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Benjamin Y M Yung - One of the best experts on this subject based on the ideXlab platform.
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uv stimulation of nucleophosmin b23 expression is an immediate early Gene Response induced by damaged dna
Journal of Biological Chemistry, 2002Co-Authors: Benjamin Y M YungAbstract:Nucleophosmin/B23 (NPM/B23), a nucleolar protein, was rapidly up-regulated after UV irradiation (at 254 nm; 30 J/m(2)) in NIH 3T3 cells and HeLa/S3 cells. Levels of NPM/B23 mRNA peaked 45-60 min after UV treatment and returned to baseline by 12 h. Transcription inhibitor actinomycin D (5 microg/ml) prevented the UV-induced increase of NPM/B23 mRNA, suggesting that UV induction of NPM/B23 was mediated at the transcriptional level. Moreover, UV-induced NPM/B23 expression was super-induced by cycloheximide (20 microg/ml), which was characteristic of Immediate-Early Gene Response. The transcriptional activation of NPM/B23 by UV was also confirmed by NPM/B23 promoter activity assay. Thymine dinucleotide, mimicking the effects of UV-induced DNA damage, was able to trigger NPM/B23 expression in the absence of genomic DNA damage. UV-induced activation of NPM/B23 promoter could not be blocked by UV-inducible pathway inhibitors, such as those of growth factor tyrosine kinase, mitogen-activated protein kinase, AP-1, NF-kappaB, and DNA-dependent kinase. Our results indicate that UV stimulation of NPM/B23 expression may be mediated through a novel UV-inducible pathway and is an Immediate-Early Gene Response induced by damaged DNA. Induction of Immediate-Early Gene is an initial step in the regulation of cellular and genomic Responses to external stimuli. Our results thus provide important evidence for an involvement of NPM/B23 in the acute Response of mammalian cells to environmental stress.
Russell D Fernald - One of the best experts on this subject based on the ideXlab platform.
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evolutionary conservation of the egr 1 immediate early Gene Response in a teleost
The Journal of Comparative Neurology, 2005Co-Authors: Sabrina S Burmeister, Russell D FernaldAbstract:Immediate-Early Gene expression is a key part of a neuron’s Response to behaviorally relevant stimuli and, as a result, localization of Immediate-Early Gene expression can be a useful marker for neural activity. We characterized the Immediate-Early Gene egr-1 (also called zif268, NGFI-A, krox-24, ZENK) in the teleost Astatotilapia (Haplochromis) burtoni. We compared the A. burtoni egr-1 predicted protein sequence to that of other vertebrates, characterized its Gene expression time course, and localized its induced expression throughout the brain. The A. burtoni egr-1 predicted protein shared putative functional domains with egr-1 of other vertebrates and shared 81% sequence similarity with zebrafish and 66% with mouse. We identified distinct mammalian and teleost inserts rich in serine residues within one activation domain, suggesting convergent Responses to selection pressures to increase the number of serine residues in this region. Functionally, we found that A. burtoni egr-1 Gene expression peaked near 30 minutes after pharmacological stimulation and thereby displayed the transient expression above basal levels characteristic of egr-1 expression in birds and mammals. Finally, we observed distinct patterns of egr-1 Gene induction in the brain by natural and pharmacological stimuli. Unstimulated males had very low expression levels of egr-1, whereas males stimulated by their normal environment showed higher levels of expression specific to particular brain regions. Males injected with a glutamate receptor agonist also had region-specific induction of egr-1 expression. We conclude that the egr-1 Immediate-Early Gene Response is evolutionarily conserved and will, therefore, be useful for identifying functional neural Responses in nontraditional model species. J. Comp. Neurol. 481:220 –232, 2005. © 2004 Wiley-Liss, Inc.
Michail V Sitkovsky - One of the best experts on this subject based on the ideXlab platform.
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transient up regulation of p2y2 nucleotide receptor mrna expression is an immediate early Gene Response in activated thymocytes
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Masahiro Koshiba, Sergey Apasov, V Sverdlov, P Chen, Laurie Erb, John T Turner, Gary A Weisman, Michail V SitkovskyAbstract:In studies designed to understand the roles of P2 nucleotide receptors in differentiation of T lymphocytes, we observed a transient and protein synthesis-independent enhancement of mRNA expression for the G protein-coupled P2Y2 receptor in mouse thymocytes after the addition of steroid hormone or T cell receptor (TCR) crosslinking by anti-TCR mAb. Conversely, dexamethasone-induced increases in mRNA expression for the ligand-gated ion channel P2X1 receptor was detected in rat, but not mouse, thymocytes, raising questions about the previously suggested role of P2X1 receptors in thymocyte apoptosis. Flow cytometry analysis of thymocyte subsets excluded the possibility that the observed increases in P2Y2 receptor mRNA expression were due to the enrichment of steroid-treated cells with an P2Y2 mRNA-rich thymocyte subset. Triggering of TCR-mediated intracellular signaling pathways through crosslinking of TCR or by addition of phorbol ester and Ca2+ ionophore also resulted in the up-regulation of P2Y2, but not P2X1, receptor mRNA. It is proposed that the rapid increase of P2Y2 receptor mRNA expression could be a common early event in Responses of T cells to different activating stimuli. Taken together with the recently discovered ability of nucleotide receptor-initiated signaling to antagonize or enhance the effects of TCR crosslinking or steroids on thymocytes, the observed rapid up-regulation of P2Y2 receptor mRNA expression may reflect an immediate early Gene Response where newly expressed cell surface nucleotide receptors provide regulatory feedback signaling from extracellular ATP in the T cell differentiation process.
Sandra A Lavish - One of the best experts on this subject based on the ideXlab platform.
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stimulation by parathyroid hormone of interleukin 6 and leukemia inhibitory factor expression in osteoblasts is an immediate early Gene Response induced by camp signal transduction
Journal of Biological Chemistry, 1996Co-Authors: Edward M Greenfield, Mark C Horowitz, Sandra A LavishAbstract:Abstract Parathyroid hormone and other agents that stimulate bone resorption function, at least in part, by inducing osteoblasts to secrete cytokines that stimulate osteoclast differentiation and activity. We previously demonstrated that parathyroid hormone induces expression by osteoblasts of interleukin-6 and leukemia inhibitory factor without affecting the 16 other cytokines that were examined. We also showed that stimulation of osteoclast activity by parathyroid hormone is dependent on activation of the cAMP signal transduction pathway and secretion of interleukin-6 by osteoblasts. In the current study, we demonstrate that the rapid and transient stimulation of interleukin-6 and leukemia inhibitory factor is inhibited by actinomycin D and superinduced by protein synthesis inhibitors, the classical characteristics of an Immediate-Early Gene Response. Moreover, activation of cAMP signal transduction by parathyroid hormone and parathyroid hormone-related protein is necessary and sufficient to induce both interleukin-6 and leukemia inhibitory factor. In addition, cAMP analogues as well as vasoactive intestinal peptide and isoproterenol, two neuropeptides that stimulate bone resorption by activating cAMP signal transduction in osteoblasts, also induce interleukin-6 and leukemia inhibitory factor in these cells. Taken together with our previous results, this study suggests that interleukin-6 is crucial for stimulation of bone resorption not only by parathyroid hormone, but also by parathyroid hormone-related protein, vasoactive intestinal peptide, and β-adrenergic agonists, like isoproterenol.
Sabrina S Burmeister - One of the best experts on this subject based on the ideXlab platform.
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evolutionary conservation of the egr 1 immediate early Gene Response in a teleost
The Journal of Comparative Neurology, 2005Co-Authors: Sabrina S Burmeister, Russell D FernaldAbstract:Immediate-Early Gene expression is a key part of a neuron’s Response to behaviorally relevant stimuli and, as a result, localization of Immediate-Early Gene expression can be a useful marker for neural activity. We characterized the Immediate-Early Gene egr-1 (also called zif268, NGFI-A, krox-24, ZENK) in the teleost Astatotilapia (Haplochromis) burtoni. We compared the A. burtoni egr-1 predicted protein sequence to that of other vertebrates, characterized its Gene expression time course, and localized its induced expression throughout the brain. The A. burtoni egr-1 predicted protein shared putative functional domains with egr-1 of other vertebrates and shared 81% sequence similarity with zebrafish and 66% with mouse. We identified distinct mammalian and teleost inserts rich in serine residues within one activation domain, suggesting convergent Responses to selection pressures to increase the number of serine residues in this region. Functionally, we found that A. burtoni egr-1 Gene expression peaked near 30 minutes after pharmacological stimulation and thereby displayed the transient expression above basal levels characteristic of egr-1 expression in birds and mammals. Finally, we observed distinct patterns of egr-1 Gene induction in the brain by natural and pharmacological stimuli. Unstimulated males had very low expression levels of egr-1, whereas males stimulated by their normal environment showed higher levels of expression specific to particular brain regions. Males injected with a glutamate receptor agonist also had region-specific induction of egr-1 expression. We conclude that the egr-1 Immediate-Early Gene Response is evolutionarily conserved and will, therefore, be useful for identifying functional neural Responses in nontraditional model species. J. Comp. Neurol. 481:220 –232, 2005. © 2004 Wiley-Liss, Inc.
