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Salcedo-Tacuma D, Howells G, Mchose C, Gutierrez-Diaz A, Schupp J, Smith DM. ProEnd: A Comprehensive Database for Identifying HbYX Motif-Containing Proteins Across the Tree of Life. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598080. [PMID: 38895466 PMCID: PMC11185799 DOI: 10.1101/2024.06.08.598080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
The proteasome plays a crucial role in cellular homeostasis by degrading misfolded, damaged, or unnecessary proteins. Understanding the regulatory mechanisms of proteasome activity is vital, particularly the interaction with activators containing the hydrophobic-tyrosine-any amino acid (HbYX) motif. Here, we present ProEnd, a comprehensive database designed to identify and catalog HbYX motif-containing proteins across the tree of life. Using a simple bioinformatics pipeline, we analyzed approximately 73 million proteins from 22,000 reference proteomes in the UniProt/SwissProt database. Our findings reveal the widespread presence of HbYX motifs in diverse organisms, highlighting their evolutionary conservation and functional significance. Notably, we observed an interesting prevalence of these motifs in viral proteomes, suggesting strategic interactions with the host proteasome. As validation two novel HbYX proteins found in this database were tested and found to directly interact with the proteasome. ProEnd's extensive dataset and user-friendly interface enable researchers to explore the potential proteasomal regulator landscape, generating new hypotheses to advance proteasome biology. This resource is set to facilitate the discovery of novel therapeutic targets, enhancing our approach to treating diseases such as neurodegenerative disorders and cancer. Link: http://proend.org/.
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Affiliation(s)
- David Salcedo-Tacuma
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Giovanni Howells
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Coleman Mchose
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - Aimer Gutierrez-Diaz
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala 75007, Sweden
| | - Jane Schupp
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
| | - David M. Smith
- Department of Biochemistry and Molecular Medicine, West Virginia University School of Medicine, 4 Medical Center Dr., Morgantown, WV USA
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
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2
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Shi X, Xie X, Guo Y, Zhang J, Gong Z, Zhang K, Mei J, Xia X, Xia H, Ning N, Xiao Y, Yang Q, Wang GL, Liu W. A fungal core effector exploits the OsPUX8B.2-OsCDC48-6 module to suppress plant immunity. Nat Commun 2024; 15:2559. [PMID: 38519521 PMCID: PMC10959940 DOI: 10.1038/s41467-024-46903-7] [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: 07/05/2023] [Accepted: 03/12/2024] [Indexed: 03/25/2024] Open
Abstract
Proteins containing a ubiquitin regulatory X (UBX) domain are cofactors of Cell Division Cycle 48 (CDC48) and function in protein quality control. However, whether and how UBX-containing proteins participate in host-microbe interactions remain unclear. Here we show that MoNLE1, an effector from the fungal pathogen Magnaporthe oryzae, is a core virulence factor that suppresses rice immunity by specifically interfering with OsPUX8B.2. The UBX domain of OsPUX8B.2 is required for its binding to OsATG8 and OsCDC48-6 and controls its 26 S proteasome-dependent stability. OsPUX8B.2 and OsCDC48-6 positively regulate plant immunity against blast fungus, while the high-temperature tolerance heat-shock protein OsBHT, a putative cytoplasmic substrate of OsPUX8B.2-OsCDC48-6, negatively regulates defense against blast infection. MoNLE1 promotes the nuclear migration and degradation of OsPUX8B.2 and disturbs its association with OsBHT. Given the high conservation of MoNLE1 among fungal isolates, plants with broad and durable blast resistance might be generated by engineering intracellular proteins resistant to MoNLE1.
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Affiliation(s)
- Xuetao Shi
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Xin Xie
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yuanwen Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Junqi Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Ziwen Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Kai Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Mei
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Xinyao Xia
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Haoxue Xia
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Na Ning
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yutao Xiao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518000, China
| | - Qing Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH, 43210, USA
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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3
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Thomas T, Salcedo-Tacuma D, Smith DM. Structure, Function, and Allosteric Regulation of the 20S Proteasome by the 11S/PA28 Family of Proteasome Activators. Biomolecules 2023; 13:1326. [PMID: 37759726 PMCID: PMC10526260 DOI: 10.3390/biom13091326] [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: 07/17/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
The proteasome, a complex multi-catalytic protease machinery, orchestrates the protein degradation essential for maintaining cellular homeostasis, and its dysregulation also underlies many different types of diseases. Its function is regulated by many different mechanisms that encompass various factors such as proteasome activators (PAs), adaptor proteins, and post-translational modifications. This review highlights the unique characteristics of proteasomal regulation through the lens of a distinct family of regulators, the 11S, REGs, or PA26/PA28. This ATP-independent family, spanning from amoebas to mammals, exhibits a common architectural structure; yet, their cellular biology and criteria for protein degradation remain mostly elusive. We delve into their evolution and cellular biology, and contrast their structure and function comprehensively, emphasizing the unanswered questions regarding their regulatory mechanisms and broader roles in proteostasis. A deeper understanding of these processes will illuminate the roles of this regulatory family in biology and disease, thus contributing to the advancement of therapeutic strategies.
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Affiliation(s)
- Taylor Thomas
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - David Salcedo-Tacuma
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - David M. Smith
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
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4
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Krüger G, Kirkpatrick J, Mahieu E, Franzetti B, Gabel F, Carlomagno T. A real-time analysis of GFP unfolding by the AAA+ unfoldase PAN. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 350:107431. [PMID: 37058954 DOI: 10.1016/j.jmr.2023.107431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 05/10/2023]
Abstract
Protein quality control systems are essential to maintain a healthy proteome. They often consist of an unfoldase unit, typically an AAA+ ATPase, coupled with a protease unit. In all kingdoms of life, they function to eliminate misfolded proteins, and thus prevent that their aggregates do harm to the cell, and to rapidly regulate protein levels in the presence of environmental changes. Despite the huge progress made in the past two decades in understanding the mechanism of function of protein degradation systems, the fate of the substrate during the unfolding and proteolytic processes remains poorly understood. Here we exploit an NMR-based approach to monitor GFP processing by the archaeal PAN unfoldase and the PAN-20S degradation system in real time. We find that PAN-dependent unfolding of GFP does not involve the release of partially-folded GFP molecules resulting from futile unfolding attempts. In contrast, once stably engaged with PAN, GFP molecules are efficiently transferred to the proteolytic chamber of the 20S subunit, despite the only weak affinity of PAN for the 20S subunit in the absence of substrate. This is essential to guarantee that unfolded but not proteolyzed proteins are not released into solution, where they would form toxic aggregates. The results of our studies are in good agreement with previous results derived from real-time small-angle-neutron-scattering experiments and have the advantage of allowing the investigation of substrates and products at amino-acid resolution.
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Affiliation(s)
- Georg Krüger
- Institute of Organic Chemistry and Centre of Biomolecular Drug Design, Leibniz University Hannover, Schneiderberg 38, D-30167 Hannover, Germany
| | - John Kirkpatrick
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT Birmingham, United Kingdom
| | - Emilie Mahieu
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Bruno Franzetti
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Frank Gabel
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Teresa Carlomagno
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT Birmingham, United Kingdom.
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5
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Zhang S, Huang G, Versloot R, Bruininks BMH, Telles de Souza PC, Marrink SJ, Maglia G. Bottom-up fabrication of a proteasome-nanopore that unravels and processes single proteins. Nat Chem 2021; 13:1192-1199. [PMID: 34795436 PMCID: PMC7612055 DOI: 10.1038/s41557-021-00824-w] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 09/22/2021] [Indexed: 02/08/2023]
Abstract
The precise assembly and engineering of molecular machines capable of handling biomolecules play crucial roles in most single-molecule methods. In this work we use components from all three domains of life to fabricate an integrated multiprotein complex that controls the unfolding and threading of individual proteins across a nanopore. This 900 kDa multicomponent device was made in two steps. First, we designed a stable and low-noise β-barrel nanopore sensor by linking the transmembrane region of bacterial protective antigen to a mammalian proteasome activator. An archaeal 20S proteasome was then built into the artificial nanopore to control the unfolding and linearized transport of proteins across the nanopore. This multicomponent molecular machine opens the door to two approaches in single-molecule protein analysis, in which selected substrate proteins are unfolded, fed to into the proteasomal chamber and then addressed either as fragmented peptides or intact polypeptides.
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6
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Alderson TR, Kay LE. NMR spectroscopy captures the essential role of dynamics in regulating biomolecular function. Cell 2021; 184:577-595. [PMID: 33545034 DOI: 10.1016/j.cell.2020.12.034] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/09/2020] [Accepted: 12/21/2020] [Indexed: 01/02/2023]
Abstract
Biomolecules are in constant motion. To understand how they function, and why malfunctions can cause disease, it is necessary to describe their three-dimensional structures in terms of dynamic conformational ensembles. Here, we demonstrate how nuclear magnetic resonance (NMR) spectroscopy provides an essential, dynamic view of structural biology that captures biomolecular motions at atomic resolution. We focus on examples that emphasize the diversity of biomolecules and biochemical applications that are amenable to NMR, such as elucidating functional dynamics in large molecular machines, characterizing transient conformations implicated in the onset of disease, and obtaining atomic-level descriptions of intrinsically disordered regions that make weak interactions involved in liquid-liquid phase separation. Finally, we discuss the pivotal role that NMR has played in driving forward our understanding of the biomolecular dynamics-function paradigm.
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Affiliation(s)
- T Reid Alderson
- Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Chemistry, The University of Toronto, Toronto, ON M5S A18, Canada.
| | - Lewis E Kay
- Department of Biochemistry, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, The University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Chemistry, The University of Toronto, Toronto, ON M5S A18, Canada; Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
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7
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Majumder P, Baumeister W. Proteasomes: unfoldase-assisted protein degradation machines. Biol Chem 2020; 401:183-199. [PMID: 31665105 DOI: 10.1515/hsz-2019-0344] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/02/2019] [Indexed: 01/05/2023]
Abstract
Proteasomes are the principal molecular machines for the regulated degradation of intracellular proteins. These self-compartmentalized macromolecular assemblies selectively degrade misfolded, mistranslated, damaged or otherwise unwanted proteins, and play a pivotal role in the maintenance of cellular proteostasis, in stress response, and numerous other processes of vital importance. Whereas the molecular architecture of the proteasome core particle (CP) is universally conserved, the unfoldase modules vary in overall structure, subunit complexity, and regulatory principles. Proteasomal unfoldases are AAA+ ATPases (ATPases associated with a variety of cellular activities) that unfold protein substrates, and translocate them into the CP for degradation. In this review, we summarize the current state of knowledge about proteasome - unfoldase systems in bacteria, archaea, and eukaryotes, the three domains of life.
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Affiliation(s)
- Parijat Majumder
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany
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8
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Gates SN, Martin A. Stairway to translocation: AAA+ motor structures reveal the mechanisms of ATP-dependent substrate translocation. Protein Sci 2020; 29:407-419. [PMID: 31599052 PMCID: PMC6954725 DOI: 10.1002/pro.3743] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 09/28/2019] [Accepted: 09/30/2019] [Indexed: 12/31/2022]
Abstract
Translocases of the AAA+ (ATPases Associated with various cellular Activities) family are powerful molecular machines that use the mechano-chemical coupling of ATP hydrolysis and conformational changes to thread DNA or protein substrates through their central channel for many important biological processes. These motors comprise hexameric rings of ATPase subunits, in which highly conserved nucleotide-binding domains form active-site pockets near the subunit interfaces and aromatic pore-loop residues extend into the central channel for substrate binding and mechanical pulling. Over the past 2 years, 41 cryo-EM structures have been solved for substrate-bound AAA+ translocases that revealed spiral-staircase arrangements of pore-loop residues surrounding substrate polypeptides and indicating a conserved hand-over-hand mechanism for translocation. The subunits' vertical positions within the spiral arrangements appear to be correlated with their nucleotide states, progressing from ATP-bound at the top to ADP or apo states at the bottom. Studies describing multiple conformations for a particular motor illustrate the potential coupling between ATP-hydrolysis steps and subunit movements to propel the substrate. Experiments with double-ring, Type II AAA+ motors revealed an offset of hydrolysis steps between the two ATPase domains of individual subunits, and the upper ATPase domains lacking aromatic pore loops frequently form planar rings. This review summarizes the critical advances provided by recent studies to our structural and functional understanding of hexameric AAA+ translocases, as well as the important outstanding questions regarding the underlying mechanisms for coordinated ATP-hydrolysis and mechano-chemical coupling.
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Affiliation(s)
- Stephanie N. Gates
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCalifornia
- California Institute for Quantitative BiosciencesUniversity of California at BerkeleyBerkeleyCalifornia
- Howard Hughes Medical InstituteUniversity of California at BerkeleyBerkeleyCalifornia
| | - Andreas Martin
- Department of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCalifornia
- California Institute for Quantitative BiosciencesUniversity of California at BerkeleyBerkeleyCalifornia
- Howard Hughes Medical InstituteUniversity of California at BerkeleyBerkeleyCalifornia
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9
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Stach L, Morgan RM, Makhlouf L, Douangamath A, von Delft F, Zhang X, Freemont PS. Crystal structure of the catalytic D2 domain of the AAA+ ATPase p97 reveals a putative helical split-washer-type mechanism for substrate unfolding. FEBS Lett 2019; 594:933-943. [PMID: 31701538 PMCID: PMC7154655 DOI: 10.1002/1873-3468.13667] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/29/2019] [Accepted: 10/31/2019] [Indexed: 01/14/2023]
Abstract
Several pathologies have been associated with the AAA+ ATPase p97, an enzyme essential to protein homeostasis. Heterozygous polymorphisms in p97 have been shown to cause neurological disease, while elevated proteotoxic stress in tumours has made p97 an attractive cancer chemotherapy target. The cellular processes reliant on p97 are well described. High‐resolution structural models of its catalytic D2 domain, however, have proved elusive, as has the mechanism by which p97 converts the energy from ATP hydrolysis into mechanical force to unfold protein substrates. Here, we describe the high‐resolution structure of the p97 D2 ATPase domain. This crystal system constitutes a valuable tool for p97 inhibitor development and identifies a potentially druggable pocket in the D2 domain. In addition, its P61 symmetry suggests a mechanism for substrate unfolding by p97. Database The atomic coordinates and structure factors have been deposited in the PDB database under the accession numbers http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G2V, http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G2W, http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G2X, http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G2Y, http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G2Z and http://www.rcsb.org/pdb/search/structidSearch.do?structureId=6G30.
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Affiliation(s)
- Lasse Stach
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, UK
| | - Rhodri Marc Morgan
- Centre for Structural Biology, Department of Life Sciences, Imperial College London, UK
| | - Linda Makhlouf
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, UK
| | - Alice Douangamath
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK
| | - Frank von Delft
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK.,Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, UK.,Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa
| | - Xiaodong Zhang
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, UK
| | - Paul S Freemont
- Section of Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, UK
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10
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Banerjee P, Chanchal, Jain D. Sensor I Regulated ATPase Activity of FleQ Is Essential for Motility to Biofilm Transition in Pseudomonas aeruginosa. ACS Chem Biol 2019; 14:1515-1527. [PMID: 31268665 DOI: 10.1021/acschembio.9b00255] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Members of the AAA+ (ATPase associated with various cellular activities) family of ATPases couple chemical energy derived from ATP hydrolysis for generation of mechanical force, resulting in conformational changes. The hydrolysis is brought about by highly conserved domains and motifs. The sensor I motif is critical for sensing and hydrolysis of the nucleotide. Pseudomonas aeruginosa FleQ is an ATPase that is a positive regulator of flagellar gene expression. We have determined the crystal structures of the ATPase domain of wild-type FleQ and sensor I mutants H287N and H287A in complex with ATPγS and Mg2+ to 2.4, 1.95, and 2.25 Å resolution, respectively. The structural data highlight the role of sensor I in regulating the ATPase activity. The in vitro and in vivo data demonstrate that the moderate ATPase activity of FleQ due to the presence of histidine in sensor I is essential for maintaining the monotrichous phenotype and for the rapid motility to biofilm transition.
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Affiliation(s)
- Priyajit Banerjee
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India
- Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha 751024, India
| | - Chanchal
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India
- Manipal Academy of Higher Education, Karnataka 576104, India
| | - Deepti Jain
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, India
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11
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Abstract
In this issue of Molecular Cell, Weith et al. (2018) demonstrate that p97, together with a SEP adaptor, can catalyze ordered subunit exchange to facilitate the biogenesis of protein phosphatase-1 (PP1) holoenzyme, establishing a novel ubiquitin-independent "segregase" function for this versatile ATPase.
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Affiliation(s)
- Lihui Wang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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12
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Cotranslocational processing of the protein substrate calmodulin by an AAA+ unfoldase occurs via unfolding and refolding intermediates. Proc Natl Acad Sci U S A 2018; 115:E4786-E4795. [PMID: 29735657 DOI: 10.1073/pnas.1721811115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Protein remodeling by AAA+ enzymes is central for maintaining proteostasis in a living cell. However, a detailed structural description of how this is accomplished at the level of the substrate molecules that are acted upon is lacking. Here, we combine chemical cross-linking and methyl transverse relaxation-optimized NMR spectroscopy to study, at atomic resolution, the stepwise unfolding and subsequent refolding of the two-domain substrate calmodulin by the VAT AAA+ unfoldase from Thermoplasma acidophilum By engineering intermolecular disulphide bridges between the substrate and VAT we trap the substrate at different stages of translocation, allowing structural studies throughout the translocation process. Our results show that VAT initiates substrate translocation by pulling on intrinsically unstructured N or C termini of substrate molecules without showing specificity for a particular amino acid sequence. Although the B1 domain of protein G is shown to unfold cooperatively, translocation of calmodulin leads to the formation of intermediates, and these differ on an individual domain level in a manner that depends on whether pulling is from the N or C terminus. The approach presented generates an atomic resolution picture of substrate unfolding and subsequent refolding by unfoldases that can be quite different from results obtained via in vitro denaturation experiments.
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13
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The AAA+ ATPase p97, a cellular multitool. Biochem J 2017; 474:2953-2976. [PMID: 28819009 PMCID: PMC5559722 DOI: 10.1042/bcj20160783] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/17/2017] [Accepted: 07/21/2017] [Indexed: 12/17/2022]
Abstract
The AAA+ (ATPases associated with diverse cellular activities) ATPase p97 is essential to a wide range of cellular functions, including endoplasmic reticulum-associated degradation, membrane fusion, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation and chromatin-associated processes, which are regulated by ubiquitination. p97 acts downstream from ubiquitin signaling events and utilizes the energy from ATP hydrolysis to extract its substrate proteins from cellular structures or multiprotein complexes. A multitude of p97 cofactors have evolved which are essential to p97 function. Ubiquitin-interacting domains and p97-binding domains combine to form bi-functional cofactors, whose complexes with p97 enable the enzyme to interact with a wide range of ubiquitinated substrates. A set of mutations in p97 have been shown to cause the multisystem proteinopathy inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia. In addition, p97 inhibition has been identified as a promising approach to provoke proteotoxic stress in tumors. In this review, we will describe the cellular processes governed by p97, how the cofactors interact with both p97 and its ubiquitinated substrates, p97 enzymology and the current status in developing p97 inhibitors for cancer therapy.
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14
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Esaki M, Islam MT, Tani N, Ogura T. Deviation of the typical AAA substrate-threading pore prevents fatal protein degradation in yeast Cdc48. Sci Rep 2017; 7:5475. [PMID: 28710470 PMCID: PMC5511170 DOI: 10.1038/s41598-017-05806-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/02/2017] [Indexed: 01/15/2023] Open
Abstract
Yeast Cdc48 is a well-conserved, essential chaperone of ATPases associated with diverse cellular activity (AAA) proteins, which recognizes substrate proteins and modulates their conformations to carry out many cellular processes. However, the fundamental mechanisms underlying the diverse pivotal roles of Cdc48 remain unknown. Almost all AAA proteins form a ring-shaped structure with a conserved aromatic amino acid residue that is essential for proper function. The threading mechanism hypothesis suggests that this residue guides the intrusion of substrate proteins into a narrow pore of the AAA ring, thereby becoming unfolded. By contrast, the aromatic residue in one of the two AAA rings of Cdc48 has been eliminated through evolution. Here, we show that artificial retrieval of this aromatic residue in Cdc48 is lethal, and essential features to support the threading mechanism are required to exhibit the lethal phenotype. In particular, genetic and biochemical analyses of the Cdc48 lethal mutant strongly suggested that when in complex with the 20S proteasome, essential proteins are abnormally forced to thread through the Cdc48 pore to become degraded, which was not detected in wild-type Cdc48. Thus, the widely applicable threading model is less effective for wild-type Cdc48; rather, Cdc48 might function predominantly through an as-yet-undetermined mechanism.
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Affiliation(s)
- Masatoshi Esaki
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan. .,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, 332-0012, Japan.
| | - Md Tanvir Islam
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Kumamoto, 860-8556, Japan.,Department of Microbiology, Jessore University of Science and Technology, Jessore, 7408, Bangladesh
| | - Naoki Tani
- Liaison Laboratory Research Promotion Center, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Teru Ogura
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama, 332-0012, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Kumamoto, 860-8556, Japan
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15
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Yedidi RS, Wendler P, Enenkel C. AAA-ATPases in Protein Degradation. Front Mol Biosci 2017; 4:42. [PMID: 28676851 PMCID: PMC5476697 DOI: 10.3389/fmolb.2017.00042] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 06/06/2017] [Indexed: 11/13/2022] Open
Abstract
Proteolytic machineries containing multisubunit protease complexes and AAA-ATPases play a key role in protein quality control and the regulation of protein homeostasis. In these protein degradation machineries, the proteolytically active sites are formed by either threonines or serines which are buried inside interior cavities of cylinder-shaped complexes. In eukaryotic cells, the proteasome is the most prominent protease complex harboring AAA-ATPases. To degrade protein substrates, the gates of the axial entry ports of the protease need to be open. Gate opening is accomplished by AAA-ATPases, which form a hexameric ring flanking the entry ports of the protease. Protein substrates with unstructured domains can loop into the entry ports without the assistance of AAA-ATPases. However, folded proteins require the action of AAA-ATPases to unveil an unstructured terminus or domain. Cycles of ATP binding/hydrolysis fuel the unfolding of protein substrates which are gripped by loops lining up the central pore of the AAA-ATPase ring. The AAA-ATPases pull on the unfolded polypeptide chain for translocation into the proteolytic cavity of the protease. Conformational changes within the AAA-ATPase ring and the adjacent protease chamber create a peristaltic movement for substrate degradation. The review focuses on new technologies toward the understanding of the function and structure of AAA-ATPases to achieve substrate recognition, unfolding and translocation into proteasomes in yeast and mammalian cells and into proteasome-equivalent proteases in bacteria and archaea.
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Affiliation(s)
| | - Petra Wendler
- Department of Biochemistry, Institute of Biochemistry and Biology, University of PotsdamPotsdam, Germany
| | - Cordula Enenkel
- Department of Biochemistry, University of TorontoToronto, ON, Canada
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16
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Ye Y, Tang WK, Zhang T, Xia D. A Mighty "Protein Extractor" of the Cell: Structure and Function of the p97/CDC48 ATPase. Front Mol Biosci 2017; 4:39. [PMID: 28660197 PMCID: PMC5468458 DOI: 10.3389/fmolb.2017.00039] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/22/2017] [Indexed: 12/13/2022] Open
Abstract
p97/VCP (known as Cdc48 in S. cerevisiae or TER94 in Drosophila) is one of the most abundant cytosolic ATPases. It is highly conserved from archaebacteria to eukaryotes. In conjunction with a large number of cofactors and adaptors, it couples ATP hydrolysis to segregation of polypeptides from immobile cellular structures such as protein assemblies, membranes, ribosome, and chromatin. This often results in proteasomal degradation of extracted polypeptides. Given the diversity of p97 substrates, this "segregase" activity has profound influence on cellular physiology ranging from protein homeostasis to DNA lesion sensing, and mutations in p97 have been linked to several human diseases. Here we summarize our current understanding of the structure and function of this important cellular machinery and discuss the relevant clinical implications.
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Affiliation(s)
- Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, United States
| | - Wai Kwan Tang
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| | - Ting Zhang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, United States
| | - Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
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17
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Saffert P, Enenkel C, Wendler P. Structure and Function of p97 and Pex1/6 Type II AAA+ Complexes. Front Mol Biosci 2017; 4:33. [PMID: 28611990 PMCID: PMC5447069 DOI: 10.3389/fmolb.2017.00033] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/05/2017] [Indexed: 12/16/2022] Open
Abstract
Protein complexes of the Type II AAA+ (ATPases associated with diverse cellular activities) family are typically hexamers of 80–150 kDa protomers that harbor two AAA+ ATPase domains. They form double ring assemblies flanked by associated domains, which can be N-terminal, intercalated or C-terminal to the ATPase domains. Most prominent members of this family include NSF (N-ethyl-maleimide sensitive factor), p97/VCP (valosin-containing protein), the Pex1/Pex6 complex and Hsp104 in eukaryotes and ClpB in bacteria. Tremendous efforts have been undertaken to understand the conformational dynamics of protein remodeling type II AAA+ complexes. A uniform mode of action has not been derived from these works. This review focuses on p97/VCP and the Pex1/6 complex, which both structurally remodel ubiquitinated substrate proteins. P97/VCP plays a role in many processes, including ER- associated protein degradation, and the Pex1/Pex6 complex dislocates and recycles the transport receptor Pex5 from the peroxisomal membrane during peroxisomal protein import. We give an introduction into existing knowledge about the biochemical and cellular activities of the complexes before discussing structural information. We particularly emphasize recent electron microscopy structures of the two AAA+ complexes and summarize their structural differences.
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Affiliation(s)
- Paul Saffert
- Department of Biochemistry, Institute of Biochemistry and Biology, University of PotsdamPotsdam, Germany
| | - Cordula Enenkel
- Department of Biochemistry, University of TorontoToronto, ON, Canada
| | - Petra Wendler
- Department of Biochemistry, Institute of Biochemistry and Biology, University of PotsdamPotsdam, Germany
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18
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Ubiquitin- and ATP-dependent unfoldase activity of P97/VCP•NPLOC4•UFD1L is enhanced by a mutation that causes multisystem proteinopathy. Proc Natl Acad Sci U S A 2017; 114:E4380-E4388. [PMID: 28512218 DOI: 10.1073/pnas.1706205114] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
p97 is a "segregase" that plays a key role in numerous ubiquitin (Ub)-dependent pathways such as ER-associated degradation. It has been hypothesized that p97 extracts proteins from membranes or macromolecular complexes to enable their proteasomal degradation; however, the complex nature of p97 substrates has made it difficult to directly observe the fundamental basis for this activity. To address this issue, we developed a soluble p97 substrate-Ub-GFP modified with K48-linked ubiquitin chains-for in vitro p97 activity assays. We demonstrate that WT p97 can unfold proteins and that this activity is dependent on the p97 adaptor NPLOC4-UFD1L, ATP hydrolysis, and substrate ubiquitination, with branched chains providing maximal stimulation. Furthermore, we show that a p97 mutant that causes inclusion body myopathy, Paget's disease of bone, and frontotemporal dementia in humans unfolds substrate faster, suggesting that excess activity may underlie pathogenesis. This work overcomes a significant barrier in the study of p97 and will allow the future dissection of p97 mechanism at a level of detail previously unattainable.
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19
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Ripstein ZA, Huang R, Augustyniak R, Kay LE, Rubinstein JL. Structure of a AAA+ unfoldase in the process of unfolding substrate. eLife 2017; 6. [PMID: 28390173 PMCID: PMC5423775 DOI: 10.7554/elife.25754] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/06/2017] [Indexed: 12/19/2022] Open
Abstract
AAA+ unfoldases are thought to unfold substrate through the central pore of their hexameric structures, but how this process occurs is not known. VAT, the Thermoplasma acidophilum homologue of eukaryotic CDC48/p97, works in conjunction with the proteasome to degrade misfolded or damaged proteins. We show that in the presence of ATP, VAT with its regulatory N-terminal domains removed unfolds other VAT complexes as substrate. We captured images of this transient process by electron cryomicroscopy (cryo-EM) to reveal the structure of the substrate-bound intermediate. Substrate binding breaks the six-fold symmetry of the complex, allowing five of the six VAT subunits to constrict into a tight helix that grips an ~80 Å stretch of unfolded protein. The structure suggests a processive hand-over-hand unfolding mechanism, where each VAT subunit releases the substrate in turn before re-engaging further along the target protein, thereby unfolding it.
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Affiliation(s)
- Zev A Ripstein
- The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Rui Huang
- Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada
| | - Rafal Augustyniak
- Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada
| | - Lewis E Kay
- The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada
| | - John L Rubinstein
- The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada
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20
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Fundamental Characteristics of AAA+ Protein Family Structure and Function. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2016; 2016:9294307. [PMID: 27703410 PMCID: PMC5039278 DOI: 10.1155/2016/9294307] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 07/21/2016] [Indexed: 12/22/2022]
Abstract
Many complex cellular events depend on multiprotein complexes known as molecular machines to efficiently couple the energy derived from adenosine triphosphate hydrolysis to the generation of mechanical force. Members of the AAA+ ATPase superfamily (ATPases Associated with various cellular Activities) are critical components of many molecular machines. AAA+ proteins are defined by conserved modules that precisely position the active site elements of two adjacent subunits to catalyze ATP hydrolysis. In many cases, AAA+ proteins form a ring structure that translocates a polymeric substrate through the central channel using specialized loops that project into the central channel. We discuss the major features of AAA+ protein structure and function with an emphasis on pivotal aspects elucidated with archaeal proteins.
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21
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Unfolding the mechanism of the AAA+ unfoldase VAT by a combined cryo-EM, solution NMR study. Proc Natl Acad Sci U S A 2016; 113:E4190-9. [PMID: 27402735 DOI: 10.1073/pnas.1603980113] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The AAA+ (ATPases associated with a variety of cellular activities) enzymes play critical roles in a variety of homeostatic processes in all kingdoms of life. Valosin-containing protein-like ATPase of Thermoplasma acidophilum (VAT), the archaeal homolog of the ubiquitous AAA+ protein Cdc48/p97, functions in concert with the 20S proteasome by unfolding substrates and passing them on for degradation. Here, we present electron cryomicroscopy (cryo-EM) maps showing that VAT undergoes large conformational rearrangements during its ATP hydrolysis cycle that differ dramatically from the conformational states observed for Cdc48/p97. We validate key features of the model with biochemical and solution methyl-transverse relaxation optimized spectroscopY (TROSY) NMR experiments and suggest a mechanism for coupling the energy of nucleotide hydrolysis to substrate unfolding. These findings illustrate the unique complementarity between cryo-EM and solution NMR for studies of molecular machines, showing that the structural properties of VAT, as well as the population distributions of conformers, are similar in the frozen specimens used for cryo-EM and in the solution phase where NMR spectra are recorded.
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22
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Xia D, Tang WK, Ye Y. Structure and function of the AAA+ ATPase p97/Cdc48p. Gene 2016. [DOI: 10.1016/j.gene.2016.02.042 and 21=21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2022]
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23
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Xia D, Tang WK, Ye Y. Structure and function of the AAA+ ATPase p97/Cdc48p. Gene 2016. [DOI: 10.1016/j.gene.2016.02.042 and 67=89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
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24
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Rijal R, Arhzaouy K, Strucksberg KH, Cross M, Hofmann A, Schröder R, Clemen CS, Eichinger L. Mutant p97 exhibits species-specific changes of its ATPase activity and compromises the UBXD9-mediated monomerisation of p97 hexamers. Eur J Cell Biol 2016; 95:195-207. [PMID: 27132113 DOI: 10.1016/j.ejcb.2016.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/22/2016] [Accepted: 03/29/2016] [Indexed: 11/17/2022] Open
Abstract
p97 (VCP) is a homo-hexameric triple-A ATPase that exerts a plethora of cellular processes. Heterozygous missense mutations of p97 cause at least five human neurodegenerative disorders. However, the specific molecular consequences of p97 mutations are hitherto widely unknown. Our in silico structural models of human and Dictyostelium p97 showed that the disease-causing human R93C, R155H, and R155C as well as Dictyostelium R154C, E219K, R154C/E219K p97 mutations constitute variations in surface-exposed locations. In-gel ATPase activity measurements of p97 monomers and hexamers revealed significant mutation- and species-specific differences. While all human p97 mutations led to an increase in ATPase activity, no changes could be detected for the Dictyostelium R154C mutant, which is orthologous to human R155C. The E219K mutation led to an almost complete loss of activity, which was partially recuperated in the R154C/E219K double-mutant indicating p97 inter-domain communication. By means of co-immunoprecipitation experiments we identified an UBX-domain containing Dictyostelium protein as a novel p97 interaction partner. We categorized all UBX-domain containing Dictyostelium proteins and named the interaction partner UBXD9. Pull-down assays and surface plasmon resonance analyses of Dictyostelium UBXD9 or the human orthologue TUG/ASPL/UBXD9 demonstrated direct interactions with p97 as well as species-, mutation- and ATP-dependent differences in the binding affinities. Sucrose density gradient assays revealed that both human and Dictyostelium UBXD9 proteins very efficiently disassembled wild-type, but to a lesser extent mutant p97 hexamers into monomers. Our results are consistent with a scenario in which p97 point mutations lead to differences in enzymatic activities and molecular interactions, which in the long-term result in a late-onset and progressive multisystem disease.
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Affiliation(s)
- Ramesh Rijal
- Centre for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Khalid Arhzaouy
- Centre for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Karl-Heinz Strucksberg
- Centre for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Megan Cross
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Queensland 4111, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Queensland 4111, Australia; Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3030, Australia
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Christoph S Clemen
- Centre for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany.
| | - Ludwig Eichinger
- Centre for Biochemistry, Institute of Biochemistry I, Medical Faculty, University of Cologne, 50931 Cologne, Germany.
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25
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Xia D, Tang WK, Ye Y. Structure and function of the AAA+ ATPase p97/Cdc48p. Gene 2016; 583:64-77. [PMID: 26945625 DOI: 10.1016/j.gene.2016.02.042] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 11/29/2022]
Abstract
p97 (also known as valosin-containing protein (VCP) in mammals or Cdc48p in Saccharomyces cerevisiae) is an evolutionarily conserved ATPase present in all eukaryotes and archaebacteria. In conjunction with a collection of cofactors and adaptors, p97/Cdc48p performs an array of biological functions mostly through modulating the stability of 'client' proteins. Using energy from ATP hydrolysis, p97/Cdc48p segregates these molecules from immobile cellular structures such as protein assemblies, membrane organelles, and chromatin. Consequently, the released polypeptides can be efficiently degraded by the ubiquitin proteasome system or recycled. This review summarizes our current understanding of the structure and function of this essential cellular chaperoning system.
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Affiliation(s)
- Di Xia
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States.
| | - Wai Kwan Tang
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States
| | - Yihong Ye
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, United States.
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26
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Barthelme D, Sauer RT. Origin and Functional Evolution of the Cdc48/p97/VCP AAA+ Protein Unfolding and Remodeling Machine. J Mol Biol 2015; 428:1861-9. [PMID: 26608813 DOI: 10.1016/j.jmb.2015.11.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/03/2015] [Accepted: 11/16/2015] [Indexed: 01/25/2023]
Abstract
The AAA+ Cdc48 ATPase (alias p97 or VCP) is a key player in multiple ubiquitin-dependent cell signaling, degradation, and quality control pathways. Central to these broad biological functions is the ability of Cdc48 to interact with a large number of adaptor proteins and to remodel macromolecular proteins and their complexes. Different models have been proposed to explain how Cdc48 might couple ATP hydrolysis to forcible unfolding, dissociation, or remodeling of cellular clients. In this review, we provide an overview of possible mechanisms for substrate unfolding/remodeling by this conserved and essential AAA+ protein machine and their adaption and possible biological function throughout evolution.
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Affiliation(s)
- Dominik Barthelme
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Max Planck Institute for Infection Biology, Berlin 10117, Germany
| | - Robert T Sauer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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27
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Mechanistic and Structural Insights into the Prion-Disaggregase Activity of Hsp104. J Mol Biol 2015; 428:1870-85. [PMID: 26608812 DOI: 10.1016/j.jmb.2015.11.016] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 11/23/2022]
Abstract
Hsp104 is a dynamic ring translocase and hexameric AAA+ protein found in yeast, which couples ATP hydrolysis to disassembly and reactivation of proteins trapped in soluble preamyloid oligomers, disordered protein aggregates, and stable amyloid or prion conformers. Here, we highlight advances in our structural understanding of Hsp104 and how Hsp104 deconstructs Sup35 prions. Although the atomic structure of Hsp104 hexamers remains uncertain, volumetric reconstruction of Hsp104 hexamers in ATPγS, ADP-AlFx (ATP hydrolysis transition-state mimic), and ADP via small-angle x-ray scattering has revealed a peristaltic pumping motion upon ATP hydrolysis. This pumping motion likely drives directional substrate translocation across the central Hsp104 channel. Hsp104 initially engages Sup35 prions immediately C-terminal to their cross-β structure. Directional pulling by Hsp104 then resolves N-terminal cross-β structure in a stepwise manner. First, Hsp104 fragments the prion. Second, Hsp104 unfolds cross-β structure. Third, Hsp104 releases soluble Sup35. Deletion of the Hsp104 N-terminal domain yields a hypomorphic disaggregase, Hsp104(∆N), with an altered pumping mechanism. Hsp104(∆N) fragments Sup35 prions without unfolding cross-β structure or releasing soluble Sup35. Moreover, Hsp104(∆N) activity cannot be enhanced by mutations in the middle domain that potentiate disaggregase activity. Thus, the N-terminal domain is critical for the full repertoire of Hsp104 activities.
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28
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Valosin-containing protein (VCP/p97) is capable of unfolding polyubiquitinated proteins through its ATPase domains. Biochem Biophys Res Commun 2015; 463:453-7. [PMID: 26043696 DOI: 10.1016/j.bbrc.2015.05.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 05/29/2015] [Indexed: 11/21/2022]
Abstract
Valosin-containing protein (VCP or p97) is required for the proteasomal degradation of polyubiquitinated proteins. However, the molecular mechanism for VCP to process the polyubiquitinated proteins remains unclear. Here, we show that VCP can unfold polyubiquitinated proteins. It preferably unfolds the pentaubiquitin-over monoubiquin-conjugated dihydrofolate reductase (Ub5-DHFR or Ub-DHFR) in a dose dependent manner. In addition, the unfolding activity of VCP does not depend on its ATPase activity, on the contrary, ATP and its non-hydrolysable analogs suppress the unfolding of Ub5-DHFR. The structural and functional analysis showed that either D1 or D2 domain of VCP is sufficient to carry out this unfolding activity. The structure of the substrates also affects its unfolding by VCP. VCP is unable to unfold Ub5-DHFR in a tight structure when it binds with methotrexate, a folate analog with high affinity to DHFR. Thus, these results support that VCP is capable of unfolding polyubiquitinated proteins and suggest that VCP may facilitate the proteasomal degradation of polyubiquitinated proteins through its unfolding activity.
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29
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Sousa R. Structural mechanisms of chaperone mediated protein disaggregation. Front Mol Biosci 2014; 1:12. [PMID: 25988153 PMCID: PMC4428496 DOI: 10.3389/fmolb.2014.00012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 08/27/2014] [Indexed: 11/13/2022] Open
Abstract
The ClpB/Hsp104 and Hsp70 classes of molecular chaperones use ATP hydrolysis to dissociate protein aggregates and complexes, and to move proteins through membranes. ClpB/Hsp104 are members of the AAA+ family of proteins which form ring-shaped hexamers. Loops lining the pore in the ring engage substrate proteins as extended polypeptides. Interdomain rotations and conformational changes in these loops coupled to ATP hydrolysis unfold and pull proteins through the pore. This provides a mechanism that progressively disrupts local secondary and tertiary structure in substrates, allowing these chaperones to dissociate stable aggregates such as β-sheet rich prions or coiled coil SNARE complexes. While the ClpB/Hsp104 mechanism appears to embody a true power-stroke in which an ATP powered conformational change in one protein is directly coupled to movement or structural change in another, the mechanism of force generation by Hsp70s is distinct and less well understood. Both active power-stroke and purely passive mechanisms in which Hsp70 captures spontaneous fluctuations in a substrate have been proposed, while a third proposed mechanism-entropic pulling-may be able to generate forces larger than seen in ATP-driven molecular motors without the conformational coupling required for a power-stroke. The disaggregase activity of these chaperones is required for thermotolerance, but unrestrained protein complex/aggregate dissociation is potentially detrimental. Disaggregating chaperones are strongly auto-repressed, and are regulated by co-chaperones which recruit them to protein substrates and activate the disaggregases via mechanisms involving either sequential transfer of substrate from one chaperone to another and/or simultaneous interaction of substrate with multiple chaperones. By effectively subjecting substrates to multiple levels of selection by multiple chaperones, this may insure that these potent disaggregases are only activated in the appropriate context.
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Affiliation(s)
- Rui Sousa
- Department of Biochemistry, University of Texas Health Science Center at San Antonio San Antonio, TX, USA
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30
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Architecture and assembly of the archaeal Cdc48*20S proteasome. Proc Natl Acad Sci U S A 2014; 111:E1687-94. [PMID: 24711419 DOI: 10.1073/pnas.1404823111] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
ATP-dependent proteases maintain protein quality control and regulate diverse intracellular functions. Proteasomes are primarily responsible for these tasks in the archaeal and eukaryotic domains of life. Even the simplest of these proteases function as large complexes, consisting of the 20S peptidase, a barrel-like structure composed of four heptameric rings, and one or two AAA+ (ATPase associated with a variety of cellular activities) ring hexamers, which use cycles of ATP binding and hydrolysis to unfold and translocate substrates into the 20S proteolytic chamber. Understanding how the AAA+ and 20S components of these enzymes interact and collaborate to execute protein degradation is important, but the highly dynamic nature of prokaryotic proteasomes has hampered structural characterization. Here, we use electron microscopy to determine the architecture of an archaeal Cdc48 ⋅ 20S proteasome, which we stabilized by site-specific cross-linking. This complex displays coaxial alignment of Cdc48 and 20S and is enzymatically active, demonstrating that AAA+ unfoldase wobbling with respect to 20S is not required for function. In the complex, the N-terminal domain of Cdc48, which regulates ATP hydrolysis and degradation, packs against the D1 ring of Cdc48 in a coplanar fashion, constraining mechanisms by which the N-terminal domain alters 20S affinity and degradation activity.
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31
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Hubert Á, Mitani Y, Tamura T, Boicu M, Nagy I. Protein complex purification from Thermoplasma acidophilum using a phage display library. J Microbiol Methods 2014; 98:15-22. [DOI: 10.1016/j.mimet.2013.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/12/2013] [Accepted: 12/12/2013] [Indexed: 11/27/2022]
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32
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Tonddast-Navaei S, Stan G. Mechanism of transient binding and release of substrate protein during the allosteric cycle of the p97 nanomachine. J Am Chem Soc 2013; 135:14627-36. [PMID: 24007343 DOI: 10.1021/ja404051b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
ATPases associated with various cellular activities (AAA+) form a superfamily of ring-shaped motor proteins that utilize cyclical allosteric motions to remodel or translocate substrate proteins (SP) through a narrow central pore. The p97 ATPase is a homohexameric, double-ring member of this superfamily that encloses a central channel with nonuniform width. A narrow compartment is present within the D1 ring and a larger cavity within the D2 ring, separated by a constriction formed by six His amino acids. We use molecular dynamics simulations to probe the interaction between p97 and an extended peptide substrate. Mechanical pulling of the substrate through the p97 pore reveals that smaller work is required for translocation from the D1 toward the D2 compartment than in the opposite direction. These distinct energetic requirements originate in structural aspects and chemical properties of the pore lining. Whereas van der Waals interactions are dominant within the D1 pore, interaction within the D2 pore are strongly electrostatic. Two charged amino acids in the D2 pore, Arg599 and Glu554, provide the largest contribution to the interaction and hinder translocation from the D2 pore. SP threading requires smaller forces when the SP is pulled from the D1 side due to lower barrier to rotation of the His side chains in the direction of the D2 pore. Based on additional simulations of SP binding to two allosteric conformations of p97, we propose that transient binding and release of SP from the pore involves a lever mechanism. Binding to the open pore conformation of p97 occurs primarily at the Arg599 side chain, where the SP backbone is engaged through electrostatic interactions and hydrogen bonds. ATP-driven conformational transitions within the D2 ring alter the chemical environment inside the p97 cavity in the closed pore state. In this state, Glu554 side chains project further into the pore and interacts strongly through van der Waals contacts with the SP backbone. Based on mutations at the two sites in each of the states we identify a specific requirement of these side chains for interaction with the substrate.
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Affiliation(s)
- Sam Tonddast-Navaei
- Department of Chemistry, University of Cincinnati , Cincinnati, Ohio 45221, United States
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Abstract
Archaea contain, both a functional proteasome and an ubiquitin-like protein conjugation system (termed sampylation) that is related to the ubiquitin proteasome system (UPS) of eukaryotes. Archaeal proteasomes have served as excellent models for understanding how proteins are degraded by the central energy-dependent proteolytic machine of eukaryotes, the 26S proteasome. While sampylation has only recently been discovered, it is thought to be linked to proteasome-mediated degradation in archaea. Unlike eukaryotes, sampylation only requires an E1 enzyme homolog of the E1-E2-E3 ubiquitylation cascade to mediate protein conjugation. Furthermore, recent evidence suggests that archaeal and eurkaryotic E1 enzyme homologs can serve dual roles in mediating protein conjugation and activating sulfur for incorporation into biomolecules. The focus of this book chapter is the energy-dependent proteasome and sampylation systems of Archaea.
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Affiliation(s)
- Julie A Maupin-Furlow
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611-0700, USA,
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Abstract
The chaperone-related, ubiquitin-selective AAA (ATPase associated with a variety of cellular activities) protein Cdc48 (also known as TER94, p97 and VCP) is a key regulator of intracellular proteolysis in eukaryotes. It uses the energy derived from ATP hydrolysis to segregate ubiquitylated proteins from stable assemblies with proteins, membranes and chromatin. Originally characterized as essential factor in proteasomal degradation pathways, Cdc48 was recently found to control lysosomal protein degradation as well. Moreover, impaired lysosomal proteolysis due to mutational inactivation of Cdc48 causes protein aggregation diseases in humans. This review introduces the major systems of intracellular proteolysis in eukaryotes and the role of protein ubiquitylation. It then discusses in detail structure, mechanism and cellular functions of Cdc48 with an emphasis on protein degradation pathways in yeast.
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Affiliation(s)
- Alexander Buchberger
- Department of Biochemistry, Biocenter, University of Würzburg, Am Hubland, 97074, Würzburg, Germany,
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Forouzan D, Ammelburg M, Hobel CF, Ströh LJ, Sessler N, Martin J, Lupas AN. The archaeal proteasome is regulated by a network of AAA ATPases. J Biol Chem 2012; 287:39254-62. [PMID: 22992741 PMCID: PMC3493965 DOI: 10.1074/jbc.m112.386458] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The proteasome is the central machinery for targeted protein degradation in archaea, Actinobacteria, and eukaryotes. In its basic form, it consists of a regulatory ATPase complex and a proteolytic core particle. The interaction between the two is governed by an HbYX motif (where Hb is a hydrophobic residue, Y is tyrosine, and X is any amino acid) at the C terminus of the ATPase subunits, which stimulates gate opening of the proteasomal α-subunits. In archaea, the proteasome-interacting motif is not only found in canonical proteasome-activating nucleotidases of the PAN/ARC/Rpt group, which are absent in major archaeal lineages, but also in proteins of the CDC48/p97/VAT and AMA groups, suggesting a regulatory network of proteasomal ATPases. Indeed, Thermoplasma acidophilum, which lacks PAN, encodes one CDC48 protein that interacts with the 20S proteasome and activates the degradation of model substrates. In contrast, Methanosarcina mazei contains seven AAA proteins, five of which, both PAN proteins, two out of three CDC48 proteins, and the AMA protein, function as proteasomal gatekeepers. The prevalent presence of multiple, distinct proteasomal ATPases in archaea thus results in a network of regulatory ATPases that may widen the substrate spectrum of proteasomal protein degradation.
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Affiliation(s)
- Dara Forouzan
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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36
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Barthelme D, Sauer RT. Identification of the Cdc48•20S proteasome as an ancient AAA+ proteolytic machine. Science 2012; 337:843-6. [PMID: 22837385 DOI: 10.1126/science.1224352] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Proteasomes are the major energy-dependent proteolytic machines in the eukaryotic and archaeal domains of life. To execute protein degradation, the 20S core peptidase combines with the AAA+ ring of the 19S regulatory particle in eukarya or with the AAA+ proteasome-activating nucleotidase ring in some archaea. Here, we find that Cdc48 and 20S from the archaeon Thermoplasma acidophilum interact to form a functional proteasome. Cdc48 is an abundant and essential double-ring AAA+ molecular machine ubiquitously present in archaea, where its function has been uncertain, and in eukarya where Cdc48 participates by largely unknown mechanisms in diverse cellular processes, including multiple proteolytic pathways. Thus, proteolysis in collaboration with the 20S peptidase may represent an ancestral function of the Cdc48 family.
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Affiliation(s)
- Dominik Barthelme
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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37
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Niwa H, Ewens CA, Tsang C, Yeung HO, Zhang X, Freemont PS. The role of the N-domain in the ATPase activity of the mammalian AAA ATPase p97/VCP. J Biol Chem 2012; 287:8561-70. [PMID: 22270372 PMCID: PMC3318706 DOI: 10.1074/jbc.m111.302778] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 01/18/2012] [Indexed: 12/04/2022] Open
Abstract
p97/valosin-containing protein (VCP) is a type II ATPase associated with various cellular activities that forms a homohexamer with each protomer containing an N-terminal domain (N-domain); two ATPase domains, D1 and D2; and a disordered C-terminal region. Little is known about the role of the N-domain or the C-terminal region in the p97 ATPase cycle. In the p97-associated human disease inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia, the majority of missense mutations are located at the N-domain D1 interface. Structure-based predictions suggest that such mutations affect the interaction of the N-domain with D1. Here we have tested ten major inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia-linked mutants for ATPase activity and found that all have increased activity over the wild type, with one mutant, p97(A232E), having three times higher activity. Further mutagenesis of p97(A232E) shows that the increase in ATPase activity is mediated through D2 and requires both the N-domain and a flexible ND1 linker. A disulfide mutation that locks the N-domain to D1 in a coplanar position reversibly abrogates ATPase activity. A cryo-EM reconstruction of p97(A232E) suggests that the N-domains are flexible. Removal of the C-terminal region also reduces ATPase activity. Taken together, our data suggest that the conformation of the N-domain in relation to the D1-D2 hexamer is directly linked to ATP hydrolysis and that the C-terminal region is required for hexamer stability. This leads us to propose a model where the N-domain adopts either of two conformations: a flexible conformation compatible with ATP hydrolysis or a coplanar conformation that is inactive.
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Affiliation(s)
- Hajime Niwa
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Caroline A. Ewens
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Chun Tsang
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Heidi O. Yeung
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Xiaodong Zhang
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Paul S. Freemont
- From the Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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Disordered form of the scaffold protein IscU is the substrate for iron-sulfur cluster assembly on cysteine desulfurase. Proc Natl Acad Sci U S A 2011; 109:454-9. [PMID: 22203963 DOI: 10.1073/pnas.1114372109] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The scaffold protein for iron-sulfur cluster assembly, apo-IscU, populates two interconverting conformational states, one disordered (D) and one structured (S) as revealed by extensive NMR assignments. At pH 8 and 25 °C, approximately 70% of the protein is S, and the lifetimes of the states are 1.3 s (S) and 0.50 s (D). Zn(II) and Fe(II) each bind and stabilize structured (S-like) states. Single amino acid substitutions at conserved residues were found that shift the equilibrium toward either the S or the D state. Cluster assembly takes place in the complex between IscU and the cysteine desulfurase, IscS, and our NMR studies demonstrate that IscS binds preferentially the D form of apo-IscU. The addition of 10% IscS to IscU was found to greatly increase H/D exchange at protected amides of IscU, to increase the rate of the S → D reaction, and to decrease the rate of the D → S reaction. In the saturated IscU:IscS complex, IscU is largely disordered. In vitro cluster assembly reactions provided evidence for the functional importance of the S&lrarr2;D equilibrium. IscU variants that favor the S state were found to undergo a lag phase, not observed with the wild type, that delayed cluster assembly; variants that favor the D state were found to assemble less stable clusters at an intermediate rate without the lag. It appears that IscU has evolved to exist in a disordered conformational state that is the initial substrate for the desulfurase and to convert to a structured state that stabilizes the cluster once it is assembled.
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Wendler P, Ciniawsky S, Kock M, Kube S. Structure and function of the AAA+ nucleotide binding pocket. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:2-14. [PMID: 21839118 DOI: 10.1016/j.bbamcr.2011.06.014] [Citation(s) in RCA: 206] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/17/2011] [Accepted: 06/27/2011] [Indexed: 10/17/2022]
Abstract
Members of the diverse superfamily of AAA+ proteins are molecular machines responsible for a wide range of essential cellular processes. In this review we summarise structural and functional data surrounding the nucleotide binding pocket of these versatile complexes. Protein Data Bank (PDB) structures of closely related AAA+ ATPase are overlaid and biologically relevant motifs are displayed. Interactions between protomers are illustrated on the basis of oligomeric structures of each AAA+ subgroup. The possible role of conserved motifs in the nucleotide binding pocket is assessed with regard to ATP binding and hydrolysis, oligomerisation and inter-subunit communication. Our comparison indicates that in particular the roles of the arginine finger and sensor 2 residues differ subtly between AAA+ subgroups, potentially providing a means for functional diversification.
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Affiliation(s)
- Petra Wendler
- Gene Center, Ludwig-Maximilians-Universität München, München, Germany.
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40
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Keyamura K, Katayama T. DnaA protein DNA-binding domain binds to Hda protein to promote inter-AAA+ domain interaction involved in regulatory inactivation of DnaA. J Biol Chem 2011; 286:29336-29346. [PMID: 21708944 DOI: 10.1074/jbc.m111.233403] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chromosomal replication is initiated from the replication origin oriC in Escherichia coli by the active ATP-bound form of DnaA protein. The regulatory inactivation of DnaA (RIDA) system, a complex of the ADP-bound Hda and the DNA-loaded replicase clamp, represses extra initiations by facilitating DnaA-bound ATP hydrolysis, yielding the inactive ADP-bound form of DnaA. However, the mechanisms involved in promoting the DnaA-Hda interaction have not been determined except for the involvement of an interaction between the AAA+ domains of the two. This study revealed that DnaA Leu-422 and Pro-423 residues within DnaA domain IV, including a typical DNA-binding HTH motif, are specifically required for RIDA-dependent ATP hydrolysis in vitro and that these residues support efficient interaction with the DNA-loaded clamp·Hda complex and with Hda in vitro. Consistently, substitutions of these residues caused accumulation of ATP-bound DnaA in vivo and oriC-dependent inhibition of cell growth. Leu-422 plays a more important role in these activities than Pro-423. By contrast, neither of these residues is crucial for DNA replication from oriC, although they are highly conserved in DnaA orthologues. Structural analysis of a DnaA·Hda complex model suggested that these residues make contact with residues in the vicinity of the Hda AAA+ sensor I that participates in formation of a nucleotide-interacting surface. Together, the results show that functional DnaA-Hda interactions require a second interaction site within DnaA domain IV in addition to the AAA+ domain and suggest that these interactions are crucial for the formation of RIDA complexes that are active for DnaA-ATP hydrolysis.
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Affiliation(s)
- Kenji Keyamura
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tsutomu Katayama
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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41
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Requirements for the catalytic cycle of the N-ethylmaleimide-Sensitive Factor (NSF). BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:159-71. [PMID: 21689688 DOI: 10.1016/j.bbamcr.2011.06.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/23/2011] [Accepted: 06/06/2011] [Indexed: 12/23/2022]
Abstract
The N-ethylmaleimide-Sensitive Factor (NSF) was one of the initial members of the ATPases Associated with various cellular Activities Plus (AAA(+)) family. In this review, we discuss what is known about the mechanism of NSF action and how that relates to the mechanisms of other AAA(+) proteins. Like other family members, NSF binds to a protein complex (i.e., SNAP-SNARE complex) and utilizes ATP hydrolysis to affect the conformations of that complex. SNAP-SNARE complex disassembly is essential for SNARE recycling and sustained membrane trafficking. NSF is a homo-hexamer; each protomer is composed of an N-terminal domain, NSF-N, and two adjacent AAA-domains, NSF-D1 and NSF-D2. Mutagenesis analysis has established specific roles for many of the structural elements of NSF-D1, the catalytic ATPase domain, and NSF-N, the SNAP-SNARE binding domain. Hydrodynamic analysis of NSF, labeled with (Ni(2+)-NTA)(2)-Cy3, detected conformational differences in NSF, in which the ATP-bound conformation appears more compact than the ADP-bound form. This indicates that NSF undergoes significant conformational changes as it progresses through its ATP-hydrolysis cycle. Incorporating these data, we propose a sequential mechanism by which NSF uses NSF-N and NSF-D1 to disassemble SNAP-SNARE complexes. We also illustrate how analytical centrifugation might be used to study other AAA(+) proteins.
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42
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Abstract
Ubiquitin-dependent processes control much of cellular physiology. We show that expression of a highly active, Epstein-Barr virus-derived deubiquitylating enzyme (EBV-DUB) blocks proteasomal degradation of cytosolic and ER-derived proteins by preemptive removal of ubiquitin from proteasome substrates, a treatment less toxic than the use of proteasome inhibitors. Recognition of misfolded proteins in the ER lumen, their dislocation to the cytosol, and degradation are usually tightly coupled but can be uncoupled by the EBV-DUB: a misfolded glycoprotein that originates in the ER accumulates in association with cytosolic chaperones as a deglycosylated intermediate. Our data underscore the necessity of a DUB activity for completion of the dislocation reaction and provide a new means of inhibition of proteasomal proteolysis with reduced cytotoxicity.
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43
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Chapman E, Fry AN, Kang M. The complexities of p97 function in health and disease. MOLECULAR BIOSYSTEMS 2010; 7:700-10. [PMID: 21152665 DOI: 10.1039/c0mb00176g] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
p97 is a homohexameric, toroidal machine that harnesses the energy of ATP binding and hydrolysis to effect structural reorganization of a diverse and primarily uncharacterized set of substrate proteins. This action has been linked to endoplasmic reticulum associated degradation (ERAD), homotypic membrane fusion, transcription factor control, cell cycle progression, DNA repair, and post-mitotic spindle disassembly. Exactly how these diverse processes use p97 is not fully understood, but it is clear that binding sites, primarily on the N- and C-domains of p97, facilitate this diversity by coordinating a growing collection of cofactors. These cofactors act at the levels of mechanism, sub-cellular localization, and substrate modification. Another unifying theme is the use of ubiquitylation. Both p97 and many of the associated cofactors have demonstrable ubiquitin-binding competence. The present review will discuss some of the current mechanistic studies and controversies and how these relate to cofactors as well as discussing potential therapeutic targeting of p97.
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Affiliation(s)
- Eli Chapman
- Department of Molecular Biology, The Scripps Research Institute, Skaggs Molecular Biology Building, 10596 Torrey Pines Road, Rm. 203, La Jolla, CA 92037, USA.
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44
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Tang WK, Li D, Li CC, Esser L, Dai R, Guo L, Xia D. A novel ATP-dependent conformation in p97 N-D1 fragment revealed by crystal structures of disease-related mutants. EMBO J 2010; 29:2217-29. [PMID: 20512113 DOI: 10.1038/emboj.2010.104] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 04/26/2010] [Indexed: 12/12/2022] Open
Abstract
Mutations in p97, a major cytosolic AAA (ATPases associated with a variety of cellular activities) chaperone, cause inclusion body myopathy associated with Paget's disease of the bone and frontotemporal dementia (IBMPFD). IBMPFD mutants have single amino-acid substitutions at the interface between the N-terminal domain (N-domain) and the adjacent AAA domain (D1), resulting in a reduced affinity for ADP. The structures of p97 N-D1 fragments bearing IBMPFD mutations adopt an atypical N-domain conformation in the presence of Mg(2+).ATPgammaS, which is reversible by ADP, showing for the first time the nucleotide-dependent conformational change of the N-domain. The transition from the ADP- to the ATPgammaS-bound state is accompanied by a loop-to-helix conversion in the N-D1 linker and by an apparent re-ordering in the N-terminal region of p97. X-ray scattering experiments suggest that wild-type p97 subunits undergo a similar nucleotide-dependent N-domain conformational change. We propose that IBMPFD mutations alter the timing of the transition between nucleotide states by destabilizing the ADP-bound form and consequently interfere with the interactions between the N-domains and their substrates.
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Affiliation(s)
- Wai Kwan Tang
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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45
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Zhao C, Matveeva EA, Ren Q, Whiteheart SW. Dissecting the N-ethylmaleimide-sensitive factor: required elements of the N and D1 domains. J Biol Chem 2009; 285:761-72. [PMID: 19887446 DOI: 10.1074/jbc.m109.056739] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
N-Ethylmaleimide-sensitive factor (NSF) is a homo-hexameric member of the AAA(+) (ATPases associated with various cellular activities plus) family. It plays an essential role in most intracellular membrane trafficking through its binding to and disassembly of soluble NSF attachment protein (SNAP) receptor (SNARE) complexes. Each NSF protomer contains an N-terminal domain (NSF-N) and two AAA domains, a catalytic NSF-D1 and a structural NSF-D2. This study presents detailed mutagenesis analyses of NSF-N and NSF-D1, dissecting their roles in ATP hydrolysis, SNAP.SNARE binding, and complex disassembly. Our results show that a positively charged surface on NSF-N, bounded by Arg(67) and Lys(105), and the conserved residues in the central pore of NSF-D1 (Tyr(296) and Gly(298)) are involved in SNAP.SNARE binding but not basal ATP hydrolysis. Mutagenesis of Sensor 1 (Thr(373)-Arg(375)), Sensor 2 (Glu(440)-Glu(442)), and Arginine Fingers (Arg(385) and Arg(388)) in NSF-D1 shows that each region plays a discrete role. Sensor 1 is important for basal ATPase activity and nucleotide binding. Sensor 2 plays a role in ATP- and SNAP-dependent SNARE complex binding and disassembly but does so in cis and not through inter-protomer interactions. Arginine Fingers are important for SNAP.SNARE complex-stimulated ATPase activity and complex disassembly. Mutants at these residues have a dominant-negative phenotype in cells, suggesting that Arginine Fingers function in trans via inter-protomer interactions. Taken together, these data establish functional roles for many of the structural elements of the N domain and of the D1 ATP-binding site of NSF.
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Affiliation(s)
- Chunxia Zhao
- Department of Molecular and Cellular Biochemistry, University of Kentucky Medical Center, Lexington, Kentucky 40536-0509, USA
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46
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Reuter CJ, Uthandi S, Puentes JA, Maupin-Furlow JA. Hydrophobic carboxy-terminal residues dramatically reduce protein levels in the haloarchaeon Haloferax volcanii. MICROBIOLOGY-SGM 2009; 156:248-255. [PMID: 19850616 DOI: 10.1099/mic.0.032995-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Proteolysis is important not only to cell physiology but also to the successful development of biocatalysts. While a wide-variety of signals are known to trigger protein degradation in bacteria and eukaryotes, these mechanisms are poorly understood in archaea, known for their ability to withstand harsh conditions. Here we present a systematic study in which single C-terminal amino acid residues were added to a reporter protein and shown to influence its levels in an archaeal cell. All 20 amino acid residues were examined for their impact on protein levels, using the reporter protein soluble modified red-shifted GFP (smRS-GFP) expressed in the haloarchaeon Haloferax volcanii as a model system. Addition of hydrophobic residues, including Leu, Cys, Met, Phe, Ala, Tyr, Ile and Val, gave the most pronounced reduction in smRS-GFP levels compared with the addition of either neutral or charged hydrophilic residues. In contrast to the altered protein levels, the C-terminal alterations had no influence on smRS-GFP-specific transcript levels, thus revealing that the effect is post-transcriptional.
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Affiliation(s)
- Christopher J Reuter
- University of Florida, Department of Microbiology and Cell Science, Gainesville, FL 32611-0700, USA
| | - Sivakumar Uthandi
- University of Florida, Department of Microbiology and Cell Science, Gainesville, FL 32611-0700, USA
| | - Jose A Puentes
- University of Florida, Department of Microbiology and Cell Science, Gainesville, FL 32611-0700, USA
| | - Julie A Maupin-Furlow
- University of Florida, Department of Microbiology and Cell Science, Gainesville, FL 32611-0700, USA
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47
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Matsushita-Ishiodori Y, Yamanaka K, Hashimoto H, Esaki M, Ogura T. Conserved aromatic and basic amino acid residues in the pore region ofCaenorhabditis elegansspastin play critical roles in microtubule severing. Genes Cells 2009; 14:925-40. [DOI: 10.1111/j.1365-2443.2009.01320.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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48
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Medalia N, Beer A, Zwickl P, Mihalache O, Beck M, Medalia O, Navon A. Architecture and molecular mechanism of PAN, the archaeal proteasome regulatory ATPase. J Biol Chem 2009; 284:22952-60. [PMID: 19363223 DOI: 10.1074/jbc.m809643200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Archaea, an hexameric ATPase complex termed PAN promotes proteins unfolding and translocation into the 20 S proteasome. PAN is highly homologous to the six ATPases of the eukaryotic 19 S proteasome regulatory complex. Thus, insight into the mechanism of PAN function may reveal a general mode of action mutual to the eukaryotic 19 S proteasome regulatory complex. In this study we generated a three-dimensional model of PAN from tomographic reconstruction of negatively stained particles. Surprisingly, this reconstruction indicated that the hexameric complex assumes a two-ring structure enclosing a large cavity. Assessment of distinct three-dimensional functional states of PAN in the presence of adenosine 5'-O-(thiotriphosphate) and ADP and in the absence of nucleotides outlined a possible mechanism linking nucleotide binding and hydrolysis to substrate recognition, unfolding, and translocation. A novel feature of the ATPase complex revealed in this study is a gate controlling the "exit port" of the regulatory complex and, presumably, translocation into the 20 S proteasome. Based on our structural and biochemical findings, we propose a possible model in which substrate binding and unfolding are linked to structural transitions driven by nucleotide binding and hydrolysis, whereas translocation into the proteasome only depends upon the presence of an unfolded substrate and binding but not hydrolysis of nucleotide.
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Affiliation(s)
- Noa Medalia
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
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49
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The two PAN ATPases from Halobacterium display N-terminal heterogeneity and form labile complexes with the 20S proteasome. Biochem J 2008; 411:387-97. [PMID: 18215129 DOI: 10.1042/bj20071502] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The PAN (proteasome-activating nucleotidase) proteins from archaea represent homologues of the eukaryotic 26S proteasome regulatory ATPases. In vitro the PAN complex has been previously shown to have a stimulatory effect on the peptidase activities of the 20S core. By using gradient ultracentrifugation we found that, in cellular extracts, the two PAN proteins from Halobacterium do not form stable high-molecular-mass complexes. Only PAN B was found to associate transiently with the 20S proteasome, thus suggesting that the two PAN proteins are not functionally redundant. The PAN B-20S proteasome complexes associate in an ATP-dependent manner and are stabilized upon nucleotide binding. The two PAN proteins were immunodetected in cellular extracts as N-terminal-truncated polypeptides. RNA-mapping experiments and sequence analysis indicated that this process involved transcript heterogeneities and dual translational initiation mechanisms. Taken together, our results suggest that PAN N-terminal modifications and their intracellular dynamics of assembly/association may constitute important determinants of proteolysis regulation.
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Yu Z, Gonciarz MD, Sundquist WI, Hill CP, Jensen GJ. Cryo-EM structure of dodecameric Vps4p and its 2:1 complex with Vta1p. J Mol Biol 2008; 377:364-77. [PMID: 18280501 DOI: 10.1016/j.jmb.2008.01.009] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 01/01/2008] [Accepted: 01/04/2008] [Indexed: 10/22/2022]
Abstract
The type I AAA (ATPase associated with a variety of cellular activities) ATPase Vps4 and its co-factor Vta1p/LIP5 function in membrane remodeling events that accompany cytokinesis, multivesicular body biogenesis, and retrovirus budding, apparently by driving disassembly and recycling of membrane-associated ESCRT (endosomal sorting complex required for transport)-III complexes. Here, we present electron cryomicroscopy reconstructions of dodecameric yeast Vps4p complexes with and without their microtubule interacting and transport (MIT) N-terminal domains and Vta1p co-factors. The ATPase domains of Vps4p form a bowl-like structure composed of stacked hexameric rings. The two rings adopt dramatically different conformations, with the "upper" ring forming an open assembly that defines the sides of the bowl and the lower ring forming a closed assembly that forms the bottom of the bowl. The N-terminal MIT domains of the upper ring localize on the symmetry axis above the cavity of the bowl, and the binding of six extended Vta1p monomers causes additional density to appear both above and below the bowl. The structures suggest models in which Vps4p MIT and Vta1p domains engage ESCRT-III substrates above the bowl and help transfer them into the bowl to be pumped through the center of the dodecameric assembly.
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Affiliation(s)
- Zhiheng Yu
- Division of Biology, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
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