scholarly journals Functional characterisation of the CRE/TATA box unit of type 2 deiodinase gene promoter in a human choriocarcinoma cell line

2004 ◽  
Vol 33 (1) ◽  
pp. 51-58 ◽  
Author(s):  
G Canettieri ◽  
A Franchi ◽  
R Sibilla ◽  
E Guzman ◽  
M Centanni
Keyword(s):  
Cell Line ◽  
Regulatory Region ◽  
Gene Promoter ◽  
Biological Properties ◽  
Site Directed Mutagenesis ◽  
Tata Box ◽  
Type Ii ◽  
Regulation Of Expression ◽  
Functional Characterisation ◽  
Choriocarcinoma Cell Line

The regulation of expression of type II deiodinase (D2) is a critical mechanism to maintain appropriate intracellular concentrations of tri-iodothyronine in selected tissues. One of the major regulators of D2 concentrations is cAMP, which potently increases human type II deiodinase (hD2) gene transcription in some tissues via a conserved cAMP response element (CRE) located in the promoter region. In addition, the regulatory region of the hD2 gene contains several TATA box/transcription start site (TSS) units, suggesting the presence of different transcripts that might be characterised by different biological properties. However, it is still unclear whether one ore more TATA box/TSS units are needed in response to cAMP or to other signals able to modulate hD2 transcription. In this study we have analysed the ability of cAMP to regulate hD2 in JEG3 cells, a human choriocarcinoma cell line highly responsive to cAMP. Transient transfection assays of different hD2 gene promoter constructs revealed that cAMP induces transcription starting from the most 5' TSS, located about 80 nucleotides from the CRE. RT-PCR studies have revealed that cAMP activates the expression of a long-lived transcript in JEG3 cells. Site-directed mutagenesis and deletion analysis of promoter constructs have shown that a single CRE/TATA box/TSS unit is needed to confer responsiveness to cAMP. By using chromatin immunoprecipitation studies, we have also demonstrated that the response to cAMP involves the binding of transcription factor CRE binding protein (CREB) to the CRE located in the hD2 promoter. In summary, in JEG3 cells cAMP induces transcription of a long-lived hD2 RNA via CREB and a single CRE/TATA box/TSS unit. This study provides new insights to the regulation of expression of hD2 in placenta.

scholarly journals Cell-specific expression of the human gastrin gene: evidence for a control element located downstream of the TATA box.

1987 ◽  
Vol 7 (12) ◽  
pp. 4329-4336 ◽  
Author(s):  
L E Theill ◽  
O Wiborg ◽  
J Vuust
Keyword(s):  
Cell Line ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Tata Box ◽  
Vector System ◽  
Control Element ◽  
Gene Fragment ◽  
Early Promoter ◽  
Sv40 Enhancer ◽  
Human Gastrin

Fragments of 5'-flanking and noncoding exon I sequences of the human gastrin gene were analyzed in transient expression assays after transfection of a variety of cell lines with the pSVCAT vector system. In the presence of the simian virus 40 (SV40) enhancer, the gastrin gene fragment from nucleotides -250 to +57, relative to the cap site, was as efficient a promoter as the SV40 early promoter itself. In the absence of the SV40 enhancer, gastrin gene 5'-flanking sequences had no promoter activity except in the murine neuroblastoma cell line N18TG2. In this cell line, the fragment from -1300 to +57 stimulated transcription as actively as the SV40 early promoter with its enhancer. This cell-specific gastrin gene promoter activity was in accordance with the finding that gastrin is synthesized in certain neuronal cells. Promoter activity declined with decreasing distance from the 5' end to the cap site and disappeared after removal of the gastrin gene TATA box. In vector constructions containing short vector-linker sequences homologous to a functionally important region of the SV40 enhancer, the gastrin gene fragment from -17 to +57 showed considerable promoter activity, exclusively in N18TG2. It is concluded that the truncated gastrin gene promoter plus the first exon contains a cell-specific element that may act in collaboration with upstream elements to facilitate the accumulation of transcripts.

scholarly journals Characterization and functional analysis of TFPI-2 gene promoter in a human choriocarcinoma cell line

2003 ◽  
Vol 109 (4) ◽  
pp. 207-215 ◽  
Author(s):  
F. Hubé ◽  
P. Reverdiau ◽  
S. Iochmann ◽  
C. Cherpi-Antar ◽  
Y. Gruel
Keyword(s):  
Functional Analysis ◽  
Cell Line ◽  
Gene Promoter ◽  
Choriocarcinoma Cell Line

scholarly journals JC Virus Regulatory Region Tandem Repeats in Plasma and Central Nervous System Isolates Correlate with Poor Clinical Outcome in Patients with Progressive Multifocal Leukoencephalopathy

2001 ◽  
Vol 75 (12) ◽  
pp. 5672-5676 ◽  
Author(s):  
Luz-Andrea Pfister ◽  
Norman L. Letvin ◽  
Igor J. Koralnik
Keyword(s):  
Clinical Outcome ◽  
Progressive Multifocal Leukoencephalopathy ◽  
Tandem Repeats ◽  
Jc Virus ◽  
Regulatory Region ◽  
Tata Box ◽  
Type I ◽  
Type Ii ◽  
Poor Clinical Outcome ◽  
Immunodeficiency Virus

ABSTRACT JC virus (JCV), the causative agent of progressive multifocal leukoencephalopathy (PML), has a hypervariable regulatory region (JCV RR). A conserved archetype form is found in the urines of healthy and immunocompromised individuals, whereas forms with tandem repeats and deletions are found in the brains of PML patients. Type I JCV RR, seen in MAD-1, the first sequenced strain of JCV, contains two 98-bp tandem repeats each containing a TATA box. Type II JCV RR has additional 23-bp and 66-bp inserts or fragments thereof and only one TATA box. We cloned and sequenced JCV RR from different anatomic compartments of PML patients and controls and correlated our findings with the patients' clinical outcome. Twenty-three different sequences were defined in 198 clones obtained from 16 patients. All 104 clones with tandem repeats were type II JCV RR. Patients with poor clinical outcome had high proportions of JCV RR clones with both tandem repeats in plasma (54%) and brain or cerebrospinal fluid (85%). In those who became survivors of PML, archetype sequences predominated in these anatomic compartments (75 and 100%, respectively). In patients with advanced human immunodeficiency virus infection without PML, only 8% of JCV RR clones obtained in the plasma contained tandem repeats. These data suggest that the presence of tandem repeats in plasma and CNS JCV RR clones is associated with poor clinical outcome in patients with PML.

scholarly journals Receptor-Mediated Host Cell Preference of a Bat-Derived Filovirus, Lloviu Virus

2020 ◽  
Vol 8 (10) ◽  
pp. 1530
Author(s):  
Yoshihiro Takadate ◽  
Rashid Manzoor ◽  
Takeshi Saito ◽  
Yurie Kida ◽  
Junki Maruyama ◽  
...  
Keyword(s):  
Cell Line ◽  
Ebola Virus ◽  
Biological Properties ◽  
Marburg Virus ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Cellular Receptors ◽  
Vesicular Stomatitis ◽  
Niemann Pick ◽  
A Site

Lloviu virus (LLOV), a bat-derived filovirus that is phylogenetically distinct from human pathogenic filoviruses such as Ebola virus (EBOV) and Marburg virus (MARV), was discovered in Europe. However, since infectious LLOV has never been isolated, the biological properties of this virus remain poorly understood. We found that vesicular stomatitis virus (VSV) pseudotyped with the glycoprotein (GP) of LLOV (VSV–LLOV) showed higher infectivity in one bat (Miniopterus sp.)-derived cell line than in the other bat-derived cell lines tested, which was distinct from the tropism of VSV pseudotyped with EBOV (VSV–EBOV) and MARV GPs. We then focused on the interaction between GP and Niemann–Pick C1 (NPC1) protein, one of the cellular receptors of filoviruses. We introduced the Miniopterus bat and human NPC1 genes into NPC1-knockout Vero E6 cells and their susceptibilities to the viruses were compared. The cell line expressing the bat NPC1 showed higher susceptibility to VSV–LLOV than that expressing human NPC1, whereas the opposite preference was seen for VSV–EBOV. Using a site-directed mutagenesis approach, amino acid residues involved in the differential tropism were identified in the NPC1 and GP molecules. Our results suggest that the interaction between GP and NPC1 is an important factor in the tropism of LLOV to a particular bat species.

Cell-specific expression of the human gastrin gene: evidence for a control element located downstream of the TATA box

1987 ◽  
Vol 7 (12) ◽  
pp. 4329-4336
Author(s):  
L E Theill ◽  
O Wiborg ◽  
J Vuust
Keyword(s):  
Cell Line ◽  
Promoter Activity ◽  
Gene Promoter ◽  
Tata Box ◽  
Vector System ◽  
Control Element ◽  
Gene Fragment ◽  
Early Promoter ◽  
Sv40 Enhancer ◽  
Human Gastrin

Fragments of 5'-flanking and noncoding exon I sequences of the human gastrin gene were analyzed in transient expression assays after transfection of a variety of cell lines with the pSVCAT vector system. In the presence of the simian virus 40 (SV40) enhancer, the gastrin gene fragment from nucleotides -250 to +57, relative to the cap site, was as efficient a promoter as the SV40 early promoter itself. In the absence of the SV40 enhancer, gastrin gene 5'-flanking sequences had no promoter activity except in the murine neuroblastoma cell line N18TG2. In this cell line, the fragment from -1300 to +57 stimulated transcription as actively as the SV40 early promoter with its enhancer. This cell-specific gastrin gene promoter activity was in accordance with the finding that gastrin is synthesized in certain neuronal cells. Promoter activity declined with decreasing distance from the 5' end to the cap site and disappeared after removal of the gastrin gene TATA box. In vector constructions containing short vector-linker sequences homologous to a functionally important region of the SV40 enhancer, the gastrin gene fragment from -17 to +57 showed considerable promoter activity, exclusively in N18TG2. It is concluded that the truncated gastrin gene promoter plus the first exon contains a cell-specific element that may act in collaboration with upstream elements to facilitate the accumulation of transcripts.

Fabrication, Characterisation, and Biological Properties of Chitosan Nanoparticles Containing Rapeseed Pollen Extract (RPE) on the MCF-7 Cell Line

2021 ◽  
pp. 1-11
Author(s):  
Vasan Khshemat ◽  
Masoud Homayouni-Tabrizi ◽  
Ali Neamati ◽  
Farzanehsadat Khadem ◽  
Mahjoubeh Irani
Keyword(s):  
Cell Line ◽  
Chitosan Nanoparticles ◽  
Biological Properties ◽  
Pollen Extract ◽  
Mcf 7

scholarly journals Silencing of the Gene for the α-Subunit of Human Chorionic Gonadotropin by the Embryonic Transcription Factor Oct-3/4

1997 ◽  
Vol 11 (11) ◽  
pp. 1651-1658 ◽  
Author(s):  
Limin Liu ◽  
Douglas Leaman ◽  
Michel Villalta ◽  
R. Michael Roberts
Keyword(s):  
Transcription Factor ◽  
Binding Site ◽  
Gene Promoter ◽  
Site Directed Mutagenesis ◽  
Mobility Shift ◽  
Α Subunit ◽  
Choriocarcinoma Cells ◽  
Human Choriocarcinoma Cells ◽  
Electrophoretic Mobility Shift Assays ◽  
Jar Cells

Abstract CG is required for maintenance of the corpus luteum during pregnancy in higher primates. As CG is a heterodimeric molecule, some form of coordinated control must be maintained over the transcription of its two subunit genes. We recently found that expression of human CG β-subunit (hCGβ) in JAr human choriocarcinoma cells was almost completely silenced by the embryonic transcription factor Oct-3/4, which bound to a unique ACAATAATCA octameric sequence in the hCGβ gene promoter. Here we report that Oct-3/4 is also a potent inhibitor of hCG α-subunit (hCGα) expression in JAr cells. Oct-3/4 reduced human GH reporter expression from the −170 hCGα promoter in either the presence or absence of cAMP by about 70% in transient cotransfection assays, but had no effect on expression from either the −148 hCGα or the −99 hCGα promoter. Unexpectedly, no Oct-3/4-binding site was identified within the −170 to −148 region of the hCGα promoter, although one was found around position −115 by both methylation interference footprinting and electrophoretic mobility shift assays. Site-directed mutagenesis of this binding site destroyed the affinity of the promoter for Oct-3/4, but did not affect repression of the promoter. Therefore, inhibition of hCGα gene transcription by Oct-3/4 appears not to involve direct binding of this factor to the site responsible for silencing. When stably transfected into JAr cells, Oct-3/4 reduced the amounts of both endogenous hCGα mRNA and protein by 70–80%. Oct-3/4 is therefore capable of silencing both hCGα and hCGβ gene expression. We suggest that as the trophoblast begins to form, reduction of Oct-3/4 expression permits the coordinated onset of transcription from the hCGα and hCGβ genes.

scholarly journals In vivo growth of a murine lymphoma cell line alters regulation of expression of HSP72.

1995 ◽  
Vol 15 (2) ◽  
pp. 1071-1078 ◽  
Author(s):  
S Davidson ◽  
P Høj ◽  
T Gabriele ◽  
R L Anderson
Keyword(s):  
Heat Shock ◽  
Cell Line ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
Lymphoma Cell Line ◽  
Regulation Of Expression ◽  
Heat Shock Element ◽  
Stressed Cells

We have identified a murine B-cell lymphoma cell line, CH1, that has a much-diminished capacity to express increased levels of heat shock proteins in response to heat stress in vitro. In particular, these cells cannot synthesize the inducible 72-kDa heat shock protein (HSP72) which is normally expressed at high levels in stressed cells. We show here that CH1 fails to transcribe HSP72 mRNA after heat shock, even though the heat shock transcription factor, HSF, is activated correctly. After heat shock, HSF from CH1 is found in the nucleus and is phosphorylated, trimerized, and capable of binding the heat shock element. We propose that additional signals which CH1 cells are unable to transduce are normally required to activate hsp72 transcription in vitro. Surprisingly, we have found that when the CH1 cells are heated in situ in a mouse, they show normal expression of HSP72 mRNA and protein. Therefore, CH1 cells have a functional hsp72 gene which can be transcribed and translated when the cells are in an appropriate environment. A diffusible factor present in ascites fluid is capable of restoring normal HSP72 induction in CH1 cells. We conclude that as-yet-undefined factors are required for regulation of the hsp72 gene or, alternatively, that heat shock in vivo causes activation of hsp70 through a novel pathway which the defect in CH1 has exposed and which is distinct from that operating in vitro. This unique system offers an opportunity to study a physiologically relevant pathway of heat shock induction and to biochemically define effectors involved in the mammalian stress response.

Sign in / Sign up

Export Citation Format

Share Document