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Ziegelhoffer T, Verma AK, Delewski W, Schilke BA, Hill PM, Pitek M, Marszalek J, Craig EA. NAC and Zuotin/Hsp70 chaperone systems coexist at the ribosome tunnel exit in vivo. Nucleic Acids Res 2024; 52:3346-3357. [PMID: 38224454 PMCID: PMC11014269 DOI: 10.1093/nar/gkae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/23/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024] Open
Abstract
The area surrounding the tunnel exit of the 60S ribosomal subunit is a hub for proteins involved in maturation and folding of emerging nascent polypeptide chains. How different factors vie for positioning at the tunnel exit in the complex cellular environment is not well understood. We used in vivo site-specific cross-linking to approach this question, focusing on two abundant factors-the nascent chain-associated complex (NAC) and the Hsp70 chaperone system that includes the J-domain protein co-chaperone Zuotin. We found that NAC and Zuotin can cross-link to each other at the ribosome, even when translation initiation is inhibited. Positions yielding NAC-Zuotin cross-links indicate that when both are present the central globular domain of NAC is modestly shifted from the mutually exclusive position observed in cryogenic electron microscopy analysis. Cross-linking results also suggest that, even in NAC's presence, Hsp70 can situate in a manner conducive for productive nascent chain interaction-with the peptide binding site at the tunnel exit and the J-domain of Zuotin appropriately positioned to drive stabilization of nascent chain binding. Overall, our results are consistent with the idea that, in vivo, the NAC and Hsp70 systems can productively position on the ribosome simultaneously.
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Affiliation(s)
- Thomas Ziegelhoffer
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
| | - Amit K Verma
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
| | - Wojciech Delewski
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
| | - Brenda A Schilke
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
| | - Paige M Hill
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
| | - Marcin Pitek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk 80-307, Poland
| | - Jaroslaw Marszalek
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk 80-307, Poland
| | - Elizabeth A Craig
- Department of Biochemistry, University of Wisconsin—Madison, Madison, WI 53726, USA
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2
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Marszalek J, De Los Rios P, Cyr D, Mayer MP, Adupa V, Andréasson C, Blatch GL, Braun JEA, Brodsky JL, Bukau B, Chapple JP, Conz C, Dementin S, Genevaux P, Genest O, Goloubinoff P, Gestwicki J, Hammond CM, Hines JK, Ishikawa K, Joachimiak LA, Kirstein J, Liberek K, Mokranjac D, Nillegoda N, Ramos CHI, Rebeaud M, Ron D, Rospert S, Sahi C, Shalgi R, Tomiczek B, Ushioda R, Ustyantseva E, Ye Y, Zylicz M, Kampinga HH. J-domain proteins: From molecular mechanisms to diseases. Cell Stress Chaperones 2024; 29:21-33. [PMID: 38320449 PMCID: PMC10939069 DOI: 10.1016/j.cstres.2023.12.002] [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: 12/04/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 02/08/2024] Open
Abstract
J-domain proteins (JDPs) are the largest family of chaperones in most organisms, but much of how they function within the network of other chaperones and protein quality control machineries is still an enigma. Here, we report on the latest findings related to JDP functions presented at a dedicated JDP workshop in Gdansk, Poland. The report does not include all (details) of what was shared and discussed at the meeting, because some of these original data have not yet been accepted for publication elsewhere or represented still preliminary observations at the time.
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Affiliation(s)
- Jaroslaw Marszalek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Paolo De Los Rios
- Institute of Physics, School of Basic Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland; Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland
| | - Douglas Cyr
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Vasista Adupa
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm S-10691, Sweden
| | - Gregory L Blatch
- Biomedical Research and Drug Discovery Research Group, Faculty of Health Sciences, Higher Colleges of Technology, Sharjah, United Arab Emirates; The Vice Chancellery, The University of Notre Dame Australia, Fremantle, Western Australia, Australia; Biomedical Biotechnology Research Unit, Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Janice E A Braun
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - J Paul Chapple
- William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary University of London, London EC1M 6BQ, United Kingdom
| | - Charlotte Conz
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Sébastien Dementin
- Aix Marseille Univ, CNRS, BIP UMR 7281, IMM, 31 Chemin Joseph Aiguier, Marseille 13402, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Olivier Genest
- Aix Marseille Univ, CNRS, BIP UMR 7281, IMM, 31 Chemin Joseph Aiguier, Marseille 13402, France
| | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Faculty of Biology and Medicine, Lausanne University, Lausanne 1015, Switzerland
| | - Jason Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA 94308, USA
| | - Colin M Hammond
- Novo Nordisk Foundation Center for Protein Research (CPR), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Molecular & Clinical Cancer Medicine, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Justin K Hines
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | - Koji Ishikawa
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg 69120, Germany
| | - Lukasz A Joachimiak
- Center for Alzheimer's and Neurodegenerative Diseases, UT Southwestern Medical Center, Dallas, TX, USA; Peter O'Donnell Jr Brain Institute, UT Southwestern Medical Center, Dallas, TX, USA
| | - Janine Kirstein
- Leibniz Institute on Aging - Fritz Lipmann Institute and Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, Jena 07745, Germany
| | - Krzysztof Liberek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Dejana Mokranjac
- LMU Munich, Biocenter-Cell Biology, Großhadernerstr. 2, Planegg-Martinsried 82152, Germany
| | - Nadinath Nillegoda
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia; Centre for Dementia and Brain Repair at the Australian Regenerative Medicine Institute, Monash University, Melbourne, Victoria, Australia
| | - Carlos H I Ramos
- Institute of Chemistry, University of Campinas-UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Mathieu Rebeaud
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne - EPFL, Lausanne CH 1015, Switzerland
| | - David Ron
- University of Cambridge, Cambridge CB2 0XY, United Kingdom
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Chandan Sahi
- Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Bhopal, Madhya Pradesh, India; IISER Bhopal, Room Number 117, AB3, Bhopal Bypass Road, Bhopal 462066, Madhya Pradesh, India
| | - Reut Shalgi
- Department of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Bartlomiej Tomiczek
- Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland
| | - Ryo Ushioda
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Elizaveta Ustyantseva
- Department of Biomedical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Yihong Ye
- National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maciej Zylicz
- Foundation for Polish Science, Warsaw 02-611, Poland
| | - Harm H Kampinga
- Department of Biomedical Sciences, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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3
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Black A, Williams TD, Soubigou F, Joshua IM, Zhou H, Lamoliatte F, Rousseau A. The ribosome-associated chaperone Zuo1 controls translation upon TORC1 inhibition. EMBO J 2023; 42:e113240. [PMID: 37984430 PMCID: PMC10711665 DOI: 10.15252/embj.2022113240] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/22/2023] Open
Abstract
Protein requirements of eukaryotic cells are ensured by proteostasis, which is mediated by tight control of TORC1 activity. Upon TORC1 inhibition, protein degradation is increased and protein synthesis is reduced through inhibition of translation initiation to maintain cell viability. Here, we show that the ribosome-associated complex (RAC)/Ssb chaperone system, composed of the HSP70 chaperone Ssb and its HSP40 co-chaperone Zuo1, is required to maintain proteostasis and cell viability under TORC1 inhibition in Saccharomyces cerevisiae. In the absence of Zuo1, translation does not decrease in response to the loss of TORC1 activity. A functional interaction between Zuo1 and Ssb is required for proper translational control and proteostasis maintenance upon TORC1 inhibition. Furthermore, we have shown that the rapid degradation of eIF4G following TORC1 inhibition is mediated by autophagy and is prevented in zuo1Δ cells, contributing to decreased survival in these conditions. We found that autophagy is defective in zuo1Δ cells, which impedes eIF4G degradation upon TORC1 inhibition. Our findings identify an essential role for RAC/Ssb in regulating translation in response to changes in TORC1 signalling.
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Affiliation(s)
- Ailsa Black
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Thomas D Williams
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Flavie Soubigou
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Ifeoluwapo M Joshua
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Houjiang Zhou
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Frederic Lamoliatte
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
| | - Adrien Rousseau
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life SciencesUniversity of DundeeDundeeUK
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4
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Chen YJ, Cheng SY, Liu CH, Tsai WC, Wu HH, Huang MD. Exploration of the truncated cytosolic Hsp70 in plants - unveiling the diverse T1 lineage and the conserved T2 lineage. FRONTIERS IN PLANT SCIENCE 2023; 14:1279540. [PMID: 38034583 PMCID: PMC10687569 DOI: 10.3389/fpls.2023.1279540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 10/18/2023] [Indexed: 12/02/2023]
Abstract
The 70-kDa heat shock proteins (Hsp70s) are chaperone proteins involved in protein folding processes. Truncated Hsp70 (Hsp70T) refers to the variant lacking a conserved C-terminal motif, which is crucial for co-chaperone interactions or protein retention. Despite their significance, the characteristics of Hsp70Ts in plants remain largely unexplored. In this study, we performed a comprehensive genome-wide analysis of 192 sequenced plant and green algae genomes to investigate the distribution and features of Hsp70Ts. Our findings unveil the widespread occurrence of Hsp70Ts across all four Hsp70 forms, including cytosolic, endoplasmic reticulum, mitochondrial, and chloroplast Hsp70s, with cytosolic Hsp70T being the most prevalent and abundant subtype. Cytosolic Hsp70T is characterized by two distinct lineages, referred to as T1 and T2. Among the investigated plant and green algae species, T1 genes were identified in approximately 60% of cases, showcasing a variable gene count ranging from one to several dozens. In contrast, T2 genes were prevalent across the majority of plant genomes, usually occurring in fewer than five gene copies per species. Sequence analysis highlights that the putative T1 proteins exhibit higher similarity to full-length cytosolic Hsp70s in comparison to T2 proteins. Intriguingly, the T2 lineage demonstrates a higher level of conservation within their protein sequences, whereas the T1 lineage presents a diverse range in the C-terminal and SBDα region, leading to categorization into four distinct subtypes. Furthermore, we have observed that T1-rich species characterized by the possession of 15 or more T1 genes exhibit an expansion of T1 genes into tandem gene clusters. The T1 gene clusters identified within the Laurales order display synteny with clusters found in a species of the Chloranthales order and another species within basal angiosperms, suggesting a conserved evolutionary relationship of T1 gene clusters among these plants. Additionally, T2 genes demonstrate distinct expression patterns in seeds and under heat stress, implying their potential roles in seed development and stress response.
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Affiliation(s)
- Yi-Jing Chen
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Sou-Yu Cheng
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Cheng-Han Liu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Wen-Chieh Tsai
- Institute of Tropical Plant Sciences and Microbiology, National Cheng Kung University, Tainan, Taiwan
| | - Hsin-Hsin Wu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Ming-Der Huang
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
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5
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Kišonaitė M, Wild K, Lapouge K, Gesé GV, Kellner N, Hurt E, Sinning I. Structural inventory of cotranslational protein folding by the eukaryotic RAC complex. Nat Struct Mol Biol 2023; 30:670-677. [PMID: 37081320 DOI: 10.1038/s41594-023-00973-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 03/20/2023] [Indexed: 04/22/2023]
Abstract
The challenge of nascent chain folding at the ribosome is met by the conserved ribosome-associated complex (RAC), which forms a chaperone triad with the Hsp70 protein Ssb in fungi, and consists of the non-canonical Hsp70 Ssz1 and the J domain protein Zuotin (Zuo1). Here we determine cryo-EM structures of Chaetomium thermophilum RAC bound to 80S ribosomes. RAC adopts two distinct conformations accommodating continuous ribosomal rotation by a flexible lever arm. It is held together by a tight interaction between the Ssz1 substrate-binding domain and the Zuo1 N terminus, and additional contacts between the Ssz1 nucleotide-binding domain and Zuo1 J- and Zuo1 homology domains, which form a rigid unit. The Zuo1 HPD motif conserved in J-proteins is masked in a non-canonical interaction by the Ssz1 nucleotide-binding domain, and allows the positioning of Ssb for activation by Zuo1. Overall, we provide the basis for understanding how RAC cooperates with Ssb in a dynamic nascent chain interaction and protein folding.
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Affiliation(s)
- Miglė Kišonaitė
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | | | - Nikola Kellner
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Ed Hurt
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany.
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6
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Knorr AG, Mackens-Kiani T, Musial J, Berninghausen O, Becker T, Beatrix B, Beckmann R. The dynamic architecture of Map1- and NatB-ribosome complexes coordinates the sequential modifications of nascent polypeptide chains. PLoS Biol 2023; 21:e3001995. [PMID: 37079644 PMCID: PMC10118133 DOI: 10.1371/journal.pbio.3001995] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/10/2023] [Indexed: 04/21/2023] Open
Abstract
Cotranslational modification of the nascent polypeptide chain is one of the first events during the birth of a new protein. In eukaryotes, methionine aminopeptidases (MetAPs) cleave off the starter methionine, whereas N-acetyl-transferases (NATs) catalyze N-terminal acetylation. MetAPs and NATs compete with other cotranslationally acting chaperones, such as ribosome-associated complex (RAC), protein targeting and translocation factors (SRP and Sec61) for binding sites at the ribosomal tunnel exit. Yet, whereas well-resolved structures for ribosome-bound RAC, SRP and Sec61, are available, structural information on the mode of ribosome interaction of eukaryotic MetAPs or of the five cotranslationally active NATs is only available for NatA. Here, we present cryo-EM structures of yeast Map1 and NatB bound to ribosome-nascent chain complexes. Map1 is mainly associated with the dynamic rRNA expansion segment ES27a, thereby kept at an ideal position below the tunnel exit to act on the emerging substrate nascent chain. For NatB, we observe two copies of the NatB complex. NatB-1 binds directly below the tunnel exit, again involving ES27a, and NatB-2 is located below the second universal adapter site (eL31 and uL22). The binding mode of the two NatB complexes on the ribosome differs but overlaps with that of NatA and Map1, implying that NatB binds exclusively to the tunnel exit. We further observe that ES27a adopts distinct conformations when bound to NatA, NatB, or Map1, together suggesting a contribution to the coordination of a sequential activity of these factors on the emerging nascent chain at the ribosomal exit tunnel.
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Affiliation(s)
- Alexandra G. Knorr
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Timur Mackens-Kiani
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Joanna Musial
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Otto Berninghausen
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Thomas Becker
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Birgitta Beatrix
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
| | - Roland Beckmann
- Department of Biochemistry, Gene Center, Ludwig-Maximilians University Munich, University of Munich, Munich, Germany
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7
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Tian J, Dewer Y, Qu C, Li F, Luo C. Heat-shock protein 70-a hub gene-underwent adaptive evolution involved in whitefly-wild tomato interaction. PEST MANAGEMENT SCIENCE 2022; 78:4471-4479. [PMID: 35796079 DOI: 10.1002/ps.7065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 06/29/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The whitefly Bemisia tabaci causes severe damage to cultivated tomato plants, but actively avoids the wild tomato Solanum habrochaites. Moreover, the mortality of whitefly increases significantly after feeding with the wild tomato. However, additional experiments are warranted to more carefully elucidate the specific molecular elements underlying the interaction between whitefly and wild tomato. RESULTS Our results showed that S. habrochaites significantly increases the mortality of whitefly adults and decreases both their fertility and fecundity. In addition, the expression of stress-response genes in whitefly after exposure to S. habrochaites was analyzed using RNA sequencing. Weighted gene co-expression network analysis was conducted to identify the hub genes to determine their potential associations with the mortality of whitefly. These results suggested that the expression of heat-shock protein (HSP), multicopper oxidase, and 2-Oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) decarboxylase genes were induced in whitefly. To validate the gene associations with whitefly mortality, a high-throughput in vivo model system and RNAi-based gene silencing were used. The results revealed that the RNAi-mediated depletion of the HSP gene, which belongs to the HSP70 subfamily, increased the mortality of whitefly. Furthermore, the selection pressure analysis showed that a total of five amino acid sites of positive selection were identified, three of which were located in the nucleotide-binding domain and the other two in the substrate-binding domain. CONCLUSIONS This is the first report on the potential implication of HSPs in whitefly-wild plant interactions. This study could more precisely identify the molecular mechanisms of whitefly in response to wild tomatoes. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Jiahui Tian
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Youssef Dewer
- Phytotoxicity Research Department, Central Agricultural Pesticide Laboratory, Agricultural Research Center, Giza, Egypt
| | - Cheng Qu
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Fengqi Li
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Chen Luo
- Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
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8
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Weidenhausen J, Kopp J, Ruger-Herreros C, Stein F, Haberkant P, Lapouge K, Sinning I. Extended N-Terminal Acetyltransferase Naa50 in Filamentous Fungi Adds to Naa50 Diversity. Int J Mol Sci 2022; 23:ijms231810805. [PMID: 36142717 PMCID: PMC9500918 DOI: 10.3390/ijms231810805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022] Open
Abstract
Most eukaryotic proteins are N-terminally acetylated by a set of Nα acetyltransferases (NATs). This ancient and ubiquitous modification plays a fundamental role in protein homeostasis, while mutations are linked to human diseases and phenotypic defects. In particular, Naa50 features species-specific differences, as it is inactive in yeast but active in higher eukaryotes. Together with NatA, it engages in NatE complex formation for cotranslational acetylation. Here, we report Naa50 homologs from the filamentous fungi Chaetomium thermophilum and Neurospora crassa with significant N- and C-terminal extensions to the conserved GNAT domain. Structural and biochemical analyses show that CtNaa50 shares the GNAT structure and substrate specificity with other homologs. However, in contrast to previously analyzed Naa50 proteins, it does not form NatE. The elongated N-terminus increases Naa50 thermostability and binds to dynein light chain protein 1, while our data suggest that conserved positive patches in the C-terminus allow for ribosome binding independent of NatA. Our study provides new insights into the many facets of Naa50 and highlights the diversification of NATs during evolution.
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Affiliation(s)
- Jonas Weidenhausen
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
| | - Jürgen Kopp
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
| | - Carmen Ruger-Herreros
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Center for Molecular Biology of the University of Heidelberg (ZMBH), 69120 Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Per Haberkant
- Proteomics Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Protein Expression and Purification Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Correspondence:
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9
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Johnson OT, Gestwicki JE. Multivalent protein-protein interactions are pivotal regulators of eukaryotic Hsp70 complexes. Cell Stress Chaperones 2022; 27:397-415. [PMID: 35670950 PMCID: PMC9346034 DOI: 10.1007/s12192-022-01281-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 05/18/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022] Open
Abstract
Heat shock protein 70 (Hsp70) is a molecular chaperone and central regulator of protein homeostasis (proteostasis). Paramount to this role is Hsp70's binding to client proteins and co-chaperones to produce distinct complexes, such that understanding the protein-protein interactions (PPIs) of Hsp70 is foundational to describing its function and dysfunction in disease. Mounting evidence suggests that these PPIs include both "canonical" interactions, which are universally conserved, and "non-canonical" (or "secondary") contacts that seem to have emerged in eukaryotes. These two categories of interactions involve discrete binding surfaces, such that some clients and co-chaperones engage Hsp70 with at least two points of contact. While the contributions of canonical interactions to chaperone function are becoming increasingly clear, it can be challenging to deconvolute the roles of secondary interactions. Here, we review what is known about non-canonical contacts and highlight examples where their contributions have been parsed, giving rise to a model in which Hsp70's secondary contacts are not simply sites of additional avidity but are necessary and sufficient to impart unique functions. From this perspective, we propose that further exploration of non-canonical contacts will generate important insights into the evolution of Hsp70 systems and inspire new approaches for developing small molecules that tune Hsp70-mediated proteostasis.
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Affiliation(s)
- Oleta T Johnson
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, CA, 94158, USA.
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10
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Micic J, Rodríguez-Galán O, Babiano R, Fitzgerald F, Fernández-Fernández J, Zhang Y, Gao N, Woolford JL, de la Cruz J. Ribosomal protein eL39 is important for maturation of the nascent polypeptide exit tunnel and proper protein folding during translation. Nucleic Acids Res 2022; 50:6453-6473. [PMID: 35639884 PMCID: PMC9226512 DOI: 10.1093/nar/gkac366] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/04/2022] [Accepted: 05/12/2022] [Indexed: 11/29/2022] Open
Abstract
During translation, nascent polypeptide chains travel from the peptidyl transferase center through the nascent polypeptide exit tunnel (NPET) to emerge from 60S subunits. The NPET includes portions of five of the six 25S/5.8S rRNA domains and ribosomal proteins uL4, uL22, and eL39. Internal loops of uL4 and uL22 form the constriction sites of the NPET and are important for both assembly and function of ribosomes. Here, we investigated the roles of eL39 in tunnel construction, 60S biogenesis, and protein synthesis. We show that eL39 is important for proper protein folding during translation. Consistent with a delay in processing of 27S and 7S pre-rRNAs, eL39 functions in pre-60S assembly during middle nucleolar stages. Our biochemical assays suggest the presence of eL39 in particles at these stages, although it is not visualized in them by cryo-electron microscopy. This indicates that eL39 takes part in assembly even when it is not fully accommodated into the body of pre-60S particles. eL39 is also important for later steps of assembly, rotation of the 5S ribonucleoprotein complex, likely through long range rRNA interactions. Finally, our data strongly suggest the presence of alternative pathways of ribosome assembly, previously observed in the biogenesis of bacterial ribosomal subunits.
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Affiliation(s)
- Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Reyes Babiano
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Fiona Fitzgerald
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - José Fernández-Fernández
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
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11
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Structural remodeling of ribosome associated Hsp40-Hsp70 chaperones during co-translational folding. Nat Commun 2022; 13:3410. [PMID: 35701497 PMCID: PMC9197937 DOI: 10.1038/s41467-022-31127-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 06/02/2022] [Indexed: 11/16/2022] Open
Abstract
Ribosome associated complex (RAC), an obligate heterodimer of HSP40 and HSP70 (Zuo1 and Ssz1 in yeast), is conserved in eukaryotes and functions as co-chaperone for another HSP70 (Ssb1/2 in yeast) to facilitate co-translational folding of nascent polypeptides. Many mechanistic details, such as the coordination of one HSP40 with two HSP70s and the dynamic interplay between RAC-Ssb and growing nascent chains, remain unclear. Here, we report three sets of structures of RAC-containing ribosomal complexes isolated from Saccharomyces cerevisiae. Structural analyses indicate that RAC on the nascent-chain-free ribosome is in an autoinhibited conformation, and in the presence of a nascent chain at the peptide tunnel exit (PTE), RAC undergoes large-scale structural remodeling to make Zuo1 J-Domain more accessible to Ssb. Our data also suggest a role of Zuo1 in orienting Ssb-SBD proximal to the PTE for easy capture of the substrate. Altogether, in accordance with previous data, our work suggests a sequence of structural remodeling events for RAC-Ssb during co-translational folding, triggered by the binding and passage of growing nascent chain from one to another. Ribosome associated complex (RAC)- HSP70 (Ssb in yeast) is a eukaryotic chaperone system involved in co-translational folding. Here, authors report structures of RAC-containing ribosomal complexes, which suggest a working model for the dynamic actions of RAC-Ssb during the process.
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12
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Kišonaitė M, Wild K, Lapouge K, Ruppert T, Sinning I. High-resolution structures of a thermophilic eukaryotic 80S ribosome reveal atomistic details of translocation. Nat Commun 2022; 13:476. [PMID: 35079002 PMCID: PMC8789840 DOI: 10.1038/s41467-022-27967-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 01/02/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractRibosomes are complex and highly conserved ribonucleoprotein assemblies catalyzing protein biosynthesis in every organism. Here we present high-resolution cryo-EM structures of the 80S ribosome from a thermophilic fungus in two rotational states, which due to increased 80S stability provide a number of mechanistic details of eukaryotic translation. We identify a universally conserved ‘nested base-triple knot’ in the 26S rRNA at the polypeptide tunnel exit with a bulged-out nucleotide that likely serves as an adaptable element for nascent chain containment and handover. We visualize the structure and dynamics of the ribosome protective factor Stm1 upon ribosomal 40S head swiveling. We describe the structural impact of a unique and essential m1acp3 Ψ 18S rRNA hyper-modification embracing the anticodon wobble-position for eukaryotic tRNA and mRNA translocation. We complete the eEF2-GTPase switch cycle describing the GDP-bound post-hydrolysis state. Taken together, our data and their integration into the structural landscape of 80S ribosomes furthers our understanding of protein biogenesis.
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13
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Calvaresi V, Truelsen LT, Larsen SB, Petersen NHT, Kirkegaard T, Rand KD. Conformational dynamics of free and membrane-bound human Hsp70 in model cytosolic and endo-lysosomal environments. Commun Biol 2021; 4:1369. [PMID: 34876699 PMCID: PMC8651726 DOI: 10.1038/s42003-021-02892-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 11/10/2021] [Indexed: 11/21/2022] Open
Abstract
The binding of the major stress-inducible human 70-kDa heat shock protein (Hsp70) to the anionic phospholipid bis-(monoacylglycero)-phosphate (BMP) in the lysosomal membrane is crucial for its impact on cellular pathology in lysosomal storage disorders. However, the conformational features of this protein-lipid complex remain unclear. Here, we apply hydrogen-deuterium exchange mass spectrometry (HDX-MS) to describe the dynamics of the full-length Hsp70 in the cytosol and its conformational changes upon translocation into lysosomes. Using wild-type and W90F mutant proteins, we also map and discriminate the interaction of Hsp70 with BMP and other lipid components of the lysosomal membrane. We identify the N-terminal of the nucleotide binding domain (residues 87-118) as the primary orchestrator of BMP interaction. We show that the conformation of this domain is significantly reorganized in the W90F mutant, explaining its inability to stabilize lysosomal membranes. Overall, our results reveal important new molecular details of the protective effect of Hsp70 in lysosomal storage diseases, which, in turn, could guide future drug development.
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Affiliation(s)
- Valeria Calvaresi
- grid.5254.60000 0001 0674 042XProtein Analysis Group, Department of Pharmacy, University of Copenhagen, 2100 Copenhagen O, Denmark
| | - Line T. Truelsen
- grid.5254.60000 0001 0674 042XProtein Analysis Group, Department of Pharmacy, University of Copenhagen, 2100 Copenhagen O, Denmark
| | - Sidsel B. Larsen
- grid.5254.60000 0001 0674 042XProtein Analysis Group, Department of Pharmacy, University of Copenhagen, 2100 Copenhagen O, Denmark
| | | | | | - Kasper D. Rand
- grid.5254.60000 0001 0674 042XProtein Analysis Group, Department of Pharmacy, University of Copenhagen, 2100 Copenhagen O, Denmark
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14
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Lee K, Ziegelhoffer T, Delewski W, Berger SE, Sabat G, Craig EA. Pathway of Hsp70 interactions at the ribosome. Nat Commun 2021; 12:5666. [PMID: 34580293 PMCID: PMC8476630 DOI: 10.1038/s41467-021-25930-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 09/08/2021] [Indexed: 11/09/2022] Open
Abstract
In eukaryotes, an Hsp70 molecular chaperone triad assists folding of nascent chains emerging from the ribosome tunnel. In fungi, the triad consists of canonical Hsp70 Ssb, atypical Hsp70 Ssz1 and J-domain protein cochaperone Zuo1. Zuo1 binds the ribosome at the tunnel exit. Zuo1 also binds Ssz1, tethering it to the ribosome, while its J-domain stimulates Ssb’s ATPase activity to drive efficient nascent chain interaction. But the function of Ssz1 and how Ssb engages at the ribosome are not well understood. Employing in vivo site-specific crosslinking, we found that Ssb(ATP) heterodimerizes with Ssz1. Ssb, in a manner consistent with the ADP conformation, also crosslinks to ribosomal proteins across the tunnel exit from Zuo1. These two modes of Hsp70 Ssb interaction at the ribosome suggest a functionally efficient interaction pathway: first, Ssb(ATP) with Ssz1, allowing optimal J-domain and nascent chain engagement; then, after ATP hydrolysis, Ssb(ADP) directly with the ribosome. Here, the authors use in vivo site-specific crosslinking to provide molecular-level insight into how the fungal Hsp70 chaperone system — the Ssb:Ssz1:Zuo1 triad — assists the folding process for the nascent peptide chain emerging from the ribosome tunnel.
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Affiliation(s)
- Kanghyun Lee
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Biochemistry and Biophysics, Institute for Neurodegenerative Diseases, University of California, San Francisco, CA, 94158, USA
| | - Thomas Ziegelhoffer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Wojciech Delewski
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Scott E Berger
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Chemistry, Lafayette College, Easton, PA, 18042, USA.,Biophysics Program, Stanford University, Stanford, CA, 94305, USA
| | - Grzegorz Sabat
- Biotechnology Center, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Elizabeth A Craig
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.
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15
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Li H, Hu L, Cuffee CW, Mohamed M, Li Q, Liu Q, Zhou L, Liu Q. Interdomain interactions dictate the function of the Candida albicans Hsp110 protein Msi3. J Biol Chem 2021; 297:101082. [PMID: 34403698 PMCID: PMC8424595 DOI: 10.1016/j.jbc.2021.101082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/29/2021] [Accepted: 08/13/2021] [Indexed: 01/27/2023] Open
Abstract
Heat shock proteins of 110 kDa (Hsp110s), a unique class of molecular chaperones, are essential for maintaining protein homeostasis. Hsp110s exhibit a strong chaperone activity preventing protein aggregation (the "holdase" activity) and also function as the major nucleotide-exchange factor (NEF) for Hsp70 chaperones. Hsp110s contain two functional domains: a nucleotide-binding domain (NBD) and substrate-binding domain (SBD). ATP binding is essential for Hsp110 function and results in close contacts between the NBD and SBD. However, the molecular mechanism of this ATP-induced allosteric coupling remains poorly defined. In this study, we carried out biochemical analysis on Msi3, the sole Hsp110 in Candida albicans, to dissect the unique allosteric coupling of Hsp110s using three mutations affecting the domain-domain interface. All the mutations abolished both the in vivo and in vitro functions of Msi3. While the ATP-bound state was disrupted in all mutants, only mutation of the NBD-SBDβ interfaces showed significant ATPase activity, suggesting that the full-length Hsp110s have an ATPase that is mainly suppressed by NBD-SBDβ contacts. Moreover, the high-affinity ATP-binding unexpectedly appears to require these NBD-SBD contacts. Remarkably, the "holdase" activity was largely intact for all mutants tested while NEF activity was mostly compromised, although both activities strictly depended on the ATP-bound state, indicating different requirements for these two activities. Stable peptide substrate binding to Msi3 led to dissociation of the NBD-SBD contacts and compromised interactions with Hsp70. Taken together, our data demonstrate that the exceptionally strong NBD-SBD contacts in Hsp110s dictate the unique allosteric coupling and biochemical activities.
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Affiliation(s)
- Hongtao Li
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Liqing Hu
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA; Department of Medicinal Chemistry, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Crist William Cuffee
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mahetab Mohamed
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Qianbin Li
- Department of Medicinal Chemistry, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Qingdai Liu
- Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, China
| | - Lei Zhou
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Qinglian Liu
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA.
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16
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Zhang Y, De Laurentiis E, Bohnsack KE, Wahlig M, Ranjan N, Gruseck S, Hackert P, Wölfle T, Rodnina MV, Schwappach B, Rospert S. Ribosome-bound Get4/5 facilitates the capture of tail-anchored proteins by Sgt2 in yeast. Nat Commun 2021; 12:782. [PMID: 33542241 PMCID: PMC7862611 DOI: 10.1038/s41467-021-20981-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 01/05/2021] [Indexed: 02/03/2023] Open
Abstract
The guided entry of tail-anchored proteins (GET) pathway assists in the posttranslational delivery of tail-anchored proteins, containing a single C-terminal transmembrane domain, to the ER. Here we uncover how the yeast GET pathway component Get4/5 facilitates capture of tail-anchored proteins by Sgt2, which interacts with tail-anchors and hands them over to the targeting component Get3. Get4/5 binds directly and with high affinity to ribosomes, positions Sgt2 close to the ribosomal tunnel exit, and facilitates the capture of tail-anchored proteins by Sgt2. The contact sites of Get4/5 on the ribosome overlap with those of SRP, the factor mediating cotranslational ER-targeting. Exposure of internal transmembrane domains at the tunnel exit induces high-affinity ribosome binding of SRP, which in turn prevents ribosome binding of Get4/5. In this way, the position of a transmembrane domain within nascent ER-targeted proteins mediates partitioning into either the GET or SRP pathway directly at the ribosomal tunnel exit. The guided entry of tail-anchored proteins (GET) pathway assists in the delivery of such proteins to the ER. Here, the authors reveal that the pathway components Get4/5 probe a region near the ribosomal exit tunnel. Upon emergence of a client protein, Get4/5 recruits Sgt2 and initiates the targeting phase of the pathway.
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Affiliation(s)
- Ying Zhang
- Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Evelina De Laurentiis
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Mascha Wahlig
- Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Namit Ranjan
- Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Simon Gruseck
- Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Tina Wölfle
- Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Marina V Rodnina
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Göttingen, Germany.,Max-Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Blanche Schwappach
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany. .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), Göttingen, Germany.
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, University of Freiburg, Freiburg, Germany. .,BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany.
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17
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Ghosh A, Shcherbik N. Cooperativity between the Ribosome-Associated Chaperone Ssb/RAC and the Ubiquitin Ligase Ltn1 in Ubiquitination of Nascent Polypeptides. Int J Mol Sci 2020; 21:ijms21186815. [PMID: 32957466 PMCID: PMC7554835 DOI: 10.3390/ijms21186815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic cells have evolved multiple mechanisms to detect and eliminate aberrant polypeptides. Co-translational protein surveillance systems play an important role in these mechanisms. These systems include ribosome-associated protein quality control (RQC) that detects aberrant nascent chains stalled on ribosomes and promotes their ubiquitination and degradation by the proteasome, and ribosome-associated chaperone Ssb/RAC, which ensures correct nascent chain folding. Despite the known function of RQC and Ssb/ribosome-associated complex (RAC) in monitoring the quality of newly generated polypeptides, whether they cooperate during initial stages of protein synthesis remains unexplored. Here, we provide evidence that Ssb/RAC and the ubiquitin ligase Ltn1, the major component of RQC, display genetic and functional cooperativity. Overexpression of Ltn1 rescues growth suppression of the yeast strain-bearing deletions of SSB genes during proteotoxic stress. Moreover, Ssb/RAC promotes Ltn1-dependent ubiquitination of nascent chains associated with 80S ribosomal particles but not with translating ribosomes. Consistent with this finding, quantitative western blot analysis revealed lower levels of Ltn1 associated with 80S ribosomes and with free 60S ribosomal subunits in the absence of Ssb/RAC. We propose a mechanism in which Ssb/RAC facilitates recruitment of Ltn1 to ribosomes, likely by detecting aberrations in nascent chains and leading to their ubiquitination and degradation.
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18
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Shishido H, Yoon JS, Yang Z, Skach WR. CFTR trafficking mutations disrupt cotranslational protein folding by targeting biosynthetic intermediates. Nat Commun 2020; 11:4258. [PMID: 32848127 PMCID: PMC7450043 DOI: 10.1038/s41467-020-18101-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 08/04/2020] [Indexed: 02/03/2023] Open
Abstract
Protein misfolding causes a wide spectrum of human disease, and therapies that target misfolding are transforming the clinical care of cystic fibrosis. Despite this success, however, very little is known about how disease-causing mutations affect the de novo folding landscape. Here we show that inherited, disease-causing mutations located within the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR) have distinct effects on nascent polypeptides. Two of these mutations (A455E and L558S) delay compaction of the nascent NBD1 during a critical window of synthesis. The observed folding defect is highly dependent on nascent chain length as well as its attachment to the ribosome. Moreover, restoration of the NBD1 cotranslational folding defect by second site suppressor mutations also partially restores folding of full-length CFTR. These findings demonstrate that nascent folding intermediates can play an important role in disease pathogenesis and thus provide potential targets for pharmacological correction.
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Affiliation(s)
- Hideki Shishido
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA
| | - Jae Seok Yoon
- CFFT Lab, Cystic Fibrosis Foundation, 44 Hartwell Ave, Lexington, MA, 02421, USA
| | - Zhongying Yang
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR, 97239, USA
| | - William R Skach
- Cystic Fibrosis Foundation, 4550 Montgomery Ave., Suite 1100N, Bethesda, MD, 20814, USA.
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19
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Takagi S, Kojima K, Ohashi S. Proteomic analysis on Aspergillus strains that are useful for industrial enzyme production. Biosci Biotechnol Biochem 2020; 84:2241-2252. [PMID: 32693695 DOI: 10.1080/09168451.2020.1794784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A simple intracellular proteomic study was conducted to investigate the biological activities of Aspergillus niger during industrial enzyme production. A strain actively secreting a heterologous enzyme was compared to a reference strain. In total, 1824 spots on 2-D gels were analyzed using MALDI-TOF MS, yielding 343 proteins. The elevated levels of UPR components, BipA, PDI, and calnexin, and proteins related to ERAD and ROS reduction, were observed in the enzyme-producer. The results suggest the occurrence of these responses in the enzyme-producers. Major glycolytic enzymes, Fba1, EnoA, and GpdA, were abundant but at a reduced level relative to the reference, indicating a potential repression of the glycolytic pathway. Interestingly, it was observed that a portion of over-expressed heterologous enzyme accumulated inside the cells and digested during fermentation, suggesting the secretion capacity of the strain was not enough for completing secretion. Newly identified conserved-proteins, likely in signal transduction, and other proteins were also investigated. Abbreviations: 2-D: two-dimensional; UPR: unfolded protein response; ER: endoplasmic reticulum; ERAD: ER-associated protein degradation; PDI: protein disulfide-isomerase; ROS: reactive oxygen species; RESS: Repression under Secretion Stress; CSAP: Conserved Small Abundant Protein; TCTP: translationally controlled tumor protein.
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Affiliation(s)
| | | | - Shinichi Ohashi
- Genome Biotechnology Laboratory, Kanazawa-Institute of Technology , Ishikawa, Japan
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20
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The ribosome-associated complex RAC serves in a relay that directs nascent chains to Ssb. Nat Commun 2020; 11:1504. [PMID: 32198371 PMCID: PMC7083937 DOI: 10.1038/s41467-020-15313-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 03/03/2020] [Indexed: 11/21/2022] Open
Abstract
The conserved ribosome-associated complex (RAC) consisting of Zuo1 (Hsp40) and Ssz1 (non-canonical Hsp70) acts together with the ribosome-bound Hsp70 chaperone Ssb in de novo protein folding at the ribosomal tunnel exit. Current models suggest that the function of Ssz1 is confined to the support of Zuo1, however, it is not known whether RAC by itself serves as a chaperone for nascent chains. Here we show that, via its rudimentary substrate binding domain (SBD), Ssz1 directly binds to emerging nascent chains prior to Ssb. Structural and biochemical analyses identify a conserved LP-motif at the Zuo1 N-terminus forming a polyproline-II helix, which binds to the Ssz1-SBD as a pseudo-substrate. The LP-motif competes with nascent chain binding to the Ssz1-SBD and modulates nascent chain transfer. The combined data indicate that Ssz1 is an active chaperone optimized for transient, low-affinity substrate binding, which ensures the flux of nascent chains through RAC/Ssb. The ribosome-associated complex (RAC), which contains the Hsp40 protein Zuo1 and the non-canonical Hsp70 protein Ssz1 forms a chaperone triad with the fungal-specific Hsp70 protein Ssb. Here the authors combine X-ray crystallography, crosslinking and biochemical experiments and present the structure of the Zuo1 N-terminus bound to Ssz1 and demonstrate that Ssz1 is an active chaperone for nascent chains.
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21
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Gribling-Burrer AS, Chiabudini M, Zhang Y, Qiu Z, Scazzari M, Wölfle T, Wohlwend D, Rospert S. A dual role of the ribosome-bound chaperones RAC/Ssb in maintaining the fidelity of translation termination. Nucleic Acids Res 2020; 47:7018-7034. [PMID: 31114879 PMCID: PMC6648330 DOI: 10.1093/nar/gkz334] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/05/2019] [Accepted: 04/25/2019] [Indexed: 11/22/2022] Open
Abstract
The yeast ribosome-associated complex RAC and the Hsp70 homolog Ssb are anchored to the ribosome and together act as chaperones for the folding and co-translational assembly of nascent polypeptides. In addition, the RAC/Ssb system plays a crucial role in maintaining the fidelity of translation termination; however, the latter function is poorly understood. Here we show that the RAC/Ssb system promotes the fidelity of translation termination via two distinct mechanisms. First, via direct contacts with the ribosome and the nascent chain, RAC/Ssb facilitates the translation of stalling-prone poly-AAG/A sequences encoding for polylysine segments. Impairment of this function leads to enhanced ribosome stalling and to premature nascent polypeptide release at AAG/A codons. Second, RAC/Ssb is required for the assembly of fully functional ribosomes. When RAC/Ssb is absent, ribosome biogenesis is hampered such that core ribosomal particles are structurally altered at the decoding and peptidyl transferase centers. As a result, ribosomes assembled in the absence of RAC/Ssb bind to the aminoglycoside paromomycin with high affinity (KD = 76.6 nM) and display impaired discrimination between stop codons and sense codons. The combined data shed light on the multiple mechanisms by which the RAC/Ssb system promotes unimpeded biogenesis of newly synthesized polypeptides.
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Affiliation(s)
- Anne-Sophie Gribling-Burrer
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Marco Chiabudini
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Ying Zhang
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Zonghao Qiu
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Mario Scazzari
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Tina Wölfle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Daniel Wohlwend
- Institute of Biochemistry, Chemical and Pharmaceutical Faculty, University of Freiburg, D-79104 Freiburg, Germany
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, Medical Faculty, University of Freiburg, D-79104 Freiburg, Germany.,BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
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22
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Abstract
Heat-shock proteins of 70 kDa (Hsp70s) are ubiquitous molecular chaperones that function in protein folding as well as other vital cellular processes. They bind and hydrolyze ATP in a nucleotide-binding domain (NBD) to control the binding and release of client polypeptides in a substrate-binding domain (SBD). However, the molecular mechanism for this allosteric action has remained unclear. Here, we develop and experimentally quantify a theoretical model for Hsp70 allostery based on equilibria among Hsp70 conformational states. We postulate that, when bound to ATP, Hsp70 is in equilibrium between a restraining state (R) that restricts ATP hydrolysis and binds peptides poorly, if at all, and a stimulating state (S) that hydrolyzes ATP relatively rapidly and has high intrinsic substrate affinity but rapid binding kinetics; after the hydrolysis to ADP, NBD and SBD disengage into an uncoupled state (U) that binds peptide substrates tightly, but now with slow kinetics of exchange.
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23
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Li H, Zhu H, Sarbeng EB, Liu Q, Tian X, Yang Y, Lyons C, Zhou L, Liu Q. An unexpected second binding site for polypeptide substrates is essential for Hsp70 chaperone activity. J Biol Chem 2019; 295:584-596. [PMID: 31806707 DOI: 10.1074/jbc.ra119.009686] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/02/2019] [Indexed: 12/14/2022] Open
Abstract
Heat shock proteins of 70 kDa (Hsp70s) are ubiquitous and highly conserved molecular chaperones. They play multiple essential roles in assisting with protein folding and maintaining protein homeostasis. Their chaperone activity has been proposed to require several rounds of binding to and release of polypeptide substrates at the substrate-binding domain (SBD) of Hsp70s. All available structures have revealed a single substrate-binding site in the SBD that binds a single segment of an extended polypeptide of 3-4 residues. However, this well-established single peptide-binding site alone has made it difficult to explain the efficient chaperone activity of Hsp70s. In this study, using purified proteins and site-directed mutagenesis, along with fluorescence polarization and luciferase-refolding assays, we report the unexpected discovery of a second peptide-binding site in Hsp70s. More importantly, the biochemical analyses suggested that this novel binding site, named here P2, is essential for Hsp70 chaperone activity. Furthermore, cross-linking and mutagenesis studies indicated that this second binding site is in the SBD adjacent to the first binding site. Taken together, our results suggest that these two essential binding sites of Hsp70s cooperate in protein folding.
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Affiliation(s)
- Hongtao Li
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Huanyu Zhu
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Evans Boateng Sarbeng
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Qingdai Liu
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Xueli Tian
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Ying Yang
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Charles Lyons
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Lei Zhou
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298
| | - Qinglian Liu
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298.
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24
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Zheng X, Zhang Y, Zhang X, Li C, Liu X, Lin Y, Liang S. Fhl1p protein, a positive transcription factor in Pichia pastoris, enhances the expression of recombinant proteins. Microb Cell Fact 2019; 18:207. [PMID: 31783868 PMCID: PMC6884909 DOI: 10.1186/s12934-019-1256-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 11/15/2019] [Indexed: 12/21/2022] Open
Abstract
Background The methylotrophic yeast Pichia pastoris is well-known for the production of a broad spectrum of functional types of heterologous proteins including enzymes, antigens, engineered antibody fragments, and next gen protein scaffolds and many transcription factors are utilized to address the burden caused by the high expression of heterologous proteins. In this article, a novel P. pastoris transcription factor currently annotated as Fhl1p, an activator of ribosome biosynthesis processing, was investigated for promoting the expression of the recombinant proteins. Results The function of Fhl1p of P. pastoris for improving the expression of recombinant proteins was verified in strains expressing phytase, pectinase and mRFP, showing that the productivity was increased by 20–35%. RNA-Seq was used to study the Fhl1p regulation mechanism in detail, confirming Fhl1p involved in the regulation of rRNA processing genes, ribosomal small/large subunit biogenesis genes, Golgi vesicle transport genes, etc., which contributed to boosting the expression of foreign proteins. The overexpressed Fhl1p strain exhibited increases in the polysome and monosome levels, showing improved translation activities. Conclusion This study illustrated that the transcription factor Fhl1p could effectively enhance recombinant protein expression in P. pastoris. Furthermore, we provided the evidence that overexpressed Fhl1p was related to more active translation state.
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Affiliation(s)
- Xueyun Zheng
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Yimin Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xinying Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Cheng Li
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xiaoxiao Liu
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Ying Lin
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China. .,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
| | - Shuli Liang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China. .,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
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25
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Deuerling E, Gamerdinger M, Kreft SG. Chaperone Interactions at the Ribosome. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033977. [PMID: 30833456 DOI: 10.1101/cshperspect.a033977] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The continuous refreshment of the proteome is critical to maintain protein homeostasis and to adapt cells to changing conditions. Thus, de novo protein biogenesis by ribosomes is vitally important to every cellular system. This process is delicate and error-prone and requires, besides cytosolic chaperones, the guidance by a specialized set of molecular chaperones that bind transiently to the translation machinery and the nascent protein to support early folding events and to regulate cotranslational protein transport. These chaperones include the bacterial trigger factor (TF), the archaeal and eukaryotic nascent polypeptide-associated complex (NAC), and the eukaryotic ribosome-associated complex (RAC). This review focuses on the structures, functions, and substrates of these ribosome-associated chaperones and highlights the most recent findings about their potential mechanisms of action.
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Affiliation(s)
- Elke Deuerling
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Martin Gamerdinger
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Stefan G Kreft
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
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26
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Wild K, Juaire KD, Soni K, Shanmuganathan V, Hendricks A, Segnitz B, Beckmann R, Sinning I. Reconstitution of the human SRP system and quantitative and systematic analysis of its ribosome interactions. Nucleic Acids Res 2019; 47:3184-3196. [PMID: 30649417 PMCID: PMC6451106 DOI: 10.1093/nar/gky1324] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/20/2018] [Accepted: 01/02/2019] [Indexed: 12/22/2022] Open
Abstract
Co-translational protein targeting to membranes depends on the regulated interaction of two ribonucleoprotein particles (RNPs): the ribosome and the signal recognition particle (SRP). Human SRP is composed of an SRP RNA and six proteins with the SRP GTPase SRP54 forming the targeting complex with the heterodimeric SRP receptor (SRαβ) at the endoplasmic reticulum membrane. While detailed structural and functional data are available especially for the bacterial homologs, the analysis of human SRP was impeded by the unavailability of recombinant SRP. Here, we describe the large-scale production of all human SRP components and the reconstitution of homogeneous SRP and SR complexes. Binding to human ribosomes is determined by microscale thermophoresis for individual components, assembly intermediates and entire SRP, and binding affinities are correlated with structural information available for all ribosomal contacts. We show that SRP RNA does not bind to the ribosome, while SRP binds with nanomolar affinity involving a two-step mechanism of the key-player SRP54. Ultrasensitive binding of SRP68/72 indicates avidity by multiple binding sites that are dominated by the C-terminus of SRP72. Our data extend the experimental basis to understand the mechanistic principles of co-translational targeting in mammals and may guide analyses of complex RNP–RNP interactions in general.
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Affiliation(s)
- Klemens Wild
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Keven D Juaire
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Komal Soni
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Vivekanandan Shanmuganathan
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, D-81377 Munich, Germany
| | - Astrid Hendricks
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Bernd Segnitz
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
| | - Roland Beckmann
- Gene Center and Center for Integrated Protein Science Munich, Department of Biochemistry, University of Munich, Feodor-Lynen-Str. 25, D-81377 Munich, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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27
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Liu Q, Liang C, Zhou L. Structural and functional analysis of the Hsp70/Hsp40 chaperone system. Protein Sci 2019; 29:378-390. [PMID: 31509306 DOI: 10.1002/pro.3725] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 08/29/2019] [Accepted: 09/03/2019] [Indexed: 12/22/2022]
Abstract
As one of the most abundant and highly conserved molecular chaperones, the 70-kDa heat shock proteins (Hsp70s) play a key role in maintaining cellular protein homeostasis (proteostasis), one of the most fundamental tasks for every living organism. In this role, Hsp70s are inextricably linked to many human diseases, most notably cancers and neurodegenerative diseases, and are increasingly recognized as important drug targets for developing novel therapeutics for these diseases. Hsp40s are a class of essential and universal partners for Hsp70s in almost all aspects of proteostasis. Thus, Hsp70s and Hsp40s together constitute one of the most important chaperone systems across all kingdoms of life. In recent years, we have witnessed significant progress in understanding the molecular mechanism of this chaperone system through structural and functional analysis. This review will focus on this recent progress, mainly from a structural perspective.
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Affiliation(s)
- Qinglian Liu
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Ce Liang
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
| | - Lei Zhou
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia
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28
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Kramer G, Shiber A, Bukau B. Mechanisms of Cotranslational Maturation of Newly Synthesized Proteins. Annu Rev Biochem 2019; 88:337-364. [DOI: 10.1146/annurev-biochem-013118-111717] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The timely production of functional proteins is of critical importance for the biological activity of cells. To reach the functional state, newly synthesized polypeptides have to become enzymatically processed, folded, and assembled into oligomeric complexes and, for noncytosolic proteins, translocated across membranes. Key activities of these processes occur cotranslationally, assisted by a network of machineries that transiently engage nascent polypeptides at distinct phases of translation. The sequence of events is tuned by intrinsic features of the nascent polypeptides and timely association of factors with the translating ribosome. Considering the dynamics of translation, the heterogeneity of cellular proteins, and the diversity of interaction partners, it is a major cellular achievement that these processes are temporally and spatially so precisely coordinated, minimizing the generation of damaged proteins. This review summarizes the current progress we have made toward a comprehensive understanding of the cotranslational interactions of nascent chains, which pave the way to their functional state.
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Affiliation(s)
- Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
| | - Ayala Shiber
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
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29
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Mayer MP. Intra-molecular pathways of allosteric control in Hsp70s. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0183. [PMID: 29735737 DOI: 10.1098/rstb.2017.0183] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2018] [Indexed: 12/17/2022] Open
Abstract
The 70 kDa heat-shock protein (Hsp70) is undoubtedly the most versatile of all molecular chaperones. Hsp70 is involved in numerous cellular protein folding processes, accompanying proteins throughout their lifespan from de novo folding at the ribosome to degradation at the proteasome, surveilling protein stability and functionality. Several properties of this ATP-dependent chaperone constitute the molecular basis for this versatility. With its substrate binding domain (SBD), Hsp70 transiently interacts with a short degenerative linear sequence motif found practically in all proteins and, in addition, with more folded protein conformers. Binding to polypeptides is tightly regulated by ATP binding and hydrolysis in the nucleotide binding domain, which is coupled to the SBD by an intricate allosteric mechanism. Hsp70 is regulated by a host of J-cochaperones, which act as targeting factors by regulating the ATPase activity of Hsp70 in synergism with the substrates themselves, and by several families of nucleotide exchange factors. In this review, I focus on the allosteric mechanism, which allows Hsp70s to interact with substrates with ultrahigh affinity through a non-equilibrium mode of action and summarize what mutagenesis and structural studies have taught us about the pathways and mechanics of interdomain communication.This article is part of a discussion meeting issue 'Allostery and molecular machines'.
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Affiliation(s)
- Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
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30
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G-Quadruplexes in Human Ribosomal RNA. J Mol Biol 2019; 431:1940-1955. [PMID: 30885721 DOI: 10.1016/j.jmb.2019.03.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 11/20/2022]
Abstract
rRNA is the single most abundant polymer in most cells. Mammalian rRNAs are nearly twice as large as those of prokaryotes. Differences in rRNA size are due to expansion segments, which contain extended tentacles in metazoans. Here we show that the terminus of an rRNA tentacle of Homo sapiens contains 10 tandem G-tracts that form highly stable G-quadruplexes in vitro. We characterized rRNA of the H. sapiens large ribosomal subunit by computation, circular dichroism, UV melting, fluorescent probes, nuclease accessibility, electrophoretic mobility shifts, and blotting. We investigated Expansion Segment 7 (ES7), oligomers derived from ES7, intact 28S rRNA, 80S ribosomes, and polysomes. We used mass spectrometry to identify proteins that bind to rRNA G-quadruplexes in cell lysates. These proteins include helicases (DDX3, CNBP, DDX21, DDX17) and heterogeneous nuclear ribonucleoproteins. Finally, by multiple sequence alignments, we observe that G-quadruplex-forming sequences are a general feature of LSU rRNA of Chordata but not, as far as we can tell, of other species. Chordata ribosomes present polymorphic tentacles with the potential to switch between inter- and intramolecular G-quadruplexes. To our knowledge, G-quadruplexes have not been reported previously in ribosomes.
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31
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Cotranslational assembly of protein complexes in eukaryotes revealed by ribosome profiling. Nature 2018; 561:268-272. [PMID: 30158700 PMCID: PMC6372068 DOI: 10.1038/s41586-018-0462-y] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 08/02/2018] [Indexed: 02/07/2023]
Abstract
The folding of newly synthesized proteins to the native state is a major
challenge within the crowded cellular environment, as non-productive
interactions can lead to misfolding, aggregation and degradation1. Cells cope with this challenge by
coupling synthesis with polypeptide folding and by using molecular chaperones to
safeguard folding cotranslationally2.
However, although most of the cellular proteome forms oligomeric assemblies3, little is known about the final step of
folding: the assembly of polypeptides into complexes. In prokaryotes, a
proof-of-concept study showed that the assembly of heterodimeric luciferase is
an organized cotranslational process that is facilitated by spatially confined
translation of the subunits encoded on a polycistronic mRNA4. In eukaryotes, however, fundamental
differences—such as the rarity of polycistronic mRNAs and different
chaperone constellations—raise the question of whether assembly is also
coordinated with translation. Here we provide a systematic and mechanistic
analysis of the assembly of protein complexes in eukaryotes using ribosome
profiling. We determined the in vivo interactions of the
nascent subunits from twelve hetero-oligomeric protein complexes of
Saccharomyces cerevisiae at near-residue resolution. We
find nine complexes assemble cotranslationally; the three complexes that do not
show cotranslational interactions are regulated by dedicated assembly
chaperones5–7. Cotranslational assembly often occurs
uni-directionally, with one fully synthesized subunit engaging its nascent
partner subunit, thereby counteracting its propensity for aggregation. The onset
of cotranslational subunit association coincides directly with the full exposure
of the nascent interaction domain at the ribosomal tunnel exit. The
ribosome-associated Hsp70 chaperone Ssb8
is coordinated with assembly. Ssb transiently engages partially synthesized
interaction domains and then dissociates before the onset of partner subunit
association, presumably to prevent premature assembly interactions. Our study
shows that cotranslational subunit association is a prevalent mechanism for the
assembly of hetero-oligomers in yeast and indicates that translation, folding
and assembly of protein complexes are integrated processes in eukaryotes.
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32
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Jung Y, Seong KM, Baek JH, Kim J. Ssb2 is a novel factor in regulating synthesis and degradation of Gcn4 in Saccharomyces cerevisiae. Mol Microbiol 2018; 110:728-740. [PMID: 30039896 DOI: 10.1111/mmi.14088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 07/20/2018] [Accepted: 07/21/2018] [Indexed: 12/17/2022]
Abstract
Yeast cells respond to environmental stress by inducing the master regulator Gcn4 to control genes involved in biosynthesis of amino acids and purine pathways. Gcn4 is a member of the basic leucine Zipper family and binds directly as a homodimer to a conserved regulatory region of target genes. Ssb2 was discovered to rescue the mutant Gcn4 which has a point mutation that decreases DNA-binding affinity. Ssb2 is part of the Hsp70 protein family responsible for protein quality control and it is thought that Ssb2 assists the passage of nascent polypeptide chains from the ribosomes. To characterize the mechanism behind the rescue of the mutant gcn4 phenotype, transcriptional activity and protein levels of Gcn4 were analyzed. We found that Ssb2 improved the expression of Gcn4 target genes by increasing the DNA-binding affinity of gcn4 mutants to target gene promoters under conditions of amino acid starvation. Gcn4 levels increased at both translational and post-translational levels without regulating GCN4 steady-state mRNA levels. We also found that the nuclear export signal of Ssb2 is required for interaction with Gcn4 and rescue of the gcn4 mutant phenotype. These findings suggest that Ssb2 is a critical factor that modulates Gcn4 functions in the nucleus and cytosol.
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Affiliation(s)
- Youjin Jung
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
| | - Ki Moon Seong
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
| | - Je-Hyun Baek
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
| | - Joon Kim
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
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33
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Conformation transitions of the polypeptide-binding pocket support an active substrate release from Hsp70s. Nat Commun 2017; 8:1201. [PMID: 29084938 PMCID: PMC5662698 DOI: 10.1038/s41467-017-01310-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/07/2017] [Indexed: 12/21/2022] Open
Abstract
Cellular protein homeostasis depends on heat shock proteins 70 kDa (Hsp70s), a class of ubiquitous and highly conserved molecular chaperone. Key to the chaperone activity is an ATP-induced allosteric regulation of polypeptide substrate binding and release. To illuminate the molecular mechanism of this allosteric coupling, here we present a novel crystal structure of an intact human BiP, an essential Hsp70 in ER, in an ATP-bound state. Strikingly, the polypeptide-binding pocket is completely closed, seemingly excluding any substrate binding. Our FRET, biochemical and EPR analysis suggests that this fully closed conformation is the major conformation for the ATP-bound state in solution, providing evidence for an active release of bound polypeptide substrates following ATP binding. The Hsp40 co-chaperone converts this fully closed conformation to an open conformation to initiate productive substrate binding. Taken together, this study provided a mechanistic understanding of the dynamic nature of the polypeptide-binding pocket in the Hsp70 chaperone cycle. Hsp70s are highly conserved molecular chaperones that play multiple essential roles in maintaining cellular protein homeostasis. Here, the authors provide structural evidence for active substrate release by Hsp70s upon ATP binding and provide insight into the molecular mechanism of ATP-driven Hsp70 chaperone activity.
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34
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The Hsp70 homolog Ssb affects ribosome biogenesis via the TORC1-Sch9 signaling pathway. Nat Commun 2017; 8:937. [PMID: 29038496 PMCID: PMC5643326 DOI: 10.1038/s41467-017-00635-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 07/15/2017] [Indexed: 01/07/2023] Open
Abstract
The Hsp70 Ssb serves a dual role in de novo protein folding and ribosome biogenesis; however, the mechanism by which Ssb affects ribosome production is unclear. Here we establish that Ssb is causally linked to the regulation of ribosome biogenesis via the TORC1-Sch9 signaling pathway. Ssb is bound to Sch9 posttranslationally and required for the TORC1-dependent phosphorylation of Sch9 at T737. Also, Sch9 lacking phosphorylation at T737 displays significantly reduced kinase activity with respect to targets involved in the regulation of ribosome biogenesis. The absence of either Ssb or Sch9 causes enhanced ribosome aggregation. Particularly with respect to proper assembly of the small ribosomal subunit, SSB and SCH9 display strong positive genetic interaction. In combination, the data indicate that Ssb promotes ribosome biogenesis not only via cotranslational protein folding, but also posttranslationally via interaction with natively folded Sch9, facilitating access of the upstream kinase TORC1 to Sch9-T737.The yeast Hsp70 homolog Ssb is a chaperone that binds translating ribosomes where it is thought to function primarily by promoting nascent peptide folding. Here the authors find that the ribosome biogenesis defect associated with the loss of Ssb is attributable to a specific disruption in TORC1 signaling rather than defects in ribosomal protein folding.
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35
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Two chaperones locked in an embrace: structure and function of the ribosome-associated complex RAC. Nat Struct Mol Biol 2017; 24:611-619. [PMID: 28771464 DOI: 10.1038/nsmb.3435] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/14/2017] [Indexed: 12/26/2022]
Abstract
Chaperones, which assist protein folding are essential components of every living cell. The yeast ribosome-associated complex (RAC) is a chaperone that is highly conserved in eukaryotic cells. The RAC consists of the J protein Zuo1 and the unconventional Hsp70 homolog Ssz1. The RAC heterodimer stimulates the ATPase activity of the ribosome-bound Hsp70 homolog Ssb, which interacts with nascent polypeptide chains to facilitate de novo protein folding. In addition, the RAC-Ssb system is required to maintain the fidelity of protein translation. Recent work reveals important details of the unique structures of RAC and Ssb and identifies how the chaperones interact with the ribosome. The new findings start to uncover how the exceptional chaperone triad cooperates in protein folding and maintenance of translational fidelity and its connection to extraribosomal functions.
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36
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Döring K, Ahmed N, Riemer T, Suresh HG, Vainshtein Y, Habich M, Riemer J, Mayer MP, O'Brien EP, Kramer G, Bukau B. Profiling Ssb-Nascent Chain Interactions Reveals Principles of Hsp70-Assisted Folding. Cell 2017; 170:298-311.e20. [PMID: 28708998 DOI: 10.1016/j.cell.2017.06.038] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/04/2017] [Accepted: 06/23/2017] [Indexed: 12/21/2022]
Abstract
The yeast Hsp70 chaperone Ssb interacts with ribosomes and nascent polypeptides to assist protein folding. To reveal its working principle, we determined the nascent chain-binding pattern of Ssb at near-residue resolution by in vivo selective ribosome profiling. Ssb associates broadly with cytosolic, nuclear, and hitherto unknown substrate classes of mitochondrial and endoplasmic reticulum (ER) nascent proteins, supporting its general chaperone function. Ssb engages most substrates by multiple binding-release cycles to a degenerate sequence enriched in positively charged and aromatic amino acids. Timely association with this motif upon emergence at the ribosomal tunnel exit requires ribosome-associated complex (RAC) but not nascent polypeptide-associated complex (NAC). Ribosome footprint densities along orfs reveal faster translation at times of Ssb binding, mainly imposed by biases in mRNA secondary structure, codon usage, and Ssb action. Ssb thus employs substrate-tailored dynamic nascent chain associations to coordinate co-translational protein folding, facilitate accelerated translation, and support membrane targeting of organellar proteins.
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Affiliation(s)
- Kristina Döring
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Nabeel Ahmed
- Bioinformatics and Genomics Graduate Program, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Trine Riemer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Harsha Garadi Suresh
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany; The Donnelly Centre, University of Toronto, 160 College Street, Toronto ON, Canada
| | - Yevhen Vainshtein
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany
| | - Markus Habich
- Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47, Cologne, Germany
| | - Jan Riemer
- Institute of Biochemistry, University of Cologne, Zuelpicher Str. 47, Cologne, Germany
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany
| | - Edward P O'Brien
- Bioinformatics and Genomics Graduate Program, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA; Department of Chemistry, Pennsylvania State University, University Park, PA, USA
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany.
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany.
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Weyer FA, Gumiero A, Lapouge K, Bange G, Kopp J, Sinning I. Structural basis of HypK regulating N-terminal acetylation by the NatA complex. Nat Commun 2017; 8:15726. [PMID: 28585574 PMCID: PMC5467210 DOI: 10.1038/ncomms15726] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/21/2017] [Indexed: 11/09/2022] Open
Abstract
In eukaryotes, N-terminal acetylation is one of the most common protein modifications involved in a wide range of biological processes. Most N-acetyltransferase complexes (NATs) act co-translationally, with the heterodimeric NatA complex modifying the majority of substrate proteins. Here we show that the Huntingtin yeast two-hybrid protein K (HypK) binds tightly to the NatA complex comprising the auxiliary subunit Naa15 and the catalytic subunit Naa10. The crystal structures of NatA bound to HypK or to a N-terminal deletion variant of HypK were determined without or with a bi-substrate analogue, respectively. The HypK C-terminal region is responsible for high-affinity interaction with the C-terminal part of Naa15. In combination with acetylation assays, the HypK N-terminal region is identified as a negative regulator of the NatA acetylation activity. Our study provides mechanistic insights into the regulation of this pivotal protein modification. N-terminal acetylation is a common eukaryotic protein modification that is primarily catalysed by the N-acetyl transferase complex A (NatA). Here, the authors present the crystal structure of NatA bound to Huntingtin yeast two-hybrid protein K (HypK) and show that HypK is a negative regulator of NatA.
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Affiliation(s)
- Felix Alexander Weyer
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
| | - Andrea Gumiero
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
| | - Gert Bange
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
| | - Jürgen Kopp
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), INF328, D-69120 Heidelberg, Germany
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38
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Weyer FA, Gumiero A, Gesé GV, Lapouge K, Sinning I. Structural insights into a unique Hsp70-Hsp40 interaction in the eukaryotic ribosome-associated complex. Nat Struct Mol Biol 2017; 24:144-151. [PMID: 28067917 DOI: 10.1038/nsmb.3349] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 12/01/2016] [Indexed: 01/19/2023]
Abstract
Cotranslational chaperones assist de novo folding of nascent polypeptides, prevent them from aggregating and modulate translation. The ribosome-associated complex (RAC) is unique in that the Hsp40 protein Zuo1 and the atypical Hsp70 chaperone Ssz1 form a stable heterodimer, which acts as a cochaperone for the Hsp70 chaperone Ssb. Here we present the structure of the Chaetomium thermophilum RAC core comprising Ssz1 and the Zuo1 N terminus. We show how the conserved allostery of Hsp70 proteins is abolished and this Hsp70-Hsp40 pair is molded into a functional unit. Zuo1 stabilizes Ssz1 in trans through interactions that in canonical Hsp70s occur in cis. Ssz1 is catalytically inert and cannot adopt the closed conformation, but the substrate binding domain β is completed by Zuo1. Our study offers insights into the coupling of a special Hsp70-Hsp40 pair, which evolved to link protein folding and translation.
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Affiliation(s)
| | - Andrea Gumiero
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | | | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
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