scholarly journals p67 isoform of mouse disabled 2 protein acts as a transcriptional activator during the differentiation of F9 cells

2000 ◽  
Vol 352 (3) ◽  
pp. 645-650 ◽  
Author(s):  
Si Young CHO ◽  
Jae Won JEON ◽  
Sang Ho LEE ◽  
Sung Soo PARK
Keyword(s):  
Transcriptional Activation ◽  
Biological Function ◽  
Signal Transduction Pathway ◽  
Activation Function ◽  
Regulatory Elements ◽  
Cell Nuclei ◽  
Induced Differentiation ◽  
Interacting Protein ◽  
F9 Cells ◽  
Transcriptional Regulatory Elements

The mouse disabled 2 (mDab2) gene is a mouse homologue of the Drosophila disabled gene and is alternatively spliced to form two isoforms, p96 and p67. Although p96 has been known to regulate the RasŐSos G-protein signal transduction pathway by interacting with Grb2, little is known about the biological function of p67. Recent studies have shown that the expression of mDab2 is markedly up-regulated during the retinoic acid (RA)-induced differentiation of F9 cells, suggesting another role for mDab2 in cell differentiation [Cho, Lee and Park (1999) Mol. Cells 9, 179Ő184). In the present study, we first elucidated the biological function of p67 isoform of mDab2 and identified its binding partner. Unlike p96, p67 largely resides in RA-treated F9 cell nuclei. In this system, p67 interacts with mouse androgen-receptor interacting protein 3, termed the mDab2 interacting protein, which acts as a transcriptional co-regulator. By using a fusion protein with a heterologous DNA-binding domain (GAL4), we showed that p67 had an intrinsic transcriptional activation function. These results suggest that mDab2 p67 may function as a transcriptional co-factor for certain complexes of transcriptional regulatory elements involved in the RA-induced differentiation of F9 cells.

scholarly journals Multiple Signal Input and Output Domains of the 160-Kilodalton Nuclear Receptor Coactivator Proteins

1999 ◽  
Vol 19 (9) ◽  
pp. 6164-6173 ◽  
Author(s):  
Han Ma ◽  
Heng Hong ◽  
Shih-Ming Huang ◽  
Ryan A. Irvine ◽  
Paul Webb ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Transcriptional Activation ◽  
Thyroid Hormone Receptor ◽  
Activation Function ◽  
Creb Binding Protein ◽  
Activation Domain ◽  
Nuclear Receptor Coactivator ◽  
Interacting Protein ◽  
Binding Domains ◽  
Signal Input

ABSTRACT Members of the 160-kDa nuclear receptor coactivator family (p160 coactivators) bind to the conserved AF-2 activation function found in the hormone binding domains of nuclear receptors (NR) and are potent transcriptional coactivators for NRs. Here we report that the C-terminal region of p160 coactivators glucocorticoid receptor interacting protein 1 (GRIP1), steroid receptor coactivator 1 (SRC-1a), and SRC-1e binds the N-terminal AF-1 activation function of the androgen receptor (AR), and p160 coactivators can thereby enhance transcriptional activation by AR. While they all interact efficiently with AR AF-1, these same coactivators have vastly different binding strengths with and coactivator effects on AR AF-2. p160 activation domain AD1, which binds secondary coactivators CREB binding protein (CBP) and p300, was previously implicated as the principal domain for transmitting the activating signal to the transcription machinery. We identified a new highly conserved motif in the AD1 region which is important for CBP/p300 binding. Deletion of AD1 only partially reduced p160 coactivator function, due to signaling through AD2, another activation domain located at the C-terminal end of p160 coactivators. C-terminal coactivator fragments lacking AD1 but containing AD2 and the AR AF-1 binding site served as efficient coactivators for full-length AR and AR AF-1. The two signal input domains (one that binds NR AF-2 domains and one that binds AF-1 domains of some but not all NRs) and the two signal output domains (AD1 and AD2) of p160 coactivators played different relative roles for two different NRs: AR and thyroid hormone receptor.

Nerve-Derived Trophic Factors and DNA Elements Controlling Expression of Genes Encoding Synaptic Proteins in Skeletal Muscle Fibers

1998 ◽  
Vol 23 (4) ◽  
pp. 366-376 ◽  
Author(s):  
Bernard J. Jasmin ◽  
Anthony O. Gramolini ◽  
Feisal A. Adatia ◽  
Lindsay Angus ◽  
Céline Boudreau-Larivière ◽  
...  
Keyword(s):  
Neuromuscular Junction ◽  
Transcriptional Activation ◽  
Recombinant Dna ◽  
Signal Transduction Pathway ◽  
Regulatory Elements ◽  
Postsynaptic Membrane ◽  
Synaptic Proteins ◽  
Trophic Factors ◽  
Recombinant Dna Technology ◽  
Genes Encoding

The neuromuscular junction represents an excellent model system for studying various critical issues in neurobiology at the molecular, cellular, and physiological levels. Our understanding of the basic events underlying synpase formation, maintenance, and plasticity has progressed considerably over the last few years primarily because of the numerous studies that have focused on this synapse and used sophisticated recombinant DNA technology. Recent data indicate that myonuclei located in the vicinity of the postsynaptic membrane are in a differential state of transcription compared to nuclei of the extrasynaptic sarcoplasm. Thus, renewal of postsynaptic membrane proteins appears to occur via a mechanism involving the local transcriptional activation of genes encoding these specialized proteins and extracellular cues originating from motoneurons. Such interaction between presynaptic nerve terminals and the postsynaptic sarcoplasm indicates that the entire signal transduction pathway is compartmentalized at the level of the neuromuscular junction. Expression of these genes appears less coregulated than originally anticipated, indicating that maintenance of the postsynaptic membrane requires the contribution of multiple extracellular signals, which ultimately urge target transcription factors to distinct DNA regulatory elements via various second messenger systems. Key words: neuromuscular junction, synapse, acetylcholinesterase, utrophin, agrin, CGRP, promoter, mRNA

scholarly journals The transcription factor GLI1 cooperates with the chromatin remodeler SMARCA2 to regulate chromatin accessibility at distal DNA regulatory elements

2020 ◽  
Vol 295 (26) ◽  
pp. 8725-8735
Author(s):  
Stephanie L. Safgren ◽  
Rachel L. O. Olson ◽  
Anne M. Vrabel ◽  
Luciana L. Almada ◽  
David L. Marks ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Micrococcal Nuclease ◽  
Gene Promoters ◽  
Interacting Protein ◽  
Transcriptional Activation Domain ◽  
Dna Regulatory Elements

The transcription factor GLI1 (GLI family zinc finger 1) plays a key role in the development and progression of multiple malignancies. To date, regulation of transcriptional activity at target gene promoters is the only molecular event known to underlie the oncogenic function of GLI1. Here, we provide evidence that GLI1 controls chromatin accessibility at distal regulatory regions by modulating the recruitment of SMARCA2 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 2) to these elements. We demonstrate that SMARCA2 endogenously interacts with GLI1 and enhances its transcriptional activity. Mapping experiments indicated that the C-terminal transcriptional activation domain of GLI1 and SMARCA2's central domains, including its ATPase motif, are required for this interaction. Interestingly, similar to SMARCA2, GLI1 overexpression increased chromatin accessibility, as indicated by results of the micrococcal nuclease assay. Further, results of assays for transposase-accessible chromatin with sequencing (ATAC-seq) after GLI1 knockdown supported these findings, revealing that GLI1 regulates chromatin accessibility at several regions distal to gene promoters. Integrated RNA-seq and ATAC-seq data analyses identified a subset of differentially expressed genes located in cis to these regulated chromatin sites. Finally, using the GLI1-regulated gene HHIP (Hedgehog-interacting protein) as a model, we demonstrate that GLI1 and SMARCA2 co-occupy a distal chromatin peak and that SMARCA2 recruitment to this HHIP putative enhancer requires intact GLI1. These findings provide insights into how GLI1 controls gene expression in cancer cells and may inform approaches targeting this oncogenic transcription factor to manage malignancies.

Biallelic transcriptional activation of oncogenic transcription factors in T-cell acute lymphoblastic leukemia

Blood ◽  
2004 ◽  
Vol 103 (5) ◽  
pp. 1909-1911 ◽  
Author(s):  
Adolfo A. Ferrando ◽  
Sabine Herblot ◽  
Teresa Palomero ◽  
Mark Hansen ◽  
Trang Hoang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
T Cell ◽  
Transcriptional Activation ◽  
Lymphoblastic Leukemia ◽  
Chromosomal Rearrangements ◽  
Regulatory Elements ◽  
Leukemic Cells ◽  
Aberrant Expression ◽  
Transcriptional Regulatory Elements ◽  
Highly Active

Abstract Aberrant expression of transcription factor oncogenes such as HOX11, HOX11L2, TAL1/SCL, LYL1, LMO1, and LMO2 can be detected in lymphoblasts from up to 80% of patients with acute T-cell lymphoblastic leukemia (T-ALL). Transcriptional activation of these oncogenes in leukemic cells typically results from chromosomal rearrangements that place them next to highly active cis-acting transcriptional regulatory elements. However, biallelic activation of TAL1 in some T-ALL cases has been previously proposed. We have used allele-specific mRNA analysis to show that trans-acting mechanisms leading to biallelic overexpression of TAL1 are involved in 10 (42%) of 24 TAL1+ informative T-ALL cases, 2 (17%) of 12 HOX11+ informative cases, and 7 (64%) of 11 LMO2+ informative cases. We propose that aberrant expression of oncogenic transcription factors in a significant fraction of T-ALLs may result from loss of the upstream transcriptional mechanisms that normally down-regulate the expression of these oncogenes during T-cell development.

scholarly journals Mating in Saccharomyces cerevisiae: The Role of the Pheromone Signal Transduction Pathway in the Chemotropic Response to Pheromone

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Kathrin Schrick ◽  
Barbara Garvik ◽  
Leland H Hartwell
Keyword(s):  
Signal Transduction ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Wild Type ◽  
Mating Partner ◽  
Map Kinase Cascade ◽  
Kinase Cascade ◽  
Wild Type Control

Abstract The mating process in yeast has two distinct aspects. One is the induction and activation of proteins required for cell fusion in response to a pheromone signal; the other is chemotropism, i.e., detection of a pheromone gradient and construction of a fusion site available to the signaling cell. To determine whether components of the signal transduction pathway necessary for transcriptional activation also play a role in chemotropism, we examined strains with null mutations in components of the signal transduction pathway for diploid formation, prezygote formation and the chemotropic process of mating partner discrimination when transcription was induced downstream of the mutation. Cells mutant for components of the mitogen-activated protein (MAP) kinase cascade (ste5, ste20, ste11, ste7 or fus3 kss1) formed diploids at a frequency 1% that of the wild-type control, but formed prezygotes as efficiently as the wild-type control and showed good mating partner discrimination, suggesting that the MAP kinase cascade is not essential for chemotropism. In contrast, cells mutant for the receptor (ste2) or the β or γ subunit (ste4 and stel8) of the G protein were extremely defective in both diploid and prezygote formation and discriminated poorly between signaling and nonsignaling mating partners, implying that these components are important for chemotropism.

scholarly journals Genome-Wide Identification and Analysis of the APETALA2 (AP2) Transcription Factor in Dendrobium officinale

2021 ◽  
Vol 22 (10) ◽  
pp. 5221
Author(s):  
Danqi Zeng ◽  
Jaime A. Teixeira da Silva ◽  
Mingze Zhang ◽  
Zhenming Yu ◽  
Can Si ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Flower Development ◽  
Regulatory Elements ◽  
Negative Control ◽  
Dendrobium Officinale ◽  
Luciferase Reporter ◽  
Pcr Analysis ◽  
Luciferase Reporter Gene ◽  
Genome Wide ◽  
Ap2 Transcription Factor

The APETALA2 (AP2) transcription factors (TFs) play crucial roles in regulating development in plants. However, a comprehensive analysis of the AP2 family members in a valuable Chinese herbal orchid, Dendrobium officinale, or in other orchids, is limited. In this study, the 14 DoAP2 TFs that were identified from the D. officinale genome and named DoAP2-1 to DoAP2-14 were divided into three clades: euAP2, euANT, and basalANT. The promoters of all DoAP2 genes contained cis-regulatory elements related to plant development and also responsive to plant hormones and stress. qRT-PCR analysis showed the abundant expression of DoAP2-2, DoAP2-5, DoAP2-7, DoAP2-8 and DoAP2-12 genes in protocorm-like bodies (PLBs), while DoAP2-3, DoAP2-4, DoAP2-6, DoAP2-9, DoAP2-10 and DoAP2-11 expression was strong in plantlets. In addition, the expression of some DoAP2 genes was down-regulated during flower development. These results suggest that DoAP2 genes may play roles in plant regeneration and flower development in D. officinale. Four DoAP2 genes (DoAP2-1 from euAP2, DoAP2-2 from euANT, and DoAP2-6 and DoAP2-11 from basal ANT) were selected for further analyses. The transcriptional activation of DoAP2-1, DoAP2-2, DoAP2-6 and DoAP2-11 proteins, which were localized in the nucleus of Arabidopsis thaliana mesophyll protoplasts, was further analyzed by a dual-luciferase reporter gene system in Nicotiana benthamiana leaves. Our data showed that pBD-DoAP2-1, pBD-DoAP2-2, pBD-DoAP2-6 and pBD-DoAP2-11 significantly repressed the expression of the LUC reporter compared with the negative control (pBD), suggesting that these DoAP2 proteins may act as transcriptional repressors in the nucleus of plant cells. Our findings on AP2 genes in D. officinale shed light on the function of AP2 genes in this orchid and other plant species.

scholarly journals Expression of laminin γ 1 cultured hepatocytes involves repeated CTC and GC elements in the LAMC1 promoter

1996 ◽  
Vol 313 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Françoise LEVAVASSEUR ◽  
Jocelyne LIÉTARD ◽  
Kohei OGAWA ◽  
Nathalie THÉRET ◽  
Peter D. BURBELO ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Hepatoma Cell ◽  
Primary Cultures ◽  
Regulatory Elements ◽  
Hepatoma Cells ◽  
Basement Membranes ◽  
Major Protein ◽  
Cultured Hepatocytes

Laminin γ1 chain is present in all basement membranes and is expressed at high levels in various diseases, such as hepatic fibrosis. We have identified cis- and trans-acting elements involved in the regulation of this gene in normal rat liver, as well as in hepatocyte primary cultures and hepatoma cell lines. Northern-blot analyses showed that laminin γ1 mRNA was barely detectable in freshly isolated hepatocytes and expressed at high levels in hepatocyte primary cultures, as early as 4 h after liver dissociation. Actinomycin D and cycloheximide treatment in vivo and in vitro indicated that laminin γ1 overexpression in cultured hepatocytes was under the control of transcriptional mechanisms. Transfection of deletion mutants of the 5´ flanking region of murine LAMC1 gene in hepatoma cells that constitutively express laminin γ1 indicated that regulatory elements were located between -594 bp and -94 bp. This segment included GC- and CTC-containing motifs. Gel-shift analyses showed that two complexes were resolved with different affinity for the CTC sequence depending on the location of the GC box. The pattern of complex formation with nuclear factors from freshly isolated and cultured hepatocytes was different from that obtained with total liver and similar to that with hepatoma cells. Southwestern analysis indicated that several polypeptides bound the CTC-rich sequence. Affinity chromatography demonstrated that a Mr 60000 polypeptide was a major protein binding to the CTC motif. This polypeptide is probably involved in the transcriptional activation of various proto-oncogenes and extracellular matrix genes that are expressed at high levels in both hepatoma cells and early hepatocyte cultures.

scholarly journals Glucocorticoid Receptor Phosphorylation Differentially Affects Target Gene Expression

2008 ◽  
Vol 22 (8) ◽  
pp. 1754-1766 ◽  
Author(s):  
Weiwei Chen ◽  
Thoa Dang ◽  
Raymond D. Blind ◽  
Zhen Wang ◽  
Claudio N. Cavasotto ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Target Genes ◽  
Divalent Cations ◽  
Phosphorylation Site ◽  
Transcriptional Response ◽  
Receptor Occupancy ◽  
Wild Type ◽  
Interacting Protein

Abstract The glucocorticoid receptor (GR) is phosphorylated at multiple sites within its N terminus (S203, S211, S226), yet the role of phosphorylation in receptor function is not understood. Using a range of agonists and GR phosphorylation site-specific antibodies, we demonstrated that GR transcriptional activation is greatest when the relative phosphorylation of S211 exceeds that of S226. Consistent with this finding, a replacement of S226 with an alanine enhances GR transcriptional response. Using a battery of compounds that perturb different signaling pathways, we found that BAPTA-AM, a chelator of intracellular divalent cations, and curcumin, a natural product with antiinflammatory properties, reduced hormone-dependent phosphorylation at S211. This change in GR phosphorylation was associated with its decreased nuclear retention and transcriptional activation. Molecular modeling suggests that GR S211 phosphorylation promotes a conformational change, which exposes a novel surface potentially facilitating cofactor interaction. Indeed, S211 phosphorylation enhances GR interaction with MED14 (vitamin D receptor interacting protein 150). Interestingly, in U2OS cells expressing a nonphosphorylated GR mutant S211A, the expression of IGF-binding protein 1 and interferon regulatory factor 8, both MED14-dependent GR target genes, was reduced relative to cells expressing wild-type receptor across a broad range of hormone concentrations. In contrast, the induction of glucocorticoid-induced leucine zipper, a MED14-independent GR target, was similar in S211A- and wild-type GR-expressing cells at high hormone levels, but was reduced in S211A cells at low hormone concentrations, suggesting a link between GR phosphorylation, MED14 involvement, and receptor occupancy. Phosphorylation also affected the magnitude of repression by GR in a gene-selective manner. Thus, GR phosphorylation at S211 and S226 determines GR transcriptional response by modifying cofactor interaction. Furthermore, the effect of GR S211 phosphorylation is gene specific and, in some cases, dependent upon the amount of activated receptor.

scholarly journals miRNA proxy approach reveals hidden functions of glycosylation

2015 ◽  
Vol 112 (23) ◽  
pp. 7327-7332 ◽  
Author(s):  
Tomasz Kurcon ◽  
Zhongyin Liu ◽  
Anika V. Paradkar ◽  
Christopher A. Vaiana ◽  
Sujeethraj Koppolu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Epithelial To Mesenchymal Transition ◽  
Biological Function ◽  
Regulatory Elements ◽  
Rapid Identification ◽  
Mesenchymal Transition ◽  
Disease States ◽  
Mesenchymal To Epithelial Transition ◽  
Genes Encoding ◽  
Target Network

Glycosylation, the most abundant posttranslational modification, holds an unprecedented capacity for altering biological function. Our ability to harness glycosylation as a means to control biological systems is hampered by our inability to pinpoint the specific glycans and corresponding biosynthetic enzymes underlying a biological process. Herein we identify glycosylation enzymes acting as regulatory elements within a pathway using microRNA (miRNA) as a proxy. Leveraging the target network of the miRNA-200 family (miR-200f), regulators of epithelial-to-mesenchymal transition (EMT), we pinpoint genes encoding multiple promesenchymal glycosylation enzymes (glycogenes). We focus on three enzymes, beta-1,3-glucosyltransferase (B3GLCT), beta-galactoside alpha-2,3-sialyltransferase 5 (ST3GAL5), and (alpha-N-acetyl-neuraminyl-2,3-beta-galactosyl-1,3)-N-acetylgalactosaminide alpha-2,6-sialyltransferase 5 (ST6GALNAC5), encoding glycans that are difficult to analyze by traditional methods. Silencing these glycogenes phenocopied the effect of miR-200f, inducing mesenchymal-to-epithelial transition. In addition, all three are up-regulated in TGF-β–induced EMT, suggesting tight integration within the EMT-signaling network. Our work indicates that miRNA can act as a relatively simple proxy to decrypt which glycogenes, including those encoding difficult-to-analyze structures (e.g., proteoglycans, glycolipids), are functionally important in a biological pathway, setting the stage for the rapid identification of glycosylation enzymes driving disease states.

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