scholarly journals Phosphorylation of BATF regulates DNA binding: a novel mechanism for AP-1 (activator protein-1) regulation

2003 ◽  
Vol 374 (2) ◽  
pp. 423-431 ◽  
Author(s):  
Christopher D. DEPPMANN ◽  
Tina M. THORNTON ◽  
Fransiscus E. UTAMA ◽  
Elizabeth J. TAPAROWSKY
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Leucine Zipper ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activator Protein 1 ◽  
Basic Leucine Zipper ◽  
Activator Protein

BATF is a member of the AP-1 (activator protein-1) family of bZIP (basic leucine zipper) transcription factors that form transcriptionally inhibitory, DNA binding heterodimers with Jun proteins. In the present study, we demonstrate that BATF is phosphorylated in vivo on multiple serine and threonine residues and at least one tyrosine residue. Reverse-polarity PAGE revealed that serine-43 and threonine-48 within the DNA binding domain of BATF are phosphorylated. To model phosphorylation of the BATF DNA binding domain, serine-43 was replaced by an aspartate residue. BATF(S43D) retains the ability to dimerize with Jun proteins in vitro and in vivo, and the BATF(S43D):Jun heterodimer localizes properly to the nucleus of cells. Interestingly, BATF(S43D) functions like wild-type BATF to reduce AP-1-mediated gene transcription, despite the observed inability of the BATF(S43D):Jun heterodimer to bind DNA. These data demonstrate that phosphorylation of serine-43 converts BATF from a DNA binding into a non-DNA binding inhibitor of AP-1 activity. Given that 40% of mammalian bZIP transcription factors contain a residue analogous to serine-43 of BATF in their DNA binding domains, the phosphorylation event described here represents a mechanism that is potentially applicable to the regulation of many bZIP proteins.

scholarly journals Assembly of a Functional Beta Interferon Enhanceosome Is Dependent on ATF-2–c-jun Heterodimer Orientation

2000 ◽  
Vol 20 (13) ◽  
pp. 4814-4825 ◽  
Author(s):  
James V. Falvo ◽  
Bhavin S. Parekh ◽  
Charles H. Lin ◽  
Ernest Fraenkel ◽  
Tom Maniatis
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Binding Site ◽  
Leucine Zipper ◽  
Critical Role ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Beta Interferon

ABSTRACT Heterodimeric transcription factors, including the basic region-leucine zipper (bZIP) protein ATF-2–c-jun, are well-characterized components of an enhanceosome that mediates virus induction of the human beta interferon (IFN-β) gene. Here we report that within the IFN-β enhanceosome the ATF-2–c-jun heterodimer binds in a specific orientation, which is required for assembly of a complex between ATF-2–c-jun and interferon regulatory factor 3 (IRF-3). We demonstrate that correct orientation of the ATF-2–c-jun binding site is required for virus induction of the IFN-β gene and for IRF-3-dependent activation of a composite ATF-2– c-jun–IRF site in the IFN-β promoter. We also show that in vitro the DNA-bound ATF-2–c-jun heterodimer adopts a fixed orientation upon the binding of IRF-3 at an adjacent site in the IFN-β enhancer and that the DNA-binding domain of IRF-3 is sufficient to mediate this effect. In addition, we show that the DNA-binding domain of ATF-2 is necessary and sufficient for selective protein-protein interactions with IRF-3. Strikingly, in vivo chromatin immunoprecipitation experiments with IFN-β reporter constructs reveal that recruitment of IRF-3 to the IFN-β promoter upon virus infection is dependent on the orientation of the ATF-2–c-jun heterodimer binding site. These observations demonstrate functional and physical cooperativity between the bZIP and IRF transcription factor families and illustrate the critical role of heterodimeric transcription factors in formation of the IFN-β enhanceosome.

Reconstitution of transcriptional activation domains by reiteration of short peptide segments reveals the modular organization of a glutamine-rich activation domain

1994 ◽  
Vol 14 (9) ◽  
pp. 6056-6067
Author(s):  
M Tanaka ◽  
W Herr
Keyword(s):  
Dna Binding ◽  
Transcriptional Activation ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activation Domain ◽  
Activation Domains ◽  
Transcriptional Activation Domain ◽  
Pou Domain

The POU domain activator Oct-2 contains an N-terminal glutamine-rich transcriptional activation domain. An 18-amino-acid segment (Q18III) from this region reconstituted a fully functional activation domain when tandemly reiterated and fused to either the Oct-2 or GAL4 DNA-binding domain. A minimal transcriptional activation domain likely requires three tandem Q18III segments, because one or two tandem Q18III segments displayed little activity, whereas three to five tandem segments were active and displayed increasing activity with increasing copy number. As with natural Oct-2 activation domains, in our assay a reiterated activation domain required a second homologous or heterologous activation domain to stimulate transcription effectively when fused to the Oct-2 POU domain. These results suggest that there are different levels of synergy within and among activation domains. Analysis of reiterated activation domains containing mutated Q18III segments revealed that leucines and glutamines, but not serines or threonines, are critical for activity in vivo. Curiously, several reiterated activation domains that were inactive in vivo were active in vitro, suggesting that there are significant functional differences in our in vivo and in vitro assays. Reiteration of a second 18-amino-acid segment from the Oct-2 glutamine-rich activation domain (Q18II) was also active, but its activity was DNA-binding domain specific, because it was active when fused to the GAL4 than to the Oct-2 DNA-binding domain. The ability of separate short peptide segments derived from a single transcriptional activation domain to activate transcription after tandem reiteration emphasizes the flexible and modular nature of a transcriptional activation domain.

scholarly journals Expression of qa-1F activator protein: identification of upstream binding sites in the qa gene cluster and localization of the DNA-binding domain.

1987 ◽  
Vol 7 (3) ◽  
pp. 1256-1266 ◽  
Author(s):  
J A Baum ◽  
R Geever ◽  
N H Giles
Keyword(s):  
Dna Binding ◽  
Gene Cluster ◽  
Transcriptional Control ◽  
Protein Identification ◽  
Regulatory Gene ◽  
Quinic Acid ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activator Protein

The qa-1F regulatory gene of Neurospora crassa encodes an activator protein required for quinic acid induction of transcription in the qa gene cluster. This activator protein was expressed in insect cell culture with a baculovirus expression vector. The activator binds to 13 sites in the gene cluster that are characterized by a conserved 16-base-pair sequence of partial dyad symmetry. One site is located between the divergently transcribed qa-1F and qa-1S regulatory genes, corroborating prior evidence that qa-1F is autoregulated and controls expression of the qa-1S repressor. Multiple upstream sites located at variable positions 5' to the qa structural genes appear to allow for greater transcriptional control by qa-1F. Full-length and truncated activator peptides were synthesized in vitro, and the DNA-binding domain was localized to the first 183 amino acids. A 28-amino acid sequence within this region shows striking homology to N-terminal sequences from other lower-eucaryotic activator proteins. A qa-1F(Ts) mutation is located within this putative DNA-binding domain.

scholarly journals DNA Bending by AraC: a Negative Mutant

1998 ◽  
Vol 180 (16) ◽  
pp. 4227-4232 ◽  
Author(s):  
Beatrice Saviola ◽  
Robert R. Seabold ◽  
Robert F. Schleif
Keyword(s):  
Dna Binding ◽  
Leucine Zipper ◽  
Dna Bending ◽  
Regulatory Protein ◽  
Transcription Activation ◽  
Binding Domain ◽  
Dominant Negative ◽  
Dna Binding Domain ◽  
Wild Type

ABSTRACT We sought a mutation in the DNA binding domain of the arabinose operon regulatory protein, AraC, of Escherichia coli that allows the protein to bind DNA normally but not activate transcription. The mutation was isolated by mutagenizing a plasmid overproducing a chimeric leucine zipper-AraC DNA binding domain and screening for proteins that were trans dominant negative with regard to wild-type AraC protein. The mutant with the lowest transcription activation of the araBAD promoter was studied further. It proved to alter a residue that had previously been demonstrated to contact DNA. Because the overproduced mutant protein still bound DNA in vivo, it is deficient in transcription activation for some reason other than absence of DNA binding. Using the phase-sensitive DNA bending assay, we found that wild-type AraC bends DNA about 90° whereas the mutant bends DNA by a smaller amount.

Expression of qa-1F activator protein: identification of upstream binding sites in the qa gene cluster and localization of the DNA-binding domain

1987 ◽  
Vol 7 (3) ◽  
pp. 1256-1266
Author(s):  
J A Baum ◽  
R Geever ◽  
N H Giles
Keyword(s):  
Dna Binding ◽  
Gene Cluster ◽  
Transcriptional Control ◽  
Protein Identification ◽  
Regulatory Gene ◽  
Quinic Acid ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Activator Protein

The qa-1F regulatory gene of Neurospora crassa encodes an activator protein required for quinic acid induction of transcription in the qa gene cluster. This activator protein was expressed in insect cell culture with a baculovirus expression vector. The activator binds to 13 sites in the gene cluster that are characterized by a conserved 16-base-pair sequence of partial dyad symmetry. One site is located between the divergently transcribed qa-1F and qa-1S regulatory genes, corroborating prior evidence that qa-1F is autoregulated and controls expression of the qa-1S repressor. Multiple upstream sites located at variable positions 5' to the qa structural genes appear to allow for greater transcriptional control by qa-1F. Full-length and truncated activator peptides were synthesized in vitro, and the DNA-binding domain was localized to the first 183 amino acids. A 28-amino acid sequence within this region shows striking homology to N-terminal sequences from other lower-eucaryotic activator proteins. A qa-1F(Ts) mutation is located within this putative DNA-binding domain.

Structure of the DNA-binding domain of the response regulator SaeR fromStaphylococcus aureus

2015 ◽  
Vol 71 (8) ◽  
pp. 1768-1776 ◽  
Author(s):  
Xiaojiao Fan ◽  
Xu Zhang ◽  
Yuwei Zhu ◽  
Liwen Niu ◽  
Maikun Teng ◽  
...  
Keyword(s):  
Dna Binding ◽  
Target Genes ◽  
Response Regulator ◽  
Regulatory System ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Promoter Regions ◽  
Winged Helix

The SaeR/S two-component regulatory system is essential for controlling the expression of many virulence factors inStaphylococcus aureus. SaeR, a member of the OmpR/PhoB family, is a response regulator with an N-terminal regulatory domain and a C-terminal DNA-binding domain. In order to elucidate how SaeR binds to the promoter regions of target genes, the crystal structure of the DNA-binding domain of SaeR (SaeRDBD) was solved at 2.5 Å resolution. The structure reveals that SaeRDBDexists as a monomer and has the canonical winged helix–turn–helix module. EMSA experiments suggested that full-length SaeR can bind to the P1 promoter and that the binding affinity is higher than that of its C-terminal DNA-binding domain. Five key residues on the winged helix–turn–helix module were verified to be important for binding to the P1 promoterin vitroand for the physiological function of SaeRin vivo.

scholarly journals Bach proteins belong to a novel family of BTB-basic leucine zipper transcription factors that interact with MafK and regulate transcription through the NF-E2 site.

1996 ◽  
Vol 16 (11) ◽  
pp. 6083-6095 ◽  
Author(s):  
T Oyake ◽  
K Itoh ◽  
H Motohashi ◽  
N Hayashi ◽  
H Hoshino ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Leucine Zipper ◽  
Basic Leucine Zipper ◽  
Significant Similarity ◽  
Btb Domain ◽  
Binding Forms ◽  
Bzip Domain ◽  
Bzip Proteins

Members of the small Maf family (MafK, MafF, and MafG) are basic region leucine zipper (bZip) proteins that can function as transcriptional activators or repressors. The dimer compositions of their DNA binding forms determine whether the small Maf family proteins activate or repress transcription. Using a yeast two-hybrid screen with a GAL4-MafK fusion protein, we have identified two novel bZip transcription factors, Bach1 and Bach2, as heterodimerization partners of MafK. In addition to a Cap'n'collar-type bZip domain, these Bach proteins possess a BTB domain which is a protein interaction motif; Bach1 and Bach2 show significant similarity to each other in these regions but are otherwise divergent. Whereas expression of Bach1 appears ubiquitous, that of Bach2 is restricted to monocytes and neuronal cells. Bach proteins bind in vitro to NF-E2 binding sites, recognition elements for the hematopoietic transcription factor NF-E2, by forming heterodimers with MafK. Furthermore, a DNA binding complex that contained MafK as well as Bach2 or a protein related closely to Bach2 was found to be present in mouse brain cells. Bach1 and Bach2 function as transcription repressors in transfection assays using fibroblast cells, but they function as a transcriptional activator and repressor, respectively, in cultured erythroid cells. The results suggest that members of the Bach family play important roles in coordinating transcription activation and repression by MafK.

scholarly journals Regulation of the Myxococcus xanthus C-Signal-Dependent Ω4400 Promoter by the Essential Developmental Protein FruA

2006 ◽  
Vol 188 (14) ◽  
pp. 5167-5176 ◽  
Author(s):  
Deborah R. Yoder-Himes ◽  
Lee Kroos
Keyword(s):  
Dna Binding ◽  
Response Regulator ◽  
Myxococcus Xanthus ◽  
Cell Movement ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Consensus Binding Site ◽  
Multicellular Development

ABSTRACT The bacterium Myxococcus xanthus employs extracellular signals to coordinate aggregation and sporulation during multicellular development. Extracellular, contact-dependent signaling that involves the CsgA protein (called C-signaling) activates FruA, a putative response regulator that governs a branched signaling pathway inside cells. One branch regulates cell movement, leading to aggregation. The other branch regulates gene expression, leading to sporulation. C-signaling is required for full expression of most genes induced after 6 h into development, including the gene identified by Tn5 lac insertion Ω4400. To determine if FruA is a direct regulator of Ω4400 transcription, a combination of in vivo and in vitro experiments was performed. Ω4400 expression was abolished in a fruA mutant. The DNA-binding domain of FruA bound specifically to DNA upstream of the promoter −35 region in vitro. Mutations between bp −86 and −77 greatly reduced binding. One of these mutations had been shown previously to reduce Ω4400 expression in vivo and make it independent of C-signaling. For the first time, chromatin immunoprecipitation (ChIP) experiments were performed on M. xanthus. The ChIP experiments demonstrated that FruA is associated with the Ω4400 promoter region late in development, even in the absence of C-signaling. Based on these results, we propose that FruA directly activates Ω4400 transcription to a moderate level prior to C-signaling and, in response to C-signaling, binds near bp −80 and activates transcription to a higher level. Also, the highly localized effects of mutations between bp −86 and −77 on DNA binding in vitro, together with recently published footprints, allow us to predict a consensus binding site of GTCG/CGA/G for the FruA DNA-binding domain.

scholarly journals Unbiased Mutagenesis of MHV68 LANA Reveals a DNA-Binding Domain Required for LANA Function In Vitro and In Vivo

2012 ◽  
Vol 8 (9) ◽  
pp. e1002906 ◽  
Author(s):  
Clinton R. Paden ◽  
J. Craig Forrest ◽  
Scott A. Tibbetts ◽  
Samuel H. Speck
Keyword(s):  
Dna Binding ◽  
Binding Domain ◽  
Dna Binding Domain

scholarly journals Fos is a preferential target of glucocorticoid receptor inhibition of AP-1 activity in vitro.

1993 ◽  
Vol 13 (6) ◽  
pp. 3782-3791 ◽  
Author(s):  
T K Kerppola ◽  
D Luk ◽  
T Curran
Keyword(s):  
Dna Binding ◽  
Glucocorticoid Receptor ◽  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Hormone Receptors ◽  
Transcription Activation ◽  
Nuclear Hormone Receptor ◽  
Binding Domain ◽  
Dna Binding Domain

Several regulatory interactions between the AP-1 and the nuclear hormone receptor families of transcription factors have been reported. However, the molecular mechanisms that underlie these interactions remain unknown, and models derived from transient-transfection experiments are contradictory. We have investigated the effect of the purified glucocorticoid receptor (GR) DNA-binding domain (GR residues 440 to 533 [GR440-533]) on DNA binding and transcription activation by Fos-Jun heterodimers and Jun homodimers. GR440-533 differentially inhibited DNA binding and transcription activation by Fos-Jun heterodimers. Inhibition of Jun homodimers required a 10-fold-higher concentration of GR440-533. An excess of Fos monomers protected Fos-Jun heterodimers from inhibition by GR440-533. Surprisingly, regions outside the leucine zipper and basic region were required for GR inhibition of Fos and Jun DNA binding. The region of GR440-533 required for inhibition of Fos-Jun DNA binding was localized to the zinc finger DNA-binding domain. However, inhibition of Fos-Jun DNA binding was independent of DNA binding by GR440-533. GR440-533 also differentially inhibited Fos-Jun heterodimer binding to the proliferin plfG element. Differential inhibition of DNA binding by different AP-1 family complexes provides a potential mechanism for the diverse interactions between nuclear hormone receptors and AP-1 family proteins at different promoters and in different cell types.

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