scholarly journals Combinatorial determinants of tissue-specific transcription in B cells and macrophages.

1997 ◽  
Vol 17 (7) ◽  
pp. 3527-3535 ◽  
Author(s):  
B S Nikolajczyk ◽  
M Cortes ◽  
R Feinman ◽  
R Sen
Keyword(s):  
B Cells ◽  
Protein Binding ◽  
Binding Sites ◽  
Leucine Zipper ◽  
Chain Gene ◽  
Tissue Specific ◽  
Protein Binding Sites ◽  
Helix Loop Helix ◽  
Heavy Chain Gene Enhancer ◽  
Immunoglobulin Mu

A tripartite domain of the immunoglobulin mu heavy-chain gene enhancer that activates transcription in B cells contains binding sites for PU.1, Ets-1, and a leucine zipper-containing basic helix-loop-helix factor. Because PU.1 is expressed only in B cells and macrophages, we tested the activity of a minimal mu enhancer fragment in macrophages by transient transfections. The minimal mu enhancer activated transcription in macrophages, and the activity was dependent on all three sites. Analysis of mutated enhancers, in which spacing and orientation of the ETS protein binding sites had been changed, suggested that the mechanisms of enhancer activation were different in B cells and macrophages. Thus, ETS protein binding sites may be combined in different ways to generate tissue-specific transcription activators. Despite the activity of the minimal enhancer in macrophages, a larger mu enhancer fragment was inactive in these cells. We propose that formation of the nucleoprotein complex that is formed on the minimal enhancer in macrophages cannot be helped by the neighboring muE elements that are essential for activity of the monomeric enhancer.

scholarly journals Exploring Functional Redundancy in the Immunoglobulin μ Heavy-Chain Gene Enhancer

1998 ◽  
Vol 18 (11) ◽  
pp. 6870-6878 ◽  
Author(s):  
Wei Dang ◽  
Barbara S. Nikolajczyk ◽  
Ranjan Sen
Keyword(s):  
Protein Binding ◽  
Heavy Chain ◽  
Binding Sites ◽  
Bhlh Protein ◽  
Chain Gene ◽  
Heavy Chain Gene ◽  
Enhancer Activity ◽  
Protein Binding Sites ◽  
Gene Enhancer ◽  
Heavy Chain Gene Enhancer

ABSTRACT Immunoglobulin (Ig) μ heavy-chain gene enhancer activity is mediated by multiple DNA binding proteins. Mutations of several protein binding sites in the enhancer do not affect enhancer activity significantly. This feature, termed redundancy, is thought to be due to functional compensation of the mutated sites by other elements within the enhancer. In this study, we identified the elements that make the basic helix-loop-helix (bHLH) protein binding sites, μE2 and μE3, redundant. The major compensatory element is a binding site for interferon regulatory factors (IRFs) and not one of several other bHLH protein binding sites. These studies also provide the first evidence for a role of IRF proteins in Ig heavy-chain gene expression. In addition, we reconstituted the activity of a monomeric μ enhancer in nonlymphoid cells and defined the domains of the ETS gene required for function.

scholarly journals Transcriptional Activation by ETS and Leucine Zipper-Containing Basic Helix-Loop-Helix Proteins

1999 ◽  
Vol 19 (4) ◽  
pp. 2946-2957 ◽  
Author(s):  
Gang Tian ◽  
Batu Erman ◽  
Haruhiko Ishii ◽  
Samudra S. Gangopadhyay ◽  
Ranjan Sen
Keyword(s):  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Transcription Activation ◽  
Chain Gene ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Gene Enhancer ◽  
Novel Interactions ◽  
Heavy Chain Gene Enhancer

ABSTRACT The immunoglobulin μ heavy-chain gene enhancer contains closely juxtaposed binding sites for ETS and leucine zipper-containing basic helix-loop-helix (bHLH-zip) proteins. To understand the μ enhancer function, we have investigated transcription activation by the combination of ETS and bHLH-zip proteins. The bHLH-zip protein TFE3, but not USF, cooperated with the ETS domain proteins PU.1 and Ets-1 to activate a tripartite domain of this enhancer. Deletion mutants were used to identify the domains of the proteins involved. Both TFE3 and USF enhanced Ets-1 DNA binding in vitro by relieving the influence of an autoinhibitory domain in Ets-1 by direct protein-protein associations. Several regions of Ets-1 were found to be necessary, whereas the bHLH-zip domain was sufficient for this effect. Our studies define novel interactions between ETS and bHLH-zip proteins that may regulate combinatorial transcription activation by these protein families.

scholarly journals TFEC, a basic helix-loop-helix protein, forms heterodimers with TFE3 and inhibits TFE3-dependent transcription activation.

1993 ◽  
Vol 13 (8) ◽  
pp. 4505-4512 ◽  
Author(s):  
G Q Zhao ◽  
Q Zhao ◽  
X Zhou ◽  
M G Mattei ◽  
B de Crombrugghe
Keyword(s):  
Dna Binding ◽  
Leucine Zipper ◽  
In Vitro Translation ◽  
Chain Gene ◽  
Adult Rats ◽  
Sequence Identity ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Heavy Chain Gene Enhancer

We have identified a new basic helix-loop-helix (BHLH) DNA-binding protein, designated TFEC, which is closely related to TFE3 and TFEB. The basic domain of TFEC is identical to the basic DNA-binding domain of TFE3 and TFEB, whereas the helix-loop-helix motif of TFEC shows 88 and 85% identity with the same domains in TFE3 and TFEB, respectively. Like the other two proteins, TFEC contains a leucine zipper motif, which has a lower degree of sequence identity with homologous domains in TFE3 and TFEB than does the BHLH segment. Little sequence identity exists outside these motifs. Unlike the two other proteins, TFEC does not contain an acidic domain, which for TFE3 mediates the ability to activate transcription. Like the in vitro translation product of TFE3, the in vitro-translated TFEC binds to the mu E3 DNA sequence of the immunoglobulin heavy-chain gene enhancer. In addition, the product of cotranslation of TFEC RNA and TFE3 RNA forms a heteromeric protein-DNA complex with mu E3 DNA. In contrast to TFE3, TFEC is unable to transactivate a reporter gene linked to a promoter containing tandem copies of the immunoglobulin mu E3 enhancer motif. Cotransfection of TFEC DNA and TFE3 DNA strongly inhibits the transactivation caused by TFE3. TFEC RNA is found in many tissues of adult rats, but the relative concentrations of TFEC and TFE3 RNAs vary considerably in these different tissues. No TFEC RNA was detectable in several cell lines, including fibroblasts, myoblasts, chondrosarcoma cells, and myeloma cells, indicating that TFEC is not ubiquitously expressed.

TFEC, a basic helix-loop-helix protein, forms heterodimers with TFE3 and inhibits TFE3-dependent transcription activation

1993 ◽  
Vol 13 (8) ◽  
pp. 4505-4512
Author(s):  
G Q Zhao ◽  
Q Zhao ◽  
X Zhou ◽  
M G Mattei ◽  
B de Crombrugghe
Keyword(s):  
Dna Binding ◽  
Leucine Zipper ◽  
In Vitro Translation ◽  
Chain Gene ◽  
Adult Rats ◽  
Sequence Identity ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Heavy Chain Gene Enhancer

We have identified a new basic helix-loop-helix (BHLH) DNA-binding protein, designated TFEC, which is closely related to TFE3 and TFEB. The basic domain of TFEC is identical to the basic DNA-binding domain of TFE3 and TFEB, whereas the helix-loop-helix motif of TFEC shows 88 and 85% identity with the same domains in TFE3 and TFEB, respectively. Like the other two proteins, TFEC contains a leucine zipper motif, which has a lower degree of sequence identity with homologous domains in TFE3 and TFEB than does the BHLH segment. Little sequence identity exists outside these motifs. Unlike the two other proteins, TFEC does not contain an acidic domain, which for TFE3 mediates the ability to activate transcription. Like the in vitro translation product of TFE3, the in vitro-translated TFEC binds to the mu E3 DNA sequence of the immunoglobulin heavy-chain gene enhancer. In addition, the product of cotranslation of TFEC RNA and TFE3 RNA forms a heteromeric protein-DNA complex with mu E3 DNA. In contrast to TFE3, TFEC is unable to transactivate a reporter gene linked to a promoter containing tandem copies of the immunoglobulin mu E3 enhancer motif. Cotransfection of TFEC DNA and TFE3 DNA strongly inhibits the transactivation caused by TFE3. TFEC RNA is found in many tissues of adult rats, but the relative concentrations of TFEC and TFE3 RNAs vary considerably in these different tissues. No TFEC RNA was detectable in several cell lines, including fibroblasts, myoblasts, chondrosarcoma cells, and myeloma cells, indicating that TFEC is not ubiquitously expressed.

EVALUATION OF TISSUE STEROID BINDING IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S223-S246 ◽  
Author(s):  
C. R. Wira ◽  
H. Rochefort ◽  
E. E. Baulieu
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Experimental System ◽  
Specific Protein ◽  
Coupling Mechanism ◽  
Target Tissue ◽  
Protein Binding Sites ◽  
Definition Of ◽  
Hormone Specificity

ABSTRACT The definition of a RECEPTOR* in terms of a receptive site, an executive site and a coupling mechanism, is followed by a general consideration of four binding criteria, which include hormone specificity, tissue specificity, high affinity and saturation, essential for distinguishing between specific and nonspecific binding. Experimental approaches are proposed for choosing an experimental system (either organized or soluble) and detecting the presence of protein binding sites. Techniques are then presented for evaluating the specific protein binding sites (receptors) in terms of the four criteria. This is followed by a brief consideration of how receptors may be located in cells and characterized when extracted. Finally various examples of oestrogen, androgen, progestagen, glucocorticoid and mineralocorticoid binding to their respective target tissues are presented, to illustrate how researchers have identified specific corticoid and mineralocorticoid binding in their respective target tissue receptors.

scholarly journals ProBiS: a web server for detection of structurally similar protein binding sites

2010 ◽  
Vol 38 (Web Server) ◽  
pp. W436-W440 ◽  
Author(s):  
J. Konc ◽  
D. Janezic
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Web Server ◽  
Protein Binding Sites ◽  
Similar Protein

scholarly journals Transcription signals and protein binding sites for sericin gene transcription in vitro

1989 ◽  
Vol 264 (31) ◽  
pp. 18707-18713 ◽  
Author(s):  
K Matsuno ◽  
C C Hui ◽  
S Takiya ◽  
T Suzuki ◽  
K Ueno ◽  
...  
Keyword(s):  
Protein Binding ◽  
Gene Transcription ◽  
Binding Sites ◽  
Protein Binding Sites ◽  
Transcription In Vitro ◽  
Transcription Signals
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