scholarly journals Double-stranded DNA templates can induce alpha-helical conformation in peptides containing lysine and alanine: functional implications for leucine zipper and helix-loop-helix transcription factors.

1994 ◽  
Vol 91 (11) ◽  
pp. 4840-4844 ◽  
Author(s):  
N. P. Johnson ◽  
J. Lindstrom ◽  
W. A. Baase ◽  
P. H. von Hippel
Keyword(s):  
Transcription Factors ◽  
Leucine Zipper ◽  
Helical Conformation ◽  
Dna Templates ◽  
Helix Loop Helix ◽  
Double Stranded Dna ◽  
Functional Implications

scholarly journals Involvement of Transcription Factor Encoded by the Mouse mi Locus (MITF ) in Expression of p75 Receptor of Nerve Growth Factor in Cultured Mast Cells of Mice

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2601-2608 ◽  
Author(s):  
Tomoko Jippo ◽  
Eiichi Morii ◽  
Kumiko Tsujino ◽  
Tohru Tsujimura ◽  
Young-Mi Lee ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Mast Cells ◽  
Leucine Zipper ◽  
Poor Response ◽  
Nerve Growth ◽  
Helix Loop Helix ◽  
3T3 Fibroblasts ◽  
Direct Binding

The mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF ). Cultured mast cells (CMCs) of mi/mi genotype showed a poor response to nerve growth factor (NGF ). Addition of NGF to the suboptimal dose of interleukin-3 (IL-3) increased the plating efficiency of normal (+/+) CMCs but not mi/mi CMCs. Although +/+ CMCs were berberine sulfate–negative when cultured with IL-3, +/+ CMCs became berberine sulfate–positive when cultured in the presence of both IL-3 and NGF, which suggested increased heparin content. In contrast, NGF did not influence the phenotype of mi/mi CMCs. The poor response of mi/mi CMCs to NGF was attributed to the deficient expression of p75 NGF receptor. The purpose of the present study is to examine the effect of MITF on p75 gene transcription. Overexpression of +-MITF or mi-MITF was observed in mi/mi CMCs to which cDNA encoding each type of MITF had been introduced using the retroviral vector. Overexpression of +-MITF but not of mi-MITF normalized the expression of p75 and the above-mentioned poor responses of mi/mi CMCs to NGF, indicating the involvement of +-MITF in p75 gene transactivation. Then, we analyzed the promoter of the p75 gene. Two CANNTG motifs recognized by bHLH-Zip–type transcription factors were conserved between the mouse and rat p75 promoters. One of these two CANNTG motifs was specifically bound by +-MITF. When the luciferase gene under the control of the p75 promoter was cotransfected into NIH/3T3 fibroblasts with cDNA encoding +-MITF or mi-MITF, luciferase activity increased significantly only when +-MITF cDNA was cotransfected. The mutation of this CANNTG motif abolished the transactivation effect of +-MITF, indicating that +-MITF transactivated the p75 gene, at least in part, through direct binding.

scholarly journals Involvement of Transcription Factor Encoded by the Mouse mi Locus (MITF ) in Expression of p75 Receptor of Nerve Growth Factor in Cultured Mast Cells of Mice

Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2601-2608 ◽  
Author(s):  
Tomoko Jippo ◽  
Eiichi Morii ◽  
Kumiko Tsujino ◽  
Tohru Tsujimura ◽  
Young-Mi Lee ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Mast Cells ◽  
Leucine Zipper ◽  
Poor Response ◽  
Nerve Growth ◽  
Helix Loop Helix ◽  
3T3 Fibroblasts ◽  
Direct Binding

Abstract The mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF ). Cultured mast cells (CMCs) of mi/mi genotype showed a poor response to nerve growth factor (NGF ). Addition of NGF to the suboptimal dose of interleukin-3 (IL-3) increased the plating efficiency of normal (+/+) CMCs but not mi/mi CMCs. Although +/+ CMCs were berberine sulfate–negative when cultured with IL-3, +/+ CMCs became berberine sulfate–positive when cultured in the presence of both IL-3 and NGF, which suggested increased heparin content. In contrast, NGF did not influence the phenotype of mi/mi CMCs. The poor response of mi/mi CMCs to NGF was attributed to the deficient expression of p75 NGF receptor. The purpose of the present study is to examine the effect of MITF on p75 gene transcription. Overexpression of +-MITF or mi-MITF was observed in mi/mi CMCs to which cDNA encoding each type of MITF had been introduced using the retroviral vector. Overexpression of +-MITF but not of mi-MITF normalized the expression of p75 and the above-mentioned poor responses of mi/mi CMCs to NGF, indicating the involvement of +-MITF in p75 gene transactivation. Then, we analyzed the promoter of the p75 gene. Two CANNTG motifs recognized by bHLH-Zip–type transcription factors were conserved between the mouse and rat p75 promoters. One of these two CANNTG motifs was specifically bound by +-MITF. When the luciferase gene under the control of the p75 promoter was cotransfected into NIH/3T3 fibroblasts with cDNA encoding +-MITF or mi-MITF, luciferase activity increased significantly only when +-MITF cDNA was cotransfected. The mutation of this CANNTG motif abolished the transactivation effect of +-MITF, indicating that +-MITF transactivated the p75 gene, at least in part, through direct binding.

scholarly journals Mechanism of conditional partner selectivity in MITF/TFE family transcription factors with a conserved coiled coil stammer motif

2019 ◽  
Vol 48 (2) ◽  
pp. 934-948 ◽  
Author(s):  
Vivian Pogenberg ◽  
Josué Ballesteros-Álvarez ◽  
Romana Schober ◽  
Ingibjörg Sigvaldadóttir ◽  
Agnieszka Obarska-Kosinska ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
High Resolution ◽  
Nuclear Localization ◽  
Leucine Zipper ◽  
Coiled Coil ◽  
Fundamental Difference ◽  
Wild Type ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix

Abstract Interrupted dimeric coiled coil segments are found in a broad range of proteins and generally confer selective functional properties such as binding to specific ligands. However, there is only one documented case of a basic-helix–loop–helix leucine zipper transcription factor—microphthalmia-associated transcription factor (MITF)—in which an insertion of a three-residue stammer serves as a determinant of conditional partner selectivity. To unravel the molecular principles of this selectivity, we have analyzed the high-resolution structures of stammer-containing MITF and an engineered stammer-less MITF variant, which comprises an uninterrupted symmetric coiled coil. Despite this fundamental difference, both MITF structures reveal identical flanking in-phase coiled coil arrangements, gained by helical over-winding and local asymmetry in wild-type MITF across the stammer region. These conserved structural properties allow the maintenance of a proper functional readout in terms of nuclear localization and binding to specific DNA-response motifs regardless of the presence of the stammer. By contrast, MITF heterodimer formation with other bHLH-Zip transcription factors is only permissive when both factors contain either the same type of inserted stammer or no insert. Our data illustrate a unique principle of conditional partner selectivity within the wide arsenal of transcription factors with specific partner-dependent functional readouts.

scholarly journals The Hog1 SAPK controls the Rtg1/Rtg3 transcriptional complex activity by multiple regulatory mechanisms

2012 ◽  
Vol 23 (21) ◽  
pp. 4286-4296 ◽  
Author(s):  
Clàudia Ruiz-Roig ◽  
Núria Noriega ◽  
Alba Duch ◽  
Francesc Posas ◽  
Eulàlia de Nadal
Keyword(s):  
Transcription Factors ◽  
Mitochondrial Function ◽  
Leucine Zipper ◽  
Regulation Of Gene Expression ◽  
Nuclear Accumulation ◽  
Dependent Manner ◽  
Complex Activity ◽  
Helix Loop Helix ◽  
Response To Stress ◽  
Transcriptional Complex

Cells modulate expression of nuclear genes in response to alterations in mitochondrial function, a response termed retrograde (RTG) regulation. In budding yeast, the RTG pathway relies on Rtg1 and Rtg3 basic helix-loop-helix leucine Zipper transcription factors. Exposure of yeast to external hyperosmolarity activates the Hog1 stress-activated protein kinase (SAPK), which is a key player in the regulation of gene expression upon stress. Several transcription factors, including Sko1, Hot1, the redundant Msn2 and Msn4, and Smp1, have been shown to be directly controlled by the Hog1 SAPK. The mechanisms by which Hog1 regulates their activity differ from one to another. In this paper, we show that Rtg1 and Rtg3 transcription factors are new targets of the Hog1 SAPK. In response to osmostress, RTG-dependent genes are induced in a Hog1-dependent manner, and Hog1 is required for Rtg1/3 complex nuclear accumulation. In addition, Hog1 activity regulates Rtg1/3 binding to chromatin and transcriptional activity. Therefore Hog1 modulates Rtg1/3 complex activity by multiple mechanisms in response to stress. Overall our data suggest that Hog1, through activation of the RTG pathway, contributes to ensure mitochondrial function as part of the Hog1-mediated osmoadaptive response.

scholarly journals Physiological and Transcriptomic Responses to Nitrogen Deficiency in Neolamarckia cadamba

2021 ◽  
Vol 12 ◽  
Author(s):  
Lu Lu ◽  
Yuanyuan Zhang ◽  
Lu Li ◽  
Na Yi ◽  
Yi Liu ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Lignin Content ◽  
Nitrogen Deficiency ◽  
Essential Elements ◽  
Ammonium Transporter ◽  
Basic Leucine Zipper ◽  
Transporter Protein ◽  
Helix Loop Helix

Nitrogen (N) is one of the abundant and essential elements for plant growth and development, and N deficiency (ND) affects plants at both physiological and transcriptomic levels. Neolamarckia cadamba is a fast-growing woody plant from the Rubiaceae family. However, the physiological and molecular impacts of ND on this species have not been well investigated. Here, we studied how N. cadamba responds to ND under hydroponic conditions. In a physiological aspect, ND led to a reduction in biomass, chlorophyll content, and photosynthetic capacity. ND also impaired the assimilation of N as the activities of glutamine synthetase (GS) and nitrate reductase (NR) were decreased in the root. Interestingly, the lignin content of stem increased progressively during the ND stress. The main transcription factors, the transcription factors that are important to N regulation has been found to be upregulated, including Nodule inception-like protein 7 (NLP7), TGACG motif-binding factor 1 (TGA1), basic helix-loop-helix protein 45 (BHLH45), NAM, ATAF1,2, CUC2 (NAC) transcription factor 43 (NAC43), and basic leucine zipper pattern 44 (bZIP44). The expression of N transporters, such as nitrate transporter 2.4 (NRT2.4), ammonium transporter 3 (AMT3), and amino acid transporter protein 3 (AAP3), was also upregulated. In addition, phosphorus- and calcium-related genes such as phosphate starvation response 2 (PHR2) and cyclic nucleotide-gated ion channel 15 (CNGC15) were expressed more abundantly in response to ND stress. Our results reveal the physiological and molecular mechanisms by which woody plants respond to ND.

scholarly journals Abnormal Expression of Mouse Mast Cell Protease 5 Gene in Cultured Mast Cells Derived From Mutant mi/mi Mice

Blood ◽  
1997 ◽  
Vol 90 (8) ◽  
pp. 3057-3066 ◽  
Author(s):  
Eiichi Morii ◽  
Tomoko Jippo ◽  
Tohru Tsujimura ◽  
Koji Hashimoto ◽  
Dae-Ki Kim ◽  
...  
Keyword(s):  
Mast Cell ◽  
Transcription Factors ◽  
Mast Cells ◽  
Promoter Region ◽  
Leucine Zipper ◽  
Consensus Sequence ◽  
Mast Cell Protease ◽  
Helix Loop Helix ◽  
Regulation Mechanisms ◽  
Mouse Mast Cell

Abstract Mast cells contain a lot of mast cell-specific proteases. We have reported that the expression of mouse mast cell protease 6 (MMCP-6) is remarkably reduced in both cultured mast cells (CMCs) and skin mast cells of mi/mi mutant mice. In the present study, we found that the expression of MMCP-5 was reduced in CMCs but not in skin mast cells of mi/mi mice, and we compared the regulation mechanisms of MMCP-5 with those of MMCP-6. The mi locus encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF ). The consensus sequence recognized and bound by bHLH-Zip transcription factors is CANNTG. The overexpression of the normal (+) MITF but not of mi-MITF normalized the poor expression of the MMCP-5 gene in mi/mi CMCs, indicating the involvement of +-MITF in transactivation of the MMCP-5 gene. Although +-MITF directly bound CANNTG motifs in the promoter region of the MMCP-6 gene and transactivated it, the binding of +-MITF to the CAGTTG motif in the promoter region of the MMCP-5 gene was not detectable. The +-MITF appeared to regulate the transactivation of the MMCP-5 gene indirectly. Moreover, addition of stem cell factor to the medium normalized the expression of the MMCP-5 but not of the MMCP-6 gene in mi/mi CMCs. Despite the significant reduction of both MMCP-5 and MMCP-6 expressions in mi/mi CMCs, their regulation mechanisms appeared to be different.

scholarly journals Mitochondria-to-Nuclear Signaling Is Regulated by the Subcellular Localization of the Transcription Factors Rtg1p and Rtg3p

2000 ◽  
Vol 11 (6) ◽  
pp. 2103-2115 ◽  
Author(s):  
Takayuki Sekito ◽  
Janet Thornton ◽  
Ronald A. Butow
Keyword(s):  
Transcription Factors ◽  
Subcellular Localization ◽  
Nuclear Localization ◽  
Leucine Zipper ◽  
Negative Regulator ◽  
Phosphorylation State ◽  
Nuclear Signaling ◽  
Helix Loop Helix ◽  
Communication Pathway ◽  
Retrograde Response

Cells modulate the expression of nuclear genes in response to changes in the functional state of mitochondria, an interorganelle communication pathway called retrograde regulation. In yeast, expression of the CIT2 gene shows a typical retrograde response in that its expression is dramatically increased in cells with dysfunctional mitochondria, such as in ρo petites. Three genes control this signaling pathway: RTG1 andRTG3, which encode basic helix-loop-helix leucine zipper transcription factors that bind as heterodimer to theCIT2 upstream activation site, and RTG2, which encodes a protein of unknown function. We show that in respiratory-competent (ρ+) cells in whichCIT2 expression is low, Rtg1p and Rtg3p exist as a complex largely in the cytoplasm, and in ρo petites in which CIT2 expression is high, they exist as a complex predominantly localized in the nucleus. Cytoplasmic Rtg3p is multiply phosphorylated and becomes partially dephosphorylated when localized in the nucleus. Rtg2p, which is cytoplasmic in both ρ+ and ρo cells, is required for the dephosphorylation and nuclear localization of Rtg3p. Interaction of Rtg3p with Rtg1p is required to retain Rtg3p in the cytoplasm of ρ+ cells; in the absence of such interaction, nuclear localization and dephosphorylation of Rtg3p is independent of Rtg2p. Our data show that Rtg1p acts as both a positive and negative regulator of the retrograde response and that Rtg2p acts to transduce mitochondrial signals affecting the phosphorylation state and subcellular localization of Rtg3p.

scholarly journals Regulation of mouse mast cell protease 6 gene expression by transcription factor encoded by the mi locus

Blood ◽  
1996 ◽  
Vol 88 (7) ◽  
pp. 2488-2494 ◽  
Author(s):  
E Morii ◽  
T Tsujimura ◽  
T Jippo ◽  
K Hashimoto ◽  
K Takebayashi ◽  
...  
Keyword(s):  
Mast Cell ◽  
Transcription Factors ◽  
Mast Cells ◽  
Leucine Zipper ◽  
Luciferase Activity ◽  
Mast Cell Protease ◽  
Helix Loop Helix ◽  
3T3 Fibroblasts ◽  
Mouse Mast Cell ◽  
Nih 3T3

The mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF). Because the expression of the mouse mast cell protease 6 (MMCP-6) gene is remarkably reduced in mast cells of mi/mi mutant mice, we investigated the effect of MITF on the transcription of the MMCP-6 gene. First, we introduced the normal (+) MITF cDNA into mi/mi cultured mast cells using the retroviral vector. Overexpression of +-MITF but not mi-MITF normalized the expression of the MMCP-6 gene, indicating the involvement of +-MITF in the MMCP-6 gene transactivation. Second, we analyzed the promoter of the MMCP-6 gene by the transient cotransfection assay. The luciferase construct under the control of the MMCP-6 promoter and the cDNA encoding +-MITF or mi-MITF were cotransfected into NIH/ 3T3 fibroblasts. The coexpression of +- MITF but not mi-MITF increased the luciferase activity 10-fold. We found a CACATG and a CATCTG motif in the MMCP-6 promoter, both of which are generally recognized by bHLH-Zip-type transcription factors. We also found a GACCTG motif that was strongly bound by +-MITF. These three motifs were necessary for the 10-fold transactivation ability of the MMCP-6 promoter by +-MITF. Mutations of each motif significantly reduced the transactivation, suggesting that +-MITF directly transactivated the MMCP-6 gene through these three motifs.

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