Structural Transitions Accompanying the Activation of Peptide Binding to the Endoplasmic Reticulum Hsp90 Chaperone GRP94†

Biochemistry ◽  
1998 ◽  
Vol 37 (16) ◽  
pp. 5709-5719 ◽  
Author(s):  
Pamela A. Wearsch ◽  
Laura Voglino ◽  
Christopher V. Nicchitta
Keyword(s):  
Endoplasmic Reticulum ◽  
Peptide Binding ◽  
Structural Transitions ◽  
Hsp90 Chaperone

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 Ligand-induced Conformational Shift in the N-terminal Domain of GRP94, an Hsp90 Chaperone

2004 ◽  
Vol 279 (44) ◽  
pp. 46162-46171 ◽  
Author(s):  
Robert M. Immormino ◽  
D. Eric Dollins ◽  
Paul L. Shaffer ◽  
Karen L. Soldano ◽  
Melissa A. Walker ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Crystal Structures ◽  
Conformational Change ◽  
Atp Hydrolysis ◽  
Dna Gyrase ◽  
Regulatory Domain ◽  
Conformational Switch ◽  
Terminal Ligand ◽  
Conformational Rearrangement ◽  
Hsp90 Chaperone

GRP94 is the endoplasmic reticulum paralog of cytoplasmic Hsp90. Models of Hsp90 action posit an ATP-dependent conformational switch in the N-terminal ligand regulatory domain of the chaperone. However, crystal structures of the isolated N-domain of Hsp90 in complex with a variety of ligands have yet to demonstrate such a conformational change. We have determined the structure of the N-domain of GRP94 in complex with ATP, ADP, and AMP. Compared with theN-ethylcarboxamidoadenosine and radicicol-bound forms, these structures reveal a large conformational rearrangement in the protein. The nucleotide-bound form exposes new surfaces that interact to form a biochemically plausible dimer that is reminiscent of those seen in structures of MutL and DNA gyrase. Weak ATP binding and a conformational change in response to ligand identity are distinctive mechanistic features of GRP94 and suggest a model for how GRP94 functions in the absence of co-chaperones and ATP hydrolysis.

Identification and characterization of molecular interactions between glucose-regulated proteins (GRPs) mortalin/GRP75/peptide-binding protein 74 (PBP74) and GRP94

2001 ◽  
Vol 357 (2) ◽  
pp. 393-398 ◽  
Author(s):  
Syuichi TAKANO ◽  
Renu WADHWA ◽  
Youji MITSUI ◽  
Sunil C. KAUL
Keyword(s):  
Endoplasmic Reticulum ◽  
Mutational Analysis ◽  
Binding Protein ◽  
Peptide Binding ◽  
Cytoplasmic Vesicles ◽  
Endoplasmic Reticulum Protein ◽  
Cellular Compartments ◽  
Identification And Characterization

A heat-shock protein (hsp) 70 family member mortalin/glucose-regulated protein (GRP) 75/peptide-binding protein 74 (PBP74) has been localized to various cellular compartments including mitochondria, endoplasmic reticulum and cytoplasmic vesicles. Here we describe its interactions with an endoplasmic reticulum protein GRP94, a member of the hsp90 family of GRPs. Interactions were identified, confirmed and characterized by far-Western screening, in vivo reporter and co-immunoprecipitation assays. Interacting domains of the two proteins were also characterized by mutational analysis. Such interactions of these two GRPs may be important for function of either or both and therefore provide important information for further studies.

scholarly journals A systematic re-examination of processing of MHCI-bound antigenic peptide precursors by endoplasmic reticulum aminopeptidase 1

2020 ◽  
Vol 295 (21) ◽  
pp. 7193-7210 ◽  
Author(s):  
George Mavridis ◽  
Richa Arya ◽  
Alexander Domnick ◽  
Jerome Zoidakis ◽  
Manousos Makridakis ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Antigen Processing ◽  
Peptide Binding ◽  
Antigenic Peptide ◽  
Antigenic Peptides ◽  
Peptide Loading ◽  
Peptide Precursors ◽  
Peptide Dissociation ◽  
Endoplasmic Reticulum Aminopeptidase 1 ◽  
Computational Analyses

Endoplasmic reticulum aminopeptidase 1 (ERAP1) trims antigenic peptide precursors to generate mature antigenic peptides for presentation by major histocompatibility complex class I (MHCI) molecules and regulates adaptive immune responses. ERAP1 has been proposed to trim peptide precursors both in solution and in preformed MHCI-peptide complexes, but which mode is more relevant to its biological function remains controversial. Here, we compared ERAP1-mediated trimming of antigenic peptide precursors in solution or when bound to three MHCI alleles, HLA-B*58, HLA-B*08, and HLA-A*02. For all MHCI-peptide combinations, peptide binding onto MHCI protected against ERAP1-mediated trimming. In only a single MHCI-peptide combination, trimming of an HLA-B*08-bound 12-mer progressed at a considerable rate, albeit still slower than in solution. Results from thermodynamic, kinetic, and computational analyses suggested that this 12-mer is highly labile and that apparent on-MHC trimming rates are always slower than that of MHCI-peptide dissociation. Both ERAP2 and leucine aminopeptidase, an enzyme unrelated to antigen processing, could trim this labile peptide from preformed MHCI complexes as efficiently as ERAP1. A pseudopeptide analogue with high affinity for both HLA-B*08 and the ERAP1 active site could not promote the formation of a ternary ERAP1/MHCI/peptide complex. Similarly, no interactions between ERAP1 and purified peptide-loading complex were detected in the absence or presence of a pseudopeptide trap. We conclude that MHCI binding protects peptides from ERAP1 degradation and that trimming in solution along with the dynamic nature of peptide binding to MHCI are sufficient to explain ERAP1 processing of antigenic peptide precursors.

scholarly journals The peptide-binding activity of GRP94 is regulated by calcium

2007 ◽  
Vol 405 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Chhanda Biswas ◽  
Olga Ostrovsky ◽  
Catherine A. Makarewich ◽  
Sherry Wanderling ◽  
Tali Gidalevitz ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Binding Site ◽  
Peptide Binding ◽  
High Capacity ◽  
Binding Activity ◽  
Peptide Binding Site ◽  
Linker Domain ◽  
Glucose Regulated Protein

GRP94 (glucose-regulated protein of 94 kDa) is a major luminal constituent of the endoplasmic reticulum with known high capacity for calcium in vivo and a peptide-binding activity in vitro. In the present study, we show that Ca2+ regulates the ability of GRP94 to bind peptides. This effect is due to a Ca2+-binding site located in the charged linker domain of GRP94, which, when occupied, enhances the association of peptides with the peptide-binding site in the N-terminal domain of the protein. We further show that grp94−/− cells are hypersensitive to perturbation of intracellular calcium and thus GRP94 is important for cellular Ca2+ storage.

scholarly journals The protein disulphide-isomerase family: unravelling a string of folds

1999 ◽  
Vol 339 (1) ◽  
pp. 1-10 ◽  
Author(s):  
David M. FERRARI ◽  
Hans-Dieter SÖLING
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Cell Adhesion ◽  
Peptide Binding ◽  
Secretory Proteins ◽  
Cytoplasmic Protein ◽  
Protein Disulphide Isomerase ◽  
Redox Active ◽  
Binding Cell ◽  
Mammalian Protein

The mammalian protein disulphide-isomerase (PDI) family encompasses several highly divergent proteins that are involved in the processing and maturation of secretory proteins in the endoplasmic reticulum. These proteins are characterized by the presence of one or more domains of roughly 95–110 amino acids related to the cytoplasmic protein thioredoxin. All but the PDI-D subfamily are composed entirely of repeats of such domains, with at least one domain containing and one domain lacking a redox-active -Cys-Xaa-Xaa-Cys- tetrapeptide. In addition to their known roles as redox catalysts and isomerases, the last few years have revealed additional functions of the PDI proteins, including peptide binding, cell adhesion and perhaps chaperone activities. Attention is now turning to the non-redox-active domains of the PDIs, which may play an important role in all of the known activities of these proteins. Thus the presence of both redox-active and -inactive domains within these proteins portends a complexity of functions differentially accommodated by the various family members.

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