scholarly journals A novel Snail-related transcription factor Smuc regulates basic helix-loop-helix transcription factor activities via specific E-box motifs

2000 ◽  
Vol 28 (2) ◽  
pp. 626-633 ◽  
Author(s):  
H. Kataoka
Keyword(s):  
Transcription Factor ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Related Transcription Factor

Murine helix-loop-helix transcriptional activator proteins binding to the E-box motif of the Akv murine leukemia virus enhancer identified by cDNA cloning

1992 ◽  
Vol 12 (8) ◽  
pp. 3449-3459
Author(s):  
A L Nielsen ◽  
N Pallisgaard ◽  
F S Pedersen ◽  
P Jørgensen
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Transcriptional Activator ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Nih 3T3 ◽  
Murine Leukemia

The enhancer region of Akv murine leukemia virus contains the sequence motif ACAGATGG. This sequence is homologous to the E-box motif originally defined as a regulatory element in the enhancers of immunoglobulin mu and kappa genes. We have used double-stranded oligonucleotide probes, corresponding to the E box of the murine leukemia virus Akv, to screen a randomly primed lambda gt11 cDNA expression library made from mouse NIH 3T3 fibroblast RNA. We have identified seven lambda clones expressing DNA-binding proteins representing two different genes termed ALF1 and ALF2. The results of sequencing ALF2 cDNA suggests that we have recovered the gene for the basic-helix-loop-helix transcription factor A1, the murine analog of the human transcription factor E47. The cDNA sequence of ALF1 codes for a new member of the basic-helix-loop-helix protein family. Two splice variants of ALF1 cDNA have been found, differing by a 72-bp insertion, coding for putative proteins of 682 and 706 amino acids. The two ALF1 mRNAs are expressed at various levels in mouse tissues. In vitro DNA binding assays, using prokaryotically expressed ALF1 proteins, demonstrated specific binding of the ALF1 proteins to the Akv murine leukemia virus E-box motif ACAGATGG. Expression in NIH 3T3 fibroblasts of GAL4-ALF1 chimeric protein stimulated expression from a minimal promoter linked to a GAL4 binding site, indicating the existence of a transcriptional activator domain in ALF1.

scholarly journals Orphan Nuclear Receptor Small Heterodimer Partner, a Novel Corepressor for a Basic Helix-Loop-Helix Transcription Factor BETA2/NeuroD

2004 ◽  
Vol 18 (4) ◽  
pp. 776-790 ◽  
Author(s):  
Joon-Young Kim ◽  
Khoi Chu ◽  
Han-Jong Kim ◽  
Hyun-A Seong ◽  
Ki-Cheol Park ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Nuclear Receptor ◽  
Transcriptional Activity ◽  
Orphan Nuclear Receptor ◽  
Small Heterodimer Partner ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Coactivator P300

Abstract Small heterodimer partner (SHP; NR0B2) is an atypical orphan nuclear receptor that lacks a conventional DNA binding domain (DBD) and represses the transcriptional activity of various nuclear receptors. In this study, we examined the novel cross talk between SHP and BETA2/NeuroD, a basic helix-loop-helix transcription factor. In vitro and in vivo protein interaction studies showed that SHP physically interacts with BETA2/NeuroD, but not its heterodimer partner E47. Moreover, confocal microscopic study and immunostaining results demonstrated that SHP colocalized with BETA2 in islets of mouse pancreas. SHP inhibited BETA2/NeuroD-dependent transactivation of an E-box reporter, whereas SHP was unable to repress the E47-mediated transactivation and the E-box mutant reporter activity. In addition, SHP repressed the BETA2-dependent activity of glucokinase and cyclin-dependent kinase inhibitor p21 gene promoters. Gel shift and in vitro protein competition assays indicated that SHP inhibits neither dimerization nor DNA binding of BETA2 and E47. Rather, SHP directly repressed BETA2 transcriptional activity and p300-enhanced BETA2/NeuroD transcriptional activity by inhibiting interaction between BETA2 and coactivator p300. We also showed that C-terminal repression domain within SHP is also required for BETA2 repression. However, inhibition of BETA2 activity was not observed by naturally occurring human SHP mutants that cannot interact with BETA2/NeuroD. Taken together, these results suggest that SHP acts as a novel corepressor for basic helix-loop-helix transcription factor BETA2/NeuroD by competing with coactivator p300 for binding to BETA2/NeuroD and by its direct transcriptional repression function.

scholarly journals Murine helix-loop-helix transcriptional activator proteins binding to the E-box motif of the Akv murine leukemia virus enhancer identified by cDNA cloning.

1992 ◽  
Vol 12 (8) ◽  
pp. 3449-3459 ◽  
Author(s):  
A L Nielsen ◽  
N Pallisgaard ◽  
F S Pedersen ◽  
P Jørgensen
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Transcriptional Activator ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
Nih 3T3 ◽  
Murine Leukemia

The enhancer region of Akv murine leukemia virus contains the sequence motif ACAGATGG. This sequence is homologous to the E-box motif originally defined as a regulatory element in the enhancers of immunoglobulin mu and kappa genes. We have used double-stranded oligonucleotide probes, corresponding to the E box of the murine leukemia virus Akv, to screen a randomly primed lambda gt11 cDNA expression library made from mouse NIH 3T3 fibroblast RNA. We have identified seven lambda clones expressing DNA-binding proteins representing two different genes termed ALF1 and ALF2. The results of sequencing ALF2 cDNA suggests that we have recovered the gene for the basic-helix-loop-helix transcription factor A1, the murine analog of the human transcription factor E47. The cDNA sequence of ALF1 codes for a new member of the basic-helix-loop-helix protein family. Two splice variants of ALF1 cDNA have been found, differing by a 72-bp insertion, coding for putative proteins of 682 and 706 amino acids. The two ALF1 mRNAs are expressed at various levels in mouse tissues. In vitro DNA binding assays, using prokaryotically expressed ALF1 proteins, demonstrated specific binding of the ALF1 proteins to the Akv murine leukemia virus E-box motif ACAGATGG. Expression in NIH 3T3 fibroblasts of GAL4-ALF1 chimeric protein stimulated expression from a minimal promoter linked to a GAL4 binding site, indicating the existence of a transcriptional activator domain in ALF1.

scholarly journals Targeting the Microphthalmia Basic Helix-Loop-Helix–Leucine Zipper Transcription Factor to a Subset of E-Box Elements In Vitro and In Vivo

1998 ◽  
Vol 18 (12) ◽  
pp. 6930-6938 ◽  
Author(s):  
I. Aksan ◽  
C. R. Goding
Keyword(s):  
Transcription Factor ◽  
Leucine Zipper ◽  
Pigment Cells ◽  
Specific Gene ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
P Gene ◽  
E Box

ABSTRACT The development of melanocytes, which are pigment-producing cells responsible for skin, hair, and eye color, is absolutely dependent on the action of the microphthalmia basic helix-loop-helix–leucine zipper (bHLH-LZ) transcription factor (Mi); mice lacking a functional Mi protein are entirely devoid of pigment cells. Mi has been shown to activate transcription of the tyrosinase,TRP-1, TRP-2, and QNR-71 genes through specific E-box elements, most notably the highly conserved M box. We investigated the mechanism which enables Mi to be recruited specifically to a restricted subset of E boxes in target promoters while being prevented from binding E-box elements in other promoters. We show both in vitro and in vivo that the presence of a T residue flanking a CATGTG E box is an essential determinant of the ability of Mi to bind DNA, and we successfully predict that the CATGTG E box from the P gene would not bind Mi. In contrast, no specific requirement for the sequences flanking a CACGTG E box was observed, and no binding to an atypical E box in the c-Kit promoter was detected. The relevance of these observations to the control of melanocyte-specific gene expression was highlighted by the fact that the E-box elements located in thetyrosinase, TRP-1, TRP-2, andQNR-71 promoters without exception possess a 5′ flanking T residue which is entirely conserved between species as diverse as man and turtle. The ability of Mi to discriminate between different E-box motifs provides a mechanism to restrict the repertoire of genes which are likely to be regulated by Mi and provides insight into the ability of bHLH-LZ transcription factors to achieve the specificity required for the precise coordination of transcription during development.

scholarly journals Efg1, a Morphogenetic Regulator in Candida albicans, Is a Sequence-Specific DNA Binding Protein

2001 ◽  
Vol 183 (13) ◽  
pp. 4090-4093 ◽  
Author(s):  
Ping Leng ◽  
Philip R. Lee ◽  
Hong Wu ◽  
Alistair J. P. Brown
Keyword(s):  
Transcription Factor ◽  
Candida Albicans ◽  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Human Pathogen ◽  
Hyphal Development ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box

ABSTRACT Efg1 is essential for hyphal development in the human pathogenCandida albicans under most conditions. Efg1 is related to basic helix-loop-helix regulators, and therefore most workers presume that Efg1 is a transcription factor. Here we confirm that Efg1 is a DNA binding protein that can interact specifically with the E box.

scholarly journals Modulation of the Expression and Transactivation of Androgen Receptor by the Basic Helix-Loop-Helix Transcription Factor Pod-1 through Recruitment of Histone Deacetylase 1

2005 ◽  
Vol 19 (9) ◽  
pp. 2245-2257 ◽  
Author(s):  
Cheol Yi Hong ◽  
Eun-Yeung Gong ◽  
Kabsun Kim ◽  
Ji Ho Suh ◽  
Hyun-Mi Ko ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Androgen Receptor ◽  
Histone Deacetylase ◽  
Promoter Activity ◽  
Bhlh Transcription Factor ◽  
Dependent Manner ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box ◽  
And Function

Abstract Androgen receptor (AR) is important in male sexual differentiation and testicular function. Here, we demonstrate the regulation of AR expression and its transactivation by the basic helix-loop-helix (bHLH) transcription factor Pod-1, the expression of which in postnatal testis reciprocally coincides with the expression of AR. Pod-1 represses the promoter activity of AR, possibly through its E-box. An AR promoter region of 169 bp, which harbors one canonical E-box, is sufficient for the Pod-1-repression and bound by purified Pod-1 proteins. Pod-1 also suppresses the transactivation of AR. Transient transfection analyses of mammalian cells show that Pod-1 represses AR transactivation in a dose-dependent manner. Furthermore, yeast two-hybrid, glutathione-S-transferase-pull-down, and coimmunoprecipitation analyses reveal that Pod-1 directly associates with AR through its N-terminal region and through the DNA binding-hinge domain of AR. Interestingly, Pod-1 recruits histone deacetylase (HDAC)-1 to inhibit both promoter activity and transactivation of AR. Overexpression of HDAC1 further inhibits the Pod-1-mediated repressions and Pod-1 directly interacts with HDAC1. Furthermore, chromatin immunoprecipitation assay reveals that HDAC1 is recruited with Pod-1 to the endogenous AR promoter and the androgen-regulated Pem promoter. Taken together, these results suggest that Pod-1, which controls AR transcription and function, may play an important role in the development and function of the testis.

scholarly journals β-Catenin Interacts with MyoD and Regulates Its Transcription Activity

2008 ◽  
Vol 28 (9) ◽  
pp. 2941-2951 ◽  
Author(s):  
Chang-Hoon Kim ◽  
Hannah Neiswender ◽  
Eun Joo Baik ◽  
Wen C. Xiong ◽  
Lin Mei
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activity ◽  
Muscle Development ◽  
Muscle Cells ◽  
Muscle Differentiation ◽  
Canonical Pathway ◽  
Transcription Activity ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
E Box

ABSTRACT Wnt regulation of muscle development is thought to be mediated by the β-catenin-TCF/LEF-dependent canonical pathway. Here we demonstrate that β-catenin, not TCF/LEF, is required for muscle differentiation. We showed that β-catenin interacts directly with MyoD, a basic helix-loop-helix transcription factor essential for muscle differentiation and enhances its binding to E box elements and transcriptional activity. MyoD-mediated transactivation is inhibited in muscle cells when β-catenin is deficient or the interaction between MyoD and β-catenin is disrupted. These results demonstrate that β-catenin is necessary for MyoD function, identifying MyoD as an effector in the Wnt canonical pathway.

scholarly journals The Basic Helix-Loop-Helix Transcription Factor Cph2 Regulates Hyphal Development in CandidaalbicansPartly via Tec1

2001 ◽  
Vol 21 (19) ◽  
pp. 6418-6428 ◽  
Author(s):  
Shelley Lane ◽  
Song Zhou ◽  
Ting Pan ◽  
Qian Dai ◽  
Haoping Liu
Keyword(s):  
Transcription Factor ◽  
Protein Kinase ◽  
Binding Sites ◽  
Regulatory Element ◽  
Ectopic Expression ◽  
Mitogen Activated Protein Kinase ◽  
Northern Analysis ◽  
Hyphal Development ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix

ABSTRACT Candida albicans undergoes a morphogenetic switch from budding yeast to hyphal growth form in response to a variety of stimuli and growth conditions. Multiple signaling pathways, including a Cph1-mediated mitogen-activated protein kinase pathway and an Efg1-mediated cyclic AMP/protein kinase A pathway, regulate the transition. Here we report the identification of a basic helix-loop-helix transcription factor of the Myc subfamily (Cph2) by its ability to promote pseudohyphal growth inSaccharomyces cerevisiae. Like sterol response element binding protein 1, Cph2 has a Tyr instead of a conserved Arg in the basic DNA binding region. Cph2 regulates hyphal development in C. albicans, ascph2/cph2 mutant strains show medium-specific impairment in hyphal development and in the induction of hypha-specific genes. However, many hypha-specific genes do not have potential Cph2 binding sites in their upstream regions. Interestingly, upstream sequences of all known hypha-specific genes are found to contain potential binding sites for Tec1, a regulator of hyphal development. Northern analysis shows that TEC1 transcription is highest in the medium in which cph2/cph2 displays a defect in hyphal development, and Cph2 is necessary for this transcriptional induction of TEC1. In vitro gel mobility shift experiments show that Cph2 directly binds to the two sterol regulatory element 1-like elements upstream of TEC1. Furthermore, the ectopic expression of TEC1 suppresses the defect ofcph2/cph2 in hyphal development. Therefore, the function of Cph2 in hyphal transcription is mediated, in part, through Tec1. We further show that this function of Cph2 is independent of the Cph1- and Efg1-mediated pathways.

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