A novel transcriptional regulator, Sll1130, negatively regulates heat-responsive genes in Synechocystis sp. PCC6803

2013 ◽  
Vol 449 (3) ◽  
pp. 751-760 ◽  
Author(s):  
Pilla Sankara Krishna ◽  
Balaga Radha Rani ◽  
M. Karthik Mohan ◽  
Iwane Suzuki ◽  
Sisinthy Shivaji ◽  
...  
Keyword(s):  
Heat Shock ◽  
Transcriptional Regulator ◽  
Hypothetical Protein ◽  
Upstream Region ◽  
Wild Type ◽  
Protein Levels ◽  
Shock Response ◽  
Inducible Genes ◽  
Hypothetical Genes ◽  
Synechocystis Sp

A conserved hypothetical protein, Sll1130, is a novel transcription factor that regulates the expression of major heat-responsive genes in Synechocystis sp. PCC6803. Synechocystis exhibited an increased thermotolerance due to disruption of sll1130. Δsll1130 cells recovered much faster than wild-type cells after they were subjected to heat shock (50°C) for 30 min followed by recovery at 34°C for 48 h. In Δsll1130 cultures, 70% of the cells were viable compared with the wild-type culture in which only 30% of the cells were viable. DNA microarray analysis revealed that in Δsll1130, expression of the heat-responsive genes such as htpG, hspA, isiA, isiB and several hypothetical genes were up-regulated. Sll1130 binds to a conserved inverted-repeat (GGCGATCGCC) located in the upstream region of the above genes. In addition, both the transcript and protein levels of sll1130 were immediately down-regulated upon shift of wild-type cells from 34 to 42°C. Collectively the results of the present study suggest that Sll1130 is a heat-responsive transcriptional regulator that represses the expression of certain heat-inducible genes at optimum growth temperatures. Upon heat shock, a quick drop in the Sll1130 levels leads to de-repression of the heat-shock genes and subsequent thermal acclimation. On the basis of the findings of the present study, we present a model which describes the heat-shock response involving Sll1130.

Identification of novel heat shock-induced long non-coding RNA in human cells

2020 ◽  
Author(s):  
Rena Onoguchi-Mizutani ◽  
Yoshihiro Kishi ◽  
Yoko Ogura ◽  
Yuuki Nishimura ◽  
Naoto Imamachi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
A549 Cells ◽  
Heat Shock Factor 1 ◽  
Protein Coding ◽  
Heat Shock Stress ◽  
Non Coding Rna ◽  
Shock Response ◽  
Inducible Protein ◽  
Inducible Genes

Abstract The heat-shock response is a crucial system for survival of organisms under heat stress. During heat-shock stress, gene expression is globally suppressed, but expression of some genes, such as chaperone genes, is selectively promoted. These selectively activated genes have critical roles in the heat-shock response, so it is necessary to discover heat-inducible genes to reveal the overall heat-shock response picture. The expression profiling of heat-inducible protein-coding genes has been well-studied, but that of non-coding genes remains unclear in mammalian systems. Here, we used RNA-seq analysis of heat shock-treated A549 cells to identify seven novel long non-coding RNAs that responded to heat shock. We focussed on CTD-2377D24.6 RNA, which is most significantly induced by heat shock, and found that the promoter region of CTD-2377D24.6 contains the binding site for transcription factor HSF1 (heat shock factor 1), which plays a central role in the heat-shock response. We confirmed that HSF1 knockdown cancelled the induction of CTD-2377D24.6 RNA upon heat shock. These results suggest that CTD-2377D24.6 RNA is a novel heat shock-inducible transcript that is transcribed by HSF1.

scholarly journals HrcA and DnaK are important for static and continuous-flow biofilm formation and disinfectant resistance in Listeria monocytogenes

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3782-3790 ◽  
Author(s):  
Stijn van der Veen ◽  
Tjakko Abee
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Peracetic Acid ◽  
Continuous Flow ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Wild Type ◽  
Shock Response ◽  
Disinfectant Resistance

The food-borne pathogen Listeria monocytogenes is able to form biofilms in food processing environments. Since biofilms are generally difficult to eradicate during clean-up procedures, they pose a major risk for the food industry. Stress resistance mechanisms involved in L. monocytogenes biofilm formation and disinfectant resistance have, to our knowledge, not been identified thus far. In this study, we investigated the role of hrcA, which encodes the transcriptional regulator of the class I heat-shock response, and dnaK, which encodes a class I heat-shock response chaperone protein, in static and continuous-flow biofilm formation and resistance against benzalkonium chloride and peracetic acid. Induction of both hrcA and dnaK during continuous-flow biofilm formation was observed using quantitative real-time PCR and promoter reporters. Furthermore, in-frame deletion and complementation mutants of hrcA and dnaK revealed that HrcA and DnaK are required to reach wild-type levels of both static and continuous-flow biofilms. Finally, disinfection treatments of planktonic-grown cells and suspended static and continuous-flow biofilm cells of wild-type and mutants showed that HrcA and DnaK are important for resistance against benzalkonium chloride and peracetic acid. In conclusion, our study revealed that HrcA and DnaK are important for L. monocytogenes biofilm formation and disinfectant resistance.

scholarly journals tRNA thiolation links translation to stress responses in Saccharomyces cerevisiae

2015 ◽  
Vol 26 (2) ◽  
pp. 270-282 ◽  
Author(s):  
Jadyn R. Damon ◽  
David Pincus ◽  
Hidde L. Ploegh
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Elevated Temperature ◽  
Heat Shock ◽  
Stress Responses ◽  
Wild Type ◽  
Trna Modifications ◽  
Shock Response ◽  
Tightly Coupled

Although tRNA modifications have been well catalogued, the precise functions of many modifications and their roles in mediating gene expression are still being elucidated. Whereas tRNA modifications were long assumed to be constitutive, it is now apparent that the modification status of tRNAs changes in response to different environmental conditions. The URM1 pathway is required for thiolation of the cytoplasmic tRNAs tGluUUC, tGlnUUG, and tLysUUU in Saccharomyces cerevisiae. We demonstrate that URM1 pathway mutants have impaired translation, which results in increased basal activation of the Hsf1-mediated heat shock response; we also find that tRNA thiolation levels in wild-type cells decrease when cells are grown at elevated temperature. We show that defects in tRNA thiolation can be conditionally advantageous, conferring resistance to endoplasmic reticulum stress. URM1 pathway proteins are unstable and hence are more sensitive to changes in the translational capacity of cells, which is decreased in cells experiencing stresses. We propose a model in which a stress-induced decrease in translation results in decreased levels of URM1 pathway components, which results in decreased tRNA thiolation levels, which further serves to decrease translation. This mechanism ensures that tRNA thiolation and translation are tightly coupled and coregulated according to need.

scholarly journals Acyadeletion mutant ofEscherichia colidevelops thermotolerance but does not exhibit a heat-shock response

1990 ◽  
Vol 55 (1) ◽  
pp. 1-6 ◽  
Author(s):  
John M. Delaney
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Response ◽  
Receptor Protein ◽  
Wild Type ◽  
E Coli ◽  
Shock Response ◽  
In The Wild ◽  
Shock Proteins

SummaryAn adenyl cyclase deletion mutant (cya) ofE. colifailed to exhibit a heat-shock response even after 30 min at 42 °C. Under these conditions, heat-shock protein synthesis was induced by 10 min in the wild-type strain. These results suggest that synthesis of heat-shock proteins inE. colirequires thecyagene. This hypothesis is supported by the finding that a presumptive cyclic AMP receptor protein (CRP) binding site exists within the promotor region of theE. coli htp Rgene. In spite of the absence of heat-shock protein synthesis, when treated at 50 °C, thecyamutant is relatively more heat resistant than wild type. Furthermore, when heat shocked at 42 °C prior to exposure at 50 °C, thecyamutant developed thermotolerance. These results suggest that heat-shock protein synthesis is not essential for development of thermotolerance inE. coli.

scholarly journals A Novel Mouse HSF3 Has the Potential to Activate Nonclassical Heat-Shock Genes during Heat Shock

2010 ◽  
Vol 21 (1) ◽  
pp. 106-116 ◽  
Author(s):  
Mitsuaki Fujimoto ◽  
Naoki Hayashida ◽  
Takuma Katoh ◽  
Kouji Oshima ◽  
Toyohide Shinkawa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Cell Survival ◽  
Null Mouse ◽  
Wild Type ◽  
Heat Shock Genes ◽  
Embryonic Fibroblasts ◽  
Large Numbers ◽  
Inducible Genes ◽  
Transcription Factor 1

The heat-shock response is characterized by the expression of a set of classical heat-shock genes, and is regulated by heat-shock transcription factor 1 (HSF1) in mammals. However, comprehensive analyses of gene expression have revealed very large numbers of inducible genes in cells exposed to heat shock. It is believed that HSF1 is required for the heat-inducible expression of these genes although HSF2 and HSF4 modulate some of the gene expression. Here, we identified a novel mouse HSF3 (mHSF3) translocated into the nucleus during heat shock. However, mHSF3 did not activate classical heat-shock genes such as Hsp70. Remarkably, overexpression of mHSF3 restored the expression of nonclassical heat-shock genes such as PDZK3 and PROM2 in HSF1-null mouse embryonic fibroblasts (MEFs). Although down-regulation of mHSF3 expression had no effect on gene expression or cell survival in wild-type MEF cells, it abolished the moderate expression of PDZK3 mRNA and reduced cell survival in HSF1-null MEF cells during heat shock. We propose that mHSF3 represents a unique HSF that has the potential to activate only nonclassical heat-shock genes to protect cells from detrimental stresses.

A 16.6-Kilodalton Protein in the Cyanobacterium Synechocystis sp. PCC 6803 Plays a Role in the Heat Shock Response

1998 ◽  
Vol 37 (6) ◽  
pp. 403-407 ◽  
Author(s):  
Sengyong Lee ◽  
Daniel J. Prochaska ◽  
Feng Fang ◽  
Susan R. Barnum
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Shock Response ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Global Transcriptional and Proteomic Analysis of the Sig1 Heat Shock Regulon of Deinococcus radiodurans

2005 ◽  
Vol 187 (10) ◽  
pp. 3339-3351 ◽  
Author(s):  
Amy K. Schmid ◽  
Heather A. Howell ◽  
John R. Battista ◽  
Scott N. Peterson ◽  
Mary E. Lidstrom
Keyword(s):  
Heat Shock ◽  
Deinococcus Radiodurans ◽  
Membrane Integrity ◽  
Small Heat Shock Protein ◽  
Hypothetical Protein ◽  
Wild Type ◽  
Function Type ◽  
New Members ◽  
In The Wild ◽  
Heat Shock Induction

ABSTRACT The sig1 gene, predicted to encode an extracytoplasmic function-type heat shock sigma factor of Deinococcus radiodurans, has been shown to play a central role in the positive regulation of the heat shock operons groESL and dnaKJ. To determine if Sig1 is required for the regulation of additional heat shock genes, we monitored the global transcriptional and proteomic profiles of a D. radiodurans R1 sig1 mutant and wild-type cells in response to elevated temperature stress. Thirty-one gene products were identified that showed heat shock induction in the wild type but not in the sig1 mutant. Quantitative real-time PCR experiments verified the transcriptional requirement of Sig1 for the heat shock induction of the mRNA of five of these genes—dnaK, groES, DR1314, pspA, and hsp20. hsp20 appears to encode a new member of the small heat shock protein superfamily, DR1314 is predicted to encode a hypothetical protein with no recognizable orthologs, and pspA is predicted to encode a protein involved in maintenance of membrane integrity. Deletion mutation analysis demonstrated the importance in heat shock protection of hsp20 and DR1314. The promoters of dnaKJE, groESL, DR1314, pspA, and hsp20 were mapped and, combined with computer-based pattern searches of the upstream regions of the 26 other Sig1 regulon members, these results suggested that Sig1 might recognize both σ70-type and σW-type promoter consensus sequences. These results expand the D. radiodurans Sig1 heat shock regulon to include 31 potential new members, including not only factors with cytoplasmic functions, such as groES and dnaK, but also those with extracytoplasmic functions, like pspA.

scholarly journals Metabolic Roles of a Rhodobacter sphaeroides Member of the ς32 Family

1998 ◽  
Vol 180 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Russell K. Karls ◽  
Jacqueline Brooks ◽  
Peter Rossmeissl ◽  
Janelle Luedke ◽  
Timothy J. Donohue
Keyword(s):  
Heat Shock ◽  
Temperature Profile ◽  
Rhodobacter Sphaeroides ◽  
Growth Temperature ◽  
Heat Shock Response ◽  
Anaerobic Respiration ◽  
Wild Type ◽  
Lower Growth ◽  
E Coli ◽  
Shock Response

ABSTRACT We report the role of a gene (rpoH) from the facultative phototroph Rhodobacter sphaeroides that encodes a protein (ς37) similar to Escherichia coliς32 and other members of the heat shock family of eubacterial sigma factors. R. sphaeroides ς37controls genes that function during environmental stress, since anR. sphaeroides ΔRpoH mutant is ∼30-fold more sensitive to the toxic oxyanion tellurite than wild-type cells. However, the ΔRpoH mutant lacks several phenotypes characteristic of E. coli cells lacking ς32. For example, anR. sphaeroides ΔRpoH mutant is not generally defective in phage morphogenesis, since it plates the lytic virus RS1, as well as its wild-type parent. In characterizing the response ofR. sphaeroides to heat, we found that its growth temperature profile is different when cells generate energy by aerobic respiration, anaerobic respiration, or photosynthesis. However, growth of the ΔRpoH mutant is comparable to that of a wild-type strain under each of these conditions. The ΔRpoH mutant mounted a heat shock response when aerobically grown cells were shifted from 30 to 42°C, but it exhibited altered induction kinetics of ∼120-, 85-, 75-, and 65-kDa proteins. There was also reduced accumulation of several presumed heat shock transcripts (rpoD PHS,groESL 1, etc.) when aerobically grown ΔRpoH cells were placed at 42°C. Under aerobic conditions, it appears that another sigma factor enables the ΔRpoH mutant to mount a heat shock response, since either RNA polymerase preparations from an ΔRpoH mutant, reconstituted Eς37, or a holoenzyme containing a 38-kDa protein (ς38) each transcribed E. coliEς32-dependent promoters. The lower growth temperature profile of photosynthetic cells is correlated with a difference in heat-inducible gene expression, since neither wild-type cells or the ΔRpoH mutant mount a typical heat shock response after such cultures were shifted from 30 to 37°C.

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