scholarly journals Biological Characterization of Plasmodium falciparum Mitochondrial Heat Shock Protein PfHsp70-3: Possible Involvement in Malaria Pathogenesis

2021 ◽  
Vol 47 (4) ◽  
pp. 1338-1351
Author(s):  
David O. Nyakundi ◽  
Aileen Boshoff
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Sub Saharan Africa ◽  
Parasite Development ◽  
Mosquito Vector ◽  
Heat Shocks ◽  
Febrile Episodes ◽  
Shock Proteins ◽  
Mitochondrial Heat Shock Protein

Malaria remains a global health burden accounting for many deaths and illnesses in sub-Saharan Africa notwithstanding many decades of research on the disease. P. falciparum, the causative agent of the most fatal form of malaria, expresses a repertoire of heat shock proteins (Hsp) that cushion the parasite against heat shocks as it shuttles between extreme temperatures in human and mosquito vector hosts. By so doing, such proteins promote parasite’s cytoprotection, survival and pathogenesis. Heat shock proteins are named according to their molecular weights and there are six P. falciparum Hsp70 (PfHsp70) found in various cell compartments with mitochondrial putative PfHsp70-3. Using indirect immunofluorescence, this study established mitochondrial localization of PfHsp70-3 though some more confirmatory studies would be needed in the future. PfHsp70-3 was found to be heat inducible and expressed during all stages of the intra-erythrocytic cycle of parasite development. This could be an indication of PfHsp70-3’s involvement in the infectivity process of P. falciparum by helping the parasite to resist heat shocks during malaria febrile episodes. Generally, the data obtained in this study will enhance the existing knowledge on the biology of P. falciparum mitochondrial heat shock protein functions and open possible avenues for targeting the specificity between PfHsp70-3 and its co-chaperones for drug development. Keywords: Malaria, P. falciparum, Heat shock proteins, PfHsp70-3, pathogenesis

scholarly journals Cross-priming of minor histocompatibility antigen-specific cytotoxic T cells upon immunization with the heat shock protein gp96.

1995 ◽  
Vol 182 (3) ◽  
pp. 885-889 ◽  
Author(s):  
D Arnold ◽  
S Faath ◽  
H Rammensee ◽  
H Schild
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Donor Cell ◽  
Class I ◽  
Heat Shock Protein Gp96 ◽  
Shock Proteins

Vaccination of mice with heat shock proteins isolated from tumor cells induces immunity to subsequent challenge with those tumor cells the heat shock protein was isolated from but not with other tumor cells (Udono, H., and P.K. Srivastava. 1994. J. Immunol. 152:5398-5403). The specificity of this immune response is caused by tumor-derived peptides bound to the heat shock proteins (Udono., H., and P.K. Srivastava. 1993. J. Exp. Med. 178:1391-1396). Our experiments show that a single immunization with the heat shock protein gp96 isolated from beta-galactosidase (beta-gal) expressing P815 cells (of DBA/2 origin) induces cytotoxic T lymphocytes (CTLs) specific for beta-gal, in addition to minor H antigens expressed by these cells. CTLs can be induced in mice that are major histocompatibility complex (MHC) identical to the gp96 donor cells (H-2d) as well as in mice with a different MHC (H-2b). Thus gp96 is able to induce "cross priming" (Matzinger, P., and M.J. Bevan. 1977. Cell. Immunol. 33:92-100), indicating that gp96-associated peptides are not limited to the MHC class I ligands of the gp96 donor cell. Our data confirm the notion that samples of all cellular antigens presentable by MHC class I molecules are represented by peptides associated with gp96 molecules of that cell, even if the fitting MHC molecule is not expressed. In addition, we extend previous reports on the in vivo immunogenicity of peptides associated gp96 molecules to two new groups of antigens, minor H antigens, and proteins expressed in the cytosol.

Progesterone enhances target gene transcription by receptor free of heat shock proteins hsp90, hsp56, and hsp70

1991 ◽  
Vol 11 (10) ◽  
pp. 4998-5004
Author(s):  
M K Bagchi ◽  
S Y Tsai ◽  
M J Tsai ◽  
B W O'Malley
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Steroid Hormone ◽  
Receptor Activation ◽  
Target Cells ◽  
Dependent Manner ◽  
Shock Proteins

Steroid receptors regulate transcription of target genes in vivo and in vitro in a steroid hormone-dependent manner. Unoccupied progesterone receptor exists in the low-salt homogenates of target cells as a functionally inactive 8 to 10S complex with several nonreceptor components such as two molecules of 90-kDa heat shock protein (hsp90), a 70-kDa heat shock protein (hsp70), and a 56-kDa heat shock protein (hsp56). Ligand-induced dissociation of receptor-associated proteins such as hsp90 has been proposed as the mechanism of receptor activation. Nevertheless, it has not been established whether, beyond release of heat shock proteins, the steroidal ligand plays a role in modulating receptor activity. To examine whether the release of these nonreceptor proteins from receptor complex results in a constitutively active receptor, we isolated an unliganded receptor form essentially free of hsp90, hsp70, and hsp56. Using a recently developed steroid hormone-responsive cell-free transcription system, we demonstrate for the first time that the dissociation of heat shock proteins is not sufficient to generate a functionally active receptor. This purified receptor still requires hormone for high-affinity binding to a progesterone response element and for efficient transcriptional activation of a target gene. When an antiprogestin, Ru486, is bound to the receptor, it fails to promote efficient transcription. We propose that in the cell, in addition to the release of receptor-associated inhibitory proteins, a distinct hormone-mediated activation event must precede efficient gene activation.

A family of related proteins is encoded by the major Drosophila heat shock gene family

1982 ◽  
Vol 2 (3) ◽  
pp. 286-292
Author(s):  
S C Wadsworth
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Sodium Dodecyl ◽  
Heat Shock Gene ◽  
Partial Digestion ◽  
Shock Gene ◽  
Shock Proteins

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 dodecyl sulfate-polyacrylamide gels. A comparison of the pattern of this group of proteins synthesized in vivo during a 5-min pulse or during continuous labeling indicates that the 72-75K proteins are probably not kinetic precursors to the major 70K heat shock protein. Partial digestion products generated with V8 protease indicated that the 70-75K heat shock proteins are closely related, but that there are clear differences between them. The partial digestion patterns obtained from heat shock proteins from the Kc cell line and from the Oregon R strain of Drosophila melanogaster are very similar. Genetic analysis of the patterns of 70-75K heat shock protein synthesis indicated that the genes encoding at least two of the three 72-75K heat shock proteins are located outside of the major 87A and 87C puff sites.

scholarly journals Small Molecule Inhibitors Targeting the Heat Shock Protein System of Human Obligate Protozoan Parasites

2019 ◽  
Vol 20 (23) ◽  
pp. 5930 ◽  
Author(s):  
Zininga ◽  
Shonhai
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Small Molecule ◽  
Molecular Chaperones ◽  
Small Molecule Inhibitors ◽  
Protozoan Parasites ◽  
Obligate Intracellular ◽  
Human Host ◽  
Shock Proteins

Obligate protozoan parasites of the kinetoplastids and apicomplexa infect human cells to complete their life cycles. Some of the members of these groups of parasites develop in at least two systems, the human host and the insect vector. Survival under the varied physiological conditions associated with the human host and in the arthropod vectors requires the parasites to modulate their metabolic complement in order to meet the prevailing conditions. One of the key features of these parasites essential for their survival and host infectivity is timely expression of various proteins. Even more importantly is the need to keep their proteome functional by maintaining its functional capabilities in the wake of physiological changes and host immune responses. For this reason, molecular chaperones (also called heat shock proteins)—whose role is to facilitate proteostasis—play an important role in the survival of these parasites. Heat shock protein 90 (Hsp90) and Hsp70 are prominent molecular chaperones that are generally induced in response to physiological stress. Both Hsp90 and Hsp70 members are functionally regulated by nucleotides. In addition, Hsp70 and Hsp90 cooperate to facilitate folding of some key proteins implicated in cellular development. In addition, Hsp90 and Hsp70 individually interact with other accessory proteins (co-chaperones) that regulate their functions. The dependency of these proteins on nucleotide for their chaperone function presents an Achille’s heel, as inhibitors that mimic ATP are amongst potential therapeutic agents targeting their function in obligate intracellular human parasites. Most of the promising small molecule inhibitors of parasitic heat shock proteins are either antibiotics or anticancer agents, whose repurposing against parasitic infections holds prospects. Both cancer cells and obligate human parasites depend upon a robust protein quality control system to ensure their survival, and hence, both employ a competent heat shock machinery to this end. Furthermore, some inhibitors that target chaperone and co-chaperone networks also offer promising prospects as antiparasitic agents. The current review highlights the progress made so far in design and application of small molecule inhibitors against obligate intracellular human parasites of the kinetoplastida and apicomplexan kingdoms.

scholarly journals Heat shock proteins and heat shock protein-antibody complexes in placental tissues

1999 ◽  
Vol 7 (4) ◽  
pp. 180-185 ◽  
Author(s):  
M. Ziegert ◽  
S.S. Witkin ◽  
I. Sziller ◽  
H. Alexander ◽  
E. Brylla ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Shock Proteins

The expression of temperature-stress proteins in a desert cactus (Opuntia ficus indica)

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 940-943 ◽  
Author(s):  
Daryl J. Somers ◽  
Randal W. Giroux ◽  
W. Gary Filion
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Stress Proteins ◽  
Protein S ◽  
Protein Families ◽  
Opuntia Ficus Indica ◽  
Stress Acclimation ◽  
Molecular Masses ◽  
Shock Proteins

Opuntia ficus indica roots grown hydroponically at 20 or 30 °C were subjected to a range of heat-shock temperatures as high as 50 °C for 2 h. Roots grown at 30 °C sustained a greater level of total protein synthesis than did 20 °C-grown roots following heat-shock treatments ≥ 45 °C. The 30 °C-grown roots synthesized 31 families of heat-shock proteins between 38 and 47 °C in comparison with 20 °C-grown roots, which synthesized 19 families of heat-shock proteins at 45 °C. In both groups of roots, the heat-shock response was dominated equally by the 71–75 and a 62 kDa heat-shock protein families. In addition, the 20 °C-grown roots expressed 11 families of cold-shock proteins following 2 h at 4 °C, five of which had similar relative molecular masses to heat-shock protein families. There were numerous qualitative differences in the heat shock protein profiles between the roots grown at 20 and 30 °C; the 30 °C-grown roots expressed several unique heat shock protein families.Key words: heat-shock protein(s), cactus, thermal stress, acclimation.

Heat shock protein synthesis over time in infective Trichinella spiralis larvae raised in suboptimal culture conditions

2004 ◽  
Vol 78 (3) ◽  
pp. 243-247 ◽  
Author(s):  
J. Martinez ◽  
J. Perez-Serrano ◽  
W.E. Bernadina ◽  
I. Rincon ◽  
F. Rodriguez-Caabeiro
Keyword(s):  
Cell Death ◽  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Trichinella Spiralis ◽  
Culture Conditions ◽  
Induce Stress ◽  
Shock Proteins ◽  
Over Time

AbstractChanges in the viability, infectivity and heat shock protein (Hsp) levels are reported in Trichinella spiralis first stage larvae (L1) stored in 199 medium for up to seven days at 37°C. These conditions induce stress that the larvae, eventually, cannot overcome. After three days of storage, the infectivity and viability were unchanged, although higher Hsp70 levels were observed. After this time, larvae gradually lost viability and infectivity, coinciding with a decrease in Hsp70 and Hsp90 and an increase in actin (a housekeeping protein). In addition, a possibly inducible heat shock protein, Hsp90i, appeared as constitutive Hsp90 disappeared. No significant changes in Hsp60 levels were detected at any time. These results suggest that heat shock proteins initially try to maintain homeostasis, but on failing, may be involved in cell death.

scholarly journals Immune Sensitization to the 60 kD Heat Shock Protein and Pregnancy Outcome

1997 ◽  
Vol 5 (2) ◽  
pp. 154-157 ◽  
Author(s):  
A. Neuer ◽  
S. Spandorfer ◽  
P. Giraldo ◽  
C. Mele ◽  
H. C. Liu ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Pregnancy Outcome ◽  
Embryo Development ◽  
Mouse Embryo ◽  
Implantation Failure ◽  
Genital Tract Infection ◽  
Shock Proteins

Heat shock proteins are highly conserved proteins present in organisms ranging from bacteria to man. They are both dominant microbial immunogens and among the first proteins produced during mammalian embryo development. Since bacterial and human heat shock proteins share a high degree of amino acid sequence homology, it has been suggested that sensitization to bacterial heat shock proteins during an infection may result in autoimmunity to human heat shock proteins. Infertile couples seeking in vitro fertilization (IVF) may have been previously sensitized to bacterial heat shock proteins as a consequence of an asymptomatic upper genital tract infection. Due to daily clinical monitoring and precisely timed fertilization these patients are an ideal study group to investigate the effect of prior sensitization to heat shock proteins on preimplantation embryo development and implantation failure. Immune sensitization at the level of the cervix to the 60 kD heat shock protein (hsp60) has been associated with implantation failure in some IVF patients. Similarly, the highest prevalence of circulating hsp60 antibodies among IVF patients was found in the sera of women whose embryos failed to develop in vitro. To more directly assess whether humoral immunity to hsp60 influenced in vitro embryo development, a mouse embryo culture model was established. Monoclonal antibody to mammalian hsp60 markedly impaired mouse embryo development in vitro. These data suggest that immune sensitization to human hsp60, possibly developed as a consequence of infection, may adversely affect pregnancy outcome in some patients.

Sign in / Sign up

Export Citation Format

Share Document