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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Postnatal brain development involves interactions between extracellular signals and preprogrammed genetic events. Immediate early genes (IEGs) are a group of genes that are induced by extracellular signals and their protein products alter transcription by binding regulatory elements in other genes. Using Northern and slot blot analysis of total RNA isolated from visual cortex, frontal cortex, and cerebellum of cats, we have determined the postnatal development patterns of mRNA expression for 5 of these genes,
c-fos
, erg-1, c-jun, jun-B, and c-myc. Each gene had a distinct developmental pattern of mRNA expression, and for a given gene, these patterns were often different in different brain structures. These results suggest that temporal changes in the combinatorial interaction of different IEGs during early postnatal life are important for normal brain development.
Brain Res
Mol
Brain Res 1992 Jan
PMID:Changes in immediate early gene expression during postnatal development of cat cortex and cerebellum. 137 68
Previous work has shown that aggregating fetal brain cell cultures are able to attain a highly differentiated state, and that their development is greatly enhanced by growth and/or differentiation factors such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and the protein kinase C-activating tumor promoter mezerein. The present study shows that in these 3-dimensional cultures the peptide growth factors EGF and bFGF as well as mezerein are able to induce the expression of the proto-oncogene
c-fos
. This induction was rapid and transient, in good agreement with observations reported from a wide variety of cell types in vitro. The maximal levels of
c-fos
mRNA found after stimulation were low in immature cultures and increased greatly as maturation progressed. Of the three factors tested, mezerein was the most potent inducer of
c-fos
. In contrast to the peptide growth factors EGF and bFGF which were found to induce
c-fos
only in glial cells, mezerein was stimulatory in glial cells as well as in neurons. A similar cell type specificity has been observed previously for the maturation-enhancing response in immature aggregate cultures. However, in the present study no correlation was found between the degree of
c-fos
induction and the extent of the maturation-enhancing stimulation. Immature cultures known to be most sensitive and responsive to these maturation-enhancing agents required relatively high doses of peptide growth factors for the induction of
c-fos
, and the maximal levels of
c-fos
mRNA elicited were much lower than those in differentiated cultures which did not show any long-term response to these stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
Brain Res
Mol
Brain Res 1992 Jan
PMID:Expression of the proto-oncogene c-fos in three-dimensional fetal brain cell cultures and the lack of correlation with maturation-inducing stimuli. 137 69
Estrogens induce transcriptional activation of
c-fos
and c-myc proto-oncogenes during mitogenic stimulation of human, chicken, mouse and rat cells in vivo and in vitro. In this paper we show that 17 beta-estradiol injected into adult ovariectomized rats increases c-jun, jun-B and jun-D gene transcription in the uterus. Kinetics and amplitude of response are different for each gene, since c-jun is activated first, within 30 min after injection, followed by jun-D and jun-B, 60 and 90 min after injection, respectively. Maximal activation of jun-B marks a drop in transcription of all the jun genes. Furthermore, transcriptional activation by 17 beta-estradiol of the growth-regulated beta- and gamma-cytoskeletal actin genes is prevented by an inhibitor of protein synthesis, indicating that it is a secondary response to the hormone. These data support the hypothesis that during growth stimulation of target cells the estrogen receptor induces transcription of regulatory genes, triggering in this way a cascade of gene regulation events that results in progression through the cell cycle.
J Steroid Biochem
Mol
Biol 1992 Mar
PMID:Transcriptional activation of jun and actin genes by estrogen during mitogenic stimulation of rat uterine cells. 137
We have studied the interaction between dihydropyridine (DHP) Ca2+ modulators and the phorbol ester phorbol 12-myristate 13-acetate (PMA) on whole cell Ca2+ currents, 45Ca2+ uptake, immediate early gene (IEG) expression, and proliferation in the rat pituitary GH4C1 cell line. When short (3- to 5-msec) depolarizing voltage clamp steps were used to activate L-type Ca2+ channels, the DHP Ca2+ agonist (-)Bay K 8644 markedly enhanced Ca2+ entry by slowing channel closing upon repolarization. In contrast, the Ca2+ agonist induced only small and inconsistent increases in
c-fos
mRNA and did not measurably increase NGFI-A. Ca2+ channel activation by depolarization with 50 mM KCl in the presence of (-)Bay K 8644 induced large increases in 45Ca2+ uptake, but failed to markedly induce either of the IEGs. The phorbol ester PMA did not alter T- or L-type Ca2+ current or 45Ca2+ uptake by GH4C1 cells, but triggered large increases in both
c-fos
and NGFI-A mRNA. In combination, PMA and (-)Bay K 8644 acted synergistically to increase mRNAs for both IEGs. The effect of the DHPs was stereospecific; (+)Bay K 8644, a Ca2+ antagonist, inhibited PMA-induced increases in
c-fos
and NGFI-A mRNAs. Both PMA and (-)Bay K 8644 inhibited the proliferation of GH4C1 cells, measured by cell count or [3H]thymidine incorporation. The inhibition by the Ca2+ agonist was stereoselective and approximately additive to that of PMA. These results indicate that the expression of
c-fos
IEG and that of NGFI-A IEG are differentially regulated by separate second messenger pathways in GH4C1 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol
Endocrinol 1992 Apr
PMID:Ca2+ channel modulation and kinase-C activation in a pituitary cell line: induction of immediate early genes and inhibition of proliferation. 137 38
We previously showed that growth of the nontumorigenic, immortal murine melanocyte line Mel-ab correlates with the depletion of protein kinase C (PKC), whereas quiescence is associated with elevated levels of this enzyme (Brooks G, et al., Cancer Res 51: 3281-3288, 1991). Here we report responses that occur in these cells downstream of PKC activation or downregulation. We examined induction of 12-O-tetradecanoylphorbol-13-acetate (TPA)-inducible sequence (TIS) gene expression in Mel-ab melanocytes and in their transformed counterparts, B16 melanoma cells. Exposure of quiescent Mel-ab cells to the PKC-activating phorbol esters TPA or sapintoxin A at 81 nM for 2 h increased levels of mRNA for six of seven TIS genes examined (twofold to 80-fold increase in steady-state RNA levels for TIS 1, 7, 8, 11, 21, and 28 (
c-fos
); TIS 10 expression was not affected). No induction of TIS gene expression was observed either in growing Mel-ab cells maintained in 324 nM phorbol 12,13-dibutyrate or in B16 cells previously unexposed to phorbol esters, in which normal PKC levels were endogenously depressed. The cAMP-elevating agents choleratoxin (10 nM) and dibutyryl cyclic AMP (2.5 mM) increased levels of TIS mRNA (with the exception of TIS 10) in both proliferating Mel-ab and B16 cells, suggesting that downregulation of the PKC pathway is specific and not a consequence of a general inhibition of all signalling pathways.
Mol
Carcinog 1992
PMID:Differential induction of 12-O-tetradecanoylphorbol-13-acetate sequence gene expression in murine melanocytes and melanoma cells. 137 17
In the present study, a relationship between convulsant activity and two cellular events, changes in calmodulin (CaM) concentration and proto-oncogene
c-fos
expression has been considered.
c-fos
has been found activated after the administration of the organochlorine insecticide lindane, the Ca2+ channel agonist Bay K, and N-methyl-D-aspartate (NMDA). The administration of the voltage-dependent Ca2+ channel antagonist nifedipine was able to block the expression elicited by lindane. The effect of lindane on
c-fos
expression could not be blocked by prior administration of MK-801, a non-competitive antagonist of the NMDA receptor. These results suggest a possible role for the voltage-dependent Ca2+ channels in the mechanism of action of lindane. By means of in situ hybridization, the different patterns of
c-fos
expression after the administration of the mentioned compounds have been described. A possible modification of the levels of CaM has also been investigated. Among all the subcellular fractions considered, only levels of nuclear CaM appeared to be affected after the different treatments. The changes observed seemed to follow a similar pattern to that described for
c-fos
induction. Calcium entry through these voltage-dependent calcium channels would be the link between membrane depolarizing events and expression of
c-fos
and/or increase in nuclear CaM.
Brain Res
Mol
Brain Res 1992 Aug
PMID:Effect of different convulsants on calmodulin levels and proto-oncogene c-fos expression in the central nervous system. 138 76
The expression of the transin,
c-fos
, and c-jun genes was assessed in transplantable osteosarcomas and malignant fibrous histiocytomas, as well as in pancreatic duct adenocarcinomas and hepatocellular carcinomas of rats and hamsters. Northern blot analysis revealed that both an undifferentiated osteosarcoma of spontaneous origin (SOS) and 4-hydroxyaminoquinoline 1-oxide (4-HAQO)-induced malignant fibrous histiocytomas with metastatic potential to the lung showed remarkably increased expression of transin mRNA transcripts. This was not the case for the other tumors. Interestingly, levels of transin mRNA were lower in lung metastatic lesions than in primary subcutaneous SOS tumors. The primary SOS and MFH expressed both
c-fos
and c-jun genes in conjunction with the transin gene, whereas the non-transin expressers, a 4-HAQO-induced osteosarcoma (COS) and the pancreatic duct adenocarcinomas, demonstrated one or the other, but not both. These results suggest a possible involvement of transin expression in the progression of spontaneous osteosarcomas and 4-HAQO-induced malignant fibrous histiocytomas in rats. Expression of the
c-fos
and c-jun genes may play a regulatory role in this process.
Mol
Carcinog 1992
PMID:Expression of the transin, c-fos, and c-jun genes in rat transplantable osteosarcomas and malignant fibrous histiocytomas. 138 42
Regulation of
c-fos
expression in mice sarcoma cell lines CBA and C3H was investigated. Each of the cell lines was represented by a pair of clones: the tumorigenic and the one, which was produced from it by cloning. It was found, that
c-fos
expression in cells of the pseudonormal phenotype was similar to that in the normal fibroblasts. Experiments with cells reverted to pseudonormal phenotype transfected transiently or permanently with an indicator plasmid fos-cat have shown, that a 600 bp sequence of the
c-fos
promotor including the TATA site, provides the expression level of the chloramphenicol acetyltransferase, correlating with the level of the
c-fos
mRNA expression. In the tumorigenic cells, permanent high activity of the cat gene expression was observed which was comparable to that in the normal fibroblasts stimulated by the embrionic serum or TPA. Activity of the transcription factors interacting with regulatory elements SRE, DSE, TRE did not correlate with the
c-fos
expression level in all the cells.
Mol
Biol (Mosk)
PMID:[Regulation of the expression of the c-fos gene in cells, reverting from being transformed to the pseudonormal phenotype]. 143 84
A cohort of the serum and growth factor regulated immediate-early gene set is induced with slower kinetics than
c-fos
. Two of the first immediate-early genes characterized as such, c-myc and JE, are contained within this subset. cis-acting genomic elements mediating induction of the slower responding subset of immediate-early genes have never been characterized. Herein we characterize two widely separated genomic elements which are together essential for induction of the murine JE gene by platelet-derived growth factor, serum, interleukin-1, and double-stranded RNA. One of these elements is novel in several regards. It is a 7-mer, TTTTGTA, found in the proximal 3' sequences downstream of the JE stop codon. The 3' element is position dependent and orientation independent. It does not function in polyadenylation, splicing, or destabilization of the JE transcript. Copies of the 7-mer or its inverse are found at comparable 3' sites in 25 immediate-early genes that encode transcription factors or cytokines. Given its general occurrence, the 7-mer may be a required cis-acting control element mediating induction of the immediate-early gene set.
Mol
Cell Biol 1992 Dec
PMID:A novel 7-nucleotide motif located in 3' untranslated sequences of the immediate-early gene set mediates platelet-derived growth factor induction of the JE gene. 144 65
The activity of p21ras is required for the proliferative response to colony-stimulating factor 1 (CSF-1), and signals transduced by both the CSF-1 receptor (CSF-1R) and p21ras stimulate transcription from promoter elements containing overlapping binding sites for Fos/Jun- and Ets-related proteins. A sequence encoding the DNA-binding domain and nuclear localization signal of human c-ets-2, which lacked portions of the c-ets-2 gene product necessary for trans activation, was fused to the bacterial lacZ gene and expressed from an actin promoter in NIH 3T3 cells expressing either the v-ras oncogene or human CSF-1R. Nuclear expression of the Ets-LacZ protein, confirmed by histochemical staining of beta-galactosidase, inhibited the activity of ras-responsive enhancer elements and suppressed morphologic transformation by v-ras as well as CSF-1R-dependent colony formation in semisolid medium. When CSF-1R-bearing cells expressing the Ets-LacZ protein were stimulated by CSF-1, induction of c-ets-2, c-jun, and
c-fos
ensued, but the c-myc response was impaired. Enforced expression of the c-myc gene overrode the suppressive effect of ets-lacZ and restored the ability of these cells to form colonies in response to CSF-1. NIH 3T3 cells engineered to express a CSF-1R (Phe-809) mutant similarly cannot form CSF-1-dependent colonies in semisolid medium and exhibit an impaired c-myc response, but expression of an exogenous myc gene resensitizes these cells to CSF-1 [M. F. Roussel, J. L. Cleveland, S. A. Shurtleff, and C. J. Sherr, Nature (London) 353:361-363, 1991]. The ability of these cells to respond to CSF-1 was also rescued by enforced expression of an endogenous c-ets-2 gene. The ets family of transcription factors therefore plays a central role in integrating both CSF-1R and ras-induced mitogenic signals and in modulating the myc response to CSF-1 stimulation.
Mol
Cell Biol 1992 Dec
PMID:Mitogenic signaling by colony-stimulating factor 1 and ras is suppressed by the ets-2 DNA-binding domain and restored by myc overexpression. 144 70
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