Showing papers on "Heat shock protein published in 1980"
TL;DR: Many specific sites in Drosophila chromatin are hypersensitive to DNase I and the positions of such sites were mapped along the regions of the genome coding for two heat shock proteins.
Abstract: Many specific sites in Drosophila chromatin are hypersensitive to DNase I. The positions of such sites were mapped along the regions of the genome coding for two heat shock proteins. Such sites lie at the 5' ends of heat shock genes and may function as elements for recognition by molecules which regulate gene activity.
968 citations
TL;DR: The level of acquired thermal resistance of Saccharomyces cerevisiae shows an excellent correlation with the cellular level of the heat shock proteins which are transiently induced by such a temperature shift.
319 citations
TL;DR: In vitro translation has been used to demonstrate that the messenger RNAs encoding the normal (25 degrees) spectrum of proteins are not broken down or irreversibly inactivated in response to the temperature change.
309 citations
TL;DR: 30°C appears to be a stasis condition for Dictyostelium which elicits a response essential for protection from lethal temperatures which suggests certain aspects of the response may be universal in eukaryotes.
162 citations
TL;DR: It is concluded that little (if any) heat shock protein becomes associated with mitochondria, despite the many lines of evidence linking the response to respiratory stress, and that their transport to the nucleus occurs very rapidly.
157 citations
TL;DR: The results indicate that the heat shock proteins of 22, 23, 26, and 27 kdaltons and at least a fraction of the 68- and 70-kdalton proteins are found in the nucleus after the heatshock, where they are present in chromatin and nucleoli preparations.
148 citations
TL;DR: In this paper, the genes for all seven major heat shock proteins of D. melanogaster are now cloned are found to exhibit a variety of patterns of organization at the five loci they occupy.
Abstract: Unique coding sequences for four heat shock proteins of Drosophila melanogaster, hsp 28, hsp 26, hsp 23, and hsp 22, are clustered in a 12-kilobase interval at chromosome subdivision 67B. The four genes are not transcribed in the same direction and each gives rise to a separate messenger RNA, with no indication of intervening sequences. Including the present results, the genes for all seven major heat shock proteins of D. melanogaster are now cloned are found to exhibit a variety of patterns of organization at the five loci they occupy.
139 citations
TL;DR: Ribosomes were found to initiate on heat-induced messages in Drosophila with a frequency of between 9 and 14 initiations per minute at 37 °C, close to that reported for other eukaryotic systems at similar temperatures.
110 citations
TL;DR: A 33 kilobase region of the 67B locus of Drosophila melanogaster genome has been isolated and genes for all seven major heat shock induced proteins have no been mapped cytologically.
Abstract: A 33 kilobase region of the 67B locus of Drosophila melanogaster genome has been isolated. The genes for the 27K, 26K, 23K and 22K heat shock induced proteins are contained within an 11 kb segment. the 27K gene, approximately 1.4 kb in length, and the 23K gene, approximately 1.0 kb in length, are separated by about 1.5 kb of spacer DNA; a third block of transcription, which encodes the 26K gene, is approximately 1.1 kb in length, and is separated from the gene for the 23K protein by 4.5 kb of spacer DNA. The 22K gene is located approximately 1.2 kb from the 26K gene. The RNAs encoding the 27K, 23K and 22K genes are transcribed from the same DNA strand. With the assignment of the four small heat shock induced proteins to 67B, genes for all seven major heat shock induced proteins have no been mapped cytologically.
79 citations
TL;DR: Changes in populations of translatable messenger ribonucleic acids (mRNA's) after heat shock of Saccharomyces cerevisiae were examined and found to correlate very closely with transient alterations in patterns of in vivo protein synthesis.
Abstract: Changes in populations of translatable messenger ribonucleic acids (mRNA's) after heat shock of Saccharomyces cerevisiae were examined and found to correlate very closely with transient alterations in patterns of in vivo protein synthesis. Initial changes included an increase in translatable species coding for polypeptides synthesized during heat shock; this increase was found to be dependent on transcription but did not require ongoing protein synthesis. A decrease was observed in the level of translatable mRNA's coding for polypeptides whose synthesis was repressed after heat shock. This decrease was much more rapid than can be explained solely by termination of transcription. Requirements for this rapid loss of RNA from the translatable pool included both transcription and an active rna1 gene product but not protein synthesis. After the initial changes in translatable RNA induced by heat shock, the patterns of both in vivo and in vitro translation products began to revert to the preshock levels. This recovery period, unlike the earlier changes, was dependent upon a requisite period of protein synthesis.
65 citations
TL;DR: The metabolism of RNA transcribed from 93 D has been compared with that of RNA coding for the major heat shock protein hsp70 in cells incubated for one hour at 35° C and the transcripts from two heat shock loci appear to be metabolized in significantly different ways.
Abstract: Characteristics of the major heat shock puff site 93 D and the RNA transcribed from it have been investigated by hybridization to polytene chromosome preparations and to recombinant DNA. By saturation in situ hybridization, the length of the transcribed region at 93 D is twice that of the mRNA coding region at the heat shock puff site 87 A. From the known length of the heat shock mRNA sequence at 87 A, we calculate that the minimum length of the transcribed region at 93 D is 9.6 kb (kb = kilobase, i.e., 1,000 nucleotides). — The metabolism of RNA transcribed from 93 D has been compared with that of RNA coding for the major heat shock protein hsp70 in cells incubated for one hour at 35° C. Hsp70 mRNA sequences, assayed by hybridization to a specific recombinant DNA probe and by in situ hybridization to 87 A, were found in both poly(A)+ and poly(A)− cytoplasmic RNA and were more concentrated in cytoplasmic RNA than in nuclear RNA. In contrast, sequences complementary to 93 D, assayed by in situ hybridization, were more concentrated in nuclear than in cytoplasmic RNA. This implies that sequences from 93 D exit from the nucleus at a lower rate and/or are turned over in the cytoplasm at a higher rate, than sequences from 87 A. Site 93 D is also unusual in that its transcribed region is represented in both poly (A)+ and poly (A)− nuclear RNA, even though 93 D-complementary RNA in the cytoplasm is predominantly poly (A)−. Finally, only 28–58% of the length of DNA transcribed at 93 D is represented in cytoplasmic RNA, indicating that only a portion of the sequences transcribed from 93 D are exported from the nucleus. The transcripts from two heat shock loci, 93 D and 87 A, thus appear to be metabolized in significantly different ways.
TL;DR: A heat shock to amebae of the amebo-flagellate Naegleria gruberi during differentiation into swimming flagellates results in the induction of heat shock proteins as well as multiple flagella.
TL;DR: Heat shocks or cold shocks were found to induce characteristic changes in the pattern of protein synthesis in Tetrahymena pyriformis as analysed on sodium dodecyl sulphate (SDS)-polyacrylamide gels, and heat-induced proteins appear to be metabolically stable and no change in protein turnover could be detected at the elevated temperature.
TL;DR: Kelley and Schlesinger as discussed by the authors showed that the protein synthesis pattern of chicken embryo fibroblasts changes dramatically after these cells are incubated at 45 degrees C for a few hours.
TL;DR: Heating at 31 degrees C produces in sea urchin gastrulae a general and severe inhibition of the protein synthesis together with a marked increase in the rate of synthesis of one or very few classes of specific proteins.
TL;DR: Evidence is presented showing that the newly synthesized proteins at 37° are not involved in repressing the transcription of most of the genes active before the heat shock, suggesting that some proteins(s) synthesized during heat shock may be involved in the regulation of RNA synthesis.
Abstract: The effect of inhibitors of protein synthesis on RNA synthesis was investigated before and during heat shock. The results indicate that proteins specifically made following heat shock might be required for the resumption, after heat shock, of the synthesis of the RNA normally made at 25°C. It has previously been shown that the heat shock proteins, with the exception of hsp 84, are found in the nucleus bound to chromatin at 37°C, and that they move to the cytoplasm on further incubation of the cells at 25°C (Arrigo et al., 1980). Taken together, these results suggest that some proteins(s) synthesized during heat shock may be involved in the regulation of RNA synthesis. However evidence is presented showing that the newly synthesized proteins at 37° are not involved in repressing the transcription of most of the genes active before the heat shock.
TL;DR: Results indicate that in the experimental system, RNA polymerase activities ATP and GTP pool concentrations and overall proteins transport were not directly related to rRNA synthesis.
Dissertation•
01 Jan 1980
TL;DR: The synthesis of the heat shock proteins on cytoplasmic rather than mitochondrial ribosomes has been shown and the effects of heat shock on the protein synthesis pattern in HeLa cells have been analyzed.
Abstract: The synthesis of the heat shock proteins on cytoplasmic rather than mitochondrial ribosomes has been shown. The time course of the synthesis of heat shock proteins in prepupal and pupal stages of Drosophila melanogaster has been analyzed. Prepupae were heat shocked at 37.5[degrees]C for 20 minutes and pupae, either at 37.5[degrees]C for 20 minutes or at 40.2[degrees]C for 40 minutes. In prepupae, all of the heat shock proteins are synthesized immediately after the shock and continue to be synthesized for two to three hours. By three hours after the shock, the synthesis of normal proteins has resumed. In pupae, the time course is similar after the milder shock. However, the more severe shock causes a drastic reduction in total protein synthesis for at least one hour after the shock. It has been shown previously that this shock causes the production in pupae of stage specific phenocopies at high penetrance, an effect which is not observed after a shock at 37.5[degrees]C for 20 minutes. The drastic decrease in total protein synthesis and the subsequent occurrence of anomalies in the resumed program of gene expression and their possible relation to phenocopy production are discussed.
The increase in activity of phenol oxidase after a shock of 40[degrees]C for 40 minutes has been investigated to determine whether a component of the enzyme is a heat shock protein. This hypothesis was tested by measuring the extent of co-banding of [superscript 35]S-methionine labeled proteins from heat shocked and non-heat shocked cells with partially purified phenol oxidase in a sucrose gradient. The results do not support such a role for any heat shock protein; a mechanism whereby phenol oxidase activity could increase after heat shock is discussed.
The 84,000 dalton heat shock protein has been purified by ammonium sulfate fractionation, chromatography on hydroxylapatite, and one- or two-dimensional gel electrophoresis. This purified protein has been used to produce antibodies in rabbits. The antibodies have been used to show, by indirect immunoprecipitation experiments, that this heat shock protein is normally synthesized in at least three D. melanogaster tissues. Indirect immunofluorescence experiments using these antibodies indicate that the 84,000 dalton protein is also present on the chromosomes of normal and heat shocked salivary glands at the interband regions. Evidence is presented to show that this binding pattern may simply reflect the high concentration of this protein in the cell.
In a separate investigation, the effects of heat shock on the protein synthesis pattern in HeLa cells have also been analyzed.