scholarly journals Cloning of the gene encoding peptide-binding protein 74 shows that it is a new member of the heat shock protein 70 family.

1993 ◽  
Vol 13 (6) ◽  
pp. 3598-3610 ◽  
Author(s):  
S Z Domanico ◽  
D C DeNagel ◽  
J N Dahlseid ◽  
J M Green ◽  
S K Pierce
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Antigen Processing ◽  
Peptide Binding ◽  
Sequence Information ◽  
Mrna Levels ◽  
Mature Protein ◽  
Hsp70 Mrna ◽  
Hsp70 Family

We have previously described peptide-binding proteins of 72 and 74 kDa (PBP72/74), which have been implicated as playing a role in antigen processing and are serologically related to the 70-kDa heat shock protein (hsp70) family. Here we report the cloning and sequencing of the cDNA encoding PBP74 in mice and in humans, accomplished by using amino acid sequence information obtained from the purified protein. We show that PBP74 is highly homologous to members of the hsp70 family but, significantly, is not identical to any known member of this family. Inspection of the cDNA nucleotide sequence indicates that it encodes a 46-residue N-terminal peptide which is not present in the mature protein. Transcription and translation in vitro of the PBP74 cDNA verified that it encodes a form of PBP74 which is larger than the mature protein. The presequence does not conform to known motifs for organelle-targeting sequences, and at present, its function is not known. By confocal microscopy, PBP74 was localized to cytoplasmic vesicles but not to the nucleus, mitochondria, or plasma membrane by using antibodies specific for the N-terminal 16 residues of PBP74. By RNA filter hybridization analysis, PBP74 mRNAs are detected in all cell types tested. Exposure of cells to heat shock does not result in an increase in the mRNA levels of PBP74, unlike the dramatic increase observed for the stress-inducible hsp70 mRNA. Thus, PBP74 appears to be a constitutive, new member of the hsp70 family.

scholarly journals Cloning of the gene encoding peptide-binding protein 74 shows that it is a new member of the heat shock protein 70 family

1993 ◽  
Vol 13 (6) ◽  
pp. 3598-3610
Author(s):  
S Z Domanico ◽  
D C DeNagel ◽  
J N Dahlseid ◽  
J M Green ◽  
S K Pierce
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Antigen Processing ◽  
Peptide Binding ◽  
Sequence Information ◽  
Mrna Levels ◽  
Mature Protein ◽  
Hsp70 Mrna ◽  
Hsp70 Family

We have previously described peptide-binding proteins of 72 and 74 kDa (PBP72/74), which have been implicated as playing a role in antigen processing and are serologically related to the 70-kDa heat shock protein (hsp70) family. Here we report the cloning and sequencing of the cDNA encoding PBP74 in mice and in humans, accomplished by using amino acid sequence information obtained from the purified protein. We show that PBP74 is highly homologous to members of the hsp70 family but, significantly, is not identical to any known member of this family. Inspection of the cDNA nucleotide sequence indicates that it encodes a 46-residue N-terminal peptide which is not present in the mature protein. Transcription and translation in vitro of the PBP74 cDNA verified that it encodes a form of PBP74 which is larger than the mature protein. The presequence does not conform to known motifs for organelle-targeting sequences, and at present, its function is not known. By confocal microscopy, PBP74 was localized to cytoplasmic vesicles but not to the nucleus, mitochondria, or plasma membrane by using antibodies specific for the N-terminal 16 residues of PBP74. By RNA filter hybridization analysis, PBP74 mRNAs are detected in all cell types tested. Exposure of cells to heat shock does not result in an increase in the mRNA levels of PBP74, unlike the dramatic increase observed for the stress-inducible hsp70 mRNA. Thus, PBP74 appears to be a constitutive, new member of the hsp70 family.

scholarly journals Calreticulin, a Peptide-binding Chaperone of the Endoplasmic Reticulum, Elicits Tumor- and Peptide-specific Immunity

1999 ◽  
Vol 189 (5) ◽  
pp. 797-802 ◽  
Author(s):  
Sreyashi Basu ◽  
Pramod K. Srivastava
Keyword(s):  
Endoplasmic Reticulum ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Antigen Processing ◽  
Peptide Binding ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Specific Immunity ◽  
Per Se

Calreticulin (CRT), a peptide-binding heat shock protein (HSP) of the endoplasmic reticulum (ER), has been shown previously to associate with peptides transported into the ER by transporter associated with antigen processing (Spee, P., and J. Neefjes. 1997. Eur. J. Immunol. 27: 2441–2449). Our studies show that CRT preparations purified from tumors elicit specific immunity to the tumor used as the source of CRT but not to an antigenically distinct tumor. The immunogenicity is attributed to the peptides associated with the CRT molecule and not to the CRT molecule per se. It is further shown that CRT molecules can be complexed in vitro to unglycosylated peptides and used to elicit peptide-specific CD8+ T cell response in spite of exogenous administration. These characteristics of CRT closely resemble those of HSPs gp96, hsp90, and hsp70, although CRT has no apparent structural homologies to them.

scholarly journals Overexpression of Mitochondrial Hsp70/Hsp75 Protects Astrocytes against Ischemic Injury in vitro

2007 ◽  
Vol 28 (5) ◽  
pp. 1009-1016 ◽  
Author(s):  
Ludmila A Voloboueva ◽  
Melissa Duan ◽  
YiBing Ouyang ◽  
John F Emery ◽  
Christian Stoy ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mitochondrial Membrane Potential ◽  
Heat Shock Protein 70 ◽  
Mitochondrial Membrane ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Hsp70 Family

Mitochondrial heat shock protein 70 (mtHsp70/Hsp75/Grp75/mortalin/TRAP-1/PBP74) is an essential mitochondrial chaperone and a member of the heat shock protein 70 (HSP70) family. Although many studies have shown the protective properties of overexpression of the cytosolic inducible member of the HSP70 family, Hsp72, few studies have investigated the protective potential of Hsp75 against ischemic injury. Mitochondria are one of the primary targets of ischemic injury in astrocytes. In this study, we analyzed the effects of Hsp75 overexpression on cellular levels of reactive oxygen species (ROS), mitochondrial membrane potential, ATP levels, and viability during the ischemia-like conditions of oxygen-glucose deprivation (OGD) or glucose deprivation (GD) in primary astrocytic cultures. We show that Hsp75 overexpression decreases ROS production and preserves mitochondrial membrane potential during GD, and preserves ATP levels and cell viability during OGD. These findings indicate that Hsp75 can provide protection against ischemia-like in vitro injury and suggest that it should be further studied as a potential candidate for protection against ischemic injury.

Direct interactions between molecular chaperones heat-shock protein (Hsp) 70 and Hsp40: yeast Hsp70 Ssa1 binds the extreme C-terminal region of yeast Hsp40 Sis1

2001 ◽  
Vol 361 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Xinguo QIAN ◽  
Wenbo HOU ◽  
Li ZHENGANG ◽  
Bingdong SHA
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Peptide Binding ◽  
Stable Complex ◽  
Amino Acid Residues ◽  
Docking Model ◽  
Upper Level ◽  
Lid Domain

Heat-shock protein 40 (Hsp40) enables Hsp70 to play critical roles in a number of cellular processes, such as protein folding, assembly, degradation and translocation in vivo. Hsp40 recognizes and binds non-native polypeptides and delivers them to Hsp70. Then Hsp40 stimulates the ATPase activity of Hsp70 to fold the polypeptides. By using yeast Hsp40 Sis1 and yeast Hsp70 Ssa1 as our model proteins, we found that the Sis1 peptide-binding fragment interacts directly with the full-length Ssa1 in vitro. Further studies showed that the C-terminal lid domain of Ssa1 could interact with Sis1 peptide-binding domain physically in vitro. The Sis1 peptide-binding fragment forms a stable complex with the Ssa1 C-terminal lid domain in solution. The interactions between these two proteins appear to be charge–charge interactions because high-ionic-strength buffer can dissociate the complex. Further mapping studies showed that the Sis1 peptide-binding fragment binds the extreme C-terminal 15 amino acid residues of Ssa1. A flexible glycine-rich region is followed by these 15 residues in the Ssa1 primary sequence. Atomic force microscopy of the Sis1–Ssa1 complex showed that only one end of the Ssa1 lid domain binds the Sis1 peptide-binding-fragment dimer at the upper level of the huge groove within the Sis1 dimer. Based on the data, we propose an ‘anchoring and docking’ model to illustrate the mechanisms by which Hsp40 interacts with Hsp70 and delivers the non-native polypeptide to Hsp70.

Expression and localisation of heat shock protein 70 in cultured bovine oocytes and embryos

Zygote ◽  
2001 ◽  
Vol 9 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Sheldon J. Kawarsky ◽  
W. Allan King
Keyword(s):  
Heat Stress ◽  
Elevated Temperature ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 70 ◽  
Laser Scanning Microscopy ◽  
Meiotic Spindle ◽  
Hsp70 Mrna ◽  
Bovine Oocytes

Effects of elevated in vitro temperature on in vitro produced early bovine embryos were analysed in order to determine its impact on the expression of heat shock protein 70 (hsp70). In vitro matured bovine oocytes, 2-cell and 8-cell embryos, and day 9 hatched blastocysts subjected to control and elevated temperature conditions were analysed by semiquantitative reverse transcription polymerase chain reaction methods for hsp70 mRNA expression. Results revealed the expression of hsp70 mRNA under control conditions and that early embryos can respond to heat stress by transcribing hsp70 mRNA. Confocal laser scanning microscopy used to localise the hsp70 protein in oocytes and embryos revealed that the distribution of hsp70 in the ooplasm of immature and mature oocytes is unaffected by exposure to elevated temperatures and that this protein was closely associated with the meiotic spindle, indicating its possible role in stabilising this structure. In 8-cell embryos derived under control conditions, hsp70 was evenly distributed in the cytoplasm but appeared as aggregates in some embryos exposed to elevated temperature. In heat-stressed hatched blastocysts, a more even distribution was noted following heat stress relative to corresponding controls, indicating their competence to respond to elevated temperature.

scholarly journals Two distinct classes of co-chaperones compete for the EEVD motif in heat shock protein 70 (Hsp70) to tune its activity

2021 ◽  
Author(s):  
Oleta T Johnson ◽  
Cory M Nadel ◽  
Emma C Carroll ◽  
Taylor Arhar ◽  
Jason E Gestwicki
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Protein Interactions ◽  
Heat Shock Protein 70 ◽  
Protein Protein Interactions ◽  
Hsp70 Family ◽  
C Terminus ◽  
Class B ◽  
Chaperone Binding

Chaperones of the heat shock protein 70 (Hsp70) family engage in protein-protein interactions (PPIs) with many co-chaperones. One hotspot for co-chaperone binding is the EEVD motif that is found at the extreme C-terminus of cytoplasmic Hsp70s. This motif is known to bind tetratricopeptide repeat (TPR) domain co-chaperones, such as the E3 ubiquitin ligase CHIP, and Class B J-domain proteins (JDPs), such as DnaJB4. Although complexes between Hsp70-CHIP and Hsp70-DnaJB4 are both important for chaperone functions, the molecular determinants that dictate the competition between these co-chaperones are not clear. Using a collection of EEVD-derived peptides, we find that DnaJB4 binds to the IEEVD motif of Hsp70s, but not the related MEEVD motif of cytoplasmic Hsp90s. Then, we explored which residues are critical for binding to CHIP and DnaJB4, revealing that they rely on some shared features of the IEEVD motif, such as the C-terminal carboxylate. However, they also had unique preferences, especially at the isoleucine position. Finally, we observed a functionally important role for competition between CHIP and DnaJB4 in vitro, as DnaJB4 can limit the ubiquitination activity of the Hsp70-CHIP complex, while CHIP suppresses the chaperone activities of Hsp70-DnaJB4. Together, these results suggest that the EEVD motif has evolved to support diverse PPIs, such that competition between co-chaperones could help guide whether Hsp70-bound proteins are folded or degraded.

76 EFFECT OF CULTURE METHOD ON THE mRNA EXPRESSION BEFORE AND AFTER CRYOPRESERVATION IN BOVINE BLASTOCYSTS

2011 ◽  
Vol 23 (1) ◽  
pp. 143
Author(s):  
A. Kuzmany ◽  
V. Havlicek ◽  
C. Wrenzycki ◽  
S. Wilkening ◽  
G. Brem ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mrna Expression ◽  
Dna Methyltransferase ◽  
Mrna Levels ◽  
Solute Carrier Family ◽  
Production Methods ◽  
Aquaporin 3 ◽  
Solute Carrier

Blastocyst mRNA expression and cryopreservability are thought to be suitable indicators of embryo quality and developmental competence and have been shown to be affected by production methods and culture systems. The aim of the present study was to assess cryosurvival and levels of mRNA expression of selected genes [occludin, desmocollin 2, solute carrier family 2 member 3 (formerly glucose transporter 3), BAX, BCL xL, heat shock protein A1A (formerly heat shock protein 70.1), aquaporin 3, and DNA methyltransferase 1a] of bovine blastocysts derived by 4 different, established culture methods [in vitro production (IVP); multiple-ovulation embryo transfer (MOET); transfer into the heifer oviducts of gametes (GIFT); or in vitro derived cleaved stage embryos (Days 2–7)]. Linear models were used for the comparison of the relative abundances of the blastocyst mRNA transcripts. Separate 1-way ANOVA were used. The production methods were used as factors, except for the comparisons between pre- and post-cryopreservation, where 2-way ANOVA were used. The level of significance was set at P ≤ 0.05. A significant difference in re-expansion rates was found only at 24 h post-thawing, with significantly higher rates in blastocysts produced in vitro compared to embryos of the Days 2–7 group. Levels of mRNA expression were assessed using RT-qPCR. Before cryopreservation of embryos, no significant inter-group differences were seen. However, significantly more desmocollin 2 mRNA expression was detected in embryos of the MOET group compared with blastocysts derived by the other production methods. Post-cryopreservation, blastocysts of 3 embryo production groups (IVP, MOET, Days 2–7) were available for analysis. Compared with levels of mRNA expression before cryopreservation, re-expanded blastocysts after cryopreservation showed a significant up-regulation of heat shock protein A1A transcripts in all groups, and of solute carrier family 2 member 3 transcripts only in the IVP-derived group. The BAX, BCL-xL, occludin, and desmocollin 2 were significantly up-regulated in embryos of the MOET and IVP groups after cryopreservation, as compared with their counterparts before cryopreservation. None of the culture groups showed any pre- v. post-cryopreservation differences in the aquaporin 3 and the DNA methyltransferase 1 mRNA levels. Blastocysts derived by transfer of in vitro derived cleaved stage embryos into the oviduct of synchronised heifers (Days 2–7) did not show any pre- v. post-cryopreservation differences in the mRNA levels of any of the assessed genes. These results merit further investigation. After the process of cryopreservation and thawing, re-expanded embryos of the MOET and IVP groups do increase their mRNA levels to prepare for hatching and further development.

Purification, crystallization and preliminary X-ray crystallographic studies of S. cerevisiae Hsp40 Sis1

1999 ◽  
Vol 55 (6) ◽  
pp. 1234-1236 ◽  
Author(s):  
Bingdong Sha ◽  
Douglas Cyr
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Atpase Activity ◽  
Molecular Chaperone ◽  
Molecular Chaperones ◽  
Heat Shock Protein 70 ◽  
Peptide Binding ◽  
X Ray ◽  
Cellular Processes

Heat-shock protein 70 (Hsp70), one of the major molecular chaperones, has been shown to play a central role in many cellular processes. Heat-shock protein 40 (Hsp40) works as a co-chaperone for Hsp70. Hsp40, bound by unfolded polypeptide, can interact directly with Hsp70 to stimulate the ATPase activity of Hsp70. Hsp40 can also bind to unfolded polypeptides and prevent them from aggregating in vitro, thus acting as an independent molecular chaperone. The S. cerevisiae Hsp40 Sis1 C-terminal peptide-binding domain has been crystallized. The crystals diffract to 2.7 Å and belong to space group P41212 or P43212 with a = 73.63, c = 80.16 Å. The structure determination by the MAD method is under way.

Expression of Heat Shock Protein 72 in Peritoneal Leukocytes is Induced by Peritoneal Dialysis

2007 ◽  
Vol 27 (3) ◽  
pp. 288-295 ◽  
Author(s):  
Lukasz Marzec ◽  
Tomasz Liberek ◽  
Michal Chmielewski ◽  
Ewa Bryl ◽  
Jacek M. Witkowski ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Peripheral Blood ◽  
Peritoneal Macrophages ◽  
Mrna Levels ◽  
Blood Monocytes ◽  
Heat Shock Protein 72 ◽  
Peritoneal Leukocytes

Background One of the main limitations of peritoneal dialysis (PD) is deterioration of functional and morphological characteristics of the peritoneum. This complication appears to be related to the low biocompatibility profile of PD fluids. Recently, induction of the heat shock protein (HSP) stress response was demonstrated in cultured human mesothelial cells exposed to PD fluid in vitro. We investigated whether expression of heat shock protein 72 (HSP-72) in peritoneal macrophages is induced upon exposure to PD fluid during continuous ambulatory PD. Methods Peritoneal leukocytes were isolated from 4-hour dwell dialysate; peripheral blood mononuclear cells (PBMC) and peripheral blood monocytes isolated from the same patients were used as a control. In separate experiments, PBMC from healthy individuals were exposed in vitro to different PD fluids or to culture media. Expression of HSP-72 was assessed by Western immunoblotting, flow cytometry, and reverse-transcription polymerase chain reaction analysis. Results Macrophages and leukocytes isolated from dialysis effluent expressed significantly increased HSP-72 and mRNA levels compared to blood monocytes and PBMC of the same patients. In vitro exposure of PBMC to fresh PD fluids resulted in significantly higher expression of HSP-72 compared to those incubated in culture medium. PBMC exposed in vitro to standard lactate-buffered dialysis fluids also expressed significantly more HSP-72 compared to cells exposed to bicarbonate/lactate-buffered fluids. Conclusion Our results indicate that exposure to PD fluids during dialysis triggers a shock response in peritoneal cells, which is manifested by significantly increased HSP-72 expression at both protein and mRNA levels. Analysis of this protein expression in peritoneal macrophages could be a new, convenient, and relevant way to assess the biocompatibility of PD fluids ex vivo.

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