The conserved amphipatic alpha-helical core motif of RARgamma and RARalpha activating domains is indispensable for RA-induced differentiation of F9 cells

2000 ◽  
Vol 113 (16) ◽  
pp. 2887-2895 ◽  
Author(s):  
J. Plassat ◽  
L. Penna ◽  
P. Chambon ◽  
C. Rochette-Egly
Keyword(s):  
Target Gene ◽  
Activation Function ◽  
Core Motif ◽  
Knock Out ◽  
F9 Cells ◽  
Helix 12 ◽  
Ec Cells ◽  
Induction Of Differentiation ◽  
Parietal Endoderm ◽  
Endodermal Differentiation

In monolayers cultures, retinoic acid (RA) induces the differentiation of F9 embryonal carcinomal (EC) cells into primitive endoderm-like cells, while a combination of RA and dibutyryl cAMP leads to parietal endoderm-like differentiation. Knock out of all RARgamma isoforms (RARgamma(-/-) line) drastically impairs primitive and subsequent parietal endodermal differentiation and affects the induction of many endogenous RA-responsive genes. Using lines that reexpress RARgamma2 or overexpress RARalpha1 lacking their AF-2AD core (RARgammadeltaAF2 and RARalphadeltaAF2, respectively), we show that this conserved amphipatic alpha-helical motif (helix 12) of the ligand binding domain, and therefore the activation function AF-2 of both receptors, is required for the induction of differentiation and target gene expression upon RA treatment of F9 EC cells. We also show that these deletion mutants behave as dominant negatives.

c-myc regulation during retinoic acid-induced differentiation of F9 cells is posttranscriptional and associated with growth arrest

1986 ◽  
Vol 6 (2) ◽  
pp. 518-524
Author(s):  
M Dean ◽  
R A Levine ◽  
J Campisi
Keyword(s):  
Retinoic Acid ◽  
Cyclic Amp ◽  
Posttranscriptional Regulation ◽  
Growth Arrest ◽  
Mrna Levels ◽  
F9 Cells ◽  
Induction Of Differentiation ◽  
Parietal Endoderm ◽  
Arrest Growth ◽  
F9 Teratocarcinoma

We have shown that c-myc mRNA levels decrease more than 20-fold when F9 teratocarcinoma stem cells are induced to arrest growth and terminally differentiate to parietal endoderm after exposure to retinoic acid and cyclic AMP (Campisi et al., Cell 36:241-247, 1984). Here, we demonstrate that although growth arrest and full expression of the differentiated phenotype required about 3 days, c-myc mRNA declined abruptly between 8 and 16 h after the addition of retinoic acid and cyclic AMP. The decline was independent of cyclic AMP. We found little or no change in the level of c-myc transcription during differentiation, although two other genes showed marked transcriptional regulation. Thus, decreased c-myc mRNA is a consequence of very early posttranscriptional regulation directed by retinoic acid. Differentiation was not fundamental to this regulation. We have shown that sodium butyrate blocks expression of the differentiated phenotype if added within 8 h of retinoic acid and cyclic AMP (Levine et al., Dev. Biol. 105:443-450, 1984). However, butyrate did not inhibit the decrease in c-myc mRNA. Furthermore, F9 cells partially arrested growth without differentiating when grown in isoleucine-deficient medium. Under these conditions, c-myc mRNA levels also declined. Our results suggest that induction of differentiation-specific genes may be under retinoic acid-mediated control dissimilar from that responsible for the decay of c-myc mRNA. In addition, they raise the possibility that growth arrest may be initiated by reduced c-myc expression.

scholarly journals c-myc regulation during retinoic acid-induced differentiation of F9 cells is posttranscriptional and associated with growth arrest.

1986 ◽  
Vol 6 (2) ◽  
pp. 518-524 ◽  
Author(s):  
M Dean ◽  
R A Levine ◽  
J Campisi
Keyword(s):  
Retinoic Acid ◽  
Cyclic Amp ◽  
Posttranscriptional Regulation ◽  
Growth Arrest ◽  
Mrna Levels ◽  
F9 Cells ◽  
Induction Of Differentiation ◽  
Parietal Endoderm ◽  
Arrest Growth ◽  
F9 Teratocarcinoma

We have shown that c-myc mRNA levels decrease more than 20-fold when F9 teratocarcinoma stem cells are induced to arrest growth and terminally differentiate to parietal endoderm after exposure to retinoic acid and cyclic AMP (Campisi et al., Cell 36:241-247, 1984). Here, we demonstrate that although growth arrest and full expression of the differentiated phenotype required about 3 days, c-myc mRNA declined abruptly between 8 and 16 h after the addition of retinoic acid and cyclic AMP. The decline was independent of cyclic AMP. We found little or no change in the level of c-myc transcription during differentiation, although two other genes showed marked transcriptional regulation. Thus, decreased c-myc mRNA is a consequence of very early posttranscriptional regulation directed by retinoic acid. Differentiation was not fundamental to this regulation. We have shown that sodium butyrate blocks expression of the differentiated phenotype if added within 8 h of retinoic acid and cyclic AMP (Levine et al., Dev. Biol. 105:443-450, 1984). However, butyrate did not inhibit the decrease in c-myc mRNA. Furthermore, F9 cells partially arrested growth without differentiating when grown in isoleucine-deficient medium. Under these conditions, c-myc mRNA levels also declined. Our results suggest that induction of differentiation-specific genes may be under retinoic acid-mediated control dissimilar from that responsible for the decay of c-myc mRNA. In addition, they raise the possibility that growth arrest may be initiated by reduced c-myc expression.

scholarly journals β-Catenin Binds to the Activation Function 2 Region of the Androgen Receptor and Modulates the Effects of the N-Terminal Domain and TIF2 on Ligand-Dependent Transcription

2003 ◽  
Vol 23 (5) ◽  
pp. 1674-1687 ◽  
Author(s):  
Liang-Nian Song ◽  
Roger Herrell ◽  
Stephen Byers ◽  
Salimuddin Shah ◽  
Elizabeth M. Wilson ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Hormone Receptors ◽  
Nuclear Translocation ◽  
Retinoic Acid Receptor ◽  
Activation Function ◽  
Steroid Hormone Receptors ◽  
Binding Assays ◽  
Peptide Motifs ◽  
Terminal Domain ◽  
Helix 12

ABSTRACT β-Catenin is a multifunctional molecule that is activated by signaling through WNT receptors. β-Catenin can also enhance the transcriptional activity of some steroid hormone receptors such as the androgen receptor and retinoic acid receptor α. Androgens can affect nuclear translocation of β-catenin and influence its subcellular distribution. Using mammalian two-hybrid binding assays, analysis of reporter gene transcription, and coimmunoprecipitation, we now show that β-catenin binds to the androgen receptor ligand-binding domain (LBD) and modulates the transcriptional effects of TIF2 and the androgen receptor N-terminal domain (NTD). In functional assays, β-catenin bound to androgen receptor only in the presence of ligand agonists, not antagonists. β-Catenin binding to the androgen receptor LBD was independent of and cooperative with the androgen receptor NTD and the p160 coactivator TIF2, both of which bind to the activation function 2 (AF-2) region of the androgen receptor. Different mutations of androgen receptor helix 3 amino acids disrupted binding of androgen receptor NTD and β-catenin. β-Catenin, androgen receptor NTD, and TIF2 binding to the androgen receptor LBD were affected similarly by a subset of helix 12 mutations, but disruption of two sites on helix 12 affected only binding of β-catenin and not of TIF2 or the androgen receptor NTD. Mutational disruption of each of five LXXLL peptide motifs in the β-catenin armadillo repeats did not disrupt either binding to androgen receptor or transcriptional coactivation. ICAT, an inhibitor of T-cell factor 4 (TCF-4), and E-cadherin binding to β-catenin also blocked binding of the androgen receptor LBD. We also demonstrated cross talk between the WNT and androgen receptor signaling pathways because excess androgen receptor could interfere with WNT signaling and excess TCF-4 inhibited the interaction of β-catenin and androgen receptor. Taken together, the data show that β-catenin can bind to the androgen receptor LBD and modulate the effects of the androgen receptor NTD and TIF2 on transcription.

Interaction of several related GC-box- and GT-box-binding proteins with the intronic enhancer is required for differential expression of the gb110 gene in embryonal carcinoma cells

1994 ◽  
Vol 14 (9) ◽  
pp. 5786-5793
Author(s):  
L Hamann ◽  
K U Bayer ◽  
K Jensen ◽  
K Harbers
Keyword(s):  
Transcription Factor ◽  
Binding Proteins ◽  
Embryonal Carcinoma ◽  
Regulatory Elements ◽  
Carcinoma Cells ◽  
Minor Importance ◽  
Embryonal Carcinoma Cells ◽  
Enhancer Element ◽  
F9 Cells ◽  
Parietal Endoderm

The molecular mechanisms by which expression of a gene is down-regulated after differentiation of F9 embryonal carcinoma cells into parietal endoderm-like cells was studied by characterizing the cis- and trans-regulatory elements of the gb110 gene. This gene encodes a putative RNA helicase, and its expression is down-regulated when F9 cells are differentiated with retinoic acid and cyclic AMP. The 5'-flanking region of the gene has all of the features of a GC-rich island promoter and seems to play only a minor role, if any, in the regulated expression. A 133-bp enhancer in the first intron was identified by transient chloramphenicol acetyltransferase assays that activated expression in undifferentiated F9 cells about 50- to 100-fold. As this enhancer was not active in differentiated F9 cells, it seems to be the prime mediator of the differentiation-specific down-regulation of the gb110 gene. Four different protein-binding sites, three of which contain GC- and GT-box motifs, were identified in the enhancer element. The fourth site, interacting with previously described transcription factor FTZ-F1/ELP, seems to be of minor importance for the activity of the enhancer. Mutational analysis showed that the cooperative interaction of several most likely related proteins with the three GC- and GT-box motifs was required for full enhancer activity. On the basis of their binding properties, at least two of these proteins seem to be identical or closely related to ubiquitous transcription factor Sp1. One of the GT-box-binding proteins was present in undifferentiated F9 cells but not, however, in its differentiated derivatives. The cell specificity of this transcription factor explains why the gb110 gene is not expressed or expressed only at low levels in parietal endoderm-like cells.

scholarly journals Expression of fibroblast growth factor by F9 teratocarcinoma cells as a function of differentiation.

1989 ◽  
Vol 108 (6) ◽  
pp. 2467-2476 ◽  
Author(s):  
S J Braunhut ◽  
L J Gudas ◽  
T Kurokawa ◽  
J Sasse ◽  
P A D'Amore
Keyword(s):  
Stem Cells ◽  
Cdna Probe ◽  
Biologically Active ◽  
Endothelial Cell Proliferation ◽  
Fibroblast Growth ◽  
Basic Fgf ◽  
F9 Cells ◽  
Parietal Endoderm ◽  
F9 Teratocarcinoma ◽  
Proliferation Assays

F9 teratocarcinoma stem cells treated with retinoic acid (RA) and dibutyryl cAMP (but2 cAMP) differentiate into embryonic parietal endoderm. Using heparin-affinity chromatography, endothelial cell proliferation assays, immunoprecipitation, and Western analysis with antibodies specific for acidic and basic fibroblast growth factors (FGFs), we detected biologically active FGF in F9 cells only after differentiation. A bovine basic FGF cDNA probe hybridized to 2.2-kb mRNAs in both F9 stem and parietal endoderm cells and to a 3.8-kb mRNA in F9 stem cells. A genomic DNA probe for acidic FGF hybridized to a 5.8-6.0-kb mRNA in both F9 stem and parietal endoderm cells, and to a 6.0-6.3-kb mRNA only in parietal endoderm cells. Although these FGF mRNAs were present in the stem cells, we could find no evidence that F9 stem cells synthesized FGFs, whereas differentiated F9 cells synthesized both acidic and basic FGF-like proteins. We conclude that biologically active factors with properties characteristic of acidic and basic FGF are expressed by F9 parietal endoderm cells after differentiation. Differentiating embryonic parietal endoderm thus may serve as a source of FGF molecules in the developing blastocyst, where these factors appear to play a central role in subsequent embryogenesis.

scholarly journals Nuclear Hormone Receptors for Heme: REV-ERBα and REV-ERBβ Are Ligand-Regulated Components of the Mammalian Clock

2008 ◽  
Vol 22 (7) ◽  
pp. 1509-1520 ◽  
Author(s):  
Thomas P. Burris
Keyword(s):  
Nuclear Receptor ◽  
Cellular Differentiation ◽  
Target Gene ◽  
Hormone Receptors ◽  
Activation Function ◽  
Nuclear Hormone Receptors ◽  
Gene Promoters ◽  
Nuclear Receptor Corepressor ◽  
Small Molecule Ligands ◽  
Target Gene Transcription

Abstract The nuclear hormone receptors (NHRs), REV-ERBα and REV-ERBβ, regulate a number of physiological functions including the circadian rhythm, lipid metabolism, and cellular differentiation. These two receptors lack the activation function-2 region that is associated with the ability of NHRs to recruit coactivators and activate target gene transcription. These NHRs have been characterized as constitutive repressors of transcription due to their lack of an identified ligand and their strong ability to recruit the corepressor, nuclear receptor corepressor. Recently, the porphyrin heme was demonstrated to function as a ligand for both REV-ERBs. Heme binds directly to the ligand-binding domain and regulates the ability of these NHRs to recruit nuclear receptor corepressor to target gene promoters. This review focuses on the physiological roles that these two receptors play and the implications of heme functioning as their ligand. The prospect that these NHRs, now known to be regulated by small molecule ligands, may be targets for development of drugs for treatment of diseases associated with aberrant circadian rhythms including metabolic and psychiatric disorders as well as cancer is also addressed.

scholarly journals Primary effusion lymphoma enhancer connectome links super-enhancers to dependency factors

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chong Wang ◽  
Luyao Zhang ◽  
Liangru Ke ◽  
Weiyue Ding ◽  
Sizun Jiang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Growth ◽  
Cell Line ◽  
Poor Prognosis ◽  
Target Gene ◽  
Primary Effusion Lymphoma ◽  
Knock Out ◽  
Growth And Survival ◽  
Super Enhancer ◽  
Genome Wide

AbstractPrimary effusion lymphoma (PEL) has a very poor prognosis. To evaluate the contributions of enhancers/promoters interactions to PEL cell growth and survival, here we produce H3K27ac HiChIP datasets in PEL cells. This allows us to generate the PEL enhancer connectome, which links enhancers and promoters in PEL genome-wide. We identify more than 8000 genomic interactions in each PEL cell line. By incorporating HiChIP data with H3K27ac ChIP-seq data, we identify interactions between enhancers/enhancers, enhancers/promoters, and promoters/promoters. HiChIP further links PEL super-enhancers to PEL dependency factors MYC, IRF4, MCL1, CCND2, MDM2, and CFLAR. CRISPR knock out of MEF2C and IRF4 significantly reduces MYC and IRF4 super-enhancer H3K27ac signal. Knock out also reduces MYC and IRF4 expression. CRISPRi perturbation of these super-enhancers by tethering transcription repressors to enhancers significantly reduces target gene expression and reduces PEL cell growth. These data provide insights into PEL molecular pathogenesis.

scholarly journals Regulatory gene function handoff allows essential gene loss in mosquitoes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Alys M. Cheatle Jarvela ◽  
Catherine S. Trelstad ◽  
Leslie Pick
Keyword(s):  
Target Gene ◽  
Essential Gene ◽  
Regulatory Gene ◽  
Mechanistic Explanation ◽  
Closely Related Species ◽  
Knock Out ◽  
Pair Rule Gene ◽  
Body Patterning ◽  
Functional Replacement ◽  
Pair Rule

AbstractRegulatory genes are often multifunctional and constrained, which results in evolutionary conservation. It is difficult to understand how a regulatory gene could be lost from one species’ genome when it is essential for viability in closely related species. The gene paired is a classic Drosophila pair-rule gene, required for formation of alternate body segments in diverse insect species. Surprisingly, paired was lost in mosquitoes without disrupting body patterning. Here, we demonstrate that a paired family member, gooseberry, has acquired paired-like expression in the malaria mosquito Anopheles stephensi. Anopheles-gooseberry CRISPR-Cas9 knock-out mutants display pair-rule phenotypes and alteration of target gene expression similar to what is seen in Drosophila and beetle paired mutants. Thus, paired was functionally replaced by the related gene, gooseberry, in mosquitoes. Our findings document a rare example of a functional replacement of an essential regulatory gene and provide a mechanistic explanation of how such loss can occur.

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