HNF-1α and endodermal transcription factors cooperatively activate Fabpl: MODY3 mutations abrogate cooperativity

2003 ◽  
Vol 285 (1) ◽  
pp. G62-G72 ◽  
Author(s):  
Joyce K. Divine ◽  
Sean P. McCaul ◽  
Theodore C. Simon
Keyword(s):  
Transcription Factors ◽  
Gene Activation ◽  
The Other ◽  
Wild Type ◽  
Critical Determinant ◽  
Fatty Acid Binding ◽  
Hepatic Expression ◽  
Synergistic Activation ◽  
Five Factors

Hepatocyte nuclear factor (HNF)-1α plays a central role in intestinal and hepatic gene regulation and is required for hepatic expression of the liver fatty acid binding protein gene ( Fabpl). An Fabpl transgene was directly activated through cognate sites by HNF-1α and HNF-1β, as well as five other endodermal factors: CDX-1, C/EBPβ, GATA-4, FoxA2, and HNF-4α. HNF-1α activated the Fabpl transgene by as much as 60-fold greater in the presence of the other five endodermal factors than in their absence, accounting for up to one-half the total transgene activation by the group of six factors. This degree of synergistic interaction suggests that multifactor cooperativity is a critical determinant of endodermal gene activation by HNF-1α. Mutations in HNF-1α that result in maturity onset diabetes of the young (MODY3) provide evidence for the in vivo significance of these synergistic interactions. An R131Q HNF-1α MODY3 mutant exhibits complete loss of synergistic activation in concert with the other endodermal transcription factors despite wild-type transactivation ability in their absence. Furthermore, whereas wild-type HNF-1α exhibited pairwise cooperative synergy with each of the other five factors, the R131Q mutant could synergize only with GATA-4 and C/EBPβ. Selective loss of synergy with other endodermal transcription factors accompanied by retention of native transactivation ability in an HNF-1α MODY mutant suggests in vivo significance for cooperative synergy.

scholarly journals Estrogen Up-Regulates Hepatic Expression of Suppressors of Cytokine Signaling-2 and -3 in Vivo and in Vitro

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5525-5531 ◽  
Author(s):  
Gary M. Leong ◽  
Sofia Moverare ◽  
Jesena Brce ◽  
Nathan Doyle ◽  
Klara Sjögren ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Hepatoma Cells ◽  
Cytokine Signaling ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Wild Type ◽  
Hepatic Expression ◽  
Suppressors Of Cytokine Signaling

Abstract Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-α, ERβ, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERβ knockout mice but not in those lacking ERα or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P < 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P < 0.05) in constructs containing a region between nucleotides −1862 and −855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERα, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.

scholarly journals The PAXFOXO1s trigger fast trans-differentiation of chick embryonic neural cells into alveolar rhabdomyosarcoma with tissue invasive properties limited by S phase entry inhibition

2020 ◽  
Author(s):  
Gloria Gonzalez Curto ◽  
Audrey Der Vartanian ◽  
Youcef Frarma ◽  
Line Manceau ◽  
Lorenzo Baldi ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Alveolar Rhabdomyosarcoma ◽  
Neural Cells ◽  
Wild Type ◽  
In Ovo ◽  
Driver Genes ◽  
Chromosome Translocations ◽  
Neural Origin ◽  
Cell Cycle Inhibition

AbstractThe chromosome translocations generating PAX3FOXO1 and PAX7FOXO1 chimeric proteins are the primary hallmarks of the paediatric cancer, Alveolar Rhabdomyosarcoma (ARMS). Despite the ability of these transcription factors to remodel chromatin landscapes and promote the expression of tumour driver genes, they only inefficiently promote malignant transformation in vivo. The reason for this is unclear. To address this, we developed an in ovo model to follow the response of spinal cord progenitors to PAXFOXO1s. Our data demonstrate that PAXFOXO1s, but not wild-type PAX3 and PAX7, trigger the trans-differentiation of neural cells into ARMS-like cells with myogenic characteristics. In parallel expression of PAXFOXO1s remodels the neural pseudo-stratified epithelium into a cohesive mesenchyme capable of tissue invasion. Surprisingly, gain for PAXFOXO1s, as for wild-type PAX3/7, reduces the levels of CDK-CYCLIN activity and arrests cells in G1. Introduction of CYCLIN D1 or MYCN overcomes PAXFOXO1s mediated cell cycle inhibition and promotes tumour growth. Together, our findings reveal a mechanism underpinning the apparent limited oncogenicity of PAXFOXO1 fusion transcription factors and support a neural origin for ARMS.

Cyclin D: CDK4/6 Kinase Activity, Regulated by GATA-1, Is Required for Megakaryocyte Polyploidization.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 780-780
Author(s):  
Andrew G. Muntean ◽  
Liyan Pang ◽  
Mortimer Poncz ◽  
Steve Dowdy ◽  
Gerd Blobel ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Transcription Factors ◽  
Cyclin D1 ◽  
Kinase Activity ◽  
Fetal Liver ◽  
Cyclin D3 ◽  
Luciferase Reporter ◽  
Cell Cycle Regulators ◽  
Wild Type

Abstract Megakaryocytes, which fragment to give rise to platelets, undergo a unique form of cell cycle, termed endomitosis, to become polyploid and terminally differentiate. During this process, cells transverse the cell cycle but the late stages of mitosis are bypassed to lead to accumulation of DNA up to 128N. While the mechanisms of polyploidization in megakaryocytes are poorly understood, a few cell cycle regulators, such as cyclin D3, have been implicated in this process. Hematopoietic transcription factors, including GATA-1 and RUNX1 are also essential for polyploidization, as both GATA1-deficient and RUNX1-null megakaryocytes undergo fewer rounds of endomitosis. Interestingly, GATA-1 deficient megakaryocytes are also smaller than their wild-type counterparts. However, the link between transcription factors and the growth and polyploidization of megakaryocytes has not been established. In our studies to identify key downstream targets of GATA-1 in the megakaryocyte lineage, we discovered that the cell cycle regulators cyclin D1 and p16 were aberrantly expressed in the absence of GATA-1: cyclin D1 expression was reduced nearly 10-fold, while that of p16ink4a was increased 10-fold. Luciferase reporter assays revealed that GATA-1, but not the leukemic isoform GATA-1s, promotes cyclinD1 expression. Consistent with these observations, megakaryocytes that express GATA-1s in place of full-length GATA-1 are smaller than their wild-type counterparts. Chromatin immunoprecipitation studies revealed that GATA-1 is bound to the cyclin D1 promoter in vivo, in primary fetal liver derived megakaryocytes. In contrast, GATA-1 is not associated with the cyclin D1 promoter in erythroid cells, which do not become polyploid. Thus, cyclin D1 is a bona fide GATA-1 target gene in megakaryocytes. To investigate whether restoration of cyclin D1 expression could rescue the polyploidization defect in GATA-1 deficient cells, we infected fetal liver progenitors isolated from GATA-1 knock-down mice with retroviruses harboring the cyclin D1 cDNA (and GFP via an IRES element) or GFP alone. Surprisingly, expression of cyclin D1 did not increase the extent of polyploidization of the GATA-1 deficient megakaryocytes. However, co-overexpression of cyclin D1 and Cdk4 resulted in a dramatic increase in polyploidization. Consistent with the model that cyclinD:Cdk4/6 also regulates cellular metabolism, we observed that the size of the doubly infected cells was also significantly increased. Finally, in support of our model that cyclin D:Cdk4/6 kinase activity is essential for endomitosis, we discovered that introduction of wild-type p16 TAT fusion protein, but not a mutant that fails to interact with Cdk4/6, significantly blocked polyploidization of primary fetal liver derived megakaryocytes. Taken together, our data reveal that the process of endomitosis and cell growth relies heavily on cyclinD:Cdk4/6 kinase activity and that the maturation defects in GATA-1 deficient megakaryocytes are due, in part, to reduced Cyclin D1 and increase p16 expression.

scholarly journals GATA3 Abundance Is a Critical Determinant of T Cell Receptor β Allelic Exclusion

2017 ◽  
Vol 37 (12) ◽  
Author(s):  
Chia-Jui Ku ◽  
JoAnn M. Sekiguchi ◽  
Bharat Panwar ◽  
Yuanfang Guan ◽  
Satoru Takahashi ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
The Other ◽  
Allelic Exclusion ◽  
Wild Type ◽  
Critical Determinant ◽  
Gata3 Expression ◽  
Immunological Process ◽  
Functional Receptor

ABSTRACT Allelic exclusion describes the essential immunological process by which feedback repression of sequential DNA rearrangements ensures that only one autosome expresses a functional T or B cell receptor. In wild-type mammals, approximately 60% of cells have recombined the DNA of one T cell receptor β (TCRβ) V-to-DJ-joined allele in a functional configuration, while the second allele has recombined only the DJ sequences; the other 40% of cells have recombined the V to the DJ segments on both alleles, with only one of the two alleles predicting a functional TCRβ protein. Here we report that the transgenic overexpression of GATA3 leads predominantly to biallelic TCRβ gene (Tcrb) recombination. We also found that wild-type immature thymocytes can be separated into distinct populations based on intracellular GATA3 expression and that GATA3LO cells had almost exclusively recombined only one Tcrb locus (that predicted a functional receptor sequence), while GATA3HI cells had uniformly recombined both Tcrb alleles (one predicting a functional and the other predicting a nonfunctional rearrangement). These data show that GATA3 abundance regulates the recombination propensity at the Tcrb locus and provide new mechanistic insight into the historic immunological conundrum for how Tcrb allelic exclusion is mediated.

scholarly journals Analysis of temporal changes in the expression of estrogen-regulated genes in the uterus

2003 ◽  
Vol 30 (3) ◽  
pp. 347-358 ◽  
Author(s):  
H Watanabe ◽  
A Suzuki ◽  
M Kobayashi ◽  
E Takahashi ◽  
M Itamoto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Expression Profiles ◽  
Gene Activation ◽  
Gene Expression Profiles ◽  
Ovariectomized Mice ◽  
Two Phases ◽  
Er Alpha ◽  
Inducible Genes

In order to understand early events caused by estrogen in vivo, temporal uterine gene expression profiles at early stages were examined using DNA microarray analysis. Ovariectomized mice were exposed to 17beta-estradiol and the temporal mRNA expression changes of ten thousand various genes were analyzed. Clustering analysis revealed that there are at least two phases of gene activation during the period up to six hours. One involved immediate-early genes, which included certain transcription factors and growth factors as well as oncogenes. The other involved early-late genes, which included genes related to RNA and protein synthesis. In clusters of down-regulated genes, transcription factors, proteases, apoptosis and cell cycle genes were found. These hormone-inducible genes were not induced in estrogen receptor (ER) alpha knockout mice. Although expression of ERbeta is known in the uterus, these findings indicate the importance of ERalpha in the changes in gene expression in the uterus.

scholarly journals BACTERIOPHAGE T4 ENDONUCLEASES II AND IV, OPPOSITELY AFFECTED BY dCMP HYDROXYMETHYLASE ACTIVITY, HAVE DIFFERENT ROLES IN THE DEGRADATION AND IN THE RNA POLYMERASE-DEPENDENT REPLICATION OF T4 CYTOSINE-CONTAINING DNA

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 669-685
Author(s):  
Karin Carlson ◽  
Aud Ȗvervatin
Keyword(s):  
Rna Polymerase ◽  
Dna Synthesis ◽  
Bacteriophage T4 ◽  
The Other ◽  
Wild Type ◽  
E Coli ◽  
Phage Dna ◽  
Dna Template ◽  
Do So

ABSTRACT Bacteriophage T4 mutants defective in gene 56 (dCTPase) synthesize DNA where cytosine (Cyt) partially or completely replaces hydroxymethylcytosine (HmCyt). This Cyt-DNA is degraded in vivo by T4 endonucleases II and IV, and by the exonuclease coded or controlled by genes 46 and 47.—Our results demonstrate that T4 endonuclease II is the principal enzyme initiating degradation of T4 Cyt-DNA. The activity of endonuclease IV, but not that of endonuclease II, was stimulated in the presence of a wild-type dCMP hydroxymethylase, also when no HmCyt was incorporated into phage DNA, suggesting the possibility of direct endonuclease IV-dCMP hydroxymethylase interactions. Endonuclease II activity, on the other hand, was almost completely inhibited in the presence of very small amounts of HmCyt (3-9% of total Cyt + HmCyt) in the DNA. Possible mechanisms for this inhibition are discussed.—The E. coli RNA polymerase modified by the products of T4 genes 33 and 55 was capable of initiating DNA synthesis on a Cyt-DNA template, although it probably cannot do so on an HmCyt template. In the presence of an active endonuclease IV, Cyt-DNA synthesis was arrested 10-30 min after infection, probably due to damage to the template. Cyt-DNA synthesis dependent on the unmodified (33  -  55  -) RNA polymerase was less sensitive to endonuclease IV action.

GATA-1 Forms Distinct Activating and Repressive Complexes in Erythroid Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 356-356
Author(s):  
John Strouboulis ◽  
Patrick Rodriguez ◽  
Edgar Bonte ◽  
Jeroen Krijgsveld ◽  
Katarzyna Kolodziej ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Chromatin Remodeling ◽  
Gene Activation ◽  
Erythroid Differentiation ◽  
Specific Gene ◽  
Erythroid Cells ◽  
In Erythroid Cells

Abstract GATA-1 is a key transcription factor essential for the differentiation of the erythroid, megakaryocytic and eosinophilic lineages. GATA-1 functions in erythropoiesis involve lineage-specific gene activation and repression of early hematopoietic transcription programs. GATA-1 is known to interact with other transcription factors, such as FOG-1, TAL-1 and Sp1 and also with CBP/p300 and the SWI/SNF chromatin remodeling complex in vitro. Despite this information the molecular basis of its essential functions in erythropoiesis remains unclear. We show here that GATA-1 is mostly present in a high (> 670kDa) molecular weight complex that appears to be dynamic during erythroid differentiation. In order to characterize the GATA-1 complex(es) from erythroid cells, we employed an in vivo biotinylation tagging approach in mouse erythroleukemic (MEL) cells1. Briefly, this involved the fusion of a small (23aa) peptide tag to GATA-1 and its specific, efficient biotinylation by the bacterial BirA biotin ligase which is co-expressed with tagged GATA-1 in MEL cells. Nuclear extracts expressing biotinylated tagged GATA-1 were bound directly to streptavidin beads and co-purifying proteins were identified by mass spectrometry. In addition to the known GATA-1-interacting transcription factors FOG-1, TAL-1 and Ldb-1, we describe novel interactions with the essential hematopoietic transcription factor Gfi-1b and the chromatin remodeling complexes MeCP1 and ACF/WCRF. Significantly, GATA-1 interaction with the repressive MeCP1 complex requires FOG-1. We also show in erythroid cells that GATA-1, FOG-1 and MeCP1 are stably bound to repressed genes representing early hematopoietic (e.g. GATA-2) or alternative lineage-specific (e.g. eosinophilic) transcription programs, whereas the GATA-1/Gfi1b complex is bound to repressed genes involved in cell proliferation. In contrast, GATA-1 and TAL-1 are bound to the active erythroid-specific EKLF gene. Our findings on GATA-1 complexes provide novel insight as to the critical roles that GATA-1 plays in many aspects of erythropoiesis by revealing the GATA-1 partners in the execution of specific functions.

Notch Signaling Is Required for Mast Cell Development in the Zebrafish.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3588-3588
Author(s):  
Sahar Da'as ◽  
Lauren C. Klein ◽  
Adolfo A. Ferrando ◽  
Jason N. Berman
Keyword(s):  
Mast Cell ◽  
Transcription Factors ◽  
Notch Signaling ◽  
Notch Pathway ◽  
Human Condition ◽  
Specific Marker ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Cell Fate Decisions

Abstract Abstract 3588 Poster Board III-525 The molecular pathways regulating mast cell (MC) development in vertebrates remain to be elucidated. The Notch signaling pathway is highly conserved in all metazoans and has been implicated in regulating hematopoietic stem cell induction and lineage cell fate decisions. Notch receptors and their ligands are expressed in a number of hematopoietic cells, including MCs. We were the first to identify zebrafish MC equivalents (Dobson et al., Blood 2008) and examine vertebrate MC transcriptional regulation in vivo. These studies demonstrated the significance of carboxypeptidase A 5 (cpa5) as a zebrafish MC-specific marker. Co-localization studies reveal zebrafish notch3 (a homologue of human NOTCH3) is expressed in a proportion of cpa5 positive cells in 7 day old embryos. Moreover, the zebrafish Notch signaling mutant, mind bomb, displays profound loss of cpa-5 expression, as do wild type zebrafish embryos treated with Compound E (Cpd E), a gamma-secretase inhibitor that blocks Notch signaling. We previously identified pu.1 and gata2 as essential transcription factors for early MC development. Interestingly, we observed a dose-dependent response, with reduced cpa5 and gata2 but preserved pu.1 expression at 50 μM Cpd E, compared with profound decreased expression of all these factors, as well as gata1 and mpo at 75 μM Cpd E. These data suggest a particular role for Notch signaling in regulating MC development, as well as a potentially broader role in regulating the myeloid and erythroid lineages. These studies are currently being validated through reciprocal experiments overexpressing notch mRNA in wild type embryos and rescue experiments overexpressing the notch intracellular domain and the above-mentioned transcription factors in Notch deficient embryos (mind bomb and Cpd E treated). We have also developed a transgenic zebrafish line expressing the human c-KIT D816V mutation found in systemic mastocytosis, which exhibits increased mast cells at the expense of erythroid cells, features in keeping with the human condition. These transgenic fish provide an opportunity to examine if Notch pathway inhibition alone, or in combination with other therapies, such as those targeting the c-KIT kinase, have a therapeutic impact in this condition. Parallel approaches in a human mastocytosis cell line are also being undertaken. These studies promise key insight into the role of Notch signaling in MC development and the opportunity to use the zebrafish as an in vivo model for identifying novel therapeutic strategies in MC diseases. Disclosures: Ferrando: Merck, Pfizer: Research Funding.

scholarly journals Complexity of CNC Transcription Factors As Revealed by Gene Targeting of the Nrf3 Locus

2004 ◽  
Vol 24 (8) ◽  
pp. 3286-3294 ◽  
Author(s):  
Anna Derjuga ◽  
Tania S. Gourley ◽  
Teresa M. Holm ◽  
Henry H. Q. Heng ◽  
Ramesh A. Shivdasani ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Leucine Zipper ◽  
B Lymphocyte ◽  
Gross Anatomy ◽  
Related Factor ◽  
Wild Type ◽  
Basic Leucine Zipper ◽  
Mild Phenotype ◽  
Age Progression

ABSTRACT Cap'n'collar (CNC) family basic leucine zipper transcription factors play crucial roles in the regulation of mammalian gene expression and development. To determine the in vivo function of the CNC protein Nrf3 (NF-E2-related factor 3), we generated mice deficient in this transcription factor. We performed targeted disruption of two Nrf3 exons coding for CNC homology, basic DNA-binding, and leucine zipper dimerization domains. Nrf3 null mice developed normally and revealed no obvious phenotypic differences compared to wild-type animals. Nrf3 −/− mice were fertile, and gross anatomy as well as behavior appeared normal. The mice showed normal age progression and did not show any apparent additional phenotype during their life span. We observed no differences in various blood parameters and chemistry values. We infected wild-type and Nrf3 −/− mice with acute lymphocytic choriomeningitis virus and found no differences in these animals with respect to their number of virus-specific CD8 and CD4 T cells as well as their B-lymphocyte response. To determine whether the mild phenotype of Nrf3 null animals is due to functional redundancy, we generated mice deficient in multiple CNC factors. Contrary to our expectations, an absence of Nrf3 does not seem to cause additional lethality in compound Nrf3 −/−/Nrf2 −/− and Nrf3 −/−/p45 −/− mice. We hypothesize that the role of Nrf3 in vivo may become apparent only after appropriate challenge to the mice.

scholarly journals In Vivo Reversion to the Wild-Type β-Lactam Resistance Phenotype Mediated by a Plasmid Carrying ampR and qnrA1 in Enterobacter cloacae

2006 ◽  
Vol 50 (9) ◽  
pp. 3175-3178
Author(s):  
J. J. González-López ◽  
M. Sabaté ◽  
S. Lavilla ◽  
M. N. Larrosa ◽  
R. M. Bartolomé ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
The Other ◽  
Resistance Pattern ◽  
Wild Type ◽  
Resistance Phenotype ◽  
Amoxicillin Clavulanate

ABSTRACT Resistance to β-lactams and quinolones in two isogenic Enterobacter cloacae isolates was studied. One was susceptible to cefoxitin and amoxicillin-clavulanate. The other one showed its natural β-lactam resistance pattern. Both isolates had a nonfunctional AmpR regulator. However, within the second one, the presence of a plasmid carrying ampR and qnrA1 allowed reversion to the wild-type β-lactam resistance phenotype and decreased susceptibility to fluoroquinolones.

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