1
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Backe SJ, Mollapour M, Woodford MR. Saccharomyces cerevisiae as a tool for deciphering Hsp90 molecular chaperone function. Essays Biochem 2023; 67:781-795. [PMID: 36912239 PMCID: PMC10497724 DOI: 10.1042/ebc20220224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 03/14/2023]
Abstract
Yeast is a valuable model organism for their ease of genetic manipulation, rapid growth rate, and relative similarity to higher eukaryotes. Historically, Saccharomyces cerevisiae has played a major role in discovering the function of complex proteins and pathways that are important for human health and disease. Heat shock protein 90 (Hsp90) is a molecular chaperone responsible for the stabilization and activation of hundreds of integral members of the cellular signaling network. Much important structural and functional work, including many seminal discoveries in Hsp90 biology are the direct result of work carried out in S. cerevisiae. Here, we have provided a brief overview of the S. cerevisiae model system and described how this eukaryotic model organism has been successfully applied to the study of Hsp90 chaperone function.
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Affiliation(s)
- Sarah J. Backe
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
| | - Mark R. Woodford
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
- Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, U.S.A
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2
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Mercier R, Yama D, LaPointe P, Johnson JL. Hsp90 mutants with distinct defects provide novel insights into cochaperone regulation of the folding cycle. PLoS Genet 2023; 19:e1010772. [PMID: 37228112 DOI: 10.1371/journal.pgen.1010772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 05/05/2023] [Indexed: 05/27/2023] Open
Abstract
Molecular chaperones play a key role in maintaining proteostasis and cellular health. The abundant, essential, cytosolic Hsp90 (Heat shock protein, 90 kDa) facilitates the folding and activation of hundreds of newly synthesized or misfolded client proteins in an ATP-dependent folding pathway. In a simplified model, Hsp70 first helps load client onto Hsp90, ATP binding results in conformational changes in Hsp90 that result in the closed complex, and then less defined events result in nucleotide hydrolysis, client release and return to the open state. Cochaperones bind and assist Hsp90 during this process. We previously identified a series of yeast Hsp90 mutants that appear to disrupt either the 'loading', 'closing' or 'reopening' events, and showed that the mutants had differing effects on activity of some clients. Here we used those mutants to dissect Hsp90 and cochaperone interactions. Overexpression or deletion of HCH1 had dramatically opposing effects on the growth of cells expressing different mutants, with a phenotypic shift coinciding with formation of the closed conformation. Hch1 appears to destabilize Hsp90-nucleotide interaction, hindering formation of the closed conformation, whereas Cpr6 counters the effects of Hch1 by stabilizing the closed conformation. Hch1 and the homologous Aha1 share some functions, but the role of Hch1 in inhibiting progression through the early stages of the folding cycle is unique. Sensitivity to the Hsp90 inhibitor NVP-AUY922 also correlates with the conformational cycle, with mutants defective in the loading phase being most sensitive and those defective in the reopening phase being most resistant to the drug. Overall, our results indicate that the timing of transition into and out of the closed conformation is tightly regulated by cochaperones. Further analysis will help elucidate additional steps required for progression through the Hsp90 folding cycle and may lead to new strategies for modulating Hsp90 function.
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Affiliation(s)
- Rebecca Mercier
- Department of Cell Biology, Faculty of Medicine and Dentistry, the University of Alberta, Edmonton, Alberta, Canada
| | - Danielle Yama
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
| | - Paul LaPointe
- Department of Cell Biology, Faculty of Medicine and Dentistry, the University of Alberta, Edmonton, Alberta, Canada
| | - Jill L Johnson
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, United States of America
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3
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Prodromou C, Aran-Guiu X, Oberoi J, Perna L, Chapple JP, van der Spuy J. HSP70-HSP90 Chaperone Networking in Protein-Misfolding Disease. Subcell Biochem 2023; 101:389-425. [PMID: 36520314 DOI: 10.1007/978-3-031-14740-1_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Molecular chaperones and their associated co-chaperones are essential in health and disease as they are key facilitators of protein-folding, quality control and function. In particular, the heat-shock protein (HSP) 70 and HSP90 molecular chaperone networks have been associated with neurodegenerative diseases caused by aberrant protein-folding. The pathogenesis of these disorders usually includes the formation of deposits of misfolded, aggregated protein. HSP70 and HSP90, plus their co-chaperones, have been recognised as potent modulators of misfolded protein toxicity, inclusion formation and cell survival in cellular and animal models of neurodegenerative disease. Moreover, these chaperone machines function not only in folding but also in proteasome-mediated degradation of neurodegenerative disease proteins. This chapter gives an overview of the HSP70 and HSP90 chaperones, and their respective regulatory co-chaperones, and explores how the HSP70 and HSP90 chaperone systems form a larger functional network and its relevance to counteracting neurodegenerative disease associated with misfolded proteins and disruption of proteostasis.
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Affiliation(s)
| | - Xavi Aran-Guiu
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Jasmeen Oberoi
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Laura Perna
- Centre for Endocrinology, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - J Paul Chapple
- Centre for Endocrinology, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK.
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4
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Alqahtani SS, Koltai T, Ibrahim ME, Bashir AHH, Alhoufie STS, Ahmed SBM, Molfetta DD, Carvalho TMA, Cardone RA, Reshkin SJ, Hifny A, Ahmed ME, Alfarouk KO. Role of pH in Regulating Cancer Pyrimidine Synthesis. J Xenobiot 2022; 12:158-180. [PMID: 35893264 PMCID: PMC9326563 DOI: 10.3390/jox12030014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/17/2022] [Accepted: 06/28/2022] [Indexed: 11/18/2022] Open
Abstract
Replication is a fundamental aspect of cancer, and replication is about reproducing all the elements and structures that form a cell. Among them are DNA, RNA, enzymes, and coenzymes. All the DNA is doubled during each S (synthesis) cell cycle phase. This means that six billion nucleic acids must be synthesized in each cycle. Tumor growth, proliferation, and mutations all depend on this synthesis. Cancer cells require a constant supply of nucleotides and other macromolecules. For this reason, they must stimulate de novo nucleotide synthesis to support nucleic acid provision. When deregulated, de novo nucleic acid synthesis is controlled by oncogenes and tumor suppressor genes that enable increased synthesis and cell proliferation. Furthermore, cell duplication must be achieved swiftly (in a few hours) and in the midst of a nutrient-depleted and hypoxic environment. This also means that the enzymes participating in nucleic acid synthesis must work efficiently. pH is a critical factor in enzymatic efficiency and speed. This review will show that the enzymatic machinery working in nucleic acid synthesis requires a pH on the alkaline side in most cases. This coincides with many other pro-tumoral factors, such as the glycolytic phenotype, benefiting from an increased intracellular pH. An increased intracellular pH is a perfect milieu for high de novo nucleic acid production through optimal enzymatic performance.
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Affiliation(s)
- Saad Saeed Alqahtani
- Department of Pharmacy Practice, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia;
- Pharmacy Practice Research Unit, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia
| | | | - Muntaser E. Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum 11111, Sudan; (M.E.I.); (A.H.H.B.)
| | - Adil H. H. Bashir
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum 11111, Sudan; (M.E.I.); (A.H.H.B.)
| | - Sari T. S. Alhoufie
- Medical Laboratories Technology Department, College of Applied Medical Sciences, Taibah University, Medina 42353, Saudi Arabia;
| | - Samrein B. M. Ahmed
- Department of Biosciences and Chemistry, College of Health, Wellbeing and Life Sciences, Sheffield Hallam University, Sheffield S1 1WB, UK;
| | - Daria Di Molfetta
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 70126 Bari, Italy; (D.D.M.); (T.M.A.C.); (R.A.C.); (S.J.R.)
| | - Tiago M. A. Carvalho
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 70126 Bari, Italy; (D.D.M.); (T.M.A.C.); (R.A.C.); (S.J.R.)
| | - Rosa Angela Cardone
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 70126 Bari, Italy; (D.D.M.); (T.M.A.C.); (R.A.C.); (S.J.R.)
| | - Stephan Joel Reshkin
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 70126 Bari, Italy; (D.D.M.); (T.M.A.C.); (R.A.C.); (S.J.R.)
| | | | - Mohamed E. Ahmed
- Research Center, Zamzam University College, Khartoum 11123, Sudan;
| | - Khalid Omer Alfarouk
- Research Center, Zamzam University College, Khartoum 11123, Sudan;
- Alfarouk Biomedical Research LLC, Temple Terrace, FL 33617, USA
- Hala Alfarouk Cancer Center, Khartoum 11123, Sudan
- Correspondence:
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5
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Singh H, Kaur K, Singh M, Kaur G, Singh P. Plant Cyclophilins: Multifaceted Proteins With Versatile Roles. FRONTIERS IN PLANT SCIENCE 2020; 11:585212. [PMID: 33193535 PMCID: PMC7641896 DOI: 10.3389/fpls.2020.585212] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/22/2020] [Indexed: 05/03/2023]
Abstract
Cyclophilins constitute a family of ubiquitous proteins that bind cyclosporin A (CsA), an immunosuppressant drug. Several of these proteins possess peptidyl-prolyl cis-trans isomerase (PPIase) activity that catalyzes the cis-trans isomerization of the peptide bond preceding a proline residue, essential for correct folding of the proteins. Compared to prokaryotes and other eukaryotes studied until now, the cyclophilin gene families in plants exhibit considerable expansion. With few exceptions, the role of the majority of these proteins in plants is still a matter of conjecture. However, recent studies suggest that cyclophilins are highly versatile proteins with multiple functionalities, and regulate a plethora of growth and development processes in plants, ranging from hormone signaling to the stress response. The present review discusses the implications of cyclophilins in different facets of cellular processes, particularly in the context of plants, and provides a glimpse into the molecular mechanisms by which these proteins fine-tune the diverse physiological pathways.
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Affiliation(s)
- Harpreet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
- Department of Bioinformatics, Hans Raj Mahila Maha Vidyalaya, Jalandhar, India
| | - Kirandeep Kaur
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
| | - Mangaljeet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
| | - Gundeep Kaur
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
- William Harvey Heart Centre, Queen Mary University of London, London, United Kingdom
| | - Prabhjeet Singh
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, India
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6
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Biebl MM, Buchner J. Structure, Function, and Regulation of the Hsp90 Machinery. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a034017. [PMID: 30745292 DOI: 10.1101/cshperspect.a034017] [Citation(s) in RCA: 166] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Heat shock protein 90 (Hsp90) is a molecular chaperone involved in the maturation of a plethora of substrates ("clients"), including protein kinases, transcription factors, and E3 ubiquitin ligases, positioning Hsp90 as a central regulator of cellular proteostasis. Hsp90 undergoes large conformational changes during its ATPase cycle. The processing of clients by cytosolic Hsp90 is assisted by a cohort of cochaperones that affect client recruitment, Hsp90 ATPase function or conformational rearrangements in Hsp90. Because of the importance of Hsp90 in regulating central cellular pathways, strategies for the pharmacological inhibition of the Hsp90 machinery in diseases such as cancer and neurodegeneration are being developed. In this review, we summarize recent structural and mechanistic progress in defining the function of organelle-specific and cytosolic Hsp90, including the impact of individual cochaperones on the maturation of specific clients and complexes with clients as well as ways of exploiting Hsp90 as a drug target.
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Affiliation(s)
- Maximilian M Biebl
- Center for Integrated Protein Science, Department of Chemistry, Technische Universität München, D-85748 Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science, Department of Chemistry, Technische Universität München, D-85748 Garching, Germany
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7
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Cox MB, Johnson JL. Evidence for Hsp90 Co-chaperones in Regulating Hsp90 Function and Promoting Client Protein Folding. Methods Mol Biol 2018; 1709:397-422. [PMID: 29177674 DOI: 10.1007/978-1-4939-7477-1_28] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Molecular chaperones are a diverse group of highly conserved proteins that transiently interact with partially folded polypeptide chains during normal cellular processes such as protein translation, translocation, and disassembly of protein complexes. Prior to folding or after denaturation, hydrophobic residues that are normally sequestered within a folded protein are exposed to the aqueous environment and are prone to aggregation or misfolding. Multiple classes of molecular chaperones, such as Hsp70s and Hsp40s, recognize and transiently bind polypeptides with exposed hydrophobic stretches in order to prevent misfolding. Other types of chaperones, such as Hsp90, have more specialized functions in that they appear to interact with only a subset of cellular proteins. This chapter focuses on the role of Hsp90 and partner co-chaperones in promoting the folding and activation of a diverse group of proteins with critical roles in cellular signaling and function.
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Affiliation(s)
- Marc B Cox
- Department of Biological Sciences, University of Texas at El Paso and the Border Biomedical Research Center, El Paso, TX, 79968, USA
| | - Jill L Johnson
- Department of Biological Sciences and the Center for Reproductive Biology, University of Idaho, Moscow, ID, 83844-3051, USA.
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8
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Sahasrabudhe P, Rohrberg J, Biebl MM, Rutz DA, Buchner J. The Plasticity of the Hsp90 Co-chaperone System. Mol Cell 2017; 67:947-961.e5. [PMID: 28890336 DOI: 10.1016/j.molcel.2017.08.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/10/2017] [Accepted: 08/08/2017] [Indexed: 11/20/2022]
Abstract
The Hsp90 system in the eukaryotic cytosol is characterized by a cohort of co-chaperones that bind to Hsp90 and affect its function. Although progress has been made regarding the underlying biochemical mechanisms, how co-chaperones influence Hsp90 client proteins in vivo has remained elusive. By investigating the effect of 12 Hsp90 co-chaperones on the activity of different client proteins in yeast, we find that deletion of co-chaperones can have a neutral or negative effect on client activity but can also lead to more active clients. Only a few co-chaperones are active on all clients studied. Closely related clients and even point mutants can depend on different co-chaperones. These effects are direct because differences in client-co-chaperone interactions can be reconstituted in vitro. Interestingly, some co-chaperones affect client conformation in vivo. Thus, co-chaperones adapt the Hsp90 cycle to the requirements of the client proteins, ensuring optimal activation.
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Affiliation(s)
- Priyanka Sahasrabudhe
- Center for Integrated Protein Science at the Department of Chemistry, Technische Universität München, 85748 Garching, Germany
| | - Julia Rohrberg
- Center for Integrated Protein Science at the Department of Chemistry, Technische Universität München, 85748 Garching, Germany
| | - Maximillian M Biebl
- Center for Integrated Protein Science at the Department of Chemistry, Technische Universität München, 85748 Garching, Germany
| | - Daniel A Rutz
- Center for Integrated Protein Science at the Department of Chemistry, Technische Universität München, 85748 Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science at the Department of Chemistry, Technische Universität München, 85748 Garching, Germany.
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9
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Zuehlke AD, Reidy M, Lin C, LaPointe P, Alsomairy S, Lee DJ, Rivera-Marquez GM, Beebe K, Prince T, Lee S, Trepel JB, Xu W, Johnson J, Masison D, Neckers L. An Hsp90 co-chaperone protein in yeast is functionally replaced by site-specific posttranslational modification in humans. Nat Commun 2017; 8:15328. [PMID: 28537252 PMCID: PMC5458067 DOI: 10.1038/ncomms15328] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 03/21/2017] [Indexed: 01/03/2023] Open
Abstract
Heat shock protein 90 (Hsp90) is an essential eukaryotic molecular chaperone. To properly chaperone its clientele, Hsp90 proceeds through an ATP-dependent conformational cycle influenced by posttranslational modifications (PTMs) and assisted by a number of co-chaperone proteins. Although Hsp90 conformational changes in solution have been well-studied, regulation of these complex dynamics in cells remains unclear. Phosphorylation of human Hsp90α at the highly conserved tyrosine 627 has previously been reported to reduce client interaction and Aha1 binding. Here we report that these effects are due to a long-range conformational impact inhibiting Hsp90α N-domain dimerization and involving a region of the middle domain/carboxy-terminal domain interface previously suggested to be a substrate binding site. Although Y627 is not phosphorylated in yeast, we demonstrate that the non-conserved yeast co-chaperone, Hch1, similarly affects yeast Hsp90 (Hsp82) conformation and function, raising the possibility that appearance of this PTM in higher eukaryotes represents an evolutionary substitution for HCH1.
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Affiliation(s)
- Abbey D Zuehlke
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Michael Reidy
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 8, Room 225, 8 Center Drive, Bethesda, Maryland 20892, USA
| | - Coney Lin
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 8, Room 225, 8 Center Drive, Bethesda, Maryland 20892, USA
| | - Paul LaPointe
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Sarah Alsomairy
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - D Joshua Lee
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Genesis M Rivera-Marquez
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Kristin Beebe
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Thomas Prince
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Sunmin Lee
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Jane B Trepel
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Wanping Xu
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
| | - Jill Johnson
- Department of Biological Sciences and the Center for Reproductive Biology, University of Idaho, Moscow, Idaho 83844, USA
| | - Daniel Masison
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 8, Room 225, 8 Center Drive, Bethesda, Maryland 20892, USA
| | - Len Neckers
- Urologic Oncologic Branch, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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10
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Hsp104 disaggregase at normal levels cures many [ PSI+] prion variants in a process promoted by Sti1p, Hsp90, and Sis1p. Proc Natl Acad Sci U S A 2017; 114:E4193-E4202. [PMID: 28484020 DOI: 10.1073/pnas.1704016114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Overproduction or deficiency of many chaperones and other cellular components cure the yeast prions [PSI+] (formed by Sup35p) or [URE3] (based on Ure2p). However, at normal expression levels, Btn2p and Cur1p eliminate most newly arising [URE3] variants but do not cure [PSI+], even after overexpression. Deficiency or overproduction of Hsp104 cures the [PSI+] prion. Hsp104 deficiency curing is a result of failure to cleave the Sup35p amyloid filaments to make new seeds, whereas Hsp104 overproduction curing occurs by a different mechanism. Hsp104(T160M) can propagate [PSI+], but cannot cure it by overproduction, thus separating filament cleavage from curing activities. Here we show that most [PSI+] variants arising spontaneously in an hsp104(T160M) strain are cured by restoration of just normal levels of the WT Hsp104. Both strong and weak [PSI+] variants are among those cured by this process. This normal-level Hsp104 curing is promoted by Sti1p, Hsp90, and Sis1p, proteins previously implicated in the Hsp104 overproduction curing of [PSI+]. The [PSI+] prion arises in hsp104(T160M) cells at more than 10-fold the frequency in WT cells. The curing activity of Hsp104 thus constitutes an antiprion system, culling many variants of the [PSI+] prion at normal Hsp104 levels.
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11
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Qiu Y, Ge Q, Wang M, Lv H, Ebrahimi M, Niu L, Teng M, Li X. The crystal structure of the Hsp90 co-chaperone Cpr7 from Saccharomyces cerevisiae. J Struct Biol 2017; 197:379-387. [PMID: 28192191 DOI: 10.1016/j.jsb.2017.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/13/2017] [Accepted: 02/08/2017] [Indexed: 10/20/2022]
Abstract
The versatility of Hsp90 can be attributed to the variety of co-chaperone proteins that modulate the role of Hsp90 in many cellular processes. As a co-chaperone of Hsp90, Cpr7 is essential for accelerating the cell growth in an Hsp90-containing trimeric complex. Here, we report the crystal structure of Cpr7 at a resolution of 1.8Å. It consists of an N-terminal PPI domain and a C-terminal TPR domain, and exhibits a U-shape conformation. Our studies revealed the aggregation state of Cpr7 in solution and the interaction properties between Cpr7 and the MEEVD sequence from the C-terminus of Hsp90. In addition, the structure and sequence analysis between Cpr7 and homologues revealed the structure basis both for the function differences between Cpr6 and Cpr7 and the functional complements between Cns1 and Cpr7. Our studies facilitate the understanding of Cpr7 and provide decent insights into the molecular mechanisms of the Hsp90 co-chaperone pathway.
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Affiliation(s)
- Yu Qiu
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Qiangqiang Ge
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Mingxing Wang
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Hui Lv
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Mohammad Ebrahimi
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Liwen Niu
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Maikun Teng
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
| | - Xu Li
- Hefei National Laboratory for Physical Sciences at Microscale, Innovation Centre for Cell Signalling Network, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
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12
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Kumar N, Gaur D, Gupta A, Puri A, Sharma D. Hsp90-Associated Immunophilin Homolog Cpr7 Is Required for the Mitotic Stability of [URE3] Prion in Saccharomyces cerevisiae. PLoS Genet 2015; 11:e1005567. [PMID: 26473735 PMCID: PMC4608684 DOI: 10.1371/journal.pgen.1005567] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/14/2015] [Indexed: 11/18/2022] Open
Abstract
The role of Hsp70 chaperones in yeast prion propagation is well established. Highly conserved Hsp90 chaperones participate in a number of cellular processes, such as client protein maturation, protein degradation, cellular signalling and apoptosis, but little is known about their role in propagation of infectious prion like aggregates. Here, we examine the influence of Hsp90 in the maintenance of yeast prion [URE3] which is a prion form of native protein Ure2, and reveal a previously unknown role of Hsp90 as an important regulator of [URE3] stability. We show that the C-terminal MEEVD pentapeptide motif, but not the client maturation activity of Hsp90, is essential for [URE3] prion stability. In testing deletions of various Hsp90 co-chaperones known to bind this motif, we find the immunophilin homolog Cpr7 is essential for [URE3] propagation. We show that Cpr7 interacts with Ure2 and enhances its fibrillation. The requirement of Cpr7 is specific for [URE3] as its deletion does not antagonize both strong and weak variant of another yeast prion [PSI+], suggesting a distinct role of the Hsp90 co-chaperone with different yeast prions. Our data show that, similar to the Hsp70 family, the Hsp90 chaperones also influence yeast prion maintenance, and that immunophilins could regulate protein multimerization independently of their activity as peptidyl-prolyl isomerases.
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Affiliation(s)
- Navinder Kumar
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Deepika Gaur
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Arpit Gupta
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Anuradhika Puri
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
| | - Deepak Sharma
- Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
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Tenge VR, Zuehlke AD, Shrestha N, Johnson JL. The Hsp90 cochaperones Cpr6, Cpr7, and Cns1 interact with the intact ribosome. EUKARYOTIC CELL 2015; 14:55-63. [PMID: 25380751 PMCID: PMC4279014 DOI: 10.1128/ec.00170-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 11/05/2014] [Indexed: 01/02/2023]
Abstract
The abundant molecular chaperone Hsp90 is essential for the folding and stabilization of hundreds of distinct client proteins. Hsp90 is assisted by multiple cochaperones that modulate Hsp90's ATPase activity and/or promote client interaction, but the in vivo functions of many of these cochaperones are largely unknown. We found that Cpr6, Cpr7, and Cns1 interact with the intact ribosome and that Saccharomyces cerevisiae lacking CPR7 or containing mutations in CNS1 exhibited sensitivity to the translation inhibitor hygromycin. Cpr6 contains a peptidyl-prolyl isomerase (PPIase) domain and a tetratricopeptide repeat (TPR) domain flanked by charged regions. Truncation or alteration of basic residues near the carboxy terminus of Cpr6 disrupted ribosome interaction. Cns1 contains an amino-terminal TPR domain and a poorly characterized carboxy-terminal domain. The isolated carboxy-terminal domain was able to interact with the ribosome. Although loss of CPR6 does not cause noticeable growth defects, overexpression of CPR6 results in enhanced growth defects in cells expressing the temperature-sensitive cns1-G90D mutation (the G-to-D change at position 90 encoded by cns1). Cpr6 mutants that exhibit reduced ribosome interaction failed to cause growth defects, indicating that ribosome interaction is required for in vivo functions of Cpr6. Together, these results represent a novel link between the Hsp90 molecular-chaperone machine and protein synthesis.
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Affiliation(s)
- Victoria R Tenge
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Abbey D Zuehlke
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Neelima Shrestha
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Jill L Johnson
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
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14
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Mutation of essential Hsp90 co-chaperones SGT1 or CNS1 renders yeast hypersensitive to overexpression of other co-chaperones. Curr Genet 2014; 60:265-76. [DOI: 10.1007/s00294-014-0432-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 05/14/2014] [Accepted: 06/03/2014] [Indexed: 12/14/2022]
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