scholarly journals Regulated transcription of the genes for actin and heat-shock proteins in culture drosophila cells

1981 ◽  
Vol 88 (2) ◽  
pp. 323-328 ◽  
Author(s):  
RC Findly ◽  
T Pederson
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Gene Transcription ◽  
Dna Sequences ◽  
Heat Shock Gene ◽  
Nuclear Rna ◽  
Gene Transcripts ◽  
Shock Gene ◽  
Shock Proteins ◽  
Drosophila Cells

The transcription of three specific genes has been examined in heat-shocked drosophila cells by hybridizing pulse-labeled nuclear RNA with cloned DNA sequences. Actin gene transcription is rapidly and profoundly suppressed upon heat shock but returns to near- normal levels after cells are placed back at their normal culture temperature (23 degrees C). Conversely, the transcription of genes coding from 70,000- and 26,000-dalton heat- shock proteins increases dramatically and with extraordinary rapidity (60 s) after heat shock. The temporal patterns of 70,000- and 26,000-dalton heat-shock gene transcription are nearly superimposable, indicating that, although they are closely linked cytologically, these genes are nevertheless tightly coregulated. The abundance of heat- shock gene transcripts reaches remarkable levels, e.g., 70,000-dalton heat-shock gene transcripts account for 2-3 percent of the nuclear RNA labeled during the first 30 min of heat shock. When heat-shocked cells are returned to 25 degrees C, the rates of transcription of the heat-shock genes fall back to the low levels characteristic of untreated cells. To confirm the low level of heat-shock gene transcription in normal cells, nuclear RNA was purified from unlabeled (and otherwise unhandled) 25 degrees C cells, end-labeled in vitro with (32)P, and hybridized to cloned heat-shock DNA sequences. These and other data establish that the genes for 70,000- and 26,000-dalton heat-shock proteins in culture drosophila cells are active at 25 degrees C, and that their rate of transcription is greatly accelerated upon heat shock rather than being activated from a true "off" state. The rapidity, magnitude, and reversibility of the shifts in actin and heat-shock gene transcription constitute compelling advantages for the use of cultured drosophila cells in studying the transcriptional regulation of eukaryotic genes, including one related to the cytoskeleton.

A family of related proteins is encoded by the major Drosophila heat shock gene family

1982 ◽  
Vol 2 (3) ◽  
pp. 286-292
Author(s):  
S C Wadsworth
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Sodium Dodecyl ◽  
Heat Shock Gene ◽  
Partial Digestion ◽  
Shock Gene ◽  
Shock Proteins

At least four proteins of 70,000 to 75,000 molecular weight (70-75K) were synthesized from mRNA which hybridized with a cloned heat shock gene previously shown to be localized to the 87A and 87C heat shock puff sites. These in vitro-synthesized proteins were indistinguishable from in vivo-synthesized heat shock-induced proteins when analyzed on sodium dodecyl sulfate-polyacrylamide gels. A comparison of the pattern of this group of proteins synthesized in vivo during a 5-min pulse or during continuous labeling indicates that the 72-75K proteins are probably not kinetic precursors to the major 70K heat shock protein. Partial digestion products generated with V8 protease indicated that the 70-75K heat shock proteins are closely related, but that there are clear differences between them. The partial digestion patterns obtained from heat shock proteins from the Kc cell line and from the Oregon R strain of Drosophila melanogaster are very similar. Genetic analysis of the patterns of 70-75K heat shock protein synthesis indicated that the genes encoding at least two of the three 72-75K heat shock proteins are located outside of the major 87A and 87C puff sites.

scholarly journals A family of related proteins is encoded by the major Drosophila heat shock gene family.

1982 ◽  
Vol 2 (3) ◽  
pp. 286-292 ◽  
Author(s):  
S C Wadsworth
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Sodium Dodecyl ◽  
Heat Shock Gene ◽  
Partial Digestion ◽  
Shock Gene ◽  
Shock Proteins

At least four proteins of 70,000 to 75,000 molecular weight (70-75K) were synthesized from mRNA which hybridized with a cloned heat shock gene previously shown to be localized to the 87A and 87C heat shock puff sites. These in vitro-synthesized proteins were indistinguishable from in vivo-synthesized heat shock-induced proteins when analyzed on sodium dodecyl sulfate-polyacrylamide gels. A comparison of the pattern of this group of proteins synthesized in vivo during a 5-min pulse or during continuous labeling indicates that the 72-75K proteins are probably not kinetic precursors to the major 70K heat shock protein. Partial digestion products generated with V8 protease indicated that the 70-75K heat shock proteins are closely related, but that there are clear differences between them. The partial digestion patterns obtained from heat shock proteins from the Kc cell line and from the Oregon R strain of Drosophila melanogaster are very similar. Genetic analysis of the patterns of 70-75K heat shock protein synthesis indicated that the genes encoding at least two of the three 72-75K heat shock proteins are located outside of the major 87A and 87C puff sites.

scholarly journals Sequences involved in temperature and ecdysterone-induced transcription are located in separate regions of a Drosophila melanogaster heat shock gene.

1986 ◽  
Vol 6 (2) ◽  
pp. 663-673 ◽  
Author(s):  
E Hoffman ◽  
V Corces
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Dna Sequences ◽  
Germ Line ◽  
Initiation Site ◽  
P Element ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Consensus Sequences ◽  
Shock Gene

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.

The expression of heat-shock genes in higher plants

1986 ◽  
Vol 314 (1166) ◽  
pp. 453-468 ◽  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Higher Plants ◽  
Structural Features ◽  
Amino Acid Sequences ◽  
Heat Shock Gene ◽  
Regulatory Sequences ◽  
Heat Shock Genes ◽  
Control Of Gene Expression ◽  
Shock Proteins

High-temperature stress or heat shock induces the vigorous synthesis of heat-shock proteins in many organisms including the higher plants. This response has been implicated in the acquisition of thermotolerance. The biological importance of a group of low-molecular-mass proteins in the response of plants is indicated by the conservation of the corresponding genes. The steady-state levels of mRNAs for these proteins shift from undetectable levels at normal temperature to about 20 000 molecules per gene in the cell after heat shock. The analysis of ‘run-off’ transcripts from isolated soybean nuclei suggests a transcriptional control of gene expression. The DNA sequence analysis of soybean heat-shock genes revealed a conservation of promoter sequences and 5'-upstream elements. A comparison of the deduced amino acid sequences of polypeptides showed a conservation of structural features in heat-shock proteins between plants and animals. The implication of a common regulatory concept in the heat-shock response makes genes belonging to this family (15-18 kDa proteins) in soybean favourable candidates for investigating thermoregulation of transcription. We have exploited the natural gene transfer system of Agrobacterium tumefaciens to introduce a soybean heat-shock gene into the genomes of sunflower and tobacco. The gene is thermoinducibly transcribed and transcripts are faithfully initiated in transgenic plants. Experiments are in progress to define the regulatory sequences 5'-upstream from the gene. The expression of heat-shock genes in a heterologous genetic background also provides the basis for studying the function of the proteins and their possible role in thermoprotection.

scholarly journals Upstream sequences required for efficient expression of a soybean heat shock gene.

1986 ◽  
Vol 6 (2) ◽  
pp. 559-565 ◽  
Author(s):  
W B Gurley ◽  
E Czarnecka ◽  
R T Nagao ◽  
J L Key
Keyword(s):  
Heat Shock ◽  
Dna Sequences ◽  
Small Heat Shock Protein ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Basal Transcription ◽  
S1 Nuclease ◽  
Soybean Seedlings ◽  
Flanking Sequences ◽  
Shock Gene

A soybean gene (Gmhsp17.5-E) encoding a small heat shock protein was introduced into primary sunflower tumors via T-DNA-mediated transformation. RNA blot hybridizations and S1-nuclease hybrid protection studies indicated that the heat shock gene containing 3.25 kilobases of 5'-flanking sequences was strongly transcribed in a thermoinducible (40 degrees C) manner. Transcriptional induction also occurred to a lesser extent upon treatment of whole tumors with sodium arsenite and CdCl2. Basal (26 degrees C) transcription was not detected in soybean seedlings, but it was quite evident in transformed tumor tissue. A 5' deletion to -1,175 base pairs with respect to the CAP site had no effect on the levels of thermoinducible transcription, but it resulted in a large increase in basal transcription. Further removal of DNA sequences (including the TATA-distal heat shock consensus element) to -95 base pairs reduced thermoinducible transcription by 95% and also greatly decreased basal transcription. The termini of the Gmhsp17.5-E RNA in the tumor were generally the same as those present in soybean RNA, with the exception of several additional 3' termini.

scholarly journals Interleukin 1 induces the expression of a heat-shock gene in chondrocytes

1991 ◽  
Vol 277 (2) ◽  
pp. 327-330 ◽  
Author(s):  
T F Cruz ◽  
R A Kandel ◽  
I R Brown
Keyword(s):  
Heat Shock ◽  
Interleukin 1 ◽  
Heat Shock Gene ◽  
Proteoglycan Synthesis ◽  
Hsp70 Mrna ◽  
Mrna Species ◽  
Shock Gene ◽  
Shock Proteins ◽  
Arthritic Joints

The presence of T cells and antibodies reactive with heat-shock proteins (hsps) in the joints of patients with rheumatoid arthritis may indicate a role of hsps in this disease. In the present study we examined whether increased temperature and interleukin 1 (IL 1), both of which are elevated in arthritic joints, induced the expression of two hsp70 genes in bovine chondrocyte cultures. We found that heat shock resulted in increased expression of constitutive and inducible hsp70 mRNA species. IL 1 and phorbol 12-myristate 13-acetate (PMA) also induced an increase in the constitutive hsp70 mRNA species, but without affecting the expression of the inducible hsp70 gene. The increase induced by IL 1 was observed only after 3 h, whereas increases induced by PMA were observed within 1 h. For all treatments, the hsp70 mRNA decreased by 24 h. Heat treatment of chondrocytes did not affect levels of collagenase and caseinase activity in the medium, nor did it alter proteoglycan synthesis by these cells.

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