scholarly journals Nucleolar accumulation of poly (A)+ RNA in heat-shocked yeast cells: implication of nucleolar involvement in mRNA transport.

1996 ◽  
Vol 7 (1) ◽  
pp. 173-192 ◽  
Author(s):  
T Tani ◽  
R J Derby ◽  
Y Hiraoka ◽  
D L Spector
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Schizosaccharomyces Pombe ◽  
Yeast Cells ◽  
Eukaryotic Cells ◽  
Rrna Synthesis ◽  
Wild Type ◽  
Mrna Transport ◽  
Shock Proteins

Transport of mRNA from the nucleus to the cytoplasm plays an important role in gene expression in eukaryotic cells. In wild-type Schizosaccharomyces pombe cells poly(A)+ RNA is uniformly distributed throughout the nucleoplasm and cytoplasm. However, we found that a severe heat shock blocks mRNA transport in S. pombe, resulting in the accumulation of bulk poly(A)+ RNA, as well as a specific intron-less transcript, in the nucleoli. Pretreatment of cells with a mild heat shock, which induces heat shock proteins, before a severe heat shock protects the mRNA transport machinery and allows mRNA transport to proceed unimpeded. In heat-shocked S. pombe cells, the nucleolar region condensed into a few compact structures. Interestingly, poly(A)+ RNA accumulated predominantly in the condensed nucleolar regions of the heat-shocked cells. These data suggest that the yeast nucleolus may play a role in mRNA transport in addition to its roles in rRNA synthesis and preribosome assembly.

scholarly journals Nucleolar accumulation of poly (A)+ RNA in heat-shocked yeast cells: implication of nucleolar involvement in mRNA transport.

1995 ◽  
Vol 6 (11) ◽  
pp. 1515-1534 ◽  
Author(s):  
T Tani ◽  
R J Derby ◽  
Y Hiraoka ◽  
D L Spector
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Schizosaccharomyces Pombe ◽  
Yeast Cells ◽  
Eukaryotic Cells ◽  
Rrna Synthesis ◽  
Wild Type ◽  
Mrna Transport ◽  
Shock Proteins

Transport of mRNA from the nucleus to the cytoplasm plays an important role in gene expression in eukaryotic cells. In wild-type Schizosaccharomyces pombe cells poly(A)+ RNA is uniformly distributed throughout the nucleoplasm and cytoplasm. However, we found that a severe heat shock blocks mRNA transport in S. pombe, resulting in the accumulation of bulk poly(A)+ RNA, as well as a specific intron-less transcript, in the nucleoli. Pretreatment of cells with a mild heat shock, which induces heat shock proteins, before a severe heat shock protects the mRNA transport machinery and allows mRNA transport to proceed unimpeded. In heat-shocked S. pombe cells, the nucleolar region condensed into a few compact structures. Interestingly, poly(A)+ RNA accumulated predominantly in the condensed nucleolar regions of the heat-shocked cells. These data suggest that the yeast nucleolus may play a role in mRNA transport in addition to its roles in rRNA synthesis and preribosome assembly.

The role of heat-shock proteins in thermotolerance

1993 ◽  
Vol 339 (1289) ◽  
pp. 279-286 ◽  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
High Temperatures ◽  
Fruit Fly ◽  
Yeast Cells ◽  
Major Protein ◽  
Wild Type ◽  
Hsp 70 ◽  
Shock Proteins

The role of heat-shock proteins (hsps) in thermotolerance was examined in the budding yeast Saccharomyces cerevisiae and in the fruit fly Drosophila melanogaster . In yeast cells, the major protein responsible for thermotolerance is hsp 100. In cells carrying mutations in the hsp 100 gene, HSP 104 , growth is normal at both high and low temperatures, but the ability of cells to survive extreme temperatures is severely impaired. The loss of thermotolerance is apparently due to the absence of the hsp 104 protein itself because, with the exception of the hsp 104 protein, no differences in protein profiles were observed between mutant and wild-type cells. Aggregates found in mutant cells at high temperatures suggest that the cause of death may be the accumulation of denatured proteins. No differences in the rates of protein degradation were observed between mutant and wild-type cells. This, and genetic analysis of cells carrying multiple hsp 70 and hsp 104 mutations, suggests that the primary function of hsp 104 is to rescue proteins from denaturation rather than to degrade them once they have been denatured. Drosophila cells do not produce a protein in the hsp 100 class in response to high temperatures. In this organism, hsp 70 appears to be the primary protein involved in thermotolerance. Thus, the relative importance of different hsps in thermotolerance changes from organism to organism.

Exertional heat injury and gene expression changes: a DNA microarray analysis study

2004 ◽  
Vol 96 (5) ◽  
pp. 1943-1953 ◽  
Author(s):  
Larry A. Sonna ◽  
C. Bruce Wenger ◽  
Scott Flinn ◽  
Holly K. Sheldon ◽  
Michael N. Sawka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Molecular Evidence ◽  
Peripheral Blood Mononuclear ◽  
Heat Injury ◽  
Shock Proteins

This study examined gene expression changes associated with exertional heat injury (EHI) in vivo and compared these changes to in vitro heat shock responses previously reported by our laboratory. Peripheral blood mononuclear cell (PBMC) RNA was obtained from four male Marine recruits (ages 17-19 yr) who presented with symptoms consistent with EHI, core temperatures ranging from 39.3 to 42.5°C, and elevations in serum enzymes such as creatine kinase. Controls were age- and gender-matched Marines from whom samples were obtained before and several days after an intense field-training exercise in the heat (“The Crucible”). Expression analysis was performed on Affymetrix arrays (containing ∼12,600 sequences) from pooled samples obtained at three times for EHI group (at presentation, 2-3 h after cooling, and 1-2 days later) and compared with control values (average signals from two chips representing pre- and post-Crucible samples). After post hoc filtering, the analysis identified 361 transcripts that had twofold or greater increases in expression at one or more of the time points assayed and 331 transcripts that had twofold or greater decreases in expression. The affected transcripts included sequences previously shown to be heat-shock responsive in PBMCs in vitro (including both heat shock proteins and non-heat shock proteins), a number of sequences whose changes in expression had not previously been noted as a result of in vitro heat shock in PBMCs (including several interferon-induced sequences), and several nonspecific stress response genes (including ubiquitin C and dual-specificity phosphatase-1). We conclude that EHI produces a broad stress response that is detectable in PBMCs and that heat stress per se can only account for some of the observed changes in transcript expression. The molecular evidence from these patients is thus consistent with the hypothesis that EHI can result from cumulative effects of multiple adverse interacting stimuli.

scholarly journals Characterizing the role of Hsp90 in production of heat shock proteins in motor neurons reveals a suppressive effect of wild-type Hsf1

2007 ◽  
Vol 12 (2) ◽  
pp. 151 ◽  
Author(s):  
David M. Taylor ◽  
Miranda L. Tradewell ◽  
Sandra Minotti ◽  
Heather D. Durham
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Motor Neurons ◽  
Suppressive Effect ◽  
Wild Type ◽  
Shock Proteins
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