scholarly journals SelexGLM differentiates androgen and glucocorticoid receptor DNA-binding preference over an extended binding site

2017 ◽  
Author(s):  
Liyang Zhang ◽  
Gabriella D. Martini ◽  
H. Tomas Rube ◽  
Judith F. Kribelbauer ◽  
Chaitanya Rastogi ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Site ◽  
Target Genes ◽  
Isothermal Calorimetry ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Relative Preference ◽  
Wide Range ◽  
Two Factors ◽  
Prostate Cancers

ABSTRACTThe DNA-binding interfaces of the androgen (AR) and glucocorticoid (GR) receptors are virtually identical, yet these transcription factors share only about a third of their genomic binding sites and regulate similarly distinct sets of target genes. To address this paradox, we determined the intrinsic specificities of the AR and GR DNA binding domains using a refined version of SELEX-seq. We developed an algorithm, SelexGLM, that quantifies binding specificity over a large (31 bp) binding-site by iteratively fitting a feature-based generalized linear model to SELEX probe counts. This analysis revealed that the DNA binding preferences of AR and GR homodimers differ significantly, both within and outside the 15bp core binding site. The relative preference between the two factors can be tuned over a wide range by changing the DNA sequence, with AR more sensitive to sequence changes than GR. The specificity of AR extends to the regions flanking the core 15bp site, where isothermal calorimetry measurements reveal that affinity is augmented by enthalpy-driven readout of poly-A sequences associated with narrowed minor groove width. We conclude that the increased specificity of AR is correlated with more enthalpy-driven binding than GR. The binding models help explain differences in AR and GR genomic binding, and provide a biophysical rationale for how promiscuous binding by GR allows functional substitution for AR in some castration-resistant prostate cancers.

scholarly journals The PAX3-FKHR fusion protein created by the t(2;13) translocation in alveolar rhabdomyosarcomas is a more potent transcriptional activator than PAX3.

1995 ◽  
Vol 15 (3) ◽  
pp. 1522-1535 ◽  
Author(s):  
W J Fredericks ◽  
N Galili ◽  
S Mukhopadhyay ◽  
G Rovera ◽  
J Bennicelli ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Fusion Protein ◽  
Target Genes ◽  
Transcriptional Activator ◽  
Wild Type ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Pediatric Solid Tumors ◽  
Single Polypeptide

Alveolar rhabdomyosarcomas are pediatric solid tumors with a hallmark cytogenetic abnormality: translocation of chromosomes 2 and 13 [t(2;13) (q35;q14)]. The genes on each chromosome involved in this translocation have been identified as the transcription factor-encoding genes PAX3 and FKHR. The NH2-terminal paired box and homeodomain DNA-binding domains of PAX3 are fused in frame to COOH-terminal regions of the chromosome 13-derived FKHR gene, a novel member of the forkhead DNA-binding domain family. To determine the role of the fusion protein in transcriptional regulation and oncogenesis, we identified the PAX3-FKHR fusion protein and characterized its function(s) as a transcription factor relative to wild-type PAX3. Antisera specific to PAX3 and FKHR were developed and used to examine PAX3 and PAX3-FKHR expression in tumor cell lines. Sequential immunoprecipitations with anti-PAX3 and anti-FKHR sera demonstrated expression of a 97-kDa PAX3-FKHR fusion protein in the t(2;13)-positive rhabdomyosarcoma Rh30 cell line and verified that a single polypeptide contains epitopes derived from each protein. The PAX3-FKHR protein was localized to the nucleus in Rh30 cells, as was wild-type PAX3, in t(2;13)-negative A673 cells. In gel shift assays using a canonical PAX binding site (e5 sequence), we found that DNA binding of PAX3-FKHR was significantly impaired relative to that of PAX3 despite the two proteins having identical PAX DNA-binding domains. However, the PAX3-FKHR fusion protein was a much more potent transcriptional activator than PAX3 as determined by transient cotransfection assays using e5-CAT reporter plasmids. The PAX3-FKHR protein may function as an oncogenic transcription factor by enhanced activation of normal PAX3 target genes.

Cooperative interactions between paired domain and homeodomain

Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2639-2650 ◽  
Author(s):  
S. Jun ◽  
C. Desplan
Keyword(s):  
Dna Binding ◽  
Dna Sequences ◽  
Target Genes ◽  
Cooperative Interaction ◽  
Paired Domain ◽  
Cooperative Interactions ◽  
Dna Binding Domains ◽  
Binding Domains

The Pax proteins are a family of transcriptional regulators involved in many developmental processes in all higher eukaryotes. They are characterized by the presence of a paired domain (PD), a bipartite DNA binding domain composed of two helix-turn-helix (HTH) motifs, the PAI and RED domains. The PD is also often associated with a homeodomain (HD) which is itself able to form homo- and hetero-dimers on DNA. Many of these proteins therefore contain three HTH motifs each able to recognize DNA. However, all PDs recognize highly related DNA sequences, and most HDs also recognize almost identical sites. We show here that different Pax proteins use multiple combinations of their HTHs to recognize several types of target sites. For instance, the Drosophila Paired protein can bind, in vitro, exclusively through its PAI domain, or through a dimer of its HD, or through cooperative interaction between PAI domain and HD. However, prd function in vivo requires the synergistic action of both the PAI domain and the HD. Pax proteins with only a PD appear to require both PAI and RED domains, while a Pax-6 isoform and a new Pax protein, Lune, may rely on the RED domain and HD. We propose a model by which Pax proteins recognize different target genes in vivo through various combinations of their DNA binding domains, thus expanding their recognition repertoire.

scholarly journals DNA-binding specificity of NGFI-A and related zinc finger transcription factors.

1995 ◽  
Vol 15 (4) ◽  
pp. 2275-2287 ◽  
Author(s):  
A H Swirnoff ◽  
J Milbrandt
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Target Genes ◽  
Zinc Fingers ◽  
Consensus Sequence ◽  
Binding Specificity ◽  
Early Gene ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Random Site

NGFI-A is the prototypic member of a family of immediate-early gene-encoded transcription factors which includes NGFI-C, Egr3, and Krox20. These proteins possess highly homologous DNA-binding domains, composed of three Cys2-His2 zinc fingers, and all bind to and activate transcription from the sequence GCGGGGGCG. We used a PCR-mediated random site selection protocol to determine whether other sites could be bound by these proteins and the extent to which their binding site preferences are similar or different. The high-affinity consensus sites generated from the selection data are similar, and the combined consensus sequence is T-G-C-G-T/g-G/A-G-G-C/a/t-G-G/T (lowercase letters indicate bases selected less frequently). Using gel shift assays, we found that sequences that diverge from the consensus were bound by NGFI-A, confirming that there is greater variability in binding sites than has generally been acknowledged. We also provide evidence that protein-DNA interactions not noted, or whose importance was not apparent from the X-ray cocrystal structure of the NGFI-A zinc fingers complexed with DNA, contribute significantly to the binding energy of these proteins and confirm that an optimal site is at least 10 instead of 9 nucleotides in length. In contrast to the similarities in binding specificity among these proteins we found that while NGFI-A, Egr3, and Krox20 have comparable DNA binding affinities and kinetics of dissociation, the affinity of NGFI-C is more than threefold lower. This could result in differential regulation of target genes in cells where NGFI-C and the other proteins are coexpressed. Furthermore, we show that this affinity difference is a property not of the zinc fingers themselves but rather of the protein context of the DNA-binding domain.

scholarly journals Induction of Candida albicans Drug Resistance Genes by Hybrid Zinc Cluster Transcription Factors

2014 ◽  
Vol 59 (1) ◽  
pp. 558-569 ◽  
Author(s):  
Sabrina Schneider ◽  
Joachim Morschhäuser
Keyword(s):  
Candida Albicans ◽  
Transcription Factors ◽  
Dna Binding ◽  
Target Genes ◽  
Efflux Pumps ◽  
Pathogenic Yeast ◽  
Fluconazole Resistance ◽  
Dna Binding Domains ◽  
Zinc Cluster ◽  
Binding Domains

ABSTRACTThe pathogenic yeastCandida albicanscan develop resistance to azole antifungal drugs by overexpressingERG11, which encodes the drug target, or the multidrug efflux pumpsMDR1andCDR1/CDR2. The constitutive upregulation of these genes is usually caused by gain-of-function mutations in the zinc cluster transcription factors Upc2, Mrr1, and Tac1, respectively. These transcription factors are also required for the induction of their target genes in drug-susceptible strains in the presence of specific stimuli. By swapping the DNA-binding domains of Mrr1, Tac1, and Upc2 we investigated if the hybrid transcription factors could activate their new target genes in response to the same signals. When Tac1 was targeted to theMDR1andERG11promoters, the expression of these genes became inducible by fluphenazine. Similarly,MDR1andCDR2were strongly upregulated by fluconazole when Upc2 was fused to the DNA-binding domains of Mrr1 and Tac1, respectively. In contrast, Mrr1 was unable to promote gene expression in response to benomyl when it was targeted to theCDR2andERG11promoters instead of theMDR1promoter. These results suggest that Tac1 and Upc2 themselves are activated by the inducers fluphenazine and fluconazole, respectively, whereas benomyl does not activate Mrr1 itself but a coregulatory factor that is present at the promoters of Mrr1 target genes. Strains in which the expression levels of Mrr1 and Tac1 target genes were controlled by Upc2 exhibited increased fluconazole resistance, demonstrating that the ability to efficiently upregulate the expression of efflux pumps in the presence of the drug results in enhanced intrinsic fluconazole resistance.

scholarly journals The bldC Developmental Locus of Streptomyces coelicolor Encodes a Member of a Family of Small DNA-Binding Proteins Related to the DNA-Binding Domains of the MerR Family

2005 ◽  
Vol 187 (2) ◽  
pp. 716-728 ◽  
Author(s):  
Alison C. Hunt ◽  
Luis Servín-González ◽  
Gabriella H. Kelemen ◽  
Mark J. Buttner
Keyword(s):  
Dna Binding ◽  
Binding Proteins ◽  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Aerial Mycelium ◽  
Dna Binding Proteins ◽  
S1 Nuclease ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Wide Range

ABSTRACT The bldC locus, required for formation of aerial hyphae in Streptomyces coelicolor, was localized by map-based cloning to the overlap between cosmids D17 and D25 of a minimal ordered library. Subcloning and sequencing showed that bldC encodes a member of a previously unrecognized family of small (58- to 78-residue) DNA-binding proteins, related to the DNA-binding domains of the MerR family of transcriptional activators. BldC family members are found in a wide range of gram-positive and gram-negative bacteria. Constructed ΔbldC mutants were defective in differentiation and antibiotic production. They failed to form an aerial mycelium on minimal medium and showed severe delays in aerial mycelium formation on rich medium. In addition, they failed to produce the polyketide antibiotic actinorhodin, and bldC was shown to be required for normal and sustained transcription of the pathway-specific activator gene actII-orf4. Although ΔbldC mutants produced the tripyrrole antibiotic undecylprodigiosin, transcripts of the pathway-specific activator gene (redD) were reduced to almost undetectable levels after 48 h in the bldC mutant, in contrast to the bldC + parent strain in which redD transcription continued during aerial mycelium formation and sporulation. This suggests that bldC may be required for maintenance of redD transcription during differentiation. bldC is expressed from a single promoter. S1 nuclease protection assays and immunoblotting showed that bldC is constitutively expressed and that transcription of bldC does not depend on any of the other known bld genes. The bldC18 mutation that originally defined the locus causes a Y49C substitution that results in instability of the protein.

scholarly journals Pax7 pioneer factor action requires both paired and homeo DNA binding domains

2020 ◽  
Author(s):  
Audrey Pelletier ◽  
Alexandre Mayran ◽  
Arthur Gouhier ◽  
James G Omichinski ◽  
Aurelio Balsalobre ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Site ◽  
Dna Sequence ◽  
Binding Sites ◽  
Paired Domain ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Target Sites ◽  
Pioneer Factor ◽  
Chromatin Opening

AbstractThe pioneer transcription factor Pax7 contains two DNA binding domains (DBD), a paired and a homeo domain. Previous work on Pax7 and the related Pax3 had shown that each DBD can bind a cognate DNA sequence, thus defining two targets of binding and possibly modalities of action. Genomic targets of Pax7 pioneer action leading to chromatin opening are enriched for composite DNA target sites containing juxtaposed binding sites for both paired and homeo domains. The present work investigated the implication of both DBDs in pioneer action. We now show that the composite sequence is a higher affinity Pax7 binding site compared to either paired or homeo binding sites and that efficient binding to this site involves both DBDs. We also show that a Pax7 monomer binds composite sites and that methylation of cytosines within the binding site does not affect binding, which is consistent with pioneer action exerted at methylated DNA sites within nucleosomal heterochromatin. Finally, introduction of single amino acid mutations in either the paired or homeo domain that impair binding to cognate DNA sequences showed that both DBDs must be intact for pioneer action. In contrast, only the paired domain is required for low affinity binding of heterochromatin sites. Thus, Pax7 pioneer action on heterochromatin requires unique protein:DNA interactions that are more complex compared to its simpler DNA binding modalities at accessible enhancer target sites.Significance StatementPioneer transcription factors have the unique ability to recognize DNA target sites within closed heterochromatin and to trigger chromatin opening. Only a fraction of the heterochromatin recruitment sites of pioneers are subject to chromatin opening. The molecular basis for this selectivity is unknown and the present work addressed the importance of DNA sequence affinity for selection of sites to open. The pioneering ability of the pioneer factor Pax7 is not strictly determined by affinity or DNA sequence of binding sites, nor by number or methylation status of DNA sites. Mutation analyses showed that recruitment to heterochromatin is primarily dependent on the Pax7 paired domain whereas the ability to open chromatin requires both paired and homeo DNA binding domains.

scholarly journals B-Cell Coactivator OBF-1 Exhibits Unusual Transcriptional Properties and Functions in a DNA-Bound Oct-1-Dependent Fashion

1999 ◽  
Vol 19 (6) ◽  
pp. 4247-4254 ◽  
Author(s):  
Andrea Krapp ◽  
Michel Strubin
Keyword(s):  
Dna Binding ◽  
B Cell ◽  
Target Genes ◽  
Regulatory Elements ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activation Domain ◽  
Activation Domains ◽  
Dna Binding Domains ◽  
Binding Domains

ABSTRACT Eukaryotic transcriptional activators generally comprise both a DNA-binding domain that recognizes specific cis-regulatory elements in the target genes and an activation domain which is essential for transcriptional stimulation. Activation domains typically behave as structurally and functionally autonomous modules that retain their intrinsic activities when directed to a promoter by a variety of heterologous DNA-binding domains. Here we report that OBF-1, a B-cell-specific coactivator for transcription factor Oct-1, challenges this traditional view in that it contains an atypical activation domain that exhibits two unexpected functional properties when tested in the yeast Saccharomyces cerevisiae. First, OBF-1 by itself has essentially no intrinsic activation potential, yet it strongly synergizes with other activation domains such as VP16 and Gal4. Second, OBF-1 exerts its effect in association with DNA-bound Oct-1 but is inactive when attached to a heterologous DNA-binding domain. These findings suggest that activation by OBF-1 is not obtained by simple recruitment of the coactivator to the promoter but requires interaction with DNA-bound Oct-1 to stimulate a step distinct from those regulated by classical activation domains.

Identification of androgen-selective androgen-response elements in the human aquaporin-5 and Rad9 genes

2008 ◽  
Vol 411 (3) ◽  
pp. 679-686 ◽  
Author(s):  
Udo Moehren ◽  
Sarah Denayer ◽  
Michael Podvinec ◽  
Guy Verrijdt ◽  
Frank Claessens
Keyword(s):  
Dna Binding ◽  
Glucocorticoid Receptors ◽  
Target Genes ◽  
Aquaporin 5 ◽  
Band Shift ◽  
Strong Activity ◽  
Response Elements ◽  
Dna Binding Domains ◽  
Binding Domains

The AR (androgen receptor) is known to influence the expression of its target genes by binding to different sets of AREs (androgen-response elements) in the DNA. One set consists of the classical steroid-response elements which are partial palindromic repeats of the 5′-TGTTCT-3′ steroid-receptor monomer-binding element. The second set contains motifs that are AR-specific and that are proposed to be partial direct repeats of the same motif. On the basis of this assumption, we used an in silico approach to identify new androgen-selective AREs in the regulatory regions of known androgen-responsive genes. We have used an extension of the NUBIScan algorithm to screen a collection of 85 known human androgen-responsive genes compiled from literature and database searches. We report the evaluation of the most promising hits resulting from this computational search by in vitro DNA-binding assays using full-size ARs and GRs (glucocorticoid receptors) as well as their isolated DBDs (DNA-binding domains). We also describe the ability of some of these motifs to confer androgen-, but not glucocorticoid-, responsiveness to reporter-gene expression. The elements found in the aquaporin-5 and the Rad9 (radiation-sensitive 9) genes showed selective AR versus GR binding in band-shift assays and a strong activity and selectivity in functional assays, both as isolated elements and in their original contexts. Our data indicate the validity of the hypothesis that selective AREs are recognizable as direct 5′-TGTTCT-3′ repeats, and extend the list of currently known selective elements.

scholarly journals PAX6, Paired Domain Influences Sequence Recognition by the Homeodomain

2002 ◽  
Vol 277 (51) ◽  
pp. 49488-49494 ◽  
Author(s):  
Rajnikant Mishra ◽  
Ivan P. Gorlov ◽  
Lian Y. Chao ◽  
Sanjaya Singh ◽  
Grady F. Saunders
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Target Genes ◽  
Missense Mutations ◽  
Paired Domain ◽  
Consensus Sequences ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Sequence Recognition ◽  
C Terminus

PAX6 functions as a transcription factor and has two DNA-binding domains, a paired domain (PD) and a homeodomain (HD), joined by a glycine-rich linker and followed by a proline-serine-threonine-rich (PST) transactivation region at the C terminus. The mechanism of PAX6 function is not clearly understood, and few target genes in vertebrates have been identified. In this report we described the functional analyses of patient missense mutations from the paired domain region of PAX6 and a paireddomain-less isoform (PD-less) of Pax6 that lacks the paired domain and part of the glycine-rich linker. The PD-less was expressed in the brain, eyes, and pancreas of mouse. The level of expression of this isoform was relatively higher in brain. The mutation sites PAX6-L46R and -C52R were located in the PD of PAX6 on either end of the 5a-polypeptide insert of the alternatively spliced form of PAX6, PAX6-5a. Another PAX6 mutant V53L described in this report was adjacent to C52R. We created corresponding mutations in PAX6 and PAX6-5a, and evaluated their transcriptional activation and DNA binding properties. The PD mutants of PAX6 (L46R, C52R, and V53L) exhibited lower transactivation activities and variable DNA binding ability than wild-type PAX6 with PD DNA-binding consensus sequences. The mutated amino acids containing PAX6-5a isoforms showed unexpected transactivation properties with a reporter containing HD DNA-binding sequences. PAX6-5a-C52R, and -V53L showed lower transactivation activities, but PAX6-5a-L46R had greater transactivation ability than PAX6-5a. The PD-less isoform of Pax6 lost its transactivational ability but could bind to the HD DNA-binding sequences. Functional analysis of the PD-less isoform of Pax6 as well as findings related to missense mutations in the PD suggest that the PD of PAX6 is required for HD function.

Androgen-receptor-specific DNA binding to an element in the first exon of the human secretory component gene

2001 ◽  
Vol 353 (3) ◽  
pp. 611-620 ◽  
Author(s):  
Annemie HAELENS ◽  
Guy VERRIJDT ◽  
Leen CALLEWAERT ◽  
Ben PEETERS ◽  
Wilfried ROMBAUTS ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Dna Sequences ◽  
Target Genes ◽  
Direct Repeat ◽  
Secretory Component ◽  
Response Elements ◽  
Dna Binding Domains ◽  
Binding Domains

Androgens and glucocorticoids are steroid hormones, which exert their effects in vivo by binding and activating their cognate receptors. These intracellular receptors are transcription factors that can bind specific DNA sequences, called hormone response elements, located near the target genes. Although the androgen receptor (AR) and the glucocorticoid receptor (GR) bind the same consensus DNA sequence, androgen-specific responses can be achieved by non-conventional androgen response elements (AREs). Here we determine the specificity mechanism of such a selective element recently identified in the first exon of the human gene for secretory component (sc ARE). This sc ARE consists of two receptor-binding hexamers separated by three nucleotides. The DNA-binding domains of the AR and GR both bind the sc ARE, but, although the AR fragment dimerizes on the element, the GR fragment does not. Comparing the affinities of the DNA-binding domains for mutant forms of the sc ARE revealed that dimeric GR binding is actively excluded by the left hexamer and more precisely by the presence of a G residue at position -3, relative to the central spacer nucleotide. Inserting a G at this position changed a non-selective element into an androgen-selective one. We postulate that the AR recognizes the sc ARE as a direct repeat of two 5′-TGTTCT-3′-like core sequences instead of the classical inverted repeat. Direct repeat binding is not possible for the GR, thus explaining the selectivity of the sc ARE. This alternative dimerization by the AR on the sc ARE is also indicated by the DNA-binding characteristics of receptor fragments in which the dimerization interfaces were swapped. In addition, the flanking and spacer sequences seem to affect the functionality of the sc ARE.

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