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Salcedo-Tacuma D, Asad N, Howells G, Anderson R, Smith DM. Proteasome hyperactivation rewires the proteome enhancing stress resistance, proteostasis, lipid metabolism and ERAD in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588128. [PMID: 38617285 PMCID: PMC11014606 DOI: 10.1101/2024.04.04.588128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Proteasome dysfunction is implicated in the pathogenesis of neurodegenerative diseases and age-related proteinopathies. Using a C. elegans model, we demonstrate that 20S proteasome hyperactivation, facilitated by 20S gate-opening, accelerates the targeting of intrinsically disordered proteins. This leads to increased protein synthesis, extensive rewiring of the proteome and transcriptome, enhanced oxidative stress defense, accelerated lipid metabolism, and peroxisome proliferation. It also promotes ER-associated degradation (ERAD) of aggregation-prone proteins, such as alpha-1 antitrypsin (ATZ) and various lipoproteins. Notably, our results reveal that 20S proteasome hyperactivation suggests a novel role in ERAD with broad implications for proteostasis-related disorders, simultaneously affecting lipid homeostasis and peroxisome proliferation. Furthermore, the enhanced cellular capacity to mitigate proteostasis challenges, alongside unanticipated acceleration of lipid metabolism is expected to contribute to the longevity phenotype of this mutant. Remarkably, the mechanism of longevity induced by 20S gate opening appears unique, independent of known longevity and stress-resistance pathways. These results support the therapeutic potential of 20S proteasome activation in mitigating proteostasis-related disorders broadly and provide new insights into the complex interplay between proteasome activity, cellular health, and aging.
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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
| | - Nadeeem. Asad
- 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
| | - Raymond Anderson
- 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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Spastin mutations impair coordination between lipid droplet dispersion and reticulum. PLoS Genet 2020; 16:e1008665. [PMID: 32315314 PMCID: PMC7173978 DOI: 10.1371/journal.pgen.1008665] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/12/2020] [Indexed: 12/22/2022] Open
Abstract
Lipid droplets (LD) are affected in multiple human disorders. These highly dynamic organelles are involved in many cellular roles. While their intracellular dispersion is crucial to ensure their function and other organelles-contact, underlying mechanisms are still unclear. Here we show that Spastin, one of the major proteins involved in Hereditary Spastic Paraplegia (HSP), controls LD dispersion. Spastin depletion in zebrafish affects metabolic properties and organelle dynamics. These functions are ensured by a conserved complex set of splice variants. M1 isoforms determine LD dispersion in the cell by orchestrating endoplasmic reticulum (ER) shape along microtubules (MTs). To further impact LD fate, Spastin modulates transcripts levels and subcellular location of other HSP key players, notably Seipin and REEP1. In pathological conditions, mutations in human Spastin M1 disrupt this mechanism and impacts LD network. Spastin depletion influences not only other key proteins but also modulates specific neutral lipids and phospholipids, revealing an impact on membrane and organelle components. Altogether our results show that Spastin and its partners converge in a common machinery that coordinates LD dispersion and ER shape along MTs. Any alteration of this system results in HSP clinical features and impacts lipids profile, thus opening new avenues for novel biomarkers of HSP.
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3
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Fan X, Lin Z, Fan G, Lu J, Hou Y, Habai G, Sun L, Yu P, Shen Y, Wen M, Wang C. The AAA protein spastin possesses two levels of basal ATPase activity. FEBS Lett 2018; 592:1625-1633. [PMID: 29710391 DOI: 10.1002/1873-3468.13075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/27/2018] [Accepted: 04/21/2018] [Indexed: 12/13/2022]
Abstract
The AAA ATPase spastin is a microtubule-severing enzyme that plays important roles in various cellular events including axon regeneration. Herein, we found that the basal ATPase activity of spastin is negatively regulated by spastin concentration. By determining a spastin crystal structure, we demonstrate the necessity of intersubunit interactions between spastin AAA domains. Neutralization of the positive charges in the microtubule-binding domain (MTBD) of spastin dramatically decreases the ATPase activity at low concentration, although the ATP-hydrolyzing potential is not affected. These results demonstrate that, in addition to the AAA domain, the MTBD region of spastin is also involved in regulating ATPase activity, making interactions between spastin protomers more complicated than expected.
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Affiliation(s)
- Xiangyu Fan
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhijie Lin
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China
| | - Guanghui Fan
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jing Lu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China
| | - Yongfei Hou
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Gulijiazi Habai
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Linyue Sun
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Pengpeng Yu
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin, China
| | - Maorong Wen
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Chunguang Wang
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
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4
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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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5
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Julien C, Lissouba A, Madabattula S, Fardghassemi Y, Rosenfelt C, Androschuk A, Strautman J, Wong C, Bysice A, O'sullivan J, Rouleau GA, Drapeau P, Parker JA, Bolduc FV. Conserved pharmacological rescue of hereditary spastic paraplegia-related phenotypes across model organisms. Hum Mol Genet 2016; 25:1088-99. [PMID: 26744324 PMCID: PMC4764191 DOI: 10.1093/hmg/ddv632] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 11/13/2015] [Accepted: 12/29/2015] [Indexed: 01/10/2023] Open
Abstract
Hereditary spastic paraplegias (HSPs) are a group of neurodegenerative diseases causing progressive gait dysfunction. Over 50 genes have now been associated with HSP. Despite the recent explosion in genetic knowledge, HSP remains without pharmacological treatment. Loss-of-function mutation of the SPAST gene, also known as SPG4, is the most common cause of HSP in patients. SPAST is conserved across animal species and regulates microtubule dynamics. Recent studies have shown that it also modulates endoplasmic reticulum (ER) stress. Here, utilizing null SPAST homologues in C. elegans, Drosophila and zebrafish, we tested FDA-approved compounds known to modulate ER stress in order to ameliorate locomotor phenotypes associated with HSP. We found that locomotor defects found in all of our spastin models could be partially rescued by phenazine, methylene blue, N-acetyl-cysteine, guanabenz and salubrinal. In addition, we show that established biomarkers of ER stress levels correlated with improved locomotor activity upon treatment across model organisms. Our results provide insights into biomarkers and novel therapeutic avenues for HSP.
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Affiliation(s)
| | | | - Surya Madabattula
- Institute for Neuroscience and Mental Health and Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Yasmin Fardghassemi
- CRCHUM and Department of Biochemistry, Université de Montréal, Montréal, Québec, Canada
| | - Cory Rosenfelt
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Alaura Androschuk
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Joel Strautman
- Institute for Neuroscience and Mental Health and Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Clement Wong
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Andrew Bysice
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Julia O'sullivan
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
| | - Guy A Rouleau
- Montreal Neurological Institute and Hospital, McGill University, Montréal, Québec, Canada
| | | | | | - François V Bolduc
- Institute for Neuroscience and Mental Health and Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada and
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6
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Monroe N, Hill CP. Meiotic Clade AAA ATPases: Protein Polymer Disassembly Machines. J Mol Biol 2015; 428:1897-911. [PMID: 26555750 DOI: 10.1016/j.jmb.2015.11.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 12/20/2022]
Abstract
Meiotic clade AAA ATPases (ATPases associated with diverse cellular activities), which were initially grouped on the basis of phylogenetic classification of their AAA ATPase cassette, include four relatively well characterized family members, Vps4, spastin, katanin and fidgetin. These enzymes all function to disassemble specific polymeric protein structures, with Vps4 disassembling the ESCRT-III polymers that are central to the many membrane-remodeling activities of the ESCRT (endosomal sorting complexes required for transport) pathway and spastin, katanin p60 and fidgetin affecting multiple aspects of cellular dynamics by severing microtubules. They share a common domain architecture that features an N-terminal MIT (microtubule interacting and trafficking) domain followed by a single AAA ATPase cassette. Meiotic clade AAA ATPases function as hexamers that can cycle between the active assembly and inactive monomers/dimers in a regulated process, and they appear to disassemble their polymeric substrates by translocating subunits through the central pore of their hexameric ring. Recent studies with Vps4 have shown that nucleotide-induced asymmetry is a requirement for substrate binding to the pore loops and that recruitment to the protein lattice via MIT domains also relieves autoinhibition and primes the AAA ATPase cassettes for substrate binding. The most striking, unifying feature of meiotic clade AAA ATPases may be their MIT domain, which is a module that is found in a wide variety of proteins that localize to ESCRT-III polymers. Spastin also displays an adjacent microtubule binding sequence, and the presence of both ESCRT-III and microtubule binding elements may underlie the recent findings that the ESCRT-III disassembly function of Vps4 and the microtubule-severing function of spastin, as well as potentially katanin and fidgetin, are highly coordinated.
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Affiliation(s)
- Nicole Monroe
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112-5650, USA
| | - Christopher P Hill
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112-5650, USA.
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7
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Johjima A, Noi K, Nishikori S, Ogi H, Esaki M, Ogura T. Microtubule severing by katanin p60 AAA+ ATPase requires the C-terminal acidic tails of both α- and β-tubulins and basic amino acid residues in the AAA+ ring pore. J Biol Chem 2015; 290:11762-70. [PMID: 25805498 DOI: 10.1074/jbc.m114.614768] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Indexed: 11/06/2022] Open
Abstract
The microtubule (MT) network is highly dynamic and undergoes dramatic reorganizations during the cell cycle. Dimers of α- and β-tubulins rapidly polymerize to and depolymerize from the end of MT fibrils in an intrinsic GTP-dependent manner. MT severing by ATP-driven enzymes such as katanin and spastin contributes significantly to microtubule dynamics, and it has been shown that katanin p60, a AAA+ family protein, has ATPase and MT-severing activities. The mechanism of MT severing by katanin p60 is poorly understood, and the residues in katanin p60 and tubulins important for severing activity were therefore explored in this study. MT-severing activity, but not ATPase activity, was inhibited by mutations of the conserved aromatic residue and the flanking basic residues in the pore region of the katanin p60 hexameric ring. When the acidic residue-rich C-terminal unstructured segment of either α- or β-tubulin was removed, polymerized MTs were resistant to katanin p60 treatment. Interactions between katanin p60 and the mutant MTs, on the other hand, were unaffected. Taken together, these findings led us to propose that the interactions between the positively charged residues of katanin p60 and the acidic tails of both tubulins are essential for efficient severing of MTs.
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Affiliation(s)
- Ai Johjima
- From the Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811
| | - Kentaro Noi
- From the Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, the Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, and the Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Shingo Nishikori
- From the Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811
| | - Hirotsugu Ogi
- the Graduate School of Engineering Science, Osaka University, Osaka 560-8531, Japan
| | - Masatoshi Esaki
- From the Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, the Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, and
| | - Teru Ogura
- From the Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, the Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, and
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8
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Caenorhabditis elegans Models of Hereditary Spastic Paraplegia. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00074-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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9
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Wen M, Wang C. The nucleotide cycle of spastin correlates with its microtubule-binding properties. FEBS J 2013; 280:3868-77. [PMID: 23745751 DOI: 10.1111/febs.12385] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 06/05/2013] [Accepted: 06/07/2013] [Indexed: 12/24/2022]
Abstract
Spastin is an AAA (ATPase associated with diverse cellular activities) protein with microtubule (MT)-severing activity. The spastin-encoding gene was identified as the most often mutated gene in the human neurodegenerative disease hereditary spastic paraplegia. Although the structure of the AAA domain of spastin has been determined, the mechanism by which spastin severs MTs remains elusive. Here, we studied the MT-binding and nucleotide-binding properties of spastin, as well as their interplay. The results suggest that ATP-bound spastin interacts strongly and cooperatively with MTs; this interaction stimulates ATP hydrolysis by spastin. After ATP hydrolysis, spastin dissociates from MTs, and then exchanges ADP for ATP in solution for the next round of work. In particular, spastin in the ternary complex of MT-spastin-ATP is the most cooperative state during the working cycle, and is probably the force-generating state that is responsible for MT severing. The results presented in this study establish the nucleotide cycle of spastin in correlation with its MT-binding properties, and provide a biochemical framework for further studies of the working mechanism of spastin.
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Affiliation(s)
- Maorong Wen
- Institute of Protein Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
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10
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Onitake A, Matsushita-Ishiodori Y, Johjima A, Esaki M, Ogura T, Yamanaka K. The C-terminal α-helix of SPAS-1, a Caenorhabditis elegans spastin homologue, is crucial for microtubule severing. J Struct Biol 2012; 179:138-42. [PMID: 22561316 DOI: 10.1016/j.jsb.2012.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Revised: 04/19/2012] [Accepted: 04/20/2012] [Indexed: 11/30/2022]
Abstract
Spastin belongs to the meiotic subfamily, together with Vps4/SKD1, fidgetin and katanin, of AAA (ATPases associated with diverse cellular activities) proteins, and functions in microtubule severing. Interestingly, all members of this subgroup specifically contain an additional α-helix at the very C-terminal end. To understand the function of the C-terminal α-helix, we characterised its deletion mutants of SPAS-1, a Caenorhabditis elegans spastin homologue, in vitro and in vivo. We found that the C-terminal α-helix plays essential roles in ATP binding, ATP hydrolysing and microtubule severing activities. It is likely that the C-terminal α-helix is required for cellular functions of members of meiotic subgroup of AAA proteins, since the C-terminal α-helix of Vps4 is also important for assembly, ATPase activity and in vivo function mediated by ESCRT-III complexes.
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Affiliation(s)
- Akinobu Onitake
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan
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11
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Bebeacua C, Förster A, McKeown C, Meyer HH, Zhang X, Freemont PS. Distinct conformations of the protein complex p97-Ufd1-Npl4 revealed by electron cryomicroscopy. Proc Natl Acad Sci U S A 2012; 109:1098-103. [PMID: 22232657 PMCID: PMC3268311 DOI: 10.1073/pnas.1114341109] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
p97 is a key regulator of numerous cellular pathways and associates with ubiquitin-binding adaptors to remodel ubiquitin-modified substrate proteins. How adaptor binding to p97 is coordinated and how adaptors contribute to substrate remodeling is unclear. Here we present the 3D electron cryomicroscopy reconstructions of the major Ufd1-Npl4 adaptor in complex with p97. Our reconstructions show that p97-Ufd1-Npl4 is highly dynamic and that Ufd1-Npl4 assumes distinct positions relative to the p97 ring upon addition of nucleotide. Our results suggest a model for substrate remodeling by p97 and also explains how p97-Ufd1-Npl4 could form other complexes in a hierarchical model of p97-cofactor assembly.
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Affiliation(s)
- Cecilia Bebeacua
- Centre for Structural Biology and Centre for Biomolecular Electron Microscopy, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom; and
| | - Andreas Förster
- Centre for Structural Biology and Centre for Biomolecular Electron Microscopy, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom; and
| | - Ciarán McKeown
- Centre for Structural Biology and Centre for Biomolecular Electron Microscopy, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom; and
| | - Hemmo H. Meyer
- Molecular Biology Laboratory, Faculty of Biology, Centre of Medical Biotechnology, University of Duisburg-Essen, 45117 Essen, Germany
| | - Xiaodong Zhang
- Centre for Structural Biology and Centre for Biomolecular Electron Microscopy, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom; and
| | - Paul S. Freemont
- Centre for Structural Biology and Centre for Biomolecular Electron Microscopy, Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, United Kingdom; and
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12
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Lumb JH, Connell JW, Allison R, Reid E. The AAA ATPase spastin links microtubule severing to membrane modelling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:192-7. [PMID: 21888932 DOI: 10.1016/j.bbamcr.2011.08.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/10/2011] [Accepted: 08/17/2011] [Indexed: 11/18/2022]
Abstract
In 1999, mutations in the gene encoding the microtubule severing AAA ATPase spastin were identified as a major cause of a genetic neurodegenerative condition termed hereditary spastic paraplegia (HSP). This finding stimulated intense study of the spastin protein and over the last decade, a combination of cell biological, in vivo, in vitro and structural studies have provided important mechanistic insights into the cellular functions of the protein, as well as elucidating cell biological pathways that might be involved in axonal maintenance and degeneration. Roles for spastin have emerged in shaping the endoplasmic reticulum and the abscission stage of cytokinesis, in which spastin appears to couple membrane modelling to microtubule regulation by severing.
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Affiliation(s)
- Jennifer H Lumb
- Department of Medical Genetics and Cambridge Institute for Medical Research, University of Cambridge, UK
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13
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Sugimoto S, Yamanaka K, Nishikori S, Miyagi A, Ando T, Ogura T. AAA+ chaperone ClpX regulates dynamics of prokaryotic cytoskeletal protein FtsZ. J Biol Chem 2009; 285:6648-57. [PMID: 20022957 DOI: 10.1074/jbc.m109.080739] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
AAA(+) chaperone ClpX has been suggested to be a modulator of prokaryotic cytoskeletal protein FtsZ, but the details of recognition and remodeling of FtsZ by ClpX are largely unknown. In this study, we have extensively investigated the nature of FtsZ polymers and mechanisms of ClpX-regulated FtsZ polymer dynamics. We found that FtsZ polymerization is inhibited by ClpX in an ATP-independent manner and that the N-terminal domain of ClpX plays a crucial role for the inhibition of FtsZ polymerization. Single molecule analysis with high speed atomic force microscopy directly revealed that FtsZ polymer is in a dynamic equilibrium between polymerization and depolymerization on a time scale of several seconds. ClpX disassembles FtsZ polymers presumably by blocking reassembly of FtsZ. Furthermore, Escherichia coli cells overproducing ClpX and N-terminal domain of ClpX show filamentous morphology with abnormal localization of FtsZ. These data together suggest that ClpX modulates FtsZ polymer dynamics in an ATP-independent fashion, which is achieved by interaction between the N-terminal domain of ClpX and FtsZ monomers or oligomers.
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Affiliation(s)
- Shinya Sugimoto
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan
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