scholarly journals Mutations Modulating Raf Signaling in Drosophila Eye Development

Genetics ◽  
1996 ◽  
Vol 142 (1) ◽  
pp. 163-171
Author(s):  
Barry J Dickson ◽  
Alexandra van der Straten ◽  
María Domínguez ◽  
Ernst Hafen
Keyword(s):  
Target Gene ◽  
Eye Development ◽  
Mitogen Activated Protein Kinase ◽  
Putative Target Gene ◽  
Raf Kinase ◽  
Putative Target ◽  
Drosophila Eye ◽  
Mitogen Activated Protein ◽  
Inductive Signal ◽  
Kinase Homologue

The R7 fate is specified during Drosophila eye development by an inductive signal transduced intracellularly via the Raf kinase. We have performed a genetic screen for dominant mutations that alter the efficiency with which cells respond to a constitutively activated Raf kinase. Such mutations may affect genes involved in signal transduction downstream of Raf. We have isolated 44 mutations that define eight genes. One of these encodes a mitogen-activated protein kinase homologue; another is a putative target gene of this signaling pathway. We present the results of this screen in detail, as well as a preliminary genetic analysis of the six loci still to be characterized molecularly.

scholarly journals Identification of the functional components of the Ras signaling pathway regulating pituitary cell-specific gene expression.

1994 ◽  
Vol 14 (3) ◽  
pp. 1553-1565 ◽  
Author(s):  
K E Conrad ◽  
J M Oberwetter ◽  
R Vaillancourt ◽  
G L Johnson ◽  
A Gutierrez-Hartmann
Keyword(s):  
Gene Expression ◽  
Pituitary Cell ◽  
Mitogen Activated Protein Kinase ◽  
Specific Gene ◽  
Ras Signaling ◽  
Raf Kinase ◽  
Prolactin Gene ◽  
Ras Signaling Pathway ◽  
Mitogen Activated Protein ◽  
Prolactin Promoter

Ras, a small GTP-binding protein, is required for functional receptor tyrosine kinase signaling. Ultimately, Ras alters the activity of specific nuclear transcription factors and regulates novel patterns of gene expression. Using a rat prolactin promoter construct in transient transfection experiments, we show that both oncogenic Ras and activated forms of Raf-1 kinase selectively stimulated the cellular rat prolactin promoter in GH4 rat pituitary cells. We also show that the Ras signal is completely blocked by an expression vector encoding a dominant-negative Raf kinase. Additionally, using a molecular genetic approach, we determined that inhibitory forms of p42 mitogen-activated protein kinase and an Ets-2 transcription factor interfere with both the Ras and the Raf activation of the rat prolactin promoter. These findings define a functional requirement for these signaling constituents in the activation of the prolactin gene, a cell-specific gene which marks the lactotroph pituitary cell type. Further, this analysis allowed us to order the components in the Ras signaling pathway as it impinges on regulation of prolactin gene transcription as Ras-->Raf kinase-->mitogen-activated protein kinase-->Ets. In contrast, we show that intact c-Jun expression inhibited the Ras-induced activation of the prolactin promoter, defining it as a negative regulator of this pathway, whereas c-Jun was able to enhance the Ras activation of an AP-1-driven promoter in GH4 cells. These data show that c-Jun is not the nuclear mediator of the Ras signal for the highly specialized, pituitary cell-specific prolactin cellular promoter. Thus, we have defined a model system which provides an ideal paradigm for studying Ras/Raf signaling pathways and their effects on neuroendocrine cell-specific gene regulation.

p22/PACAP Response Gene 1 (PRG1): A Putative Target Gene for the Tumor Suppressor p53

1998 ◽  
Vol 865 (1 VIP, PACAP, A) ◽  
pp. 27-36 ◽  
Author(s):  
HEINER SCHAFER ◽  
ANNA TRAUZOLD ◽  
THORSTEN SEBENS ◽  
WOLFGANG DEPPERT ◽  
ULRICH R. FOLSCH ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Target Gene ◽  
Tumor Suppressor P53 ◽  
Putative Target Gene ◽  
Response Gene ◽  
Putative Target

Ssc-novel-miR-106-5p reduces lipopolysaccharide-induced inflammatory response in porcine endometrial epithelial cells by inhibiting the expression of the target gene mitogen-activated protein kinase kinase kinase 14 (MAP3K14)

2019 ◽  
Vol 31 (10) ◽  
pp. 1616
Author(s):  
Yu Lian ◽  
Yu Hu ◽  
Lu Gan ◽  
Yuan-Nan Huo ◽  
Hong-Yan Luo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Epithelial Cells ◽  
Target Gene ◽  
Mitogen Activated Protein Kinase ◽  
Luciferase Reporter ◽  
Nuclear Factor ◽  
Tnf Α ◽  
Mitogen Activated Protein ◽  
Endometrial Epithelial Cells ◽  
Protein Kinase Kinase

As an important gram-negative bacterial outer membrane component, lipopolysaccharide (LPS) plays an important role in bacterial-induced endometritis in sows. However, how LPS induces endometritis is unclear. We stimulated sow endometrial epithelial cells (EECs) with LPS and detected cell viability and tumour necrosis factor-α (TNF-α) and interleukin-1 (IL-1) secretion. LPS affected EEC viability and TNF-α and IL-1 secretion in a dose-dependent manner. LPS induced differential expression in 10 of 393 miRNAs in the EECs (downregulated, nine; upregulated, one). MicroRNA (miRNA) high-throughput sequencing of the LPS-induced EECs plus bioinformatics analysis and the dual-luciferase reporter system revealed a novel miRNA target gene: mitogen-activated protein kinase kinase kinase 14 (MAP3K14). Ssc-novel-miR-106-5p mimic, inhibitor and the nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) phosphorylation inhibitor Bay11–7085 were used to detect EEC nuclear factor-κB phosphorylation levels (p-NF-κB) and TNF-α and IL-1 secretion. MiR-106-5p mimic downregulated MAP3K14 mRNA and protein expression levels, inhibited p-NF-κB levels and decreased IL-1 and TNF-α secretion, whereas miR-106-5p inhibitor had the opposite effect. Bay11–7085 inhibited p-NF-κB expression and TNF-α and IL-1 secretion. These results suggest that LPS downregulates ssc-novel-miR-106-5p expression in sow EECs to increase MAP3K14 expression, which increases p-NF-κB to promote IL-1 and TNF-α secretion.

Identification, expression, and putative target gene analysis of nuclear factor-Y (NF-Y) transcription factors in tea plant (Camellia sinensis)

Planta ◽  
2019 ◽  
Vol 250 (5) ◽  
pp. 1671-1686 ◽  
Author(s):  
Pengjie Wang ◽  
Yucheng Zheng ◽  
Yongchun Guo ◽  
Xuejin Chen ◽  
Yun Sun ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Camellia Sinensis ◽  
Target Gene ◽  
Tea Plant ◽  
Gene Analysis ◽  
Nuclear Factor ◽  
Putative Target Gene ◽  
Nuclear Factor Y ◽  
Putative Target

scholarly journals Cytosolic Ras Supports Eye Development in Drosophila

2010 ◽  
Vol 30 (24) ◽  
pp. 5649-5657 ◽  
Author(s):  
Pamela J. Sung ◽  
Aloma B. Rodrigues ◽  
Andrew Kleinberger ◽  
Steven Quatela ◽  
Erika A. Bach ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Eye Development ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Membrane Association ◽  
Ras Proteins ◽  
Eye Disc ◽  
Mosaic Analysis ◽  
Mitogen Activated Protein ◽  
Disc Cells

ABSTRACT Ras proteins associate with cellular membranes as a consequence of a series of posttranslational modifications of a C-terminal CAAX sequence that include prenylation and are thought to be required for biological activity. In Drosophila melanogaster, Ras1 is required for eye development. We found that Drosophila Ras1 is inefficiently prenylated as a consequence of a lysine in the A1 position of its CAAX sequence such that a significant pool remains soluble in the cytosol. We used mosaic analysis with a repressible cell marker (MARCM) to assess if various Ras1 transgenes could restore photoreceptor fate to eye disc cells that are null for Ras1. Surprisingly, we found that whereas Ras1 with an enhanced efficiency of membrane targeting could not rescue the Ras1 null phenotype, Ras1 that was not at all membrane targeted by virtue of a mutation of the CAAX cysteine was able to fully rescue eye development. In addition, constitutively active Ras112V,C186S not targeted to membranes produced a hypermorphic phenotype and stimulated mitogen-activated protein kinase (MAPK) signaling in S2 cells. We conclude that the membrane association of Drosophila Ras1 is not required for eye development.

scholarly journals Plasma Membrane-Targeted Raf Kinase Activates NF-κB and Human Immunodeficiency Virus Type 1 Replication in T Lymphocytes

1998 ◽  
Vol 72 (4) ◽  
pp. 2788-2794 ◽  
Author(s):  
Egbert Flory ◽  
Christoph K. Weber ◽  
Peifeng Chen ◽  
Angelika Hoffmeyer ◽  
Christian Jassoy ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Lymphocytes ◽  
Catalytic Domain ◽  
Mitogen Activated Protein Kinase ◽  
Raf Kinase ◽  
Immunodeficiency Virus ◽  
Mitogen Activated Protein ◽  
Hiv 1

ABSTRACT Increasing evidence points to a role of the mitogenic Ras/Raf/MEK/ERK signaling cascade in regulation of human immunodeficiency virus type 1 (HIV-1) gene expression. Stimulation of elements of this pathway leads to transactivation of the HIV-1 promoter. In particular, the NF-κB motif in the HIV long terminal repeat (LTR) represents a Raf-responsive element in fibroblasts. Regulation of the Raf kinase in T cells differs from findings with a variety of cell lines that the catalytic domain of Raf (RafΔ26–303) shows no activity. In this study, we restored the activity of the kinase in T cells by fusing its catalytic domain to the CAAX motif (-Cx) of Ras, thus targeting the enzyme to the plasma membrane. Constitutive activity of Raf was demonstrated by phosphorylation of mitogen-activated protein kinase kinase (MEK) and endogenous mitogen-activated protein kinase 1/2 (ERK1/2) in A3.01 T cells transfected with RafΔ26–303-Cx. Membrane-targeted Raf also stimulates NF-κB, as judged by κB-dependent reporter assays and enhanced NF-κB p65 binding on band shift analysis. Moreover, we found that active Raf transactivates the HIVNL4-3 LTR in A3.01 T lymphocytes and that dominant negative Raf (C4) blocked 12-O-tetradecanoylphorbol-13-acetate induced transactivation. When cotransfected with infectious HIVNL4-3 DNA, membrane-targeted Raf induces viral replication up to 10-fold over basal levels, as determined by the release of newly synthesized p24 gag protein. Our study clearly demonstrates that the activity of the catalytic domain of Raf in A3.01 T cells is dependent on its cellular localization. The functional consequences of active Raf in T lymphocytes include not only NF-κB activation and transactivation of the HIVNL4-3 LTR but also synthesis and release of HIV particles.

scholarly journals MicroRNA-145 Aggravates Hypoxia-Induced Injury by Targeting Rac1 in H9c2 Cells

2017 ◽  
Vol 43 (5) ◽  
pp. 1974-1986 ◽  
Author(s):  
Ximing Wang ◽  
Yanxia Zhang ◽  
Hongshan Wang ◽  
Genshang Zhao ◽  
Xianen Fa
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Underlying Mechanism ◽  
Mitogen Activated Protein Kinase ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
H9c2 Cells ◽  
Down Regulation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

Background/Aims: Myocardial infarction (MI) is a leading cause of morbidity and mortality. Here, we sought to explore the potential role and underlying mechanism of miR-145 in MI. Methods: H9c2 cells were cultured under persistent hypoxia to simulate MI. The hypoxia-induced injury was assessed on the basis of cell viability, migration, invasion and apoptosis. The expression of miR-145 was evaluated by qRT-PCR and the influence of aberrantly expressed miR-145 on H9c2 cells under hypoxia was also estimated. Utilizing bioinformatics methods, the target genes of miR-145 were verified by luciferase reporter assay. Then, effects of abnormally expressed target gene on miR-145 silenced H9c2 cells were assessed. Finally, the phosphorylation levels of key kinases in the phosphatidylinositol-3-kinase (PI3K)/AKT and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways were detected by Western blot analysis. Results: Hypoxia remarkably lowered viability, migration and invasion but promoted cell apoptosis. Meantime, the miR-145 level was up-regulated in H9c2 cells under hypoxia. Following experiments suggested that hypoxia-induced injury was exacerbated by miR-145 overexpression while was alleviated by miR-145 silence. Rac1 was predicted and further validated to be a target gene of miR-145. The influence of miR-145 silencing on H9c2 cells under hypoxia could be reversed by down-regulation of Rac1. Additionally, the phosphorylation levels of PI3K, AKT, MAPK and ERK were all elevated in miR-145 silenced cells and these alterations were reversed by down-regulation of Rac1. Conclusion: miR-145 silencing could protect H9c2 cells against hypoxia-induced injury by targeting Rac1, in which PI3K/AKT and MAPK/ERK pathways might be involved.

Identification ofPAK4as a putative target gene for amplification within 19q13.12-q13.2 in oral squamous-cell carcinoma

2009 ◽  
Vol 100 (10) ◽  
pp. 1908-1916 ◽  
Author(s):  
Asma Begum ◽  
Issei Imoto ◽  
Ken-ichi Kozaki ◽  
Hitoshi Tsuda ◽  
Emina Suzuki ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Target Gene ◽  
Putative Target Gene ◽  
Putative Target
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