scholarly journals Transcriptional Heat Shock Response in the Smallest Known Self-Replicating Cell, Mycoplasma genitalium

2006 ◽  
Vol 188 (8) ◽  
pp. 2845-2855 ◽  
Author(s):  
Oxana Musatovova ◽  
Subramanian Dhandayuthapani ◽  
Joel B. Baseman
Keyword(s):  
Heat Shock ◽  
Elevated Temperatures ◽  
Regulation Of Gene Expression ◽  
Bacterial Pathogen ◽  
Transcriptional Response ◽  
Mycoplasma Genitalium ◽  
Regulatory Sequence ◽  
Regulatory Sequences ◽  
Promoter Regions ◽  
Transient Nature

ABSTRACT Mycoplasma genitalium is a human bacterial pathogen linked to urethritis and other sexually transmitted diseases as well as respiratory and joint pathologies. Though its complete genome sequence is available, little is understood about the regulation of gene expression in this smallest known, self-replicating cell, as its genome lacks orthologues for most of the conventional bacterial regulators. Still, the transcriptional repressor HrcA (heat regulation at CIRCE [controlling inverted repeat of chaperone expression]) is predicted in the M. genitalium genome as well as three copies of its corresponding regulatory sequence CIRCE. We investigated the transcriptional response of M. genitalium to elevated temperatures and detected the differential induction of four hsp genes. Three of the up-regulated genes, which encode DnaK, ClpB, and Lon, possess CIRCE within their promoter regions, suggesting that the HrcA-CIRCE regulatory mechanism is functional. Additionally, one of three DnaJ-encoding genes was up-regulated, even though no known regulatory sequences were found in the promoter region. Transcript levels returned to control values after 1 h of incubation at 37°C, reinforcing the transient nature of the heat shock transcriptional response. Interestingly, neither of the groESL operon genes, which encode the GroEL chaperone and its cochaperone GroES, responded to heat shock. These data suggest that M. genitalium selectively regulates a limited number of genes in response to heat shock.

scholarly journals Molecular Basis of the Defective Heat Stress Response in Mycobacterium leprae

2007 ◽  
Vol 189 (24) ◽  
pp. 8818-8827 ◽  
Author(s):  
Diana L. Williams ◽  
Tana L. Pittman ◽  
Mike Deshotel ◽  
Sandra Oby-Robinson ◽  
Issar Smith ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Transcriptional Response ◽  
Mycobacterium Leprae ◽  
Heat Stress Response ◽  
Regulatory Circuits ◽  
Shock Response

ABSTRACT Mycobacterium leprae, a major human pathogen, grows poorly at 37°C. The basis for its inability to survive at elevated temperatures was investigated. We determined that M. leprae lacks a protective heat shock response as a result of the lack of transcriptional induction of the alternative sigma factor genes sigE and sigB and the major heat shock operons, HSP70 and HSP60, even though heat shock promoters and regulatory circuits for these genes appear to be intact. M. leprae sigE was found to be capable of complementing the defective heat shock response of mycobacterial sigE knockout mutants only in the presence of a functional mycobacterial sigH, which orchestrates the mycobacterial heat shock response. Since the sigH of M. leprae is a pseudogene, these data support the conclusion that a key aspect of the defective heat shock response in M. leprae is the absence of a functional sigH. In addition, 68% of the genes induced during heat shock in M. tuberculosis were shown to be either absent from the M. leprae genome or were present as pseudogenes. Among these is the hsp/acr2 gene, whose product is essential for M. tuberculosis survival during heat shock. Taken together, these results suggest that the reduced ability of M. leprae to survive at elevated temperatures results from the lack of a functional transcriptional response to heat shock and the absence of a full repertoire of heat stress response genes, including sigH.

scholarly journals Comparison of the RpoH-Dependent Regulon and General Stress Response in Neisseria gonorrhoeae

2006 ◽  
Vol 188 (13) ◽  
pp. 4769-4776 ◽  
Author(s):  
Ishara C. Gunesekere ◽  
Charlene M. Kahler ◽  
David R. Powell ◽  
Lori A. S. Snyder ◽  
Nigel J. Saunders ◽  
...  
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Neisseria Gonorrhoeae ◽  
Transcriptional Profiling ◽  
Transcriptional Response ◽  
Protein Homeostasis ◽  
Promoter Regions ◽  
General Stress Response ◽  
Genome Wide ◽  
Shock Proteins

ABSTRACT In the gammaproteobacteria the RpoH regulon is often equated with the stress response, as the regulon contains many of the genes that encode what have been termed heat shock proteins that deal with the presence of damaged proteins. However, the betaproteobacteria primarily utilize the HrcA repressor protein to control genes involved in the stress response. We used genome-wide transcriptional profiling to compare the RpoH regulon and stress response of Neisseria gonorrhoeae, a member of the betaproteobacteria. To identify the members of the RpoH regulon, a plasmid-borne copy of the rpoH gene was overexpressed during exponential-phase growth at 37°C. This resulted in increased expression of 12 genes, many of which encode proteins that are involved in the stress response in other species. The putative promoter regions of many of these up-regulated genes contain a consensus RpoH binding site similar to that of Escherichia coli. Thus, it appears that unlike other members of the betaproteobacteria, N. gonorrhoeae utilizes RpoH, and not an HrcA homolog, to regulate the stress response. In N. gonorrhoeae exposed to 42°C for 10 min, we observed a much broader transcriptional response involving 37 differentially expressed genes. Genes that are apparently not part of the RpoH regulon showed increased transcription during heat shock. A total of 13 genes were also down-regulated. From these results we concluded that although RpoH acts as the major regulator of protein homeostasis, N. gonorrhoeae has additional means of responding to temperature stress.

scholarly journals Remodeling of the Caenorhabditis elegans non-coding RNA transcriptome by heat shock

2019 ◽  
Vol 47 (18) ◽  
pp. 9829-9841 ◽  
Author(s):  
William P Schreiner ◽  
Delaney C Pagliuso ◽  
Jacob M Garrigues ◽  
Jerry S Chen ◽  
Antti P Aalto ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Heat Shock ◽  
Elevated Temperatures ◽  
Transcriptional Response ◽  
Heat Shock Factor 1 ◽  
Protein Coding ◽  
Repeat Elements ◽  
Cellular Survival ◽  
Non Coding Rna ◽  
Shock Proteins

Abstract Elevated temperatures activate a heat shock response (HSR) to protect cells from the pathological effects of protein mis-folding, cellular mis-organization, organelle dysfunction and altered membrane fluidity. This response includes activation of the conserved transcription factor heat shock factor 1 (HSF-1), which binds heat shock elements (HSEs) in the promoters of genes induced by heat shock (HS). The upregulation of protein-coding genes (PCGs), such as heat shock proteins and cytoskeletal regulators, is critical for cellular survival during elevated temperatures. While the transcriptional response of PCGs to HS has been comprehensively analyzed in a variety of organisms, the effect of this stress on the expression of non-coding RNAs (ncRNAs) has not been systematically examined. Here we show that in Caenorhabditis elegans HS induces up- and downregulation of specific ncRNAs from multiple classes, including miRNA, piRNA, lincRNA, pseudogene and repeat elements. Moreover, some ncRNA genes appear to be direct targets of the HSR, as they contain HSF-1 bound HSEs in their promoters and their expression is regulated by this factor during HS. These results demonstrate that multiple ncRNA genes respond to HS, some as direct HSF-1 targets, providing new candidates that may contribute to organismal survival during this stress.

Regulation of gene expression in corn (Zea mays L.) by heat shock

1982 ◽  
Vol 60 (5) ◽  
pp. 569-579 ◽  
Author(s):  
Chris L. Baszczynski ◽  
David B. Walden ◽  
Burr G. Atkinson
Keyword(s):  
Zea Mays ◽  
Heat Shock ◽  
Elevated Temperatures ◽  
Zea Mays L ◽  
Regulation Of Gene Expression ◽  
Relative Mass ◽  
Two Dimensional ◽  
Higher Plant ◽  
Primary Roots ◽  
New Synthesis

Subjecting 5-day-old plumules of corn (Zea mays L.) to elevated temperatures for brief periods of time causes the pattern of protein synthesis to shift from the production of a broad spectrum of proteins to the new and (or) enhanced synthesis of a small number of heat-shock polypeptides (HSPs). Most notable is the depressed synthesis of a major polypeptide (relative mass (Mr) = 93 000 and isoelectric point = 8.0) normally made at 27 °C and the enhanced and (or) new synthesis of polypeptides with Mrs of 108 000, 89 000, 84 000, 76 000, 73 000, and 18 000, following 1 h of heat shock. These six HSPs resolve into 18 spots by two-dimensional fluorographic analysis. The induction of the HSPs requires temperatures at or exceeding 35 °C for detectable synthesis. Some of the HSPs are synthesized following only 15 min at 41 °C and synthesis of all HSPs is observed within 120 min following heat shock. Recovery from heat shock is rapid; after 6 to 8 h at 27 °C following heat shock, the polypeptide pattern is indistinguishable from me control. Extracts from individual heat-shocked shoots produced polypeptide synthetic patterns identical to those from extracts from 20 shoots, regardless of whether single shoots were intact or excised during labelling. Single 5-day-old primary roots exhibited polypeptide synthetic patterns and responded to heat shock in a manner similar to shoots. This is the first demonstration of the induction of heat-shock polypeptides in a whole, intact higher plant.

scholarly journals Remodeling of the C. elegans Non-coding RNA Transcriptome by Heat Shock

2019 ◽  
Author(s):  
William P. Schreiner ◽  
Delaney C. Pagliuso ◽  
Jacob M. Garrigues ◽  
Jerry S. Chen ◽  
Antti P. Aalto ◽  
...  
Keyword(s):  
Heat Shock ◽  
Elevated Temperatures ◽  
Transcriptional Response ◽  
Heat Shock Factor 1 ◽  
Protein Coding ◽  
Repeat Elements ◽  
Cellular Survival ◽  
C Elegans ◽  
Non Coding Rna ◽  
Shock Proteins

ABSTRACTElevated temperatures activate a Heat Shock Response (HSR) to protect cells from the pathological effects of protein mis-folding, cellular mis-organization, organelle dysfunction and altered membrane fluidity. This response includes activation of the conserved transcription factor Heat Shock Factor 1 (HSF-1), which binds Heat Shock Elements (HSEs) in the promoters of genes induced by heat shock (HS). The up-regulation of protein-coding genes (PCGs), such as Heat Shock Proteins (HSPs) and cytoskeletal regulators, is critical for cellular survival during elevated temperatures. While the transcriptional response of PCGs to heat shock has been comprehensively analyzed in a variety of organisms, the effect of this stress on the expression of non-coding RNAs (ncRNAs) has not been systematically examined. Here we show that in Caenorhabditis elegans HS induces up- and down-regulation of specific ncRNAs from multiple classes, including miRNA, piRNA, lincRNA, pseudogene, and repeat elements. Moreover, some ncRNA genes appear to be direct targets of the HSR, as they contain HSF-1 bound HSEs in their promoters and their expression is regulated by this factor during HS. These results demonstrate that multiple ncRNA genes respond to HS, some as direct HSF-1 targets, providing new candidates that may contribute to organismal survival during this stress.

scholarly journals A thermo-responsive plasmid for biconditional protein expression

2018 ◽  
Author(s):  
Agathe Lermant ◽  
Alicia Magnanon ◽  
Alexandra Silvain ◽  
Paul Lubrano ◽  
Marie Lhuissier ◽  
...  
Keyword(s):  
Heat Shock ◽  
Translational Control ◽  
Cold Shock ◽  
Regulatory Sequence ◽  
Temperature Threshold ◽  
Temperature Sensitive ◽  
Regulatory Sequences ◽  
Lambda Phage ◽  
Single Plasmid ◽  
Temperature Ranges

AbstractHere we develop a temperature sensitive expression vector that allows the selective production of distinct proteins over different temperature ranges with a single plasmid. We use theE. colicold shock translational control system (the cspA 5’Untranslated Transcribed Region - UTR) to drive the expression of a desired protein below a certain temperature threshold, and the lambda phage pL/cI857 transcriptional repressor system to drive the expression of a different protein above a certain temperature threshold. In this developmental work we use the chromogenic reporter proteins amilCP (blue chromoprotein) and monomeric red fluorescent protein (mRFP) to assess the function of the thermo-sensitive regulatory sequences over the desired temperature ranges. Our results show temperature dependent response of the cold shock regulatory sequence. However, our sequence design for the heat shock regulatory sequence did not give the intended result. The integration of these two temperature sensitive elements into a single plasmid awaits the re-design of the heat shock sequence.

scholarly journals Cell Cycle-Dependent Binding of Yeast Heat Shock Factor to Nucleosomes

2000 ◽  
Vol 20 (17) ◽  
pp. 6435-6448 ◽  
Author(s):  
Christina Bourgeois Venturi ◽  
Alexander M. Erkine ◽  
David S. Gross
Keyword(s):  
Heat Shock ◽  
Nuclear Dna ◽  
Heat Shock Factor ◽  
Binding Activity ◽  
S Phase ◽  
Regulatory Sequences ◽  
Prevailing Paradigm ◽  
Cycle Dependent ◽  
Gain Access

ABSTRACT In the nucleus, transcription factors must contend with the presence of chromatin in order to gain access to their cognate regulatory sequences. As most nuclear DNA is assembled into nucleosomes, activators must either invade a stable, preassembled nucleosome or preempt the formation of nucleosomes on newly replicated DNA, which is transiently free of histones. We have investigated the mechanism by which heat shock factor (HSF) binds to target nucleosomal heat shock elements (HSEs), using as our model a dinucleosomal heat shock promoter (hsp82-ΔHSE1). We find that activated HSF cannot bind a stable, sequence-positioned nucleosome in G1-arrested cells. It can do so readily, however, following release from G1 arrest or after the imposition of either an early S- or late G2-phase arrest. Surprisingly, despite the S-phase requirement, HSF nucleosomal binding activity is restored in the absence of hsp82 replication. These results contrast with the prevailing paradigm for activator-nucleosome interactions and implicate a nonreplicative, S-phase-specific event as a prerequisite for HSF binding to nucleosomal sites in vivo.

Exogenous heat shock protein HSP70 suppresses bacterial pathogen-induced activation of human neutrophils

2010 ◽  
Vol 435 (1) ◽  
pp. 316-319 ◽  
Author(s):  
M. M. Yurinskaya ◽  
M. B. Evgen’ev ◽  
O. Yu. Antonova ◽  
M. G. Vinokurov
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Bacterial Pathogen ◽  
Human Neutrophils ◽  
Heat Shock Protein Hsp70

Identification of an upstream regulatory sequence that mediates the transcription of mox genes in Methylobacterium extorquens AM1

Microbiology ◽  
2005 ◽  
Vol 151 (11) ◽  
pp. 3723-3728 ◽  
Author(s):  
Meng Zhang ◽  
Kelly A. FitzGerald ◽  
Mary E. Lidstrom
Keyword(s):  
Promoter Activity ◽  
Site Directed Mutagenesis ◽  
Regulatory Sequence ◽  
Methylobacterium Extorquens ◽  
Promoter Regions ◽  
Enhancer Element ◽  
Conserved Sequence ◽  
Normal Expression ◽  
Genetic Constructs ◽  
Transcriptional Fusions

A multiple A-tract sequence has been identified in the promoter regions for the mxaF, pqqA, mxaW, mxbD and mxcQ genes involved in methanol oxidation in Methylobacterium extorquens AM1, a facultative methylotroph. Site-directed mutagenesis was exploited to delete or change this conserved sequence. Promoter-xylE transcriptional fusions were used to assess promoter activity in these mutants. A fiftyfold drop in the XylE activity was observed for the mxaF and pqqA promoters without this sequence, and a five- to sixfold drop in the XylE activity was observed for the mxbD and mxcQ promoters without this sequence. Mutants were generated in the chromosomal copies in which this sequence was either deleted or altered, and these mutants were unable to grow on methanol. When one of these sequences was added to Plac of Escherichia coli, which is a weak constitutive promoter in M. extorquens AM1, the activity increased two- to threefold. These results suggest that this sequence is essential for normal expression of these genes in M. extorquens AM1, and may serve as a general enhancer element for genetic constructs in this bacterium.

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