Adenovirus E1A requires synthesis of a cellular protein to establish a stable transcription complex in injected Xenopus laevis oocytes

1987 ◽  
Vol 7 (9) ◽  
pp. 3049-3056
Author(s):  
J D Richter ◽  
H C Hurst ◽  
N C Jones
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Xenopus Laevis Oocytes ◽  
Protein Synthesis Inhibitors ◽  
Adenovirus E1a ◽  
High Level

The Escherichia coli-expressed adenovirus E1A 13S mRNA product injected into Xenopus oocytes was active, as assessed by its ability to stimulate the transcription of an injected gene which is normally responsive to E1A in mammalian cells. In the presence of the protein synthesis inhibitors pactamycin or cycloheximide, E1A was correctly posttranslationally modified (phosphorylated) and transported to the nucleus; but it failed to stimulate the transcription of an injected gene containing the human heat shock protein 70 promoter. The basal (unstimulated) level of transcription of the gene was unaffected by these inhibitors. If oocytes were cultured in the presence of cycloheximide after E1A stimulated transcription, however, the high level of transcription was maintained for several hours without new protein synthesis. Results of competition studies with the same promoter (the heat shock protein 70 promoter) linked to two marked genes demonstrated that once the induction of transcription by E1A took place, the stimulated levels of transcription were maintained, even when they were challenged with excess competitor DNA. Results of these studies suggest that E1A requires the synthesis of a cellular protein to form a stable transcription complex.

scholarly journals Adenovirus E1A requires synthesis of a cellular protein to establish a stable transcription complex in injected Xenopus laevis oocytes.

1987 ◽  
Vol 7 (9) ◽  
pp. 3049-3056 ◽  
Author(s):  
J D Richter ◽  
H C Hurst ◽  
N C Jones
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Xenopus Laevis Oocytes ◽  
Protein Synthesis Inhibitors ◽  
Adenovirus E1a ◽  
High Level

The Escherichia coli-expressed adenovirus E1A 13S mRNA product injected into Xenopus oocytes was active, as assessed by its ability to stimulate the transcription of an injected gene which is normally responsive to E1A in mammalian cells. In the presence of the protein synthesis inhibitors pactamycin or cycloheximide, E1A was correctly posttranslationally modified (phosphorylated) and transported to the nucleus; but it failed to stimulate the transcription of an injected gene containing the human heat shock protein 70 promoter. The basal (unstimulated) level of transcription of the gene was unaffected by these inhibitors. If oocytes were cultured in the presence of cycloheximide after E1A stimulated transcription, however, the high level of transcription was maintained for several hours without new protein synthesis. Results of competition studies with the same promoter (the heat shock protein 70 promoter) linked to two marked genes demonstrated that once the induction of transcription by E1A took place, the stimulated levels of transcription were maintained, even when they were challenged with excess competitor DNA. Results of these studies suggest that E1A requires the synthesis of a cellular protein to form a stable transcription complex.

scholarly journals Genes for Drosophila small heat shock proteins are regulated differently by ecdysterone.

1991 ◽  
Vol 11 (12) ◽  
pp. 5937-5944 ◽  
Author(s):  
J Amin ◽  
R Mestril ◽  
R Voellmy
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Transcriptional Level ◽  
Protein Synthesis Inhibitors ◽  
Sequence Elements ◽  
Continuous Presence ◽  
High Level ◽  
Shock Proteins

Genes for small heat shock proteins (hsp27 to hsp22) are activated in late third-instar larvae of Drosophila melanogaster in the absence of heat stress. This regulation has been simulated in cultured Drosophila cells in which the genes are activated by the addition of ecdysterone. Sequence elements (HERE) involved in ecdysterone regulation of the hsp27 and hsp23 genes have been defined by transfection studies and have recently been identified as binding sites for ecdysterone receptor. We report here that the hsp27 and hsp23 genes are regulated differently by ecdysterone. The hsp27 gene is activated rapidly by ecdysterone, even in the absence of protein synthesis. In contrast, high-level expression of the hsp23 gene begins only after a lag of about 6 h, is dependent on the continuous presence of ecdysterone, and is sensitive to low concentrations of protein synthesis inhibitors. Transfection experiments with reporter constructs show that this difference in regulation is at the transcriptional level. Synthetic hsp27 or hsp23 HERE sequences confer hsp27- or hsp23-type ecdysterone regulation on a basal promoter. These findings indicate that the hsp27 gene is a primary, and the hsp23 gene is mainly a secondary, hormone-responsive gene. Ecdysterone receptor is implied to play a role in the regulation of both genes.

scholarly journals Molecular chaperone heat shock protein 70 participates in the labile phase of the development of behavioural sensitization induced by a single morphine exposure in mice

2013 ◽  
Vol 16 (3) ◽  
pp. 647-659 ◽  
Author(s):  
Wang-Jun Qin ◽  
Yan-Ting Wang ◽  
Min Zhang ◽  
Rui-Ting Wen ◽  
Qing Liu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Molecular Chaperone ◽  
Heat Shock Protein 70 ◽  
De Novo ◽  
Behavioural Plasticity ◽  
Protein Synthesis Inhibitor ◽  
Morphine Injection ◽  
Behavioural Sensitization

Abstract De-novo protein synthesis is required in the development of behavioural sensitization. A prior screening test from our laboratory has implicated heat shock protein 70 (Hsp70) as one of the proteins required in this behavioural plasticity. Thus, this study was designed to extend our understanding of the role of Hsp70 in the development of behavioural sensitization induced by a single morphine exposure in mice. First, by employing transcription inhibitor actinomycin D (AD) and protein synthesis inhibitor cycloheximide (CHX), we identified a protein synthesis-dependent labile phase (within 4 h after the first morphine injection) in the development of behavioural sensitization to a single morphine exposure. Second, Hsp70 protein expression in the nucleus accumbens correlated positively with locomotor responses of sensitized mice and, more importantly, the expression of Hsp70 increased within 1 h after the first morphine injection. Third, AD and CHX both prevented expression of Hsp70 and disrupted the development of the single morphine induced behavioural sensitization, which further implied Hsp70 was highly associated with behavioural sensitization. Finally, the selective Hsp70 inhibitor pifithrin-µ (PES) i.c.v. injected in mice prevented the development of behavioural sensitization and, critically, this inhibitory effect occurred only when PES was given within 1 h after the first morphine injection, which was within the labile phase of the development period. Taken together, we draw the conclusion that Hsp70 is crucially involved in the labile phase of the development of behavioural sensitization induced by a single morphine exposure, probably functioning as a molecular chaperone.

scholarly journals Genes for Drosophila small heat shock proteins are regulated differently by ecdysterone

1991 ◽  
Vol 11 (12) ◽  
pp. 5937-5944
Author(s):  
J Amin ◽  
R Mestril ◽  
R Voellmy
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Small Heat Shock Proteins ◽  
Transcriptional Level ◽  
Protein Synthesis Inhibitors ◽  
Sequence Elements ◽  
Continuous Presence ◽  
High Level ◽  
Shock Proteins

Genes for small heat shock proteins (hsp27 to hsp22) are activated in late third-instar larvae of Drosophila melanogaster in the absence of heat stress. This regulation has been simulated in cultured Drosophila cells in which the genes are activated by the addition of ecdysterone. Sequence elements (HERE) involved in ecdysterone regulation of the hsp27 and hsp23 genes have been defined by transfection studies and have recently been identified as binding sites for ecdysterone receptor. We report here that the hsp27 and hsp23 genes are regulated differently by ecdysterone. The hsp27 gene is activated rapidly by ecdysterone, even in the absence of protein synthesis. In contrast, high-level expression of the hsp23 gene begins only after a lag of about 6 h, is dependent on the continuous presence of ecdysterone, and is sensitive to low concentrations of protein synthesis inhibitors. Transfection experiments with reporter constructs show that this difference in regulation is at the transcriptional level. Synthetic hsp27 or hsp23 HERE sequences confer hsp27- or hsp23-type ecdysterone regulation on a basal promoter. These findings indicate that the hsp27 gene is a primary, and the hsp23 gene is mainly a secondary, hormone-responsive gene. Ecdysterone receptor is implied to play a role in the regulation of both genes.

Induction of acquired thermotolerance in Tetrahymena thermophila: effects of protein synthesis inhibitors

1985 ◽  
Vol 5 (8) ◽  
pp. 2061-2069
Author(s):  
R L Hallberg ◽  
K W Kraus ◽  
E M Hallberg
Keyword(s):  
Heat Treatment ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Cell Growth ◽  
Heat Shock Protein ◽  
Tetrahymena Thermophila ◽  
Protein Synthesis Inhibition ◽  
Nonpermissive Temperature ◽  
Protein Synthesis Inhibitors ◽  
Extended Survival

When Tetrahymena thermophila cells growing at 30 degrees C are shifted to either 40 or 43 degrees C, the kinetics and extent of induction of heat shock mRNAs in both cases are virtually indistinguishable. However, the cells shifted to 40 degrees C show a typical induction of heat shock protein (HSP) synthesis and survive indefinitely (100% after 24 h), whereas those at 43 degrees C show an abortive synthesis of HSPs and die (less than 0.01% survivors) within 1 h. Cells treated at 30 degrees C with the drugs cycloheximide or emetine, at concentrations which are initially inhibitory to protein synthesis and cell growth but from which cells can eventually recover and resume growth, are after this recovery able to survive a direct shift from 30 to 43 degrees C (ca. 70% survival after 1 h). This induction of thermotolerance by these drugs is as efficient in providing thermoprotection to cells as is a prior sublethal heat treatment which elicits the synthesis of HSPs. However, during the period when drug-treated cells recover their protein synthesis ability and simultaneously acquire the ability to subsequently survive a shift to 43 degrees C, none of the major HSPs are synthesized. The ability to survive a 1-h, 43 degrees C heat treatment, therefore, does not absolutely require the prior synthesis of HSPs. But, as extended survival at 43 degrees Celsius depends absolutely on the ability of cells to continually synthesize HSPs, it appears that a prior heat shock as well as the recovery from protein synthesis inhibition elicits a change in the protein synthetic machinery which allows the translation of HSP mRNAs at what would otherwise be a nonpermissive temperature for protein synthesis.

Neuronal DnaJ proteins HSJ1a and HSJ1b: a role in linking the Hsp70 chaperone machine to the ubiquitin–proteasome system?

2004 ◽  
Vol 32 (4) ◽  
pp. 640-642 ◽  
Author(s):  
J.P. Chapple ◽  
J. van der Spuy ◽  
S. Poopalasundaram ◽  
M.E. Cheetham
Keyword(s):  
Protein Folding ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Ubiquitin Proteasome System ◽  
Cellular Protein ◽  
Hsp70 Chaperone ◽  
Ubiquitin Proteasome ◽  
Cellular Processing

The heat-shock protein 70 chaperone machine is functionally connected to the ubiquitin–proteasome system by the co-chaperone CHIP. In this article, we discuss evidence that the neuronal DnaJ proteins HSJ1a and HSJ1b may represent a further link between the cellular protein folding and degradation machineries. We have demonstrated that HSJ1 proteins contain putative ubiquitin interaction motifs and can modulate the cellular processing of rhodopsin, a protein that is targeted for degradation by the proteasome when it is misfolded.

scholarly journals Induction of acquired thermotolerance in Tetrahymena thermophila: effects of protein synthesis inhibitors.

1985 ◽  
Vol 5 (8) ◽  
pp. 2061-2069 ◽  
Author(s):  
R L Hallberg ◽  
K W Kraus ◽  
E M Hallberg
Keyword(s):  
Heat Treatment ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Cell Growth ◽  
Heat Shock Protein ◽  
Tetrahymena Thermophila ◽  
Protein Synthesis Inhibition ◽  
Nonpermissive Temperature ◽  
Protein Synthesis Inhibitors ◽  
Extended Survival

When Tetrahymena thermophila cells growing at 30 degrees C are shifted to either 40 or 43 degrees C, the kinetics and extent of induction of heat shock mRNAs in both cases are virtually indistinguishable. However, the cells shifted to 40 degrees C show a typical induction of heat shock protein (HSP) synthesis and survive indefinitely (100% after 24 h), whereas those at 43 degrees C show an abortive synthesis of HSPs and die (less than 0.01% survivors) within 1 h. Cells treated at 30 degrees C with the drugs cycloheximide or emetine, at concentrations which are initially inhibitory to protein synthesis and cell growth but from which cells can eventually recover and resume growth, are after this recovery able to survive a direct shift from 30 to 43 degrees C (ca. 70% survival after 1 h). This induction of thermotolerance by these drugs is as efficient in providing thermoprotection to cells as is a prior sublethal heat treatment which elicits the synthesis of HSPs. However, during the period when drug-treated cells recover their protein synthesis ability and simultaneously acquire the ability to subsequently survive a shift to 43 degrees C, none of the major HSPs are synthesized. The ability to survive a 1-h, 43 degrees C heat treatment, therefore, does not absolutely require the prior synthesis of HSPs. But, as extended survival at 43 degrees Celsius depends absolutely on the ability of cells to continually synthesize HSPs, it appears that a prior heat shock as well as the recovery from protein synthesis inhibition elicits a change in the protein synthetic machinery which allows the translation of HSP mRNAs at what would otherwise be a nonpermissive temperature for protein synthesis.

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