Bacterial Heat Shock Protein Activity

Maleki, Farajollah; Khosravi, Afra; Nasser, Ahmad; Taghinejad, Hamid; Azizian, Mitra

doi:10.7860/jcdr/2016/14568.7444

Cited by 53 publications

(44 citation statements)

References 35 publications

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“…s 32 is a transcriptional activator that recognizes the heat shock promoter at heat shock-related genes [26,27] …”

Section: Regulation Of Hsp70mentioning

confidence: 99%

Role and mechanism of the Hsp70 molecular chaperone machines in bacterial pathogens

Ghazaei

2017

Journal of Medical Microbiology

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Heat shock proteins are highly conserved, stress-inducible, ubiquitous proteins that maintain homeostasis in both eukaryotes and prokaryotes. Hsp70 proteins belong to the heat shock protein family and enhance bacterial survival in hostile environments. Hsp70, known as DnaK in prokaryotes, supports numerous processes such as the assembly and disassembly of protein complexes, the refolding of misfolded and clustered proteins, membrane translocation and the regulation of regulatory proteins. The chaperone-based activity of Hsp70 depends on dynamic interactions between its two domains, known as the ATPase domain and the substrate-binding domain. It also depends on interactions between these domains and other co-chaperone molecules such as the Hsp40 protein family member DnaJ and nucleotide exchange factors. DnaJ is the primary chaperone that interacts with nascent polypeptide chains and functions to prevent their premature release from the ribosome and misfolding before it is targeted by DnaK. Adhesion of bacteria to host cells is mediated by both host and bacterial Hsp70. Following infection of the host, bacterial Hsp70 (DnaK) is in a position to initiate bacterial survival processes and trigger an immune response by the host. Any mutations in the dnaK gene have been shown to decrease the viability of bacteria inside the host. This review will give insights into the structure and mechanism of Hsp70 and its role in regulating the protein activity that contributes to pathogenesis.

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“…s 32 is a transcriptional activator that recognizes the heat shock promoter at heat shock-related genes [26,27] …”

Section: Regulation Of Hsp70mentioning

confidence: 99%

Role and mechanism of the Hsp70 molecular chaperone machines in bacterial pathogens

Ghazaei

2017

Journal of Medical Microbiology

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“…The DnaK/DnaJ/GrpE chaperone system enables bacterial cells to respond to elevated temperature (reviewed in (22)). Sodalis’s genome encodes proteins annotated as DnaK, DnaJ, and GrpE (33).…”

Section: Resultsmentioning

confidence: 99%

“…Stabilization and refolding of denatured proteins via protein chaperones comprise mechanisms that bacteria use to combat thermal stress at elevated temperatures. One of the major chaperone systems is the ATP-dependent DnaK system, which also includes the co-chaperone DnaJ and the nucleotide exchange factor GrpE (reviewed in (21, 22)). DnaK homologues are distributed across all three branches of life.…”

Section: Introductionmentioning

confidence: 99%

Thermal stress responses of Sodalis glossinidius, an indigenous bacterial symbiont of hematophagous tsetse flies

Roma

D’Souza

Somers

et al. 2019

Preprint

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Tsetse flies (Diptera: Glossinidae) house a taxonomically diverse microbiota that includes environmentally acquired bacteria, maternally transmitted symbiotic bacteria, and pathogenic African trypanosomes. Sodalis glossinidius, which is a facultative symbiont that resides intra and extracellularly within multiple tsetse tissues, has been implicated as a mediator of trypanosome infection establishment in the fly’s gut. Tsetse’s gut-associated population of Sodalis are subjected to marked temperature fluctuations each time their ectothermic fly host imbibes vertebrate blood. The molecular mechanisms that Sodalis employs to deal with this heat stress are unknown. In this study, we examined the thermal tolerance and heat shock response of Sodalis. When grown on BHI agar plates, the bacterium exhibited the most prolific growth at 25°C, and did not grow at temperatures above 30°C. Growth on BHI agar plates at 31°C was dependent on either the addition of blood to the agar or reduction in oxygen levels. Sodalis was viable in liquid cultures for 24 hours at 30°C, but began to die upon further exposure. The rate of death increased with increased temperature. Similarly, Sodalis was able to survive for 48 hours within tsetse flies housed at 30°C, while a higher temperature (37°C) was lethal. Sodalis’ genome contains homologues of the heat shock chaperone protein-encoding genes dnaK, dnaJ, and grpE, and their expression was up-regulated in thermally stressed Sodalis, both in vitro and in vivo within tsetse flies. Arrested growth of E. coli dnaK, dnaJ, or grpE mutants under thermal stress was reversed when the cells were transformed with a low copy plasmid that encoded the Sodalis homologues of these genes. The information contained in this study provides insight into how arthropod vector enteric commensals, many of which mediate their host’s ability to transmit pathogens, mitigate heat shock associated with the ingestion of a blood meal.AUTHOR SUMMARYMicroorganisms associated with insects must cope with fluctuating temperatures. Because symbiotic bacteria influence the biology of their host, how they respond to temperature changes will have an impact on the host and other microorganisms in the host. The tsetse fly and its symbionts represent an important model system for studying thermal tolerance because the fly feeds exclusively on vertebrate blood and is thus exposed to dramatic temperature shifts. Tsetse flies house a microbial community that can consist of symbiotic and environmentally acquired bacteria, viruses, and parasitic African trypanosomes. This work, which makes use of tsetse’s commensal symbiont, Sodalis glossinidius, is significance because it represents the only examination of thermal tolerance mechanisms in a bacterium that resides indigenously within an arthropod disease vector. A better understanding of the biology of thermal tolerance in Sodalis provides insight into thermal stress survival in other insect symbionts and may yield information to help control vector-borne disease.

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“…These findings represent that CagA (or other gene within the cag pathogenicity island) enhances the TLR2 Moreover, HP-HSP60 acts as a potent immunogen that stimulates human monocytes/macrophages and gastric epithelial cells to release pro-inflammatory cytokines such as IL-1, IL-6, IL-8 and TNF-α [92]. The antibody against HP-HSP60 is found in a high frequency of H. pylori-infected patients [93]. HSP60 plays a prominent role in the induction of mucosal inflammation, gastric atrophy and gastric MALT lymphoma [94].…”

Section: Accepted Manuscriptmentioning

confidence: 90%

“…response either directly or by regulating the expression of other TLR2 ligands on H. pylori.The binding of TLR2 to H. pylori 60 kDa heat-shock proteinThe 60 kDa heat-shock protein of H. pylori (HP-HSP60) is one of the most abundant proteins of H. pylori which is expressed on the surface of bacteria and plays a role in the attachment of bacteria to the gastric epithelial cells[92,93].…”

mentioning

confidence: 99%

Toll-like receptor 2: An important immunomodulatory molecule during Helicobacter pylori infection

et al. 2017

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Bacterial Heat Shock Protein Activity

Cited by 53 publications

References 35 publications

Role and mechanism of the Hsp70 molecular chaperone machines in bacterial pathogens

Role and mechanism of the Hsp70 molecular chaperone machines in bacterial pathogens

Thermal stress responses of Sodalis glossinidius, an indigenous bacterial symbiont of hematophagous tsetse flies

Toll-like receptor 2: An important immunomodulatory molecule during Helicobacter pylori infection

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