151
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Eckert K, Saliou JM, Monlezun L, Vigouroux A, Atmane N, Caillat C, Quevillon-Chéruel S, Madiona K, Nicaise M, Lazereg S, Van Dorsselaer A, Sanglier-Cianférani S, Meyer P, Moréra S. The Pih1-Tah1 cochaperone complex inhibits Hsp90 molecular chaperone ATPase activity. J Biol Chem 2010; 285:31304-12. [PMID: 20663878 DOI: 10.1074/jbc.m110.138263] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Hsp90 (heat shock protein 90) is an ATP-dependent molecular chaperone regulated by collaborating proteins called cochaperones. This machinery is involved in the conformational activation of client proteins like signaling kinases, transcription factors, or ribonucleoproteins (RNP) such as telomerase. TPR (TetratricoPeptide Repeat)-containing protein associated with Hsp90 (Tah1) and protein interacting with Hsp90 (Pih1) have been identified in Saccharomyces cerevisiae as two Hsp90 cochaperones involved in chromatin remodeling complexes and small nucleolar RNP maturation. Tah1 possesses a minimal TPR domain and binds specifically to the Hsp90 C terminus, whereas Pih1 displays no homology to other protein motifs and has been involved in core RNP protein interaction. While Pih1 alone was unstable and was degraded from its N terminus, we showed that Pih1 and Tah1 form a stable heterodimeric complex that regulates Hsp90 ATPase activity. We used different biophysical approaches such as analytical ultracentrifugation, microcalorimetry, and noncovalent mass spectrometry to characterize the Pih1-Tah1 complex and its interaction with Hsp90. We showed that the Pih1-Tah1 heterodimer binds to Hsp90 with a similar affinity and the same stoichiometry as Tah1 alone. However, the Pih1-Tah1 complex antagonizes Tah1 activity on Hsp90 and inhibits the chaperone ATPase activity. We further identified the region within Pih1 responsible for interaction with Tah1 and inhibition of Hsp90, allowing us to suggest an interaction model for the Pih1-Tah1/Hsp90 complex. These results, together with previous reports, suggest a role for the Pih1-Tah1 cochaperone complex in the recruitment of client proteins such as core RNP proteins to Hsp90.
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Affiliation(s)
- Kelvin Eckert
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, 91198 Gif-sur-Yvette, France
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152
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Schülke JP, Wochnik GM, Lang-Rollin I, Gassen NC, Knapp RT, Berning B, Yassouridis A, Rein T. Differential impact of tetratricopeptide repeat proteins on the steroid hormone receptors. PLoS One 2010; 5:e11717. [PMID: 20661446 PMCID: PMC2908686 DOI: 10.1371/journal.pone.0011717] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 06/24/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Tetratricopeptide repeat (TPR) motif containing co-chaperones of the chaperone Hsp90 are considered control modules that govern activity and specificity of this central folding platform. Steroid receptors are paradigm clients of Hsp90. The influence of some TPR proteins on selected receptors has been described, but a comprehensive analysis of the effects of TPR proteins on all steroid receptors has not been accomplished yet. METHODOLOGY AND PRINCIPAL FINDINGS We compared the influence of the TPR proteins FK506 binding proteins 51 and 52, protein phosphatase-5, C-terminus of Hsp70 interacting protein, cyclophillin 40, hepatitis-virus-B X-associated protein-2, and tetratricopeptide repeat protein-2 on all six steroid hormone receptors in a homogeneous mammalian cell system. To be able to assess each cofactor's effect on the transcriptional activity of on each steroid receptor we employed transient transfection in a reporter gene assay. In addition, we evaluated the interactions of the TPR proteins with the receptors and components of the Hsp90 chaperone heterocomplex by coimmunoprecipitation. In the functional assays, corticosteroid and progesterone receptors displayed the most sensitive and distinct reaction to the TPR proteins. Androgen receptor's activity was moderately impaired by most cofactors, whereas the Estrogen receptors' activity was impaired by most cofactors only to a minor degree. Second, interaction studies revealed that the strongly receptor-interacting co-chaperones were all among the inhibitory proteins. Intriguingly, the TPR-proteins also differentially co-precipitated the heterochaperone complex components Hsp90, Hsp70, and p23, pointing to differences in their modes of action. CONCLUSION AND SIGNIFICANCE The results of this comprehensive study provide important insight into chaperoning of diverse client proteins via the combinatorial action of (co)-chaperones. The differential effects of the TPR proteins on steroid receptors bear on all physiological processes related to steroid hormone activity.
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MESH Headings
- Animals
- Cell Line
- Cell Line, Tumor
- Peptidyl-Prolyl Isomerase F
- Cyclophilins/genetics
- Cyclophilins/metabolism
- HSP40 Heat-Shock Proteins/genetics
- HSP40 Heat-Shock Proteins/metabolism
- Heat-Shock Proteins
- Humans
- Immunoblotting
- Immunoprecipitation
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/metabolism
- Mice
- Molecular Chaperones
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Phosphoprotein Phosphatases/genetics
- Phosphoprotein Phosphatases/metabolism
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, Mineralocorticoid/genetics
- Receptors, Mineralocorticoid/metabolism
- Receptors, Progesterone/genetics
- Receptors, Progesterone/metabolism
- Receptors, Steroid/genetics
- Receptors, Steroid/metabolism
- Tacrolimus Binding Proteins/genetics
- Tacrolimus Binding Proteins/metabolism
- Ubiquitin-Protein Ligases/genetics
- Ubiquitin-Protein Ligases/metabolism
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Affiliation(s)
- Jan-Philip Schülke
- Chaperone Research Group, Max Planck Institute of Psychiatry, Munich, Germany
| | | | | | | | | | - Barbara Berning
- Chaperone Research Group, Max Planck Institute of Psychiatry, Munich, Germany
| | | | - Theo Rein
- Chaperone Research Group, Max Planck Institute of Psychiatry, Munich, Germany
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153
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Stankiewicz M, Nikolay R, Rybin V, Mayer MP. CHIP participates in protein triage decisions by preferentially ubiquitinating Hsp70-bound substrates. FEBS J 2010; 277:3353-67. [DOI: 10.1111/j.1742-4658.2010.07737.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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154
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Pemberton TJ, Kay JE. Identification and comparative analysis of the peptidyl-prolyl cis/trans isomerase repertoires of H. sapiens, D. melanogaster, C. elegans, S. cerevisiae and Sz. pombe. Comp Funct Genomics 2010; 6:277-300. [PMID: 18629211 PMCID: PMC2447506 DOI: 10.1002/cfg.482] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 05/01/2005] [Accepted: 05/26/2005] [Indexed: 11/11/2022] Open
Abstract
The peptidyl-prolyl cis/trans isomerase (PPIase) class of proteins comprises three
member families that are found throughout nature and are present in all the major
compartments of the cell. Their numbers appear to be linked to the number of genes in
their respective genomes, although we have found the human repertoire to be smaller
than expected due to a reduced cyclophilin repertoire. We show here that whilst the
members of the cyclophilin family (which are predominantly found in the nucleus
and cytoplasm) and the parvulin family (which are predominantly nuclear) are
largely conserved between different repertoires, the FKBPs (which are predominantly
found in the cytoplasm and endoplasmic reticulum) are not. It therefore appears
that the cyclophilins and parvulins have evolved to perform conserved functions,
while the FKBPs have evolved to fill ever-changing niches within the constantly
evolving organisms. Many orthologous subgroups within the different PPIase families
appear to have evolved from a distinct common ancestor, whereas others, such as the
mitochondrial cyclophilins, appear to have evolved independently of one another. We
have also identified a novel parvulin within Drosophila melanogaster that is unique to
the fruit fly, indicating a recent evolutionary emergence. Interestingly, the fission yeast
repertoire, which contains no unique cyclophilins and parvulins, shares no PPIases
solely with the budding yeast but it does share a majority with the higher eukaryotes
in this study, unlike the budding yeast. It therefore appears that, in comparison with
Schizosaccharomyces pombe, Saccharomyces cerevisiae is a poor representation of the
higher eukaryotes for the study of PPIases.
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Affiliation(s)
- Trevor J Pemberton
- The Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton ,East Sussex BN1 9PX, United Kingdom.
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155
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Abstract
Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone that facilitates the maturation of a wide range of proteins (known as clients). Clients are enriched in signal transducers, including kinases and transcription factors. Therefore, HSP90 regulates diverse cellular functions and exerts marked effects on normal biology, disease and evolutionary processes. Recent structural and functional analyses have provided new insights on the transcriptional and biochemical regulation of HSP90 and the structural dynamics it uses to act on a diverse client repertoire. Comprehensive understanding of how HSP90 functions promises not only to provide new avenues for therapeutic intervention, but to shed light on fundamental biological questions.
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156
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Yi F, Doudevski I, Regan L. HOP is a monomer: investigation of the oligomeric state of the co-chaperone HOP. Protein Sci 2010; 19:19-25. [PMID: 19866486 DOI: 10.1002/pro.278] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The co-chaperone Hsp70-Hsp90 organizing protein (HOP) plays a central role in protein folding in vivo, binding to both Hsp70 and Hsp90 and bringing them together in a functional complex. Reports in the literature concerning the oligomeric state of HOP have been inconsistent-is it a monomer, dimer, or higher order oligomer? Knowing the oligomeric state of HOP is important, because it places limits on the number and types of multiprotein complexes that can form during the folding cycle. Thus, the number of feasible models is simplified. Here, we explicitly investigate the oligomeric state of HOP using three complementary methods: gel filtration chromatography, sedimentation equilibrium analytical ultracentrifugation (AUC), and an in vivo coexpression assay. We find that HOP does not behave like a monomeric globular protein on gel filtration. Rather its behavior is consistent with it being either an elongated monomer or a dimer. We follow-up on these studies using sedimentation equilibrium AUC, which separates on the basis of molecular weight (MW), independent of shape. Sedimentation equilibrium AUC clearly shows that HOP is a monomer, with no indication of higher MW species. Finally, we use an in vivo coexpression assay that also supports the conclusion that HOP is a monomer.
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Affiliation(s)
- Fang Yi
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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157
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Kadota Y, Shirasu K, Guerois R. NLR sensors meet at the SGT1–HSP90 crossroad. Trends Biochem Sci 2010; 35:199-207. [DOI: 10.1016/j.tibs.2009.12.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2009] [Revised: 12/15/2009] [Accepted: 12/16/2009] [Indexed: 12/21/2022]
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158
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Zurawska A, Urbanski J, Matuliene J, Baraniak J, Klejman MP, Filipek S, Matulis D, Bieganowski P. Mutations that increase both Hsp90 ATPase activity in vitro and Hsp90 drug resistance in vivo. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:575-83. [PMID: 20226818 DOI: 10.1016/j.bbamcr.2010.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 11/29/2022]
Abstract
Hsp90 inhibitors are currently tested in clinical trials as anticancer agents. We investigated whether inhibitor resistance may arise as a result of a point mutation in Hsp90. We used yeast cells that expressed human Hsp90beta to select inhibitor-resistant mutants from the randomly mutagenized library. Single amino acid substitution, I123T, in a selected mutant was sufficient to confer inhibitor resistance. Transfection of human cells with the HSP90beta I123T and the corresponding HSP90alpha I128T yielded cell lines resistant to inhibitors of the Hsp90 ATPase. Unexpectedly, mutations did not result in diminished inhibitor binding in vitro. Similarly resistant cells were obtained after transfection with previously described A116N and T31I mutants of HSP90beta that cause increase in ATPase activity in vitro. Inhibitor-resistant phenotypes of the I123T and A116N mutants depended on their increased affinity for Aha1, whereas T31I mutation did not result in increased Aha1 binding. These results show possible scenario by which resistance may arise in patients treated with Hsp90 inhibitors. Additionally, our results show that each isoform of Hsp90 can alone sustain cellular functions.
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Affiliation(s)
- Anna Zurawska
- International Institute of Molecular and Cell Biology, Warsaw, Poland
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159
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Abstract
Hsp90 molecular chaperones are required for the stability and activity of a diverse range of client proteins that have critical roles in signal transduction, cellular trafficking, chromatin remodeling, cell growth, differentiation, and reproduction. Mammalian cells contain three types of Hsp90s: cytosolic Hsp90, mitochondrial Trap-1, and Grp94 of the endoplasmic reticulum. Each of the Hsp90s, as well as the bacterial homolog, HtpG, hydrolyze ATP and undergo similar conformational changes. Unlike the other forms of Hsp90, cytosolic Hsp90 function is dependent on a battery of co-chaperone proteins that regulate the ATPase activity of Hsp90 or direct Hsp90 to interact with specific client proteins. This review will summarize what is known about Hsp90's ability to mediate the folding and activation of diverse client proteins that contribute to human diseases, such as cancer and fungal and viral infections.
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Affiliation(s)
- Abbey Zuehlke
- Department of Microbiology, Molecular Biology and Biochemistry and the Center for Reproductive Biology, University of Idaho, Moscow ID 83844-3052
| | - Jill L. Johnson
- Department of Microbiology, Molecular Biology and Biochemistry and the Center for Reproductive Biology, University of Idaho, Moscow ID 83844-3052
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160
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Qiao Y, Lee SI, Piao R, Jiang W, Ham TH, Chin JH, Piao Z, Han L, Kang SY, Koh HJ. Fine mapping and candidate gene analysis of the floury endosperm gene, FLO(a), in rice. Mol Cells 2010; 29:167-74. [PMID: 20016946 DOI: 10.1007/s10059-010-0010-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 10/19/2009] [Accepted: 10/28/2009] [Indexed: 10/20/2022] Open
Abstract
In addition to its role as an energy source for plants, animals and humans, starch is also an environmentally friendly alternative to fossil fuels. In rice, the eating and cooking quality of the grain is determined by its starch properties. The floury endosperm of rice has been explored as an agronomical trait in breeding and genetics studies. In the present study, we characterized a floury endosperm mutant, flo(a), derived from treatment of Oryza sativa ssp. japonica cultivar Hwacheong with MNU. The innermost endosperm of the flo(a) mutant exhibited floury characteristics while the outer layer of the endosperm appeared normal. Starch granules in the flo(a) mutant formed a loosely-packed crystalline structure and X-ray diffraction revealed that the overall crystallinity of the starch was decreased compared to wild-type. The FLO(a) gene was isolated via a map-based cloning approach and predicted to encode the tetratricopeptide repeat domain-containing protein, OsTPR. Three mutant alleles contain a nucleotide substitution that generated one stop codon or one splice site, respectively, which presumably disrupts the interaction of the functionally conserved TPR motifs. Taken together, our map-based cloning approach pinpointed an OsTPR as a strong candidate of FLO(a), and the proteins that contain TPR motifs might play a significant role in rice starch biosynthetic pathways.
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Affiliation(s)
- Yongli Qiao
- Department of Plant Science, Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul, 151-921, Korea
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161
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Brandt GEL, Blagg BSJ. Alternate strategies of Hsp90 modulation for the treatment of cancer and other diseases. Curr Top Med Chem 2010; 9:1447-61. [PMID: 19860731 DOI: 10.2174/156802609789895683] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 09/07/2009] [Indexed: 12/13/2022]
Abstract
The 90 kDa heat shock protein (Hsp90) has become a validated target for the development of anti-cancer agents. Several Hsp90 inhibitors are currently under clinical trial investigation for the treatment of cancer. All of these agents inhibit Hsp90's protein folding activity by binding to the N-terminal ATP binding site of the Hsp90 molecular chaperone. Administration of these investigational drugs elicits induction of the heat shock response, or the overexpression of several Hsps, which exhibit antiapoptotic and pro-survival effects that may complicate the application of these inhibitors. To circumvent this issue, alternate mechanisms for Hsp90 inhibition that do not elicit the heat shock response have been identified and pursued. After providing background on the structure, function, and mechanism of the Hsp90 protein folding machinery, this review describes several mechanisms of Hsp90 modulation via small molecules that do not induce the heat shock response.
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Affiliation(s)
- Gary E L Brandt
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, Kansas, 66045-7582, USA
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162
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Zhang T, Li Y, Yu Y, Zou P, Jiang Y, Sun D. Characterization of celastrol to inhibit hsp90 and cdc37 interaction. J Biol Chem 2009; 284:35381-9. [PMID: 19858214 PMCID: PMC2790967 DOI: 10.1074/jbc.m109.051532] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 09/29/2009] [Indexed: 12/20/2022] Open
Abstract
The molecular chaperone heat shock protein 90 (Hsp90) is required for the stabilization and conformational maturation of various oncogenic proteins in cancer. The loading of protein kinases to Hsp90 is actively mediated by the cochaperone Cdc37. The crucial role of the Hsp90-Cdc37 complex has made it an exciting target for cancer treatment. In this study, we characterize Hsp90 and Cdc37 interaction and drug disruption using a reconstituted protein system. The GST pull-down assay and ELISA assay show that Cdc37 binds to ADP-bound/nucleotide-free Hsp90 but not ATP-bound Hsp90. Celastrol disrupts Hsp90-Cdc37 complex formation, whereas the classical Hsp90 inhibitors (e.g. geldanamycin) have no effect. Celastrol inhibits Hsp90 ATPase activity without blocking ATP binding. Proteolytic fingerprinting indicates celastrol binds to Hsp90 C-terminal domain to protect it from trypsin digestion. These data suggest that celastrol may represent a new class of Hsp90 inhibitor by modifying Hsp90 C terminus to allosterically regulate its chaperone activity and disrupt Hsp90-Cdc37 complex.
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Affiliation(s)
- Tao Zhang
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
| | - Yanyan Li
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
| | - Yanke Yu
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
| | - Peng Zou
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
| | - Yiqun Jiang
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
| | - Duxin Sun
- From the Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109
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163
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Tsutsumi S, Mollapour M, Graf C, Lee CT, Scroggins BT, Xu W, Haslerova L, Hessling M, Konstantinova AA, Trepel JB, Panaretou B, Buchner J, Mayer MP, Prodromou C, Neckers L. Hsp90 charged-linker truncation reverses the functional consequences of weakened hydrophobic contacts in the N domain. Nat Struct Mol Biol 2009; 16:1141-7. [PMID: 19838189 DOI: 10.1038/nsmb.1682] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 08/26/2009] [Indexed: 11/10/2022]
Abstract
Heat shock protein 90 (Hsp90) is an essential molecular chaperone in eukaryotes, as it regulates diverse signal transduction nodes that integrate numerous environmental cues to maintain cellular homeostasis. Hsp90 also is secreted from normal and transformed cells and regulates cell motility. Here, we have identified a conserved hydrophobic motif in a beta-strand at the boundary between the N domain and charged linker of Hsp90, whose mutation not only abrogated Hsp90 secretion but also inhibited its function. These Hsp90 mutants lacked chaperone activity in vitro and failed to support yeast viability. Notably, truncation of the charged linker reduced solvent accessibility of this beta-strand and restored chaperone activity to these mutants. These data underscore the importance of beta-strand 8 for Hsp90 function and demonstrate that the functional consequences of weakened hydrophobic contacts in this region are reversed by charged-linker truncation.
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Affiliation(s)
- Shinji Tsutsumi
- Urologic Oncology Branch, National Cancer Institute, Bethesda, Maryland, USA
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164
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Li Y, Zhang T, Jiang Y, Lee HF, Schwartz SJ, Sun D. (-)-Epigallocatechin-3-gallate inhibits Hsp90 function by impairing Hsp90 association with cochaperones in pancreatic cancer cell line Mia Paca-2. Mol Pharm 2009; 6:1152-9. [PMID: 19438225 DOI: 10.1021/mp900037p] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
(-)-Epigallocatechin-3-gallate [(-)-EGCG], the most abundant polyphenolic catechin in green tea, showed chemoprevention and anticancer activities. (-)-EGCG was reported to bind to the C-terminal domain of heat shock protein 90 (Hsp90). The purpose of this study is to investigate (-)-EGCG as a novel Hsp90 inhibitor to impair Hsp90 superchaperone complex for simultaneous downregulation of oncogenic proteins in pancreatic cancer cells. MTS assay showed that (-)-EGCG exhibited antiproliferative activity against pancreatic cancer cell line Mia Paca-2 in vitro with IC50 below 50 muM. (-)-EGCG increased caspase-3 activity up to 3-fold in a time- and concentration-dependent manner. Western blotting analysis demonstrated that (-)-EGCG induced downregulation of oncogenic Hsp90 client proteins by approximately 70-95%, including Akt, Cdk4, Raf-1, Her-2, and pERK. Co-immunoprecipitation showed that (-)-EGCG decreased the association of cochaperones p23 and Hsc70 with Hsp90 by more than 50%, while it had little effect on the ATP binding to Hsp90. Proteolytic fingerprinting assay confirmed direct binding between (-)-EGCG and the Hsp90 C-terminal domain. These data suggest that the binding of (-)-EGCG to Hsp90 impairs the association of Hsp90 with its cochaperones, thereby inducing degradation of Hsp90 client proteins, resulting antiproliferating effects in pancreatic cancer cells.
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Affiliation(s)
- Yanyan Li
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA
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165
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Romano SA, Cordeiro Y, Lima LMTR, Lopes MH, Silva JL, Foguel D, Linden R. Reciprocal remodeling upon binding of the prion protein to its signaling partner hop/STIl. FASEB J 2009; 23:4308-16. [DOI: 10.1096/fj.09-138974] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Sebastián A. Romano
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | - Yraima Cordeiro
- Faculdade de Farmácia Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | | | | | - Jerson L. Silva
- Instituto de Bioquímica Médica Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | - Débora Foguel
- Instituto de Bioquímica Médica Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
| | - Rafael Linden
- Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil
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166
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Retzlaff M, Stahl M, Eberl HC, Lagleder S, Beck J, Kessler H, Buchner J. Hsp90 is regulated by a switch point in the C-terminal domain. EMBO Rep 2009; 10:1147-53. [PMID: 19696785 DOI: 10.1038/embor.2009.153] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 06/10/2009] [Accepted: 06/10/2009] [Indexed: 11/09/2022] Open
Abstract
Heat shock protein 90 (Hsp90) is an abundant, dimeric ATP-dependent molecular chaperone, and ATPase activity is essential for its in vivo functions. S-nitrosylation of a residue located in the carboxy-terminal domain has been shown to affect Hsp90 activity in vivo. To understand how variation of a specific amino acid far away from the amino-terminal ATP-binding site regulates Hsp90 functions, we mutated the corresponding residue and analysed yeast and human Hsp90 variants both in vivo and in vitro. Here, we show that this residue is a conserved, strong regulator of Hsp90 functions, including ATP hydrolysis and chaperone activity. Unexpectedly, the variants alter both the C-terminal and N-terminal association properties of Hsp90, and shift its conformational equilibrium within the ATPase cycle. Thus, S-nitrosylation of this residue allows the fast and efficient fine regulation of Hsp90.
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Affiliation(s)
- Marco Retzlaff
- Center for Integrated Protein Science, Department of Chemistry, Technische Universität München, Garching, Germany
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167
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Gaiser AM, Brandt F, Richter K. The Non-canonical Hop Protein from Caenorhabditis elegans Exerts Essential Functions and Forms Binary Complexes with Either Hsc70 or Hsp90. J Mol Biol 2009; 391:621-34. [DOI: 10.1016/j.jmb.2009.06.051] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 05/28/2009] [Accepted: 06/18/2009] [Indexed: 10/20/2022]
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168
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Hainzl O, Lapina MC, Buchner J, Richter K. The charged linker region is an important regulator of Hsp90 function. J Biol Chem 2009; 284:22559-67. [PMID: 19553666 DOI: 10.1074/jbc.m109.031658] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hsp90 is an ATP-dependent molecular chaperone which assists the maturation of a large set of target proteins. Members of the highly conserved Hsp90 family are found from bacteria to higher eukaryotes, with homologues in different organelles. The core architecture of Hsp90 is defined by the N-terminal ATP binding domain followed by the middle domain and the C-terminal dimerization domain. A long, highly charged linker between the N-terminal domain and the middle domain is a feature characteristic for Hsp90s of eukaryotic organisms. We set out to clarify the function of this linker by studying the effects of deletions in this region in vivo and in vitro. Here we show that increasing deletions in the charged linker region lead to defects ranging from mild temperature sensitivity to a lethal phenotype. The lethal deletion variants investigated in this study still exhibit ATPase activity. Deletion of the charged linker ultimately causes a loss of Hsp90 regulation by co-chaperones, as the sensitivity for Aha1-mediated ATPase acceleration declines, and binding of p23/Sba1 is lost in non-viable deletion constructs. In vivo client assays additionally demonstrated that the deletion of the linker had a pronounced effect on the ability of Hsp90 to facilitate client activation. A partial reconstruction of the linker sequence showed that the supplementation by artificial sequences can rescue the functionality of Hsp90 and restore the conformational flexibility of the protein, required for the processing of client proteins.
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Affiliation(s)
- Otmar Hainzl
- Center for Integrated Protein Science and Department of Chemistry, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
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169
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Li Y, Zhang T, Schwartz SJ, Sun D. New developments in Hsp90 inhibitors as anti-cancer therapeutics: mechanisms, clinical perspective and more potential. Drug Resist Updat 2009; 12:17-27. [PMID: 19179103 DOI: 10.1016/j.drup.2008.12.002] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 11/26/2008] [Accepted: 12/04/2008] [Indexed: 12/20/2022]
Abstract
The molecular chaperone Hsp90 (heat shock protein 90) is a promising target in cancer therapy. Preclinical and clinical evaluations of a variety of Hsp90 inhibitors have shown anti-tumor effect as a single agent and in combination with chemotherapy. Current Hsp90 inhibitors are categorized into several classes based on distinct modes of inhibition, including (i) blockade of ATP binding, (ii) disruption of co-chaperone/Hsp90 interactions, (iii) antagonism of client/Hsp90 associations and (iv) interference with post-translational modifications of Hsp90. The different functions of Hsp90 isoforms and the isoform selectivity of drugs need further investigation. The correlation of cell surface Hsp90 with cancer metastasis and the emerging involvement of Hsp90 inhibition in cancer stem cells have become exciting areas that could be exploited. Therefore, the aim of this review is (1) to summarize the up-to-date knowledge of mechanistic studies and clinical prospect of currently available Hsp90 inhibitors, (2) to enhance our perspectives for designing and discovering novel Hsp90 inhibitors, and (3) to provide an insight into less-understood potential of Hsp90 inhibition in cancer therapy.
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Affiliation(s)
- Yanyan Li
- Department of Pharmaceutical Sciences, University of Michigan, MI 48109, USA
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170
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Song HO, Lee W, An K, Lee HS, Cho JH, Park ZY, Ahnn J. C. elegans STI-1, the homolog of Sti1/Hop, is involved in aging and stress response. J Mol Biol 2009; 390:604-17. [PMID: 19467242 DOI: 10.1016/j.jmb.2009.05.035] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 05/19/2009] [Accepted: 05/20/2009] [Indexed: 11/25/2022]
Abstract
Environmental and physiological stresses such as heat shock, oxidative stress, heavy metals, and pathogenic conditions induce cellular stress response. This response is often mediated by heat shock proteins that function as molecular chaperones. A stress-inducible cochaperone, Sti1/Hop (Hsp organizer protein), functions as an adaptor protein that simultaneously binds with Hsp70 and Hsp90 to transfer client proteins from Hsp70 to Hsp90. However, the biological role of STI-1 in vivo is poorly understood in metazoans. Here, we report the characterization of the Caenorhabditis elegans homolog of Sti1/Hop, which is approximately 56% identical with human STI-1. C. elegans STI-1 (CeSTI-1) is expressed in the pharynx, intestine, nervous system, and muscle from larvae to adults. Analysis of proteins immunoprecipitated with anti-STI-1 antibody by mass spectrometry revealed that CeSTI-1 can bind with both Hsp70 and Hsp90 homologs like its mammalian counterpart. sti-1 expression is elevated by heat stress, and an sti-1(jh125) null mutant shows decreased fertility under heat stress conditions. These mutants also show abnormally high lethality in extreme heat and may be functioning with DAF-16 in thermotolerance. In addition, sti-1(jh125) mutants have a shortened life span. Our results confirm that CeSTI-1 is a cochaperone protein that may maintain homeostatic functions during episodes of stress and can regulate longevity in nematodes.
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Affiliation(s)
- Hyun-Ok Song
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
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171
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Prodromou C, Nuttall JM, Millson SH, Roe SM, Sim TS, Tan D, Workman P, Pearl LH, Piper PW. Structural basis of the radicicol resistance displayed by a fungal hsp90. ACS Chem Biol 2009; 4:289-97. [PMID: 19236053 DOI: 10.1021/cb9000316] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Heat shock protein 90 (Hsp90) is a promising cancer drug target, as multiple oncogenic proteins are destabilized simultaneously when it loses its activity in tumor cells. Highly selective Hsp90 inhibitors, including the natural antibiotics geldanamycin (GdA) and radicicol (RAD), inactivate this essential molecular chaperone by occupying its nucleotide binding site. Often cancer drug therapy is compromised by the development of resistance, but a resistance to these Hsp90 inhibitors should not arise readily by mutation of those amino acids within Hsp90 that facilitate inhibitor binding, as these are required for the essential ATP binding/ATPase steps of the chaperone cycle and are tightly conserved. Despite this, the Hsp90 of a RAD-producing fungus is shown to possess an unusually low binding affinity for RAD but not GdA. Within its nucleotide binding site a normally conserved leucine is replaced by isoleucine, though the chaperone ATPase activity is not severely affected. Inserted into the Hsp90 of yeast, this conservative leucine to isoleucine substitution recreated this lowered affinity for RAD in vitro. It also generated a substantially enhanced resistance to RAD in vivo. Co-crystal structures reveal that the change to isoleucine is associated with a localized increase in the hydration of an Hsp90-bound RAD but not GdA. To the best of our knowledge, this is the first demonstration that it is possible for Hsp90 inhibitor resistance to arise by subtle alteration to the structure of Hsp90 itself.
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Affiliation(s)
- Chrisostomos Prodromou
- Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - James M. Nuttall
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, U.K
| | - Stefan H. Millson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, U.K
| | - S. Mark Roe
- Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - Tiow-Suan Sim
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, S117597, Singapore
| | - Doreen Tan
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, S117597, Singapore
| | - Paul Workman
- Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, 15 Cotswold Road, Sutton, Surrey SM2 5NG, U.K
| | - Laurence H. Pearl
- Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - Peter W. Piper
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, Sheffield S10 2TN, U.K
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172
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Morra G, Verkhivker G, Colombo G. Modeling signal propagation mechanisms and ligand-based conformational dynamics of the Hsp90 molecular chaperone full-length dimer. PLoS Comput Biol 2009; 5:e1000323. [PMID: 19300478 PMCID: PMC2649446 DOI: 10.1371/journal.pcbi.1000323] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 02/06/2009] [Indexed: 12/16/2022] Open
Abstract
Hsp90 is a molecular chaperone essential for protein folding and activation in normal homeostasis and stress response. ATP binding and hydrolysis facilitate Hsp90 conformational changes required for client activation. Hsp90 plays an important role in disease states, particularly in cancer, where chaperoning of the mutated and overexpressed oncoproteins is important for function. Recent studies have illuminated mechanisms related to the chaperone function. However, an atomic resolution view of Hsp90 conformational dynamics, determined by the presence of different binding partners, is critical to define communication pathways between remote residues in different domains intimately affecting the chaperone cycle. Here, we present a computational analysis of signal propagation and long-range communication pathways in Hsp90. We carried out molecular dynamics simulations of the full-length Hsp90 dimer, combined with essential dynamics, correlation analysis, and a signal propagation model. All-atom MD simulations with timescales of 70 ns have been performed for complexes with the natural substrates ATP and ADP and for the unliganded dimer. We elucidate the mechanisms of signal propagation and determine “hot spots” involved in interdomain communication pathways from the nucleotide-binding site to the C-terminal domain interface. A comprehensive computational analysis of the Hsp90 communication pathways and dynamics at atomic resolution has revealed the role of the nucleotide in effecting conformational changes, elucidating the mechanisms of signal propagation. Functionally important residues and secondary structure elements emerge as effective mediators of communication between the nucleotide-binding site and the C-terminal interface. Furthermore, we show that specific interdomain signal propagation pathways may be activated as a function of the ligand. Our results support a “conformational selection model” of the Hsp90 mechanism, whereby the protein may exist in a dynamic equilibrium between different conformational states available on the energy landscape and binding of a specific partner can bias the equilibrium toward functionally relevant complexes. Dynamic processes underlie the functions of all proteins. Hence, to understand, control, and design protein functions in the cell, we need to unravel the basic principles of protein dynamics. This is fundamental in studying the mechanisms of a specific class of proteins known as molecular chaperones, which oversee the correct conformational maturation of other proteins. In particular, molecular chaperones of the stress response machinery have become the focus of intense research, because their upregulation is responsible for the ability of tumor cells to cope with unfavorable environments. This is largely centered on the expression and function of the molecular chaperone Hsp90, which has provided an attractive target for therapeutic intervention in cancer. Experiments have shown that the chaperone functions through a nucleotide-directed conformational cycle. Here, we show that it is possible to identify the effects of nucleotide-related chemical differences on functionally relevant motions at the atomic level of resolution. The protein may fluctuate at equilibrium among different available dynamic states, and binding of a specific partner may shift the equilibrium toward the thermodynamically most stable complexes. These results provide us with important mechanistic insight for the identification of new regulatory sites and the design of possible new drugs.
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Affiliation(s)
- Giulia Morra
- Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Gennady Verkhivker
- Department of Pharmaceutical Chemistry, School of Pharmacy and Center for Bioinformatics, University of Kansas, Lawrence, Kansas, United States of America
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail: (GV); (GC)
| | - Giorgio Colombo
- Istituto di Chimica del Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Milano, Italy
- * E-mail: (GV); (GC)
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173
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Dissection of the ATP-induced conformational cycle of the molecular chaperone Hsp90. Nat Struct Mol Biol 2009; 16:287-93. [PMID: 19234467 DOI: 10.1038/nsmb.1565] [Citation(s) in RCA: 266] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 01/22/2009] [Indexed: 12/12/2022]
Abstract
The molecular chaperone heat-shock protein 90 (Hsp90) couples ATP hydrolysis to conformational changes driving a reaction cycle that is required for substrate activation. Recent structural analysis provided snapshots of the open and closed states of Hsp90, which mark the starting and end points of these changes. Using fluorescence resonance energy transfer (FRET), we dissected the cycle kinetically and identified the intermediates on the pathway. The conformational transitions are orders of magnitude slower than the ATP-hydrolysis step and thus are the limiting events during the reaction cycle. Furthermore, these structural changes can be tightly regulated by cochaperones, being completely inhibited by Sti1 or accelerated by Aha1. In fact, even in the absence of nucleotide, Aha1 induces Hsp90 rearrangements that speed up the conformational cycle. This comprehensive reconstitution of the Hsp90 cycle defines a controlled progression through distinct intermediates that can be modulated by conformation-sensitive cochaperones.
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174
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Abstract
Heat shock protein 90 has emerged as a promising target for the treatment of cancer and neurodegenerative diseases. This review summarizes recent advancements towards the development of natural products as they pertain to the biological and chemical understanding of this molecular chaperone.
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Affiliation(s)
- M W Amolins
- Department of Medicinal Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Malott 4070, Lawrence, Kansas 66045-7563, USA
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175
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Baird D, Stefan C, Audhya A, Weys S, Emr SD. Assembly of the PtdIns 4-kinase Stt4 complex at the plasma membrane requires Ypp1 and Efr3. ACTA ACUST UNITED AC 2009; 183:1061-74. [PMID: 19075114 PMCID: PMC2600738 DOI: 10.1083/jcb.200804003] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The phosphoinositide phosphatidylinositol 4-phosphate (PtdIns4P) is an essential signaling lipid that regulates secretion and polarization of the actin cytoskeleton. In Saccharomyces cerevisiae, the PtdIns 4-kinase Stt4 catalyzes the synthesis of PtdIns4P at the plasma membrane (PM). In this paper, we identify and characterize two novel regulatory components of the Stt4 kinase complex, Ypp1 and Efr3. The essential gene YPP1 encodes a conserved protein that colocalizes with Stt4 at cortical punctate structures and regulates the stability of this lipid kinase. Accordingly, Ypp1 interacts with distinct regions on Stt4 that are necessary for the assembly and recruitment of multiple copies of the kinase into phosphoinositide kinase (PIK) patches. We identify the membrane protein Efr3 as an additional component of Stt4 PIK patches. Efr3 is essential for assembly of both Ypp1 and Stt4 at PIK patches. We conclude that Ypp1 and Efr3 are required for the formation and architecture of Stt4 PIK patches and ultimately PM-based PtdIns4P signaling.
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Affiliation(s)
- Dan Baird
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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176
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Vaughan CK, Piper PW, Pearl LH, Prodromou C. A common conformationally coupled ATPase mechanism for yeast and human cytoplasmic HSP90s. FEBS J 2008; 276:199-209. [PMID: 19032597 PMCID: PMC2702006 DOI: 10.1111/j.1742-4658.2008.06773.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformationally coupled mechanism by which ATP is utilized by yeast Hsp90 is now well characterized. In contrast, ATP utilization by human Hsp90s is less well studied, and appears to operate differently. To resolve these conflicting models, we have conducted a side-by-side biochemical analysis in a series of mutant yeast and human Hsp90s that have been both mechanistically and structurally characterized with regard to the crystal structure of the yeast Hsp90 protein. We show that each monomer of the human Hsp90 dimer is mutually dependent on the other for ATPase activity. Fluorescence studies confirmed that the N-terminal domains of Hsp90β come into close association with each other. Mutations that directly affect the conformational dynamics of the ATP-lid segment had marked effects, with T31I (yeast T22I) and A116N (yeast A107N) stimulating, and T110I (yeast T101I) inhibiting, human and yeast ATPase activity to similar extents, showing that ATP-dependent lid closure is a key rate-determining step in both systems. Mutation of residues implicated in N-terminal dimerization of yeast Hsp90 (L15R and L18R in yeast, L24R and L27R in humans) significantly reduced the ATPase activity of yeast and human Hsp90s, showing that ATP-dependent association of the N-terminal domains in the Hsp90 dimer is also essential in both systems. Furthermore, cross-linking studies of the hyper-active yeast A107N and human A116N ATP-lid mutants showed enhanced dimerization, suggesting that N-terminal association is a direct consequence of ATP binding and lid closure in both systems.
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Affiliation(s)
- Cara K Vaughan
- Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, London, UK
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177
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Hsp90-dependent activation of protein kinases is regulated by chaperone-targeted dephosphorylation of Cdc37. Mol Cell 2008; 31:886-95. [PMID: 18922470 PMCID: PMC2568865 DOI: 10.1016/j.molcel.2008.07.021] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 06/19/2008] [Accepted: 07/01/2008] [Indexed: 11/22/2022]
Abstract
Activation of protein kinase clients by the Hsp90 system is mediated by the cochaperone protein Cdc37. Cdc37 requires phosphorylation at Ser13, but little is known about the regulation of this essential posttranslational modification. We show that Ser13 of uncomplexed Cdc37 is phosphorylated in vivo, as well as in binary complex with a kinase (C-K), or in ternary complex with Hsp90 and kinase (H-C-K). Whereas pSer13-Cdc37 in the H-C-K complex is resistant to nonspecific phosphatases, it is efficiently dephosphorylated by the chaperone-targeted protein phosphatase 5 (PP5/Ppt1), which does not affect isolated Cdc37. We show that Cdc37 and PP5/Ppt1 associate in Hsp90 complexes in yeast and in human tumor cells, and that PP5/Ppt1 regulates phosphorylation of Ser13-Cdc37 in vivo, directly affecting activation of protein kinase clients by Hsp90-Cdc37. These data reveal a cyclic regulatory mechanism for Cdc37, in which its constitutive phosphorylation is reversed by targeted dephosphorylation in Hsp90 complexes.
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178
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Shimamoto S, Takata M, Tokuda M, Oohira F, Tokumitsu H, Kobayashi R. Interactions of S100A2 and S100A6 with the tetratricopeptide repeat proteins, Hsp90/Hsp70-organizing protein and kinesin light chain. J Biol Chem 2008; 283:28246-58. [PMID: 18669640 PMCID: PMC2661394 DOI: 10.1074/jbc.m801473200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 07/09/2008] [Indexed: 11/06/2022] Open
Abstract
S100A2 and S100A6 interact with several target proteins in a Ca2+-regulated manner. However, the exact intracellular roles of the S100 proteins are unclear. In this study we identified Hsp70/Hsp90-organizing protein (Hop) and kinesin light chain (KLC) as novel targets of S100A2 and S100A6. Hop directly associates with Hsp70 and Hsp90 through the tetratricopeptide (TPR) domains and regulates Hop-Hsp70 and Hop-Hsp90 complex formation. We have found that S100A2 and S100A6 bind to the TPR domain of Hop, resulting in inhibition of the Hop-Hsp70 and Hop-Hsp90 interactions in vitro. Although endogenous Hsp70 and Hsp90 interact with Hop in resting Cos-7 cells, but not with S100A6, stimulation of these cells with ionomycin caused a Hop-S100A6 interaction, resulting in the dissociation of Hsp70 and Hsp90 from Hop. Similarly, glutathione S-transferase pulldown and co-immunoprecipitation experiments revealed that S100A6 binds to the TPR domain of KLC, resulting in inhibition of the KLC-c-Jun N-terminal kinase (JNK)-interacting protein 1 (JIP-1) interaction in vitro. The transiently expressed JIP-1 interacts with KLC in resting Cos-7 cells but not with S100A6. Stimulation of these cells with ionomycin also caused a KLC-S100A6 interaction, resulting in dissociation of JIP-1 from KLC. These results strongly suggest that the S100 proteins modulate Hsp70-Hop-Hsp90 multichaperone complex formation and KLC-cargo interaction via Ca2+-dependent S100 protein-TPR protein complex formation in vivo as well as in vitro. Moreover, we have shown that S100A2 and S100A6 interact with another TPR protein Tom70 and regulate the Tom70-ligand interaction in vitro. Thus, our findings suggest a new intracellular Ca2+-signaling pathway via S100 proteins-TPR motif interactions.
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Affiliation(s)
- Seiko Shimamoto
- Department of Signal Transduction Sciences, Kagawa University Faculty of Medicine, 1750-1 Ikenobe, Kita-gun, Kagawa 761-0793, Japan
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179
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Chaiyarit P, Jintakanon D, Klanrit P, Siritapetawee M, Thongprasom K. Immunohistochemical analyses of survivin and heat shock protein 90 expression in patients with oral lichen planus. J Oral Pathol Med 2008; 38:55-62. [DOI: 10.1111/j.1600-0714.2008.00713.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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180
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Panaretou B, Zhai C. The heat shock proteins: Their roles as multi-component machines for protein folding. FUNGAL BIOL REV 2008. [DOI: 10.1016/j.fbr.2009.04.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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181
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Millson S, Vaughan C, Zhai C, Ali M, Panaretou B, Piper P, Pearl L, Prodromou C. Chaperone ligand-discrimination by the TPR-domain protein Tah1. Biochem J 2008; 413:261-8. [PMID: 18412542 PMCID: PMC2865030 DOI: 10.1042/bj20080105] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 04/11/2008] [Accepted: 04/15/2008] [Indexed: 01/22/2023]
Abstract
Tah1 [TPR (tetratricopeptide repeat)-containing protein associated with Hsp (heat-shock protein) 90] has been identified as a TPR-domain protein. TPR-domain proteins are involved in protein-protein interactions and a number have been characterized that interact either with Hsp70 or Hsp90, but a few can bind both chaperones. Independent studies suggest that Tah1 interacts with Hsp90, but whether it can also interact with Hsp70/Ssa1 has not been investigated. Amino-acid-sequence alignments suggest that Tah1 is most similar to the TPR2b domain of Hop (Hsp-organizing protein) which when mutated reduces binding to both Hsp90 and Hsp70. Our alignments suggest that there are three TPR-domain motifs in Tah1, which is consistent with the architecture of the TPR2b domain. In the present study we find that Tah1 is specific for Hsp90, and is able to bind tightly the yeast Hsp90, and the human Hsp90alpha and Hsp90beta proteins, but not the yeast Hsp70 Ssa1 isoform. Tah1 acheives ligand discrimination by favourably binding the methionine residue in the conserved MEEVD motif (Hsp90) and positively discriminating against the first valine residue in the VEEVD motif (Ssa1). In the present study we also show that Tah1 can affect the ATPase activity of Hsp90, in common with some other TPR-domain proteins.
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Key Words
- atpase activity
- heat-shock protein 90 (hsp90)
- heat-shock protein 70 (hsp70)
- tetratricopeptide-repeat-containing protein associated with heat-shock protein 90 (tah1)
- tetratricopeptide repeat (tpr) domain
- stress-inducible protein 1/heat-shock protein organizing protein/p60 (sti1/hop/p60)
- chip, c-terminal of heat-shock protein 70-interacting protein
- cpr6, cyclosporin-sensitive proline rotamase 6
- fkbp51, fk506-binding protein 51
- gst, glutathione transferase
- hop, heat-shock-protein-organizing protein
- hsp, heat-shock protein
- itc, isothermal titration calorimetry
- sti1, stress-inducible protein 1 (the yeast homologue of hop)
- csti1, c-terminal of sti1
- tah1, tetratricopeptide-repeat-containing protein associated with hsp90
- tpr, tetratricopeptide repeat
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Affiliation(s)
- Stefan H. Millson
- *Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, U.K
| | - Cara K. Vaughan
- †Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - Chao Zhai
- ‡Pharmaceutical Science Research Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Maruf M. U. Ali
- †Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - Barry Panaretou
- ‡Pharmaceutical Science Research Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, U.K
| | - Peter W. Piper
- *Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, U.K
| | - Laurence H. Pearl
- †Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
| | - Chrisostomos Prodromou
- †Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, U.K
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182
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Affiliation(s)
- Sebastian Karl Wandinger
- Department of Chemistry and the Center for Integrated Protein Science, Technische Universität München, 85747 Garching, Germany
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183
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Richter K, Soroka J, Skalniak L, Leskovar A, Hessling M, Reinstein J, Buchner J. Conserved conformational changes in the ATPase cycle of human Hsp90. J Biol Chem 2008; 283:17757-65. [PMID: 18400751 DOI: 10.1074/jbc.m800540200] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The dimeric molecular chaperone Hsp90 is required for the activation and stabilization of hundreds of substrate proteins, many of which participate in signal transduction pathways. The activation process depends on the hydrolysis of ATP by Hsp90. Hsp90 consists of a C-terminal dimerization domain, a middle domain, which may interact with substrate protein, and an N-terminal ATP-binding domain. A complex cycle of conformational changes has been proposed for the ATPase cycle of yeast Hsp90, where a critical step during the reaction requires the transient N-terminal dimerization of the two protomers. The ATPase cycle of human Hsp90 is less well understood, and significant differences have been proposed regarding key mechanistic aspects. ATP hydrolysis by human Hsp90alpha and Hsp90beta is 10-fold slower than that of yeast Hsp90. Despite these differences, our experiments suggest that the underlying enzymatic mechanisms are highly similar. In both cases, a concerted conformational rearrangement involving the N-terminal domains of both subunits is controlling the rate of ATP turnover, and N-terminal cross-talk determines the rate-limiting steps. Furthermore, similar to yeast Hsp90, the slow ATP hydrolysis by human Hsp90s can be stimulated up to over 100-fold by the addition of the co-chaperone Aha1 from either human or yeast origin. Together, our results show that the basic principles of the Hsp90 ATPase reaction are conserved between yeast and humans, including the dimerization of the N-terminal domains and its regulation by the repositioning of the ATP lid from its original position to a catalytically competent one.
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Affiliation(s)
- Klaus Richter
- Center for Integrated Protein Science and Department of Chemistry, Technische Universität München, Garching, Germany
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184
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Abstract
The molecular chaperone Hsp90 (90 kDa heat-shock protein) is a remarkably versatile protein involved in the stress response and in normal homoeostatic control mechanisms. It interacts with 'client proteins', including protein kinases, transcription factors and others, and either facilitates their stabilization and activation or directs them for proteasomal degradation. By this means, Hsp90 displays a multifaceted ability to influence signal transduction, chromatin remodelling and epigenetic regulation, development and morphological evolution. Hsp90 operates as a dimer in a conformational cycle driven by ATP binding and hydrolysis at the N-terminus. The cycle is also regulated by a group of co-chaperones and accessory proteins. Here we review the biology of the Hsp90 molecular chaperone, emphasizing recent progress in our understanding of structure-function relationships and the identification of new client proteins. In addition we describe the exciting progress that has been made in the development of Hsp90 inhibitors, which are now showing promise in the clinic for cancer treatment. We also identify the gaps in our current understanding and highlight important topics for future research.
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185
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Kosmaoglou M, Schwarz N, Bett JS, Cheetham ME. Molecular chaperones and photoreceptor function. Prog Retin Eye Res 2008; 27:434-49. [PMID: 18490186 PMCID: PMC2568879 DOI: 10.1016/j.preteyeres.2008.03.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Molecular chaperones facilitate and regulate protein conformational
change within cells. This encompasses many fundamental cellular processes:
including the correct folding of nascent chains; protein transport and
translocation; signal transduction and protein quality control. Chaperones are,
therefore, important in several forms of human disease, including
neurodegeneration. Within the retina, the highly specialized photoreceptor cell
presents a fascinating paradigm to investigate the specialization of molecular
chaperone function and reveals unique chaperone requirements essential to
photoreceptor function. Mutations in several photoreceptor proteins lead to
protein misfolding mediated neurodegeneration. The best characterized of these
are mutations in the molecular light sensor, rhodopsin, which cause autosomal
dominant retinitis pigmentosa. Rhodopsin biogenesis is likely to require
chaperones, while rhodopsin misfolding involves molecular chaperones in quality
control and the cellular response to protein aggregation. Furthermore, the
specialization of components of the chaperone machinery to photoreceptor
specific roles has been revealed by the identification of mutations in molecular
chaperones that cause inherited retinal dysfunction and degeneration. These
chaperones are involved in several important cellular pathways and further
illuminate the essential and diverse roles of molecular
chaperones.
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Affiliation(s)
- Maria Kosmaoglou
- Division of Molecular and Cellular Neuroscience, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1 V 9EL, UK
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186
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Holmes JL, Sharp SY, Hobbs S, Workman P. Silencing of HSP90 Cochaperone AHA1 Expression Decreases Client Protein Activation and Increases Cellular Sensitivity to the HSP90 Inhibitor 17-Allylamino-17-Demethoxygeldanamycin. Cancer Res 2008; 68:1188-97. [DOI: 10.1158/0008-5472.can-07-3268] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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187
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Onuoha SC, Coulstock ET, Grossmann JG, Jackson SE. Structural studies on the co-chaperone Hop and its complexes with Hsp90. J Mol Biol 2008; 379:732-44. [PMID: 18485364 DOI: 10.1016/j.jmb.2008.02.013] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Revised: 01/25/2008] [Accepted: 02/08/2008] [Indexed: 12/22/2022]
Abstract
The tetratricopeptide repeat domain (TPR)-containing co-chaperone Hsp-organising protein (Hop) plays a critical role in mediating interactions between Heat Shock Protein (Hsp)70 and Hsp90 as part of the cellular assembly machine. It also modulates the ATPase activity of both Hsp70 and Hsp90, thus facilitating client protein transfer between the two. Despite structural work on the individual domains of Hop, no structure for the full-length protein exists, nor is it clear exactly how Hop interacts with Hsp90, although it is known that its primary binding site is the C-terminal MEEVD motif. Here, we have undertaken a biophysical analysis of the structure and binding of Hop to Hsp90 using a variety of truncation mutants of both Hop and Hsp90, in addition to mutants of Hsp90 that are thought to modulate the conformation, in particular the N-terminal dimerisation of the chaperone. The results establish that whilst the primary binding site of Hop is the C-terminal MEEVD peptide of Hsp90, binding also occurs at additional sites in the C-terminal and middle domain. In contrast, we show that another TPR-containing co-chaperone, CyP40, binds solely to the C-terminus of Hsp90. Truncation mutants of Hop were generated and used to investigate the dimerisation interface of the protein. In good agreement with recently published data, we find that the TPR2a domain that contains the Hsp90-binding site is also the primary site for dimerisation. However, our results suggest that residues within the TPR2b may play a role. Together, these data along with shape reconstruction analysis from small-angle X-ray scattering measurements are used to generate a solution structure for full-length Hop, which we show has an overall butterfly-like quaternary structure. Studies on the nucleotide dependence of Hop binding to Hsp90 establish that Hop binds to the nucleotide-free, 'open' state of Hsp90. However, the Hsp90-Hop complex is weakened by the conformational changes that occur in Hsp90 upon ATP binding. Together, the data are used to propose a detailed model of how Hop may help present the client protein to Hsp90 by aligning the bound client on Hsp70 with the middle domain of Hsp90. It is likely that Hop binds to both monomers of Hsp90 in the form of a clamp, interacting with residues in the middle domain of Hsp90, thus preventing ATP hydrolysis, possibly by the prevention of association of N-terminal and middle domains in individual Hsp90 monomers.
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Affiliation(s)
- S C Onuoha
- Chemistry Department, Lensfield Road, University of Cambridge, Cambridge CB2 1EW, UK
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188
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Radanyi C, Le Bras G, Messaoudi S, Bouclier C, Peyrat JF, Brion JD, Marsaud V, Renoir JM, Alami M. Synthesis and biological activity of simplified denoviose-coumarins related to novobiocin as potent inhibitors of heat-shock protein 90 (hsp90). Bioorg Med Chem Lett 2008; 18:2495-8. [PMID: 18304811 DOI: 10.1016/j.bmcl.2008.01.128] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 01/30/2008] [Accepted: 01/31/2008] [Indexed: 11/17/2022]
Abstract
A new series of coumarin inhibitors of hsp90 lacking the noviose moiety as well as substituents on C-7 and C-8 positions of the aromatic ring was synthesised and their hsp90 inhibitory activity has been delineated: for example, their capacity to induce the degradation of client proteins and to inhibit estradiol-induced transcription in human breast cancer cells. In cell proliferation assay, the most active compound 5g was approximately 8 times more potent than the parent novobiocin natural compound.
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Affiliation(s)
- Christine Radanyi
- Univ Paris-Sud, CNRS, UMR 8612, Laboratoire de Pharmacologie Cellulaire et Moléculaire des Anticancéreux, Faculté de Pharmacie, IFR 141, 5 rue J.-B. Clément, Châtenay-Malabry F-92296, France
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189
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Jones C, Anderson S, Singha UK, Chaudhuri M. Protein phosphatase 5 is required for Hsp90 function during proteotoxic stresses in Trypanosoma brucei. Parasitol Res 2008; 102:835-44. [PMID: 18193284 DOI: 10.1007/s00436-007-0817-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Accepted: 11/19/2007] [Indexed: 12/20/2022]
Abstract
Trypanosoma brucei, a parasitic protozoan that causes African trypanosomiasis in human and domestic animals, adapt in various environments during their digenetic life cycle. In this study, we found that Hsp90 is crucial for the survival of this parasite. Inhibition of Hsp90 activity by geldanamycin (GA) reduced cell growth and increased the level of Hsp90. Both the bloodstream and procyclic forms of T. brucei showed a several-fold greater sensitivity than the mammalian cells to GA and also to 17-AAG, a less toxic derivative of GA, suggesting that Hsp90 could be a potential chemotherapeuric target for African trypanosomiasis. T. brucei Hsp90 interacts with the protein phosphatase 5 (PP5) in vivo. Under normal growth conditions, T. brucei PP5 (TbPP5) and Hsp90 are primarily localized in the cytosol. However, with increase in growth temperature and GA treatment, these proteins translocate to the nucleus. Overproduction of TbPP5 by genetic manipulation reduced the growth inhibitory effect of GA, while knockdown of TbPP5 reduced cell growth more in the presence of GA, as compared to parental control. Depletion of TbPP5, however, did not prevent the induction of Hsp90 protein level during GA treatment. Together, these results suggest that TbPP5 positively regulates the function of Hsp90 to maintain cellular homeostasis during proteotoxic stresses in T. brucei.
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Affiliation(s)
- Candace Jones
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
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190
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Donnelly A, Blagg BSJ. Novobiocin and additional inhibitors of the Hsp90 C-terminal nucleotide-binding pocket. Curr Med Chem 2008; 15:2702-17. [PMID: 18991631 PMCID: PMC2729083 DOI: 10.2174/092986708786242895] [Citation(s) in RCA: 235] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The 90 kDa heat shock proteins (Hsp90), which are integrally involved in cell signaling, proliferation, and survival, are ubiquitously expressed in cells. Many proteins in tumor cells are dependent upon the Hsp90 protein folding machinery for their stability, refolding, and maturation. Inhibition of Hsp90 uniquely targets client proteins associated with all six hallmarks of cancer. Thus, Hsp90 has emerged as a promising target for the treatment of cancer. Hsp90 exists as a homodimer, which contains three domains. The N-terminal domain contains an ATP-binding site that binds the natural products geldanamycin and radicicol. The middle domain is highly charged and has high affinity for co-chaperones and client proteins. Initial studies by Csermely and co-workers suggested a second ATP-binding site in the C-terminus of Hsp90. This C-terminal nucleotide binding pocket has been shown to not only bind ATP, but cisplatin, novobiocin, epilgallocatechin-3-gallate (EGCG) and taxol. The coumarin antibiotics novobiocin, clorobiocin, and coumermycin A1 were isolated from several streptomyces strains and exhibit potent activity against Gram-positive bacteria. These compounds bind type II topoisomerases, including DNA gyrase, and inhibit the enzyme-catalyzed hydrolysis of ATP. As a result, novobiocin analogues have garnered the attention of numerous researchers as an attractive agent for the treatment of bacterial infection. Novobiocin was reported to bind weakly to the newly discovered Hsp90 C-terminal ATP binding site ( approximately 700 M in SkBr3 cells) and induce degradation of Hsp90 client proteins. Structural modification of this compound has led to an increase of 1000-fold in activity in anti-proliferative assays. Recent studies of structure-activity relationship (SAR) by Renoir and co-workers highlighted the crucial role of the C-4 and/or C-7 positions of the coumarin and removal of the noviose moiety, which appeared to be essential for degradation of Hsp90 client proteins. Unlike the N-terminal ATP binding site, there is no reported co-crystal structure of Hsp90 C-terminus bound to any inhibitor. The Hsp90 C-terminal domain, however, is known to contain a conserved pentapeptide sequence (MEEVD) which is recognized by co-chaperones. Cisplatin is a platinum-containing chemotherapeutic used to treat various types of cancers, including testicular, ovarian, bladder, and small cell lung cancer. Most notably, cisplatin coordinates to DNA bases, resulting in cross-linked DNA, which prohibits rapidly dividing cells from duplicating DNA for mitosis. Itoh and co-workers reported that cisplatin decreases the chaperone activity of Hsp90. This group applied bovine brain cytosol to a cisplatin affinity column, eluted with cisplatin and detected Hsp90 in the eluent. Subsequent experiments indicated that cisplatin exhibits high affinity for Hsp90. Moreover Csermely and co-workers determined that the cisplatin binding site is located proximal to the C-terminal ATP binding site. EGCG is one of the active ingredients found in green tea. EGCG is known to inhibit the activity of many Hsp90-dependent client proteins, including telomerase, several kinases, and the aryl hydrocarbon receptor (AhR). Recently Gasiewicz and co-workers reported that EGCG manifests its antagonistic activity against AhR through binding Hsp90. Similar to novobiocin, EGCG was shown to bind the C-terminus of Hsp90. Unlike previously identified N-terminal Hsp90 inhibitors, EGCG does not appear to prevent Hsp90 from forming multiprotein complexes. Studies are currently underway to determine whether EGCG competes with novobiocin or cisplatin binding. Taxol, a well-known drug for the treatment of cancer, is responsible for the stabilization of microtubules and the inhibition of mitosis. Previous studies have shown that taxol induces the activation of kinases and transcription factors, and mimics the effect of bacterial lipopolysaccharide (LPS), an attribute unrelated to its tubulin-binding properties. Rosen and co-workers prepared a biotinylated taxol derivative and performed affinity chromatography experiments with lysates from both mouse brain and macrophage cell lines. These studies led to identification of two chaperones, Hsp70 and Hsp90, by mass spectrometry. In contrast to typical Hsp90-binding drugs, taxol exhibits a stimulatory response. Recently it was reported that the geldanamycin derivative 17-AAG behaves synergistically with taxol-induced apoptosis. This review describes the different C-terminal inhibitors of Hsp90, with specific emphasis on structure-activity relationship studies of novobiocin and their effects on anti-proliferative activity.
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Affiliation(s)
- Alison Donnelly
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045-7563, USA
| | - Brian S. J. Blagg
- Department of Medicinal Chemistry, 1251 Wescoe Hall Drive, Malott 4070, The University of Kansas, Lawrence, Kansas 66045-7563, USA
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191
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Stafford LJ, Vaidya KS, Welch DR. Metastasis suppressors genes in cancer. Int J Biochem Cell Biol 2008; 40:874-91. [DOI: 10.1016/j.biocel.2007.12.016] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 12/17/2007] [Accepted: 12/18/2007] [Indexed: 01/31/2023]
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192
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Botër M, Amigues B, Peart J, Breuer C, Kadota Y, Casais C, Moore G, Kleanthous C, Ochsenbein F, Shirasu K, Guerois R. Structural and functional analysis of SGT1 reveals that its interaction with HSP90 is required for the accumulation of Rx, an R protein involved in plant immunity. THE PLANT CELL 2007; 19:3791-804. [PMID: 18032631 PMCID: PMC2174866 DOI: 10.1105/tpc.107.050427] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 10/07/2007] [Accepted: 10/31/2007] [Indexed: 05/18/2023]
Abstract
SGT1 (for suppressor of G2 allele of skp1) and RAR1 (for required for Mla12 resistance) are highly conserved eukaryotic proteins that interact with the molecular chaperone HSP90 (for heat shock protein90). In plants, SGT1, RAR1, and HSP90 are essential for disease resistance triggered by a number of resistance (R) proteins. Here, we present structural and functional characterization of plant SGT1 proteins. Random mutagenesis of Arabidopsis thaliana SGT1b revealed that its CS (for CHORD-SGT1) and SGS (for SGT1 specific) domains are essential for disease resistance. NMR-based interaction surface mapping and mutational analyses of the CS domain showed that the CHORD II domain of RAR1 and the N-terminal domain of HSP90 interact with opposite sides of the CS domain. Functional analysis of the CS mutations indicated that the interaction between SGT1 and HSP90 is required for the accumulation of Rx, a potato (Solanum tuberosum) R protein. Biochemical reconstitution experiments suggest that RAR1 may function to enhance the SGT1-HSP90 interaction by promoting ternary complex formation.
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Affiliation(s)
- Marta Botër
- Sainsbury Laboratory, John Ines Centre, Norwich NR4 7UH, United Kingdom
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193
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Wayne N, Bolon DN. Dimerization of Hsp90 is required for in vivo function. Design and analysis of monomers and dimers. J Biol Chem 2007; 282:35386-95. [PMID: 17908693 DOI: 10.1074/jbc.m703844200] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heat shock protein 90 (Hsp90) plays a central role in signal transduction and has emerged as a promising target for anti-cancer therapeutics, but its molecular mechanism is poorly understood. At physiological concentration, Hsp90 predominantly forms dimers, but the function of full-length monomers in cells is not clear. Hsp90 contains three domains: the N-terminal and middle domains contribute directly to ATP binding and hydrolysis and the C domain mediates dimerization. To study the function of Hsp90 monomers, we used a single-chain strategy that duplicated the C-terminal dimerization domain. This novel monomerization strategy had the dual effect of stabilizing the C domain to denaturation and hindering intermolecular association of the ATPase domain. The resulting construct was predominantly monomeric at physiological concentration and did not function to support yeast viability as the sole Hsp90. The monomeric construct was also defective at ATP hydrolysis and the activation of a kinase and steroid receptor substrate in yeast cells. The ability to support yeast growth was rescued by the addition of a coiled-coil dimerization domain, indicating that the parental single-chain construct is functionally defective because it is monomeric.
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Affiliation(s)
- Natalie Wayne
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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194
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Grad I, Picard D. The glucocorticoid responses are shaped by molecular chaperones. Mol Cell Endocrinol 2007; 275:2-12. [PMID: 17628337 DOI: 10.1016/j.mce.2007.05.018] [Citation(s) in RCA: 249] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 05/23/2007] [Accepted: 05/24/2007] [Indexed: 12/26/2022]
Abstract
The glucocorticoid receptor is a known regulator of a variety of physiological processes. Its mode of action is well defined: upon hormone binding, it undergoes a conformational change, translocates to the nucleus and modulates the transcription of target genes. Molecular chaperones have a widely recognized role in the folding of newly made proteins, but their participation in further maturation of folded proteins to their active states and beyond tends to be underestimated. This review presents the current knowledge on how the Hsp70 and Hsp90 chaperone machines help to shape the responses to glucocorticoids. We discuss the contributions of these molecular chaperones to folding, activation, intracellular transport, transcriptional regulation, and decay of the glucocorticoid receptor.
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Affiliation(s)
- Iwona Grad
- Département de Biologie Cellulaire, Université de Genève, Sciences III, 30 quai Ernest-Ansermet, 1211 Genève 4, Switzerland
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195
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Brown MA, Zhu L, Schmidt C, Tucker PW. Hsp90--from signal transduction to cell transformation. Biochem Biophys Res Commun 2007; 363:241-6. [PMID: 17826744 PMCID: PMC2528838 DOI: 10.1016/j.bbrc.2007.08.054] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 08/03/2007] [Indexed: 11/30/2022]
Abstract
The molecular chaperone, Hsp90, facilitates the maturation and/or activation of over 100 'client proteins' involved in signal transduction and transcriptional regulation. Largely an enigma among the families of heat shock proteins, Hsp90 is central to processes broadly ranging from cell cycle regulation to cellular transformation. Here, we review the contemporary body of knowledge regarding the biochemical mechanisms of Hsp90 and update the most current paradigms defining its involvement in both normal and pathological cell physiology.
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Affiliation(s)
| | | | | | - Philip W. Tucker
- *Corresponding Author: Philip W. Tucker, Section of Molecular Genetics and Microbiology and Institute for Cellular and Molecular Biology, The University of Texas at Austin, 1 University Station A5000, Austin, TX 78712, USA. Phone: (512) 475-7705; Fax (512) 475-7707; E-mail:
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196
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Millson SH, Truman AW, Rácz A, Hu B, Panaretou B, Nuttall J, Mollapour M, Söti C, Piper PW. Expressed as the sole Hsp90 of yeast, the alpha and beta isoforms of human Hsp90 differ with regard to their capacities for activation of certain client proteins, whereas only Hsp90beta generates sensitivity to the Hsp90 inhibitor radicicol. FEBS J 2007; 274:4453-63. [PMID: 17681020 DOI: 10.1111/j.1742-4658.2007.05974.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Heat shock protein 90 (Hsp90) is a molecular chaperone required for the activity of many of the most important regulatory proteins of eukaryotic cells (the Hsp90 'clients'). Vertebrates have two isoforms of cytosolic Hsp90, Hsp90alpha and Hsp90beta. Hsp90beta is expressed constitutively to a high level in most tissues and is generally more abundant than Hsp90alpha, whereas Hsp90alpha is stress-inducible and overexpressed in many cancerous cells. Expressed as the sole Hsp90 of yeast, human Hsp90alpha and Hsp90beta are both able to provide essential Hsp90 functions. Activations of certain Hsp90 clients (heat shock transcription factor, v-src) were more efficient with Hsp90alpha, rather than Hsp90beta, present in the yeast. In contrast, activation of certain other clients (glucocorticoid receptor; extracellular signal-regulated kinase-5 mitogen-activated protein kinase) was less affected by the human Hsp90 isoform present in these cells. Remarkably, whereas expression of Hsp90beta as the sole Hsp90 of yeast rendered cells highly sensitive to the Hsp90 inhibitor radicicol, comparable expression of Hsp90alpha did not. This raises the distinct possibility that, also for mammalian systems, alterations to the Hsp90alpha/Hsp90beta ratio (as with heat shock) might be a significant factor affecting cellular susceptibility to Hsp90 inhibitors.
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Affiliation(s)
- Stefan H Millson
- Department of Molecular Biology and Biotechnology, The University of Sheffield, UK
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197
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Richardson JM, Dornan J, Opamawutthikul M, Bruce S, Page AP, Walkinshaw MD. Cloning, expression and characterisation of FKB-6, the sole large TPR-containing immunophilin from C. elegans. Biochem Biophys Res Commun 2007; 360:566-72. [PMID: 17610845 DOI: 10.1016/j.bbrc.2007.06.080] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 06/09/2007] [Indexed: 11/19/2022]
Abstract
We have cloned, expressed, purified and characterised ceFKB-6, the only large tetratricopeptide repeat motif-containing immunophilin in Caenorhabditis elegans which is similar to the human orthologues FKBP51 and FKBP52. It shows increased peptidyl prolyl isomerase activity, the measured k(cat)/K(m) of 1.3 x 10(6) M(-1) s(-1)is twofold greater than that of hFKBP12 and hFKBP51. NMR studies of the interaction between FKB-6 and the C-terminal DAF-21 pentapeptide MEEVD show interactions consistent with those found between the large human immunophilin TPR domains and human Hsp90. In vivo localisation studies show that the fkb-6 gene is expressed in all stages from embryo to adult with predominant expression being noted in the adult dorsal and ventral nerve cords.
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Affiliation(s)
- Julia M Richardson
- School of Biological Sciences, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
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198
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Ren M, Santhanam A, Lee P, Caplan A, Garrett S. Alteration of the protein kinase binding domain enhances function of the Saccharomyces cerevisiae molecular chaperone Cdc37. EUKARYOTIC CELL 2007; 6:1363-72. [PMID: 17573546 PMCID: PMC1951142 DOI: 10.1128/ec.00165-07] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cdc37 is a molecular chaperone that has a general function in the biogenesis of protein kinases. We identified mutations within the putative "protein kinase binding domain" of Cdc37 that alleviate the conditional growth defect of a strain containing a temperature-sensitive allele, tpk2(Ts), of the cyclic AMP-dependent protein kinase (PKA). These dominant mutations alleviate the temperature-sensitive growth defect by elevating PKA activity, as judged by their effects on PKA-regulated processes, localization and phosphorylation of the PKA effector Msn2, as well as in vitro PKA activity. Although the tpk2(Ts) growth defect is also alleviated by Cdc37 overproduction, the CDC37 dominant mutants contain wild-type Cdc37 protein levels. In addition, Saccharomyces cerevisiae Ste11 protein kinase has an elevated physical interaction with the altered Cdc37 protein. These results implicate specific amino-terminal residues in the interaction between Cdc37 and client protein kinases and provide further genetic and biochemical support for a model in which Cdc37 functions as a molecular chaperone for protein kinases.
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Affiliation(s)
- Min Ren
- Graduate School of Biomedical Sciences, Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, 225 Warren St., Newark, NJ 07101, USA
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199
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Flom G, Behal R, Rosen L, Cole D, Johnson J. Definition of the minimal fragments of Sti1 required for dimerization, interaction with Hsp70 and Hsp90 and in vivo functions. Biochem J 2007; 404:159-67. [PMID: 17300223 PMCID: PMC1868838 DOI: 10.1042/bj20070084] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The molecular chaperone Hsp (heat-shock protein) 90 is critical for the activity of diverse cellular client proteins. In a current model, client proteins are transferred from Hsp70 to Hsp90 in a process mediated by the co-chaperone Sti1/Hop, which may simultaneously interact with Hsp70 and Hsp90 via separate TPR (tetratricopeptide repeat) domains, but the mechanism and in vivo importance of this function is unclear. In the present study, we used truncated forms of Sti1 to determine the minimal regions required for the Hsp70 and Hsp90 interaction, as well as Sti1 dimerization. We found that both TPR1 and TPR2B contribute to the Hsp70 interaction in vivo and that mutations in both TPR1 and TPR2B were required to disrupt the in vitro interaction of Sti1 with the C-terminus of the Hsp70 Ssa1. The TPR2A domain was required for the Hsp90 interaction in vivo, but the isolated TPR2A domain was not sufficient for the Hsp90 interaction unless combined with the TPR2B domain. However, isolated TPR2A was both necessary and sufficient for purified Sti1 to migrate as a dimer in solution. The DP2 domain, which is essential for in vivo function, was dispensable for the Hsp70 and Hsp90 interaction, as well as Sti1 dimerization. As evidence for the role of Sti1 in mediating the interaction between Hsp70 and Hsp90 in vivo, we identified Sti1 mutants that result in reduced recovery of Hsp70 in Hsp90 complexes. We also identified two Hsp90 mutants that exhibit a reduced Hsp70 interaction, which may help clarify the mechanism of client transfer between the two molecular chaperones.
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Affiliation(s)
- Gary Flom
- Department of Microbiology, Molecular Biology and Biochemistry, and the Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3052, U.S.A
| | - Robert H. Behal
- Department of Microbiology, Molecular Biology and Biochemistry, and the Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3052, U.S.A
| | - Luke Rosen
- Department of Microbiology, Molecular Biology and Biochemistry, and the Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3052, U.S.A
| | - Douglas G. Cole
- Department of Microbiology, Molecular Biology and Biochemistry, and the Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3052, U.S.A
| | - Jill L. Johnson
- Department of Microbiology, Molecular Biology and Biochemistry, and the Center for Reproductive Biology, University of Idaho, Moscow, ID 83844-3052, U.S.A
- To whom correspondence should be addressed (email )
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200
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Scholten JCM, Culley DE, Nie L, Munn KJ, Chow L, Brockman FJ, Zhang W. Development and assessment of whole-genome oligonucleotide microarrays to analyze an anaerobic microbial community and its responses to oxidative stress. Biochem Biophys Res Commun 2007; 358:571-7. [PMID: 17498652 DOI: 10.1016/j.bbrc.2007.04.160] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Accepted: 04/26/2007] [Indexed: 11/20/2022]
Abstract
The application of DNA microarray technology to investigate multiple-species microbial communities presents great challenges. In this study, we reported the design and quality assessment of four whole genome oligonucleotide microarrays for two syntroph bacteria, Desulfovibrio vulgaris and Syntrophobacter fumaroxidans, and two archaeal methanogens, Methanosarcina barkeri, and Methanospirillum hungatei, and their application to analyze global gene expression in a four-species microbial community in response to oxidative stress. In order to minimize the possibility of cross-hybridization, cross-genome comparison was performed to assure all probes unique to each genome so that the microarrays could provide species-level resolution. Microarray quality was validated by the good reproducibility of experimental measurements of multiple biological and analytical replicates. This study showed that S. fumaroxidans and M. hungatei responded to the oxidative stress with up-regulation of several genes known to be involved in reactive oxygen species (ROS) detoxification, such as catalase and rubrerythrin in S. fumaroxidans and thioredoxin and heat shock protein Hsp20 in M. hungatei. However, D. vulgaris seemed to be less sensitive to the oxidative stress as a member of a four-species community, since no gene involved in ROS detoxification was up-regulated. Our work demonstrated the successful application of microarrays to a multiple-species microbial community, and our preliminary results indicated that this approach could provide novel insights on the metabolism within microbial communities.
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Affiliation(s)
- Johannes C M Scholten
- Microbiology Department, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
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