Heat Pulse
Mostrando 25-36 de 101 artigos, teses e dissertações.
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25. A family of related proteins is encoded by the major Drosophila heat shock gene family.
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 dodecy
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26. Heat-induced accumulation and futile cycling of trehalose in Saccharomyces cerevisiae.
Heat shock resulted in rapid accumulation of large amounts of trehalose in Saccharomyces cerevisiae. In cultures growing exponentially on glucose, the trehalose content of the cells increased from 0.01 to 1 g/g of protein within 1 h after the incubation temperature was shifted from 27 to 40 degrees C. When the temperature was readjusted to 27 degrees C, the
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27. A Study of Heat Stress in Extremely Hot Environments, and the Infra-red Reflectance of Some Potential Shielding Materials
In the course of evaluating industrial heat exposures, three very hot environments having heat stress indices over 300 have been analysed by the techniques of Haines and Hatch (1952) and Belding and Hatch (1955). In addition, pulse and oral temperature measurements were made on three subjects exposed to these environments. These studies indicate that the met
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28. Characterization of the Agrobacterium tumefaciens heat shock response: evidence for a sigma 32-like sigma factor.
We have characterized the heat shock response of Agrobacterium tumefaciens and compared it with the well-characterized Escherichia coli heat shock response. Four major heat shock proteins with apparent molecular masses of 98, 75, 65, and 20 kDa were identified by pulse-labelling cultures after temperature upshift. The three largest proteins comigrated with p
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29. Heat shock protects germinating conidiospores of Neurospora crassa against freezing injury.
Germinating conidiospores of Neurospora crassa that were exposed to 45 degrees C, a temperature that induces a heat shock response, were protected from injury caused by freezing in liquid nitrogen and subsequent thawing at 0 degrees C. Whereas up to 90% of the control spores were killed by this freezing and slow thawing, a prior heat shock increased cell sur
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30. Polycistronic transcripts in trypanosomes and their accumulation during heat shock: evidence for a precursor role in mRNA synthesis.
Maturation of mRNA precursors in trypanosomes involves an apparent trans splicing event in which a 39-nucleotide miniexon sequence, common to all trypanosome mRNAs, is joined to the 5' end of a protein-coding exon. We demonstrate that the processing machinery responsible for the maturation of tubulin mRNA precursors in Trypanosoma brucei can be disrupted by
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31. RNA-Linked Nascent DNA Fragments in Escherichia coli*
Nucleic acid that is extracted from E. coli labeled by a brief pulse of [3H]dT and depatured by treatment with heat, formamide, or formaldehyde bands in a region with a density higher than that of single-stranded E. coli DNA in a Cs2SO4 equilibrium density gradient. If treated with alkali or RNase, it then exhibits the density of single-stranded DNA. These r
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32. Quantitative analysis of the heat shock response of Saccharomyces cerevisiae.
Transient protein synthesis in Saccharomyces cerevisiae, after shift from 21-23 degrees C to 37 degrees C, was quantitatively analyzed. Pulse-labeled proteins were separated by two-dimensional gel electrophoresis, and autoradiograms of the gels were analyzed by a recently described method involving a computer-coupled film scanning system. In this way, the ra
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33. Characterization of the heat shock response in Brucella abortus and isolation of the genes encoding the GroE heat shock proteins.
In an effort to define the heat shock response in the bovine intracellular pathogen Brucella abortus, a rough variant lacking extensive lipopolysaccharide was pulse-labeled with [35S]methionine following exposure to elevated temperatures. The major heat shock proteins observed following sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiog
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34. Fusion of Escherichia coli heat-stable enterotoxin and heat-labile enterotoxin B subunit.
The 3' terminus of the DNA coding for the extracellular Escherichia coli heat-stable enterotoxin (ST) devoid of transcription and translation stop signals was fused to the 5' terminus of the DNA coding for the periplasmic B subunit of the heat-labile enterotoxin (LTB) deleted of ribosomal binding sites and leader peptide. By RNA-DNA hybridization analysis, i
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35. Transcription, export and turnover of Hsp70 and alpha beta, two Drosophila heat shock genes sharing a 400 nucleotide 5' upstream region.
A highly homologous 400 nucleotide sequence flanks the 5' end and extends 64 NT into the transcribed portion of all five hsp70 and seven alpha beta heat shock genes in Drosophila melanogaster (1-4). To determine the extent to which this sequence dictates coordinate regulation, we compared the total mass, continuous labeling and pulse-labeling of hsp70 and al
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36. The sigma B-dependent promoter of the Bacillus subtilis sigB operon is induced by heat shock.
sigma B, a secondary sigma factor of Bacillus subtilis, was found to increase 5- to 10-fold when cultures were shifted from 37 to 48 degrees C. Western blot (immunoblot) analyses, in which monoclonal antibodies specific for the sigB operon products RsbV, RsbW, and sigma B were used to probe extracts from wild-type and mutant B. subtilis strains, revealed tha