scholarly journals mTFE3, an X-linked transcriptional activator containing basic helix-loop-helix and zipper domains, utilizes the zipper to stabilize both DNA binding and multimerization.

1992 ◽  
Vol 12 (2) ◽  
pp. 817-827 ◽  
Author(s):  
C Roman ◽  
A G Matera ◽  
C Cooper ◽  
S Artandi ◽  
S Blain ◽  
...  
Keyword(s):  
Dna Binding ◽  
Heavy Chain ◽  
Leucine Zipper ◽  
Immunoglobulin Heavy Chain ◽  
Functional Roles ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
The Individual ◽  
Bhlh Proteins ◽  
High Degree

Southwestern (DNA-protein) screening of a murine L-cell cDNA library by using a probe for the microE3 site in the immunoglobulin heavy-chain enhancer yielded a clone, mTFE3, which is a member of the subset of basic helix-loop-helix (BHLH) proteins that also contain a leucine zipper (ZIP). Since the individual contribution of these domains is not well understood for proteins which contain them both, mutational analyses were performed to assess the functional roles of the HLH and ZIP regions for DNA binding and multimerization. The HLH region is stringently required for DNA binding but not for multimerization. The ZIP region is not stringently required for binding or multimerization, but stabilizes both multimer formation and DNA binding. A high degree of conservation at both the amino acid and nucleotide levels between the human transcription factor TFE3 and mTFE3 suggests that mTFE3 is the murine homolog of human TFE3. By using fluorescent in situ hybridization, mTFE3 was mapped to mouse chromosome X in band A2, which is just below the centromere. We show that in addition to the immunoglobulin heavy-chain microE3 site, mTFE3 binds to transcriptional elements important for lymphoid-specific, muscle-specific, and ubiquitously expressed genes. Binding of mTFE3 to DNA induces DNA bending.

mTFE3, an X-linked transcriptional activator containing basic helix-loop-helix and zipper domains, utilizes the zipper to stabilize both DNA binding and multimerization

1992 ◽  
Vol 12 (2) ◽  
pp. 817-827
Author(s):  
C Roman ◽  
A G Matera ◽  
C Cooper ◽  
S Artandi ◽  
S Blain ◽  
...  
Keyword(s):  
Dna Binding ◽  
Heavy Chain ◽  
Leucine Zipper ◽  
Immunoglobulin Heavy Chain ◽  
Functional Roles ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
The Individual ◽  
Bhlh Proteins ◽  
High Degree

Southwestern (DNA-protein) screening of a murine L-cell cDNA library by using a probe for the microE3 site in the immunoglobulin heavy-chain enhancer yielded a clone, mTFE3, which is a member of the subset of basic helix-loop-helix (BHLH) proteins that also contain a leucine zipper (ZIP). Since the individual contribution of these domains is not well understood for proteins which contain them both, mutational analyses were performed to assess the functional roles of the HLH and ZIP regions for DNA binding and multimerization. The HLH region is stringently required for DNA binding but not for multimerization. The ZIP region is not stringently required for binding or multimerization, but stabilizes both multimer formation and DNA binding. A high degree of conservation at both the amino acid and nucleotide levels between the human transcription factor TFE3 and mTFE3 suggests that mTFE3 is the murine homolog of human TFE3. By using fluorescent in situ hybridization, mTFE3 was mapped to mouse chromosome X in band A2, which is just below the centromere. We show that in addition to the immunoglobulin heavy-chain microE3 site, mTFE3 binds to transcriptional elements important for lymphoid-specific, muscle-specific, and ubiquitously expressed genes. Binding of mTFE3 to DNA induces DNA bending.

scholarly journals Displacement of an E-box-binding repressor by basic helix-loop-helix proteins: implications for B-cell specificity of the immunoglobulin heavy-chain enhancer.

1994 ◽  
Vol 14 (9) ◽  
pp. 6153-6163 ◽  
Author(s):  
T Genetta ◽  
D Ruezinsky ◽  
T Kadesch
Keyword(s):  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Zinc Finger Protein ◽  
Immunoglobulin Heavy Chain ◽  
Bhlh Protein ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Bhlh Proteins

The activity of the immunoglobulin heavy-chain (IgH) enhancer is restricted to B cells, although it binds both B-cell-restricted and ubiquitous transcription factors. Activation of the enhancer in non-B cells upon overexpression of the basic helix-loop-helix (bHLH) protein E2A appears to be mediated not only by the binding of E2A to its cognate E box but also by the resulting displacement of a repressor from that same site. We have identified a "two-handed" zinc finger protein, denoted ZEB, the DNA-binding specificity of which mimics that of the cellular repressor. By employing a derivative E box that binds ZEB but not E2A, we have shown that the repressor is active in B cells and the IgH enhancer is silenced in the absence of binding competition by bHLH proteins. Hence, we propose that a necessary prerequisite of enhancer activity is the B-cell-specific displacement of a ZEB-like repressor by bHLH proteins.

Displacement of an E-box-binding repressor by basic helix-loop-helix proteins: implications for B-cell specificity of the immunoglobulin heavy-chain enhancer

1994 ◽  
Vol 14 (9) ◽  
pp. 6153-6163
Author(s):  
T Genetta ◽  
D Ruezinsky ◽  
T Kadesch
Keyword(s):  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Zinc Finger Protein ◽  
Immunoglobulin Heavy Chain ◽  
Bhlh Protein ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Bhlh Proteins

The activity of the immunoglobulin heavy-chain (IgH) enhancer is restricted to B cells, although it binds both B-cell-restricted and ubiquitous transcription factors. Activation of the enhancer in non-B cells upon overexpression of the basic helix-loop-helix (bHLH) protein E2A appears to be mediated not only by the binding of E2A to its cognate E box but also by the resulting displacement of a repressor from that same site. We have identified a "two-handed" zinc finger protein, denoted ZEB, the DNA-binding specificity of which mimics that of the cellular repressor. By employing a derivative E box that binds ZEB but not E2A, we have shown that the repressor is active in B cells and the IgH enhancer is silenced in the absence of binding competition by bHLH proteins. Hence, we propose that a necessary prerequisite of enhancer activity is the B-cell-specific displacement of a ZEB-like repressor by bHLH proteins.

scholarly journals Selective utilization of basic helix-loop-helix-leucine zipper proteins at the immunoglobulin heavy-chain enhancer.

1997 ◽  
Vol 17 (1) ◽  
pp. 18-23 ◽  
Author(s):  
R S Carter ◽  
P Ordentlich ◽  
T Kadesch
Keyword(s):  
Heavy Chain ◽  
Leucine Zipper ◽  
Physiological Role ◽  
Immunoglobulin Heavy Chain ◽  
Dominant Negative ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Derivatives Of

The microE3 E box within the immunoglobulin heavy-chain (IgH) enhancer binds several proteins of the basic helix-loop-helix-leucine zipper (bHLHzip) class, including TFE3, USF1, and Max. Both TFE3 and USF have been described as transcriptional activators, and so we investigated their possible roles in activating the IgH enhancer in vivo. Although TFE3 activated various enhancer-based reporters, both USF1 and Max effectively inhibited transcription. Inhibition by USF correlated with the lack of a strong activation domain and was the result of the protein neutralizing the microE3 site. The effects of dominant-negative derivatives of TFE3 and USF1 confirmed that TFE3, or a TFE3-like protein, is the primary cellular bHLHzip protein that activates the IgH enhancer. In addition to providing a physiological role for TFE3, our results call into question the traditional view of USF1 as an obligate transcriptional activator.

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.

scholarly journals A basic helix-loop-helix-leucine zipper transcription complex in yeast functions in a signaling pathway from mitochondria to the nucleus.

1997 ◽  
Vol 17 (3) ◽  
pp. 1110-1117 ◽  
Author(s):  
Y Jia ◽  
B Rothermel ◽  
J Thornton ◽  
R A Butow
Keyword(s):  
Leucine Zipper ◽  
Citrate Synthase ◽  
Glyoxylate Cycle ◽  
Gene Encoding ◽  
Sequence Element ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Bhlh Proteins ◽  
Basic Region

The expression of some nuclear genes in Saccharomyces cerevisiae, such as the CIT2 gene, which encodes a glyoxylate cycle isoform of citrate synthase, is responsive to the functional state of mitochondria. Previous studies identified a basic helix-loop-helix-leucine zipper (bHLH/Zip) transcription factor encoded by the RTG1 gene that is required for both basal expression of the CIT2 gene and its increased expression in respiratory-deficient cells. Here, we describe the cloning and characterization of RTG3, a gene encoding a 54-kDa bHLH/Zip protein that is also required for CIT2 expression. Rtg3p binds together with Rtg1p to two identical sites oriented as inverted repeats 28 bp apart in a regulatory upstream activation sequence element (UASr) in the CIT2 promoter. The core binding site for the Rtg1p-Rtg3p heterodimer is 5'-GGTCAC-3', which differs from the canonical E-box site, CANNTG, to which most other bHLH proteins bind. We demonstrate that both of the Rtg1p-Rtg3p binding sites in the UAS(r) element are required in vivo and act synergistically for CIT2 expression. The basic region of Rtg3p conforms well to the basic region of most bHLH proteins, whereas the basic region of Rtg1p does not. These findings suggest that the Rtg1p-Rtg3p complex interacts in a novel way with its DNA target sites.

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.

The DNA target determines the dimerization partner selected by bHLHZ-like hybrid proteins AhRJun and ArntFos

2017 ◽  
Vol 13 (3) ◽  
pp. 476-488 ◽  
Author(s):  
Ichiro Inamoto ◽  
Gang Chen ◽  
Jumi A. Shin
Keyword(s):  
Gene Regulation ◽  
Transcription Factors ◽  
Dna Binding ◽  
Molecular Basis ◽  
Leucine Zipper ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Hybrid Proteins ◽  
Protein Partner ◽  
Basic Region

The molecular basis of protein–partner selection and DNA binding of the basic helix–loop–helix (bHLH) and basic region-leucine zipper (bZIP) superfamilies of dimeric transcription factors is fundamental toward understanding gene regulation.

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