 and HIF-2 Regulatory Elements of the Erythropoietin Gene

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4763-4763
Author(s):  
Donghoon Yoon ◽  
Hyojin Kim ◽  
Minyoung Jang ◽  
Jihyun Song ◽  
Gregory E Arnold ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Specific Binding ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Mrna Levels ◽  
Specific Element ◽  
Α Subunit ◽  
Tissue Specific

Abstract Hypoxia regulates erythropoiesis and other essential processes via hypoxia-inducible transcription factors (HIFs). HIFs are heterodimers that consist of an α subunit (3 isotypes with significant homology; HIF-1α, HIF-2α, HIF-3α), and a common b-subunit; HIF-1 and HIF-2, in some instances exhibiting tissue- and gene-specific gene regulation. Erythropoietin (EPO) was the first identified HIF-1 target gene with the defined HIF-1 binding sequence. However, subsequent works suggested that HIF-2 also regulates EPO transcription and that there are other regulatory elements of EPO gene (i.e. Kidney Inducible Element KIE, Negative Regulatory Element NRE, and Negative Regulatory Liver specific Element NRLE). In silico analysis of the human EPO genome found two additional potential HIF-binding elements in the KIE and NRE regions. The comparative analysis of phylogenically conserved sequences of human, mouse, dog, and rat Epo genes further refined these mouse Epo gene HIF-binding elements as mKIE, mNRE1, mNRE2, and mNRLE2. We treated mice in hypoxia chamber (8% O2) and monitored changes of Epo mRNA levels in liver, kidney, brain, spleen, and bone marrow. All tested tissues increased Epo transcription during hypoxia. Bone marrow, spleen, kidney, and brain showed a peak of induction of Epo transcript at 3 hours of hypoxia treatment, while liver reached the highest level at 6 hours. Mice were sacrificed and organs were harvested, and in vivo chromatin immunoprecipitation (ChIPs) was performed with antibodies against HIF-1α and HIF- 2α and tissue-specific binding regions were defined. The results from these studies are summarized below. HIF-1 mKIE rnNRE mNRE2 mNRLE2 Norm Hyp Norm Hyp Norm Hyp Norm Hyp Liver − + − − + − ? ? Kidney − + − − + − + − Brain − + − − − + − + BM − + − − − − − + Splsen − + − − − − − + HIF-2 mKIE mNRE mNRE2 mNRLE2 Norm Hyp Norm Hyp Norm Hyp Norm Hyp “+” denotes presence and “-” absence of binding of HIF-1 and HIF-2, “?” – indicates inconclusive results. “Norm” - normoxia, “Hyp” - hypoxia. Liver − + − − − + − + Kidney + − − − + − ? ? Brain − − − − − − − + BM − − − − − − + − Spleen − + − − − − − + In conclusion, we demonstrate the differential hypoxia-induced binding of HIF-1 and HIF-2 at different HIF binding elements in the tissues known to express Epo. Further studies will be required to define the function of these HIF-1 and HIF-2 binding elements in tissue specific Epo expression and their role in health and disease.

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