A role for GATA5 in Xenopus endoderm specification

Development ◽  
2000 ◽  
Vol 127 (20) ◽  
pp. 4345-4360 ◽  
Author(s):  
H. Weber ◽  
C.E. Symes ◽  
M.E. Walmsley ◽  
A.R. Rodaway ◽  
R.K. Patient
Keyword(s):  
Transcription Factor ◽  
Dominant Negative ◽  
Marker Genes ◽  
Independent Manner ◽  
Fgf Receptor ◽  
T Box ◽  
Gata Factors ◽  
Dorsal Mesoderm ◽  
Liver And Pancreas ◽  
Convergence And Extension

The endoderm gives rise to the gut and tissues that develop as outgrowths of the gut tube, including the lungs, liver and pancreas. Here we show that GATA5, a zinc-finger transcription factor, is expressed in the yolk-rich vegetal cells of Xenopus embryos from the early gastrula stage onwards, when these cells become committed to form endoderm. At mid-gastrula stages, GATA5 is restricted to the sub-blastoporal endoderm and is the first molecular marker for this subset of endodermal cells so far identified. We show that GATA4 and GATA5 are potent inducers of endodermal marker genes in animal cap assays, while other GATA factors induce these genes only weakly, if at all. When injected into the dorsal marginal zone, GATA5 respecifies prospective mesoderm towards an endodermal fate, thereby disrupting the convergence and extension movements normally undergone by the dorsal mesoderm. The resulting phenotype is very similar to those seen after injection of dominant negative versions of the FGF-receptor or the T-box transcription factor, Xbra and can be rescued by eFGF. The ability of GATA5 to respecify ectodermal and mesodermal cells towards endoderm suggests an important role for GATA5 in the formation of this germlayer. In animal cap assays, GATA5 is induced by concentrations of activin above those known to induce dorsal mesoderm and heart, in an FGF-independent manner. These data indicate that the emerging view for endodermal induction in general, namely that it is specified by high levels of TGF-beta in the absence of FGF signalling, is specifically true for sub-blastoporal endoderm.

scholarly journals CREB Activation Induces Adipogenesis in 3T3-L1 Cells

2000 ◽  
Vol 20 (3) ◽  
pp. 1008-1020 ◽  
Author(s):  
Jane E. B. Reusch ◽  
Lilliester A. Colton ◽  
Dwight J. Klemm
Keyword(s):  
Transcription Factor ◽  
Dominant Negative ◽  
Marker Genes ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Fatty Acid Binding ◽  
Fat Composition ◽  
Specific Factors ◽  
Necessary And Sufficient ◽  
Physiological And Biochemical

ABSTRACT Obesity is the result of numerous, interacting behavioral, physiological, and biochemical factors. One increasingly important factor is the generation of additional fat cells, or adipocytes, in response to excess feeding and/or large increases in body fat composition. The generation of new adipocytes is controlled by several “adipocyte-specific” transcription factors that regulate preadipocyte proliferation and adipogenesis. Generally these adipocyte-specific factors are expressed only following the induction of adipogenesis. The transcription factor(s) that are involved in initiating adipocyte differentiation have not been identified. Here we demonstrate that the transcription factor, CREB, is constitutively expressed in preadipocytes and throughout the differentiation process and that CREB is stimulated by conventional differentiation-inducing agents such as insulin, dexamethasone, and dibutyryl cAMP. Stably transfected 3T3-L1 preadipocytes were generated in which we could induce the expression of either a constitutively active CREB (VP16-CREB) or a dominant-negative CREB (KCREB). Inducible expression of VP16-CREB alone was sufficient to initiate adipogenesis as determined by triacylglycerol storage, cell morphology, and the expression of two adipocyte marker genes, peroxisome proliferator activated receptor gamma 2, and fatty acid binding protein. Alternatively, KCREB alone blocked adipogenesis in cells treated with conventional differentiation-inducing agents. These data indicate that activation of CREB was necessary and sufficient to induce adipogenesis. Finally, CREB was shown to bind to putative CRE sequences in the promoters of several adipocyte-specific genes. These data firmly establish CREB as a primary regulator of adipogenesis and suggest that CREB may play similar roles in other cells and tissues.

An essential role for retinoid signaling in anteroposterior neural patterning

Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 373-379 ◽  
Author(s):  
B. Blumberg ◽  
J. Bolado ◽  
T.A. Moreno ◽  
C. Kintner ◽  
R.M. Evans ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Marker Genes ◽  
Neural Patterning ◽  
Retinoid Signaling ◽  
Retinoid Receptors ◽  
Neural Fate ◽  
Dorsal Mesoderm ◽  
Neural Ectoderm ◽  
Vertebrate Central Nervous System

The vertebrate central nervous system (CNS) is induced by signals emanating from the dorsal mesoderm, or organizer, that divert the ectoderm away from an epidermal and towards a neural fate. Additional signals from the organizer pattern the neural ectoderm along the anteroposterior axis. We devised highly specific methods utilizing constitutively active or dominant negative receptors to evaluate the role of retinoids in neural patterning. Microinjection of these reagents either augments or reduces retinoid signaling in specific regions of the embryo. We show that increased receptor activity suppresses anterior neural structures while dominant negative receptors lead to anterior enhancement. Similarly, microinjection of the dominant negative receptor leads to the loss of posterior marker genes. We demonstrate that retinoid receptors comprise a critical component in neural posteriorization and are required for proper neuronal differentiation. These results support a quantitative role for retinoid signaling in regionalization of the CNS.

Gata-Independent Regulation of Red Cell Specific Gene Expression.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1736-1736
Author(s):  
Jenna L. Galloway ◽  
Rebecca A. Wingert ◽  
Christine Thisse ◽  
Bernard Thisse ◽  
Leonard I. Zon
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Regulation Of Gene Expression ◽  
Actin Binding ◽  
Specific Gene ◽  
Cellular Functions ◽  
Novel Genes ◽  
Independent Manner ◽  
Repeat Protein ◽  
Gata Factors

Abstract During vertebrate embryonic hematopoiesis, the first blood cells can be identified by expression of the transcription factor genes scl and GATA2, followed by expression of GATA1, a gene required for the erythroid lineage. A high-throughput in situ hybridization screen in zebrafish analyzed the expression pattern of 3700 clones from a hematopoietic cDNA library and discovered 24 genes with expression in the blood. Examination of gene expression in Biklf, GATA1, GATA2, and GATA1/GATA2-deficient animals revealed that most blood genes are dependent upon GATA factors for expression rather than the Krüppel-like transcription factor Biklf. Three novel genes, expressed specifically in erythroid precursors, did not require GATA factors for their expression, demonstrating that some blood genes are regulated in a GATA-independent manner. These three genes were kelch-repeat protein (kelch repeats have been implicated in diverse cellular functions from actin binding to sequestering transcriptions factors), kiaa0650, which contains an SMC-hinge domain, and testhymin, which has no known structural motifs. By using combinations of antisense morpholinos to the known hematopoietic genes biklf , GATA1, GATA2, and scl, we were able to examine the regulation of these novel genes in double and triple knock-down embryos. While expression of kelch-repeat protein was lost in the absence of GATA1 and Biklf, expression of testhymin and kiaa0650 was maintained in GATA1/GATA2/Biklf-deficient embryos, suggesting that these similarly expressed genes are differentially regulated. As with GATA1, kiaa0650 and kelch-repeat protein required Scl for their expression in the early hematopoietic mesoderm while testhymin did not. Furthermore, loss of Scl and GATA2 did not completely ablate testhymin expression, suggesting that this gene is induced by factors upstream or parallel to Scl and GATA2. Taken together, our zebrafish studies establish a regulation of gene expression by a developmental hierarchy of specific transcription factors that act in combination during blood cell maturation.

A truncated FGF receptor blocks neural induction by endogenous Xenopus inducers

Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 869-880 ◽  
Author(s):  
C. Launay ◽  
V. Fromentoux ◽  
D.L. Shi ◽  
J.C. Boucaut
Keyword(s):  
Neural Induction ◽  
Cement Gland ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Fgf Receptor ◽  
Dorsal Mesoderm ◽  
Poorly Differentiated ◽  
Neural Marker ◽  
Fgf Signalling

We have examined the role of fibroblast growth factor (FGF) signalling in neural induction. The approach takes advantage of the fact that both noggin and the dominant negative mutant activin receptor (delta1XAR1) directly induce neural tissues in the absence of dorsal mesoderm. A truncated FGF receptor (XFD) is co-expressed with noggin or delta1XAR1 in both whole embryos and isolated animal caps. We demonstrate that inhibition of FGF signalling prevents neural induction by both factors. Furthermore, neural induction by organizers (the dorsal lip of blastopore and Hensen's node) is also blocked by inhibiting FGF signalling in ectoderm. It has been proposed that the specification of anterior neuroectoderm, including the cement gland, occurs in a sequential manner as gastrulation proceeds. We show that the specification of the most anterior neuroectoderm by noggin may occur before gastrulation and does not require FGF signalling, since both the cement gland marker XCG-1 and the anterior neural marker Otx-2 are normally expressed in ectodermal explants co-injected with noggin and XFD RNAs, but the cement gland cells are poorly differentiated. In contrast, the expression of both genes induced by CSKA.noggin, which is expressed after the mid-blastula transition, is strongly inhibited by the presence of XFD. Therefore the noggin-mediated neural induction that takes place at gastrula stages is abolished in the absence of FGF signalling. Since inhibition of FGF signalling blocks the neuralizing effect of different neural inducers that function through independent mechanisms, we propose that FGF receptor-related-signalling is required for the response to inducing signals of ectodermal cells from gastrula.

Mutation P291fsinsC in the transcription factor hepatocyte nuclear factor-1alpha is dominant negative

Diabetes ◽  
1998 ◽  
Vol 47 (8) ◽  
pp. 1231-1235 ◽  
Author(s):  
K. Yamagata ◽  
Q. Yang ◽  
K. Yamamoto ◽  
H. Iwahashi ◽  
J. Miyagawa ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dominant Negative ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor

scholarly journals Glucocorticoid Receptor β (GRβ): Beyond Its Dominant-Negative Function

2021 ◽  
Vol 22 (7) ◽  
pp. 3649
Author(s):  
Patricia Ramos-Ramírez ◽  
Omar Tliba
Keyword(s):  
Current Knowledge ◽  
Inflammatory Diseases ◽  
Cell Communication ◽  
Cell Types ◽  
The Body ◽  
Dominant Negative ◽  
Negative Effects ◽  
Independent Manner ◽  
Distinct Cell ◽  
Induced Apoptosis

Glucocorticoids (GCs) act via the GC receptor (GR), a receptor ubiquitously expressed in the body where it drives a broad spectrum of responses within distinct cell types and tissues, which vary in strength and specificity. The variability of GR-mediated cell responses is further extended by the existence of GR isoforms, such as GRα and GRβ, generated through alternative splicing mechanisms. While GRα is the classic receptor responsible for GC actions, GRβ has been implicated in the impairment of GRα-mediated activities. Interestingly, in contrast to the popular belief that GRβ actions are restricted to its dominant-negative effects on GRα-mediated responses, GRβ has been shown to have intrinsic activities and “directly” regulates a plethora of genes related to inflammatory process, cell communication, migration, and malignancy, each in a GRα-independent manner. Furthermore, GRβ has been associated with increased cell migration, growth, and reduced sensitivity to GC-induced apoptosis. We will summarize the current knowledge of GRβ-mediated responses, with a focus on the GRα-independent/intrinsic effects of GRβ and the associated non-canonical signaling pathways. Where appropriate, potential links to airway inflammatory diseases will be highlighted.

scholarly journals Protein kinase C-theta isoenzyme selective stimulation of the transcription factor complex AP-1 in T lymphocytes.

1996 ◽  
Vol 16 (4) ◽  
pp. 1842-1850 ◽  
Author(s):  
G Baier-Bitterlich ◽  
F Uberall ◽  
B Bauer ◽  
F Fresser ◽  
H Wachter ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Kinase C ◽  
Pkc Isoforms ◽  
Pkc Alpha ◽  
Transcriptional Complex ◽  
Induced Signal ◽  
Transcription Factor Complex

T-lymphocyte stimulation requires activation of several protein kinases, including the major phorbol ester receptor protein kinase C (PKC), ultimately leading to induction of lymphokines, such as interleukin-2 (IL-2). The revelant PKC isoforms which are involved in the activation cascades of nuclear transcription factors involved in IL-2 production have not yet been clearly defined. We have examined the potential role of two representative PKC isoforms in the induction of the IL-2 gene, i.e., PKC-alpha and PKC-theta, the latter being expressed predominantly in hematopoietic cell lines, particularly T cells. Similar to that of PKC-alpha, PKC-theta overexpression in murine EL4 thymoma cells caused a significant increase in phorbol 12-myristate 13-acetate (PMA)-induced transcriptional activation of full-length IL-2-chloramphenicol acetyltransferase (CAT) and NF-AT-CAT but not of NF-IL2A-CAT or NF-kappaB promoter-CAT reporter gene constructs. Importantly, the critical AP-1 enhancer element was differentially modulated by these two distinct PKC isoenzymes, since only PKC-theta but not PKC-alpha overexpression resulted in an approximately 2.8-fold increase in AP-1-collagenase promoter CAT expression in comparison with the vector control. Deletion of the AP-1 enhancer site in the collagenase promoter rendered it unresponsive to PKC-theta. Expression of a constitutively active mutant PKC-theta A148E (but not PKC-alpha A25E) was sufficient to induce activation of AP-1 transcription factor complex in the absence of PMA stimulation. Conversely, a catalytically inactive PKC-theta K409R (but not PKC-alpha K368R) mutant abrogated endogenous PMA-mediated activation of AP-1 transcriptional complex. Dominant negative mutant Ha-RasS17N completely inhibited the PKC-O A148E-induced signal, PKC-O. Expression of a constitutively active mutant PKC-O A148E (but not PKC-alpha A25E) was sufficient to induce activation of AP-1 transcription factor complex in the absence of PMA stimulation. Conversely, a catalytically inactive PKC-O K409R (but not PKC-alpha K368R) mutant abrogated endogenous PMA-mediated activation of AP-1 transcriptional complex. Dominant negative mutant Ha-enRasS17N completely inhibited in the PKC-O A148E-induced signal, identifying PKC-theta as a specific constituent upstream of or parallel to Ras in the signaling cascade leading to AP transcriptional activation.

scholarly journals Assessing the role of the T-box transcription factor Eomes in B cell differentiation during either Th1 or Th2 cell-biased responses

PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0208343 ◽  
Author(s):  
Lucy Cooper ◽  
Lauren Hailes ◽  
Amania Sheikh ◽  
Colby Zaph ◽  
Gabrielle T. Belz ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Differentiation ◽  
B Cell ◽  
B Cell Differentiation ◽  
T Box ◽  
Th2 Cell

scholarly journals The T Box Transcription Factor TBX2 Promotes Epithelial-Mesenchymal Transition and Invasion of Normal and Malignant Breast Epithelial Cells

PLoS ONE ◽  
2012 ◽  
Vol 7 (7) ◽  
pp. e41355 ◽  
Author(s):  
Bin Wang ◽  
Linsey E. Lindley ◽  
Virneliz Fernandez-Vega ◽  
Megan E. Rieger ◽  
Andrew H. Sims ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Epithelial Cells ◽  
Epithelial Mesenchymal Transition ◽  
Breast Epithelial Cells ◽  
Mesenchymal Transition ◽  
T Box ◽  
Malignant Breast ◽  
Breast Epithelial
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