scholarly journals Regulation of Calreticulin Gene Expression by Calcium

1997 ◽  
Vol 138 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Mathilde Waser ◽  
Nasrin Mesaeli ◽  
Charlotte Spencer ◽  
Marek Michalak
Keyword(s):  
Gene Expression ◽  
Genomic Dna ◽  
Chloramphenicol Acetyltransferase ◽  
Ionophore A23187 ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Transcription Analysis ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

We have isolated and characterized a 12-kb mouse genomic DNA fragment containing the entire calreticulin gene and 2.14 kb of the promoter region. The mouse calreticulin gene consists of nine exons and eight introns, and it spans 4.2 kb of genomic DNA. A 1.8-kb fragment of the calreticulin promoter was subcloned into a reporter gene plasmid containing chloramphenicol acetyltransferase. This construct was then used in transient and stable transfection of NIH/ 3T3 cells. Treatment of transfected cells either with the Ca2+ ionophore A23187, or with the ER Ca2+-ATPase inhibitor thapsigargin, resulted in a five- to sevenfold increase of the expression of chloramphenicol acetyltransferase protein. Transactivation of the calreticulin promoter was also increased by fourfold in NIH/3T3 cells treated with bradykinin, a hormone that induces Ca2+ release from the intracellular Ca2+ stores. Analysis of the promoter deletion constructs revealed that A23187- and thapsigargin-responsive regions are confined to two regions (−115 to −260 and −685 to −1,763) in the calreticulin promoter that contain the CCAAT nucleotide sequences. Northern blot analysis of cells treated with A23187, or with thapsigargin, revealed a fivefold increase in calreticulin mRNA levels. Thapsigargin also induced a fourfold increase in calreticulun protein levels. Importantly, we show by nuclear run-on transcription analysis that calreticulin gene transcription is increased in NIH/3T3 cells treated with A23187 and thapsigargin in vivo. This increase in gene expression required over 4 h of continuous incubation with the drugs and was also sensitive to treatment with cycloheximide, suggesting that it is dependent on protein synthesis. Changes in the concentration of extracellular and cytoplasmic Ca2+ did not affect the increased expression of the calreticulin gene. These studies suggest that stress response to the depletion of intracellular Ca2+ stores induces expression of the calreticulin gene in vitro and in vivo.

Induction of c-Ha-ras gene expression by double-stranded RNA and interferon requirement

1990 ◽  
Vol 10 (8) ◽  
pp. 4424-4426
Author(s):  
A Maran ◽  
I D Goldberg ◽  
B M Steinberg
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Ras Gene ◽  
Double Stranded Rna ◽  
Beta Interferon ◽  
Nih 3T3 ◽  
Nih 3T3 Cells ◽  
Rna Levels

The addition of double-stranded RNA (dsRNA) to NIH 3T3 cells led to an increase in the RNA levels of c-Ha-ras. The double-stranded configuration was required for the increase in c-Ha-ras mRNA levels, as heat-denatured dsRNA and single-stranded RNA did not have any effect. Nuclear run-on transcription experiments indicated that the increase in c-Ha-ras mRNA levels stimulated by dsRNA was due to transcriptional activation of the gene. The induction of c-Ha-ras gene expression by dsRNA was inhibited by anti-beta interferon antibodies, suggesting that interferon might mediate the induction.

scholarly journals Induction of c-Ha-ras gene expression by double-stranded RNA and interferon requirement.

1990 ◽  
Vol 10 (8) ◽  
pp. 4424-4426 ◽  
Author(s):  
A Maran ◽  
I D Goldberg ◽  
B M Steinberg
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Ras Gene ◽  
Double Stranded Rna ◽  
Beta Interferon ◽  
Nih 3T3 ◽  
Nih 3T3 Cells ◽  
Rna Levels

The addition of double-stranded RNA (dsRNA) to NIH 3T3 cells led to an increase in the RNA levels of c-Ha-ras. The double-stranded configuration was required for the increase in c-Ha-ras mRNA levels, as heat-denatured dsRNA and single-stranded RNA did not have any effect. Nuclear run-on transcription experiments indicated that the increase in c-Ha-ras mRNA levels stimulated by dsRNA was due to transcriptional activation of the gene. The induction of c-Ha-ras gene expression by dsRNA was inhibited by anti-beta interferon antibodies, suggesting that interferon might mediate the induction.

Platelet-derived growth factor does not induce c-fos in NIH 3T3 cells expressing the EJ-ras oncogene

1988 ◽  
Vol 8 (11) ◽  
pp. 5052-5055
Author(s):  
A H Lin ◽  
V E Groppi ◽  
R R Gorman
Keyword(s):  
Growth Factor ◽  
Phorbol Myristate Acetate ◽  
Cellular Transformation ◽  
Platelet Derived Growth Factor ◽  
Ionophore A23187 ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Myristate Acetate ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Platelet-derived growth factor (PDGF), the calcium ionophore A23187, and the tumor promoter phorbol myristate acetate stimulated c-fos mRNA levels in control NIH 3T3 cells. However, NIH 3T3 cells transformed by EJ-ras DNA transfection, which have diminished PDGF-stimulated phospholipase C activity, showed a 95% reduction in PDGF-stimulated c-fos mRNA levels. The responses to A23187 and phorbol myristate acetate were also attenuated, but not as severely as the PDGF-mediated induction. The reduction in PDGF-stimulated c-fos induction did not appear to be a general result of cellular transformation, since src-transformed NIH 3T3 cells displayed a strong PDGF-stimulated c-fos induction. Despite the reduction in PDGF-stimulated c-fos induction, EJ-ras-transformed cells still responded mitogenically to PDGF. These data suggest that the magnitude of c-fos induction cannot be directly correlated with PDGF-stimulated mitogenesis in EJ-ras-transformed NIH 3T3 cells.

scholarly journals Platelet-derived growth factor does not induce c-fos in NIH 3T3 cells expressing the EJ-ras oncogene.

1988 ◽  
Vol 8 (11) ◽  
pp. 5052-5055 ◽  
Author(s):  
A H Lin ◽  
V E Groppi ◽  
R R Gorman
Keyword(s):  
Growth Factor ◽  
Phorbol Myristate Acetate ◽  
Cellular Transformation ◽  
Platelet Derived Growth Factor ◽  
Ionophore A23187 ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Myristate Acetate ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Platelet-derived growth factor (PDGF), the calcium ionophore A23187, and the tumor promoter phorbol myristate acetate stimulated c-fos mRNA levels in control NIH 3T3 cells. However, NIH 3T3 cells transformed by EJ-ras DNA transfection, which have diminished PDGF-stimulated phospholipase C activity, showed a 95% reduction in PDGF-stimulated c-fos mRNA levels. The responses to A23187 and phorbol myristate acetate were also attenuated, but not as severely as the PDGF-mediated induction. The reduction in PDGF-stimulated c-fos induction did not appear to be a general result of cellular transformation, since src-transformed NIH 3T3 cells displayed a strong PDGF-stimulated c-fos induction. Despite the reduction in PDGF-stimulated c-fos induction, EJ-ras-transformed cells still responded mitogenically to PDGF. These data suggest that the magnitude of c-fos induction cannot be directly correlated with PDGF-stimulated mitogenesis in EJ-ras-transformed NIH 3T3 cells.

Mutation of amino acids in pp60c-src that are phosphorylated by protein kinases C and A

1989 ◽  
Vol 9 (6) ◽  
pp. 2453-2463
Author(s):  
P Yaciuk ◽  
J K Choi ◽  
D Shalloway
Keyword(s):  
Protein Kinase ◽  
3T3 Cells ◽  
Triple Mutant ◽  
Dependent Protein Kinase ◽  
Mutant Proteins ◽  
Tetradecanoyl Phorbol Acetate ◽  
Dependent Protein ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

The product of the c-src proto-oncogene, pp60c-src, is phosphorylated at Ser-17 by cyclic AMP-dependent protein kinase A and at Ser-12 by calcium-phospholipid-dependent protein kinase C (when stimulated by 12-O-tetradecanoyl phorbol acetate). We tested the effects of Ser----Ala and Ser----Glu mutations at these sites in pp60c-src and in pp60c-src(F527) (a mutant whose transforming activities are enhanced by Tyr-527----Phe mutation) by transfecting single-, double-, and triple-mutant src expression plasmids into NIH 3T3 cells. Tryptic phosphopeptide analyses of the mutant proteins confirmed prior biochemical identifications of the phosphorylation sites and showed that neither separate nor coordinate mutations at Ser-12 and Ser-17 affected Tyr-416, Tyr-527, or Ser-48 phosphorylation or prevented mitosis-specific phosphorylations of either pp60c-src or pp60c-src(F527). Ser-12 mutation did not affect phosphorylation of the Ser-17-containing peptide, but mutation of Ser-17 significantly increased phosphorylation at Ser-12. Specific kinase activities (both with and without in vivo 12-O-tetradecanoyl phorbol acetate treatment) and the abilities of pp60c-src and pp60c-src(F527) to induce foci, transformed morphologies, and anchorage-independent growth were unaffected by any of the serine mutations. Thus, pp60c-src transforming activity in NIH 3T3 cells is relatively insensitive to phosphorylation at these sites, but there is a suggestion that Ser-17 phosphorylation may have a subtle regulatory effect.

scholarly journals Differential early viral gene expression in two stages of human papillomavirus type 16 DNA-induced malignant transformation.

1987 ◽  
Vol 7 (6) ◽  
pp. 2165-2172 ◽  
Author(s):  
S Yasumoto ◽  
J Doniger ◽  
J A DiPaolo
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Malignant Transformation ◽  
Cell Lines ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
3T3 Cells ◽  
Hpv 16 ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Human papillomavirus (HPV) type 16 DNA induces progressive transformation in NIH 3T3 cells. Two types of cell lines, PM3T3G0 and PM3T3Fo, were isolated by G418 or focus selection, respectively, after transfection of cells by a recombinant HPV 16 DNA carrying the neo gene. These cell lines exhibited distinct phenotypes compared with controls. Saturation densities of PM3T3G0 and PM3T3Fo lines were two- to three- and five- to sevenfold greater than that of control NIH 3T3 cells, respectively. Neither cell type required high serum for growth, in contrast to NIH 3T3 cells. PM3T3G0 lines were premalignant, whereas PM3T3Fo lines manifested tumorigenicity within 2 weeks. Subpopulations of three PM3T3G0 lines underwent progressive transformation as reflected by focus formation. Analysis of HPV 16-specific mRNA species demonstrated that high levels of early and late gene expression were detected in premalignant PM3T3G0 lines, whereas relatively low quantities of selected gene messages were expressed in malignant transformants. Thus, high levels of viral gene expression are not crucial for malignant transformation.

scholarly journals Leukemia-Related Transcription Factor TEL Is Negatively Regulated through Extracellular Signal-Regulated Kinase-Induced Phosphorylation

2004 ◽  
Vol 24 (8) ◽  
pp. 3227-3237 ◽  
Author(s):  
Kazuhiro Maki ◽  
Honoka Arai ◽  
Kazuo Waga ◽  
Ko Sasaki ◽  
Fumihiko Nakamura ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Dna Binding ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Dominant Negative Effect ◽  
Phosphorylation Sites ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

ABSTRACT TEL is an ETS family transcription factor that possesses multiple putative mitogen-activated protein kinase phosphorylation sites. We here describe the functional regulation of TEL via ERK pathways. Overexpressed TEL becomes phosphorylated in vivo by activated ERK. TEL is also directly phosphorylated in vitro by ERK. The inducible phosphorylation sites are Ser213 and Ser257. TEL binds to a common docking domain in ERK. In vivo ERK-dependent phosphorylation reduces trans-repressional and DNA-binding abilities of TEL for ETS-binding sites. A mutant carrying substituted glutamates on both Ser213 and Ser257 functionally mimics hyperphosphorylated TEL and also shows a dominant-negative effect on TEL-induced transcriptional suppression. Losing DNA-binding affinity through phosphorylation but heterodimerizing with unmodified TEL could be an underlying mechanism. Moreover, the glutamate mutant dominantly interferes with TEL-induced erythroid differentiation in MEL cells and growth suppression in NIH 3T3 cells. Finally, endogenous TEL is dephosphorylated in parallel with ERK inactivation in differentiating MEL cells and is phosphorylated through ERK activation in Ras-transformed NIH 3T3 cells. These data indicate that TEL is a constituent downstream of ERK in signal transduction systems and is physiologically regulated by ERK in molecular and biological features.

scholarly journals Transformation of NIH 3T3 cells by cotransfection with c-src and nuclear oncogenes.

1987 ◽  
Vol 7 (10) ◽  
pp. 3582-3590 ◽  
Author(s):  
D Shalloway ◽  
P J Johnson ◽  
E O Freed ◽  
D Coulter ◽  
W A Flood
Keyword(s):  
3T3 Cells ◽  
Focus Formation ◽  
Adenovirus E1a ◽  
Rous Sarcoma ◽  
Cellular Homolog ◽  
Sarcoma Virus ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

pp60c-src, the cellular homolog of the Rous sarcoma virus transforming protein, does not completely transform cells even when present at high levels, but has been shown to be involved in polyomavirus-induced transformation when activated by polyomavirus middle T (pmt)-antigen binding. Here we show that cotransfection, but not solo transfection, of expression plasmids for c-src and either adenovirus E1A, v-myc, c-myc, or the 5' half of polyomavirus large T (pltN) antigen into NIH 3T3 cells induces anchorage-independent growth, enhanced focus formation, and, for pltN cotransfection, tumorigenicity in adult NFS mice. Enhancement of transformation was not observed with polyomavirus small t (pst) antigen. Cotransfection of c-src with pltN induced modification of pp60c-src that altered its electrophoretic mobility and in vivo phosphorylation state and stimulated its in vitro kinase activity. Similar alterations were not seen after c-src-E1A cotransfection, suggesting that at least two different mechanisms of enhancement are involved.

scholarly journals Induction of Syncytia by Neuropathogenic Murine Leukemia Viruses Depends on Receptor Density, Host Cell Determinants, and the Intrinsic Fusion Potential of Envelope Protein

1999 ◽  
Vol 73 (11) ◽  
pp. 9377-9385 ◽  
Author(s):  
Maeran Chung ◽  
Krishnakumar Kizhatil ◽  
Lorraine M. Albritton ◽  
Glen N. Gaulton
Keyword(s):  
Host Cell ◽  
Cell Fusion ◽  
Syncytium Formation ◽  
Receptor Expression ◽  
Receptor Density ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Murine Leukemia ◽  
Nih 3T3 Cells

ABSTRACT Infection by the neuropathogenic murine leukemia virus (MLV) TR1.3 results in hemorrhagic disease that correlates directly to in vivo syncytium formation of brain capillary endothelial cells (BCEC). This phenotype maps to amino acid 102 in the envelope (Env) protein of TR1.3. Substitution of glycine (G) for tryptophan (W) at this position (W102G Env) in the nonpathogenic MLV FB29 induces both syncytium formation and neurologic disease in vivo. Using an in vitro gene reporter cell fusion assay, we showed that fusion either with murine NIH 3T3 cells or with nonmurine target cells that expressed receptors at or below endogenous murine levels mirrored that seen in BCEC in vivo. In these instances only TR1.3 and W102G Env induced cell fusion. In contrast, when receptor levels on nonmurine cells were raised above endogenous murine levels, FB29 Env was as fusogenic as the neuropathogenic TR1.3 and W102G Env. These results indicate that TR1.3 Env and W102G Env are intrinsically more fusogenic than FB29 Env, that the induction of fusion requires a threshold number of receptors that is greater for FB29 Env than for TR1.3 or W102G Env, and that receptor density on murine NIH 3T3 cells and BCEC is below the threshold for FB29-dependent fusion. Surprisingly, receptor density on NIH 3T3 cells could not be increased by stable expression of exogenous receptors, and FB29-dependent fusion was not observed in NIH 3T3 cells that transiently expressed elevated receptor numbers. These results suggest that an additional undefined host cell factor(s) may limit both receptor expression and fusion potential in murine cells.

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