scholarly journals Regulation of synthesis and turnover of an interferon-inducible mRNA.

1986 ◽  
Vol 6 (6) ◽  
pp. 2062-2067 ◽  
Author(s):  
J Kusari ◽  
G C Sen
Keyword(s):  
Actinomycin D ◽  
Ifn Gamma ◽  
Putative Protein ◽  
Ifn Alpha ◽  
Regulation Of Synthesis ◽  
Inducible Protein ◽  
High Level ◽  
Inhibitor Of Protein Synthesis ◽  
Interferon Inducible Protein ◽  
In Cells

Regulation of synthesis and turnover of an interferon (IFN)-inducible mRNA, mRNA 561, in HeLa monolayer cells was studied. Cytoplasmic levels of this mRNA were estimated by hybridization analyses with a cDNA clone that we have isolated as a probe. IFN-alpha A induced a high level of this mRNA in a transient fashion, whereas no induction was observed in response to IFN-gamma. Surprisingly little mRNA 561 was induced in cells treated simultaneously with IFN-alpha A and an inhibitor of protein synthesis, suggesting that in addition to IFN-alpha A, an interferon-inducible protein was needed for induction of this mRNA. Apparently this putative protein could be induced by IFN-gamma as well. Thus, although little mRNA 561 was synthesized in cells treated either with IFN-gamma alone or with IFN-alpha A and cycloheximide, a large quantity of this mRNA was induced in cells which had been pretreated with IFN-gamma and then treated with IFN-alpha A and cycloheximide. Once mRNA 561 was induced by IFN-alpha A, it turned over rapidly. This rapid turnover could be blocked by actinomycin D or cycloheximide indicating that another IFN-inducible protein may mediate this process.

Regulation of synthesis and turnover of an interferon-inducible mRNA

1986 ◽  
Vol 6 (6) ◽  
pp. 2062-2067
Author(s):  
J Kusari ◽  
G C Sen
Keyword(s):  
Actinomycin D ◽  
Ifn Gamma ◽  
Putative Protein ◽  
Ifn Alpha ◽  
Regulation Of Synthesis ◽  
Inducible Protein ◽  
High Level ◽  
Inhibitor Of Protein Synthesis ◽  
Interferon Inducible Protein ◽  
In Cells

Regulation of synthesis and turnover of an interferon (IFN)-inducible mRNA, mRNA 561, in HeLa monolayer cells was studied. Cytoplasmic levels of this mRNA were estimated by hybridization analyses with a cDNA clone that we have isolated as a probe. IFN-alpha A induced a high level of this mRNA in a transient fashion, whereas no induction was observed in response to IFN-gamma. Surprisingly little mRNA 561 was induced in cells treated simultaneously with IFN-alpha A and an inhibitor of protein synthesis, suggesting that in addition to IFN-alpha A, an interferon-inducible protein was needed for induction of this mRNA. Apparently this putative protein could be induced by IFN-gamma as well. Thus, although little mRNA 561 was synthesized in cells treated either with IFN-gamma alone or with IFN-alpha A and cycloheximide, a large quantity of this mRNA was induced in cells which had been pretreated with IFN-gamma and then treated with IFN-alpha A and cycloheximide. Once mRNA 561 was induced by IFN-alpha A, it turned over rapidly. This rapid turnover could be blocked by actinomycin D or cycloheximide indicating that another IFN-inducible protein may mediate this process.

scholarly journals Inhibition of angiogenesis by interleukin-12 is mediated by the interferon-inducible protein 10

Blood ◽  
1996 ◽  
Vol 87 (9) ◽  
pp. 3877-3882 ◽  
Author(s):  
C Sgadari ◽  
AL Angiolillo ◽  
G Tosato
Keyword(s):  
Interleukin 12 ◽  
Human Interferon ◽  
Ifn Gamma ◽  
Mouse Splenocytes ◽  
Angiogenesis Inhibition ◽  
Inhibition Of Angiogenesis ◽  
Inducible Protein ◽  
Interferon Inducible Protein

Interleukin 12 (IL-12), a multifunctional cytokine produced by macrophages and B-cell lines, induces interferon-gamma (IFN-gamma) production, stimulates growth of both T and natural killer cells, promotes Th1-type helper T-cell responses, and inhibits neovascularization. Because the human interferon-inducible protein 10 (IP-10) can also inhibit neovascularization, we tested whether IP-10, induced by IL-12 through the intermediate IFN-gamma, might be a mediator of IL-12 angiogenesis inhibition. We report here that murine IL-12 profoundly inhibited basic fibroblast growth factor (bFGF)- induced Matrigel neovascularization in vivo, and that this effect of IL- 12 was neutralized by systemic administration of antibodies to either murine IFN-gamma or IP-10. Murine IL-12 induced murine IP-10 expression in mouse splenocytes, and human IFN-gamma induced human IP-10 expression in purified human endothelial cells, suggesting that IL-12 can induce IP-10 expression in certain cells. These results document the important role of IP-10 as a mediator of angiogenesis inhibition by IL-12, and raise the possibility that IP-10 may also contribute to the antitumor effect of IL-12.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

scholarly journals Stockpiling of Cdc25 during a DNA replication checkpoint arrest in Schizosaccharomyces pombe.

1996 ◽  
Vol 16 (1) ◽  
pp. 86-93 ◽  
Author(s):  
R Kovelman ◽  
P Russell
Keyword(s):  
Dna Replication ◽  
Schizosaccharomyces Pombe ◽  
Replication Checkpoint ◽  
Activation Assay ◽  
M Phase ◽  
Dna Replication Checkpoint ◽  
High Level ◽  
Tyrosyl Phosphorylation ◽  
In Cells

The DNA replication checkpoint couples the onset of mitosis with the completion of S phase. It is clear that in the fission yeast Schizosaccharomyces pombe, operation of this checkpoint requires maintenance of the inhibitory tyrosyl phosphorylation of Cdc2. Cdc25 phosphatase induces mitosis by dephosphorylating tyrosine 15 of Cdc2. In this report, Cdc25 is shown to accumulate to a very high level in cells arrested in S. This shows that mechanisms which modulate the abundance of Cdc25 are unconnected to the DNA replication checkpoint. Using a Cdc2/cyclin B activation assay, we found that Cdc25 activity increased approximately 10-fold during transit through M phase. Cdc25 was activated by phosphorylations that were dependent on Cdc2 activity in vivo. Cdc25 activation was suppressed in cells arrested in G1 and S. However, Cdc25 was more highly modified and appeared to be somewhat more active in S than in G1. This finding might be connected to the fact that progression from G1 to S increases the likelihood that constitutive Cdc25 overproduction will cause inappropriate mitosis.

c-myc RNA degradation in growing and differentiating cells: possible alternate pathways

1989 ◽  
Vol 9 (1) ◽  
pp. 288-295
Author(s):  
S G Swartwout ◽  
A J Kinniburgh
Keyword(s):  
Actinomycin D ◽  
Rna Degradation ◽  
Transcriptional Elongation ◽  
Rna Turnover ◽  
Rapid Degradation ◽  
Polyadenylated Rna ◽  
Myc Gene ◽  
Fail Safe ◽  
Kinetics Of ◽  
In Cells

Transcripts of the proto-oncogene c-myc are composed of a rapidly degraded polyadenylated RNA species and an apparently much more stable, nonadenylated RNA species. In this report, the extended kinetics of c-myc RNA turnover have been examined in rapidly growing cells and in cells induced to differentiate. When transcription was blocked with actinomycin D in rapidly growing cells, poly(A)+ c-myc was rapidly degraded (t1/2 = 12 min). c-myc RNA lacking poly(A) initially remained at or near control levels; however, after 80 to 90 min it was degraded with kinetics similar to those of poly(A)+ c-myc RNA. These bizarre kinetics are due to the deadenylation of poly(A)+ c-myc RNA to form poly(A)- c-myc, thereby initially maintaining the poly(A)- c-myc RNA pool when transcription is blocked. In contrast to growing cells, cells induced to differentiate degraded both poly(A)+ and poly(A)- c-myc RNA rapidly. The rapid disappearance of both RNA species in differentiating cells suggests that a large proportion of the poly(A)+ c-myc RNA was directly degraded without first being converted to poly(A)- c-myc RNA. Others have shown that transcriptional elongation of the c-myc gene is rapidly blocked in differentiating cells. We therefore hypothesize that in differentiating cells a direct, rapid degradation of poly(A)+ c-myc RNA may act as a backup or fail-safe system to ensure that c-myc protein is not synthesized. This tandem system of c-myc turnoff may also make cells more refractory to mutations which activate constitutive c-myc expression.

PS1-018 . Human Cytomegalovirus induces redistribution of the interferon inducible protein IFI16 from nucleus to cytoplasm

Cytokine ◽  
2011 ◽  
Vol 56 (1) ◽  
pp. 21
Author(s):  
Grazia R. Gariano ◽  
Deborah Gatti ◽  
Valentina Dell’Oste ◽  
Matteo Bronzini ◽  
Anna Luganini ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Inducible Protein ◽  
Interferon Inducible Protein

scholarly journals Interferon-Inducible Ubiquitin E2, Ubc8, Is a Conjugating Enzyme for Protein ISGylation

2004 ◽  
Vol 24 (21) ◽  
pp. 9592-9600 ◽  
Author(s):  
Keun Il Kim ◽  
Nadia V. Giannakopoulos ◽  
Herbert W. Virgin ◽  
Dong-Er Zhang
Keyword(s):  
Small Interfering Rna ◽  
Special Role ◽  
Interferon Treatment ◽  
Interferon Signaling ◽  
Alpha Beta ◽  
Inducible Protein ◽  
Eukaryotic Organisms ◽  
Interfering Rna ◽  
Interferon Inducible Protein ◽  
Conjugating Enzyme

ABSTRACT Protein ISGylation is unique among ubiquitin-like conjugation systems in that the expression and conjugation processes are induced by specific stimuli, mainly via the alpha/beta interferon signaling pathway. It has been suggested that protein ISGylation plays a special role in the immune response, because of its interferon-signal dependency and its appearance only in higher eukaryotic organisms. Here, we report the identification of an ISG15-conjugating enzyme, Ubc8. Like other components of the protein ISGylation system (ISG15, UBE1L, and UBP43), Ubc8 is an interferon-inducible protein. Ubc8 clearly mediates protein ISGylation in transfection assays. The reduction of Ubc8 expression by small interfering RNA causes a decrease in protein ISGylation in HeLa cells upon interferon treatment. Neither UbcH7/UbcM4, the closest homologue of Ubc8 among known ubiquitin E2s, nor the small ubiquitin-like modifier E2 Ubc9 supports protein ISGylation. These findings strongly suggest that Ubc8 is a major ISG15-conjugating enzyme responsible for protein ISGylation upon interferon stimulation. Furthermore, we established an assay system to detect ISGylated target proteins by cotransfection of ISG15, UBE1L, and Ubc8 together with a target protein to be analyzed. This method provides an easy and effective way to identify new targets for the ISGylation system and will facilitate related studies.

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