1
|
Krishnamoorthy V, Foglizzo M, Dilley RL, Wu A, Datta A, Dutta P, Campbell LJ, Degtjarik O, Musgrove LJ, Calabrese AN, Zeqiraj E, Greenberg RA. The SPATA5-SPATA5L1 ATPase complex directs replisome proteostasis to ensure genome integrity. Cell 2024; 187:2250-2268.e31. [PMID: 38554706 PMCID: PMC11055677 DOI: 10.1016/j.cell.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 12/27/2023] [Accepted: 03/02/2024] [Indexed: 04/02/2024]
Abstract
Ubiquitin-dependent unfolding of the CMG helicase by VCP/p97 is required to terminate DNA replication. Other replisome components are not processed in the same fashion, suggesting that additional mechanisms underlie replication protein turnover. Here, we identify replisome factor interactions with a protein complex composed of AAA+ ATPases SPATA5-SPATA5L1 together with heterodimeric partners C1orf109-CINP (55LCC). An integrative structural biology approach revealed a molecular architecture of SPATA5-SPATA5L1 N-terminal domains interacting with C1orf109-CINP to form a funnel-like structure above a cylindrically shaped ATPase motor. Deficiency in the 55LCC complex elicited ubiquitin-independent proteotoxicity, replication stress, and severe chromosome instability. 55LCC showed ATPase activity that was specifically enhanced by replication fork DNA and was coupled to cysteine protease-dependent cleavage of replisome substrates in response to replication fork damage. These findings define 55LCC-mediated proteostasis as critical for replication fork progression and genome stability and provide a rationale for pathogenic variants seen in associated human neurodevelopmental disorders.
Collapse
Affiliation(s)
- Vidhya Krishnamoorthy
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - Martina Foglizzo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Robert L Dilley
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA.
| | - Angela Wu
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - Arindam Datta
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - Parul Dutta
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
| | - Lisa J Campbell
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Oksana Degtjarik
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Laura J Musgrove
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Antonio N Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Elton Zeqiraj
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
| | - Roger A Greenberg
- Department of Cancer Biology, Penn Center for Genome Integrity, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6160, USA.
| |
Collapse
|
2
|
Shein M, Hitzenberger M, Cheng TC, Rout SR, Leitl KD, Sato Y, Zacharias M, Sakata E, Schütz AK. Characterizing ATP processing by the AAA+ protein p97 at the atomic level. Nat Chem 2024; 16:363-372. [PMID: 38326645 PMCID: PMC10914628 DOI: 10.1038/s41557-024-01440-0] [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: 03/24/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
The human enzyme p97 regulates various cellular pathways by unfolding hundreds of protein substrates in an ATP-dependent manner, making it an essential component of protein homeostasis and an impactful pharmacological target. The hexameric complex undergoes substantial conformational changes throughout its catalytic cycle. Here we elucidate the molecular motions that occur at the active site in the temporal window immediately before and after ATP hydrolysis by merging cryo-EM, NMR spectroscopy and molecular dynamics simulations. p97 populates a metastable reaction intermediate, the ADP·Pi state, which is poised between hydrolysis and product release. Detailed snapshots reveal that the active site is finely tuned to trap and eventually discharge the cleaved phosphate. Signalling pathways originating at the active site coordinate the action of the hexamer subunits and couple hydrolysis with allosteric conformational changes. Our multidisciplinary approach enables a glimpse into the sophisticated spatial and temporal orchestration of ATP handling by a prototype AAA+ protein.
Collapse
Affiliation(s)
- Mikhail Shein
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany
- Bavarian NMR Center, Technical University of Munich, Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Manuel Hitzenberger
- Physics Department and Center of Protein Assemblies, Technical University of Munich, Garching, Germany.
| | - Tat Cheung Cheng
- Institute for Neuropathology, University Medical Center Göttingen, Göttingen, Germany
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany
| | - Smruti R Rout
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany
- Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen, Germany
| | - Kira D Leitl
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany
- Bavarian NMR Center, Technical University of Munich, Garching, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Yusuke Sato
- Center for Research on Green Sustainable Chemistry, Graduate School of Engineering, Tottori University, Tottori, Japan
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Martin Zacharias
- Physics Department and Center of Protein Assemblies, Technical University of Munich, Garching, Germany.
| | - Eri Sakata
- Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, Göttingen, Germany.
- Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen, Germany.
| | - Anne K Schütz
- Faculty for Chemistry and Pharmacy, Ludwig-Maximilians-Universität München, München, Germany.
- Bavarian NMR Center, Technical University of Munich, Garching, Germany.
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.
| |
Collapse
|
3
|
Soontrapa P, Seven NA, Liewluck T, Cui G, Mer G, Milone M. Adolescent-onset multisystem proteinopathy due to a novel VCP variant. Neuromuscul Disord 2024; 34:89-94. [PMID: 38159460 DOI: 10.1016/j.nmd.2023.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 01/03/2024]
Abstract
Valosin-containing protein (VCP) pathogenic variants are the most common cause of multisystem proteinopathy presenting with inclusion body myopathy, amyotrophic lateral sclerosis/frontotemporal dementia, and Paget disease of bone in isolation or in combination. We report a patient manifesting with adolescent-onset myopathy caused by a novel heterozygous VCP variant (c.467G > T, p.Gly156Val). The myopathy manifested asymmetrically in lower limbs and extended to proximal, axial, and upper limb muscles, with loss of ambulation at age 35. Creatine kinase value was normal. Alkaline phosphatase was elevated. Electromyography detected mixed low amplitude, short duration and high amplitude, long duration motor unit potentials. Muscle biopsy showed features of inclusion body myopathy, which in combination with newly diagnosed Paget disease of bone, supported the VCP variant pathogenicity. In conclusion, VCP-multisystem proteinopathy is not only a disease of adulthood but can have a pediatric onset and should be considered in differential diagnosis of neuromuscular weakness in the pediatric population.
Collapse
Affiliation(s)
- Pannathat Soontrapa
- Department of Neurology, Division of Neuromuscular Medicine, Mayo Clinic, Rochester, MN, United States of America; Department of Medicine, Division of Neurology, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nathan A Seven
- Department of Neurology, Division of Neuromuscular Medicine, Mayo Clinic, Rochester, MN, United States of America
| | - Teerin Liewluck
- Department of Neurology, Division of Neuromuscular Medicine, Mayo Clinic, Rochester, MN, United States of America
| | - Gaofeng Cui
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States of America
| | - Georges Mer
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States of America
| | - Margherita Milone
- Department of Neurology, Division of Neuromuscular Medicine, Mayo Clinic, Rochester, MN, United States of America.
| |
Collapse
|
4
|
Yu G, Bai Y, Zhang ZY. Valosin-Containing Protein (VCP)/p97 Oligomerization. Subcell Biochem 2024; 104:485-501. [PMID: 38963497 DOI: 10.1007/978-3-031-58843-3_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Valosin-containing protein (VCP), also known as p97, is an evolutionarily conserved AAA+ ATPase essential for cellular homeostasis. Cooperating with different sets of cofactors, VCP is involved in multiple cellular processes through either the ubiquitin-proteasome system (UPS) or the autophagy/lysosomal route. Pathogenic mutations frequently found at the interface between the NTD domain and D1 ATPase domain have been shown to cause malfunction of VCP, leading to degenerative disorders including the inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD), amyotrophic lateral sclerosis (ALS), and cancers. Therefore, VCP has been considered as a potential therapeutic target for neurodegeneration and cancer. Most of previous studies found VCP predominantly exists and functions as a hexamer, which unfolds and extracts ubiquitinated substrates from protein complexes for degradation. However, recent studies have characterized a new VCP dodecameric state and revealed a controlling mechanism of VCP oligomeric states mediated by the D2 domain nucleotide occupancy. Here, we summarize our recent knowledge on VCP oligomerization, regulation, and potential implications of VCP in cellular function and pathogenic progression.
Collapse
Affiliation(s)
- Guimei Yu
- School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, China
| | - Yunpeng Bai
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Zhong-Yin Zhang
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
5
|
Valimehr S, Sethi A, Shukla M, Bhattacharyya S, Kazemi M, Rouiller I. Molecular Mechanisms Driving and Regulating the AAA+ ATPase VCP/p97, an Important Therapeutic Target for Treating Cancer, Neurological and Infectious Diseases. Biomolecules 2023; 13:biom13050737. [PMID: 37238606 DOI: 10.3390/biom13050737] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/15/2023] [Accepted: 04/13/2023] [Indexed: 05/28/2023] Open
Abstract
p97/VCP, a highly conserved type II ATPase associated with diverse cellular activities (AAA+ ATPase), is an important therapeutic target in the treatment of neurodegenerative diseases and cancer. p97 performs a variety of functions in the cell and facilitates virus replication. It is a mechanochemical enzyme that generates mechanical force from ATP-binding and hydrolysis to perform several functions, including unfolding of protein substrates. Several dozens of cofactors/adaptors interact with p97 and define the multifunctionality of p97. This review presents the current understanding of the molecular mechanism of p97 during the ATPase cycle and its regulation by cofactors and small-molecule inhibitors. We compare detailed structural information obtained in different nucleotide states in the presence and absence of substrates and inhibitors. We also review how pathogenic gain-of-function mutations modify the conformational changes of p97 during the ATPase cycle. Overall, the review highlights how the mechanistic knowledge of p97 helps in designing pathway-specific modulators and inhibitors.
Collapse
Affiliation(s)
- Sepideh Valimehr
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
- Bio21 Ian Holmes Imaging Centre, Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Ashish Sethi
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
- Australian Nuclear Science Technology Organisation, The Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC 3168, Australia
| | - Manjari Shukla
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, Jodhpur 342030, Rajasthan, India
| | - Sudipta Bhattacharyya
- Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, Jodhpur 342030, Rajasthan, India
| | - Mohsen Kazemi
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Isabelle Rouiller
- Department of Biochemistry & Pharmacology, The University of Melbourne, Melbourne, VIC 3010, Australia
- Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins, The University of Melbourne, Melbourne, VIC 3010, Australia
| |
Collapse
|
6
|
Wu D, Liu Y, Dai Y, Wang G, Lu G, Chen Y, Li N, Lin J, Gao N. Comprehensive structural characterization of the human AAA+ disaggregase CLPB in the apo- and substrate-bound states reveals a unique mode of action driven by oligomerization. PLoS Biol 2023; 21:e3001987. [PMID: 36745679 PMCID: PMC9934407 DOI: 10.1371/journal.pbio.3001987] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 02/16/2023] [Accepted: 01/04/2023] [Indexed: 02/07/2023] Open
Abstract
The human AAA+ ATPase CLPB (SKD3) is a protein disaggregase in the mitochondrial intermembrane space (IMS) and functions to promote the solubilization of various mitochondrial proteins. Loss-of-function CLPB mutations are associated with a few human diseases with neutropenia and neurological disorders. Unlike canonical AAA+ proteins, CLPB contains a unique ankyrin repeat domain (ANK) at its N-terminus. How CLPB functions as a disaggregase and the role of its ANK domain are currently unclear. Herein, we report a comprehensive structural characterization of human CLPB in both the apo- and substrate-bound states. CLPB assembles into homo-tetradecamers in apo-state and is remodeled into homo-dodecamers upon substrate binding. Conserved pore-loops (PLs) on the ATPase domains form a spiral staircase to grip and translocate the substrate in a step-size of 2 amino acid residues. The ANK domain is not only responsible for maintaining the higher-order assembly but also essential for the disaggregase activity. Interactome analysis suggests that the ANK domain may directly interact with a variety of mitochondrial substrates. These results reveal unique properties of CLPB as a general disaggregase in mitochondria and highlight its potential as a target for the treatment of various mitochondria-related diseases.
Collapse
Affiliation(s)
- Damu Wu
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Yan Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuhao Dai
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Academy of Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Guopeng Wang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Guoliang Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yan Chen
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Changping Laboratory, Beijing, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
- * E-mail: (JL); (NG)
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China
- Changping Laboratory, Beijing, China
- National Biomedical Imaging Center, Peking University, Beijing, China
- * E-mail: (JL); (NG)
| |
Collapse
|
7
|
Shen X, Sun P, Zhang H, Yang H. Mitochondrial quality control in the brain: The physiological and pathological roles. Front Neurosci 2022; 16:1075141. [PMID: 36578825 PMCID: PMC9791200 DOI: 10.3389/fnins.2022.1075141] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
The human brain has high energetic expenses and consumes over 20% of total oxygen metabolism. Abnormal brain energy homeostasis leads to various brain diseases. Among multiple factors that contribute to these diseases, mitochondrial dysfunction is one of the most common causes. Maintenance of mitochondrial integrity and functionality is of pivotal importance to brain energy generation. Mitochondrial quality control (MQC), employing the coordination of multiple mechanisms, is evolved to overcome many mitochondrial defects. Thus, not surprisingly, aberrant mitochondrial quality control results in a wide range of brain disorders. Targeting MQC to preserve and restore mitochondrial function has emerged as a promising therapeutic strategy for the prevention and treatment of brain diseases. Here, we set out to summarize the current understanding of mitochondrial quality control in brain homeostasis. We also evaluate potential pharmaceutically and clinically relevant targets in MQC-associated brain disorders.
Collapse
|
8
|
Ma C, Wu D, Chen Q, Gao N. Structural dynamics of AAA + ATPase Drg1 and mechanism of benzo-diazaborine inhibition. Nat Commun 2022; 13:6765. [PMID: 36351914 PMCID: PMC9646744 DOI: 10.1038/s41467-022-34511-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 10/27/2022] [Indexed: 11/11/2022] Open
Abstract
The type II AAA + ATPase Drg1 is a ribosome assembly factor, functioning to release Rlp24 from the pre-60S particle just exported from nucleus, and its activity in can be inhibited by a drug molecule diazaborine. However, molecular mechanisms of Drg1-mediated Rlp24 removal and diazaborine-mediated inhibition are not fully understood. Here, we report Drg1 structures in different nucleotide-binding and benzo-diazaborine treated states. Drg1 hexamers transits between two extreme conformations (planar or helical arrangement of protomers). By forming covalent adducts with ATP molecules in both ATPase domain, benzo-diazaborine locks Drg1 hexamers in a symmetric and non-productive conformation to inhibits both inter-protomer and inter-ring communication of Drg1 hexamers. We also obtained a substrate-engaged mutant Drg1 structure, in which conserved pore-loops form a spiral staircase to interact with the polypeptide through a sequence-independent manner. Structure-based mutagenesis data highlight the functional importance of the pore-loop, the D1-D2 linker and the inter-subunit signaling motif of Drg1, which share similar regulatory mechanisms with p97. Our results suggest that Drg1 may function as an unfoldase that threads a substrate protein within the pre-60S particle.
Collapse
Affiliation(s)
- Chengying Ma
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China ,Changping Laboratory, 102206 Beijing, China
| | - Damu Wu
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China
| | - Qian Chen
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China
| | - Ning Gao
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, 100871 Beijing, China ,Changping Laboratory, 102206 Beijing, China ,grid.11135.370000 0001 2256 9319National Biomedical Imaging Center, Peking University, 100871 Beijing, China
| |
Collapse
|
9
|
Ahlstedt BA, Ganji R, Raman M. The functional importance of VCP to maintaining cellular protein homeostasis. Biochem Soc Trans 2022; 50:1457-1469. [PMID: 36196920 PMCID: PMC9704522 DOI: 10.1042/bst20220648] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/09/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022]
Abstract
The AAA-ATPase (ATPases associated with diverse cellular activities) valosin-containing protein (VCP), is essential for many cellular pathways including but not limited to endoplasmic reticulum-associated degradation (ERAD), DNA damage responses, and cell cycle regulation. VCP primarily identifies ubiquitylated proteins in these pathways and mediates their unfolding and degradation by the 26S proteasome. This review summarizes recent research on VCP that has uncovered surprising new ways that this ATPase is regulated, new aspects of recognition of substrates and novel pathways and substrates that utilize its activity.
Collapse
Affiliation(s)
- Brittany A. Ahlstedt
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, U.S.A
| | - Rakesh Ganji
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, U.S.A
| | - Malavika Raman
- Department of Developmental Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA, U.S.A
| |
Collapse
|
10
|
Huntington B, Zhao L, Bron P, Shahul Hameed UF, Arold ST, Qureshi BM. Thicker Ice Improves the Integrity and Angular Distribution of CDC48A Hexamers on Cryo-EM Grids. Front Mol Biosci 2022; 9:890390. [PMID: 35782862 PMCID: PMC9247313 DOI: 10.3389/fmolb.2022.890390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/26/2022] [Indexed: 11/21/2022] Open
Abstract
Many cryogenic electron microscopy (cryo-EM) single particle analyses are constrained by the sample preparation step upon which aggregation, dissociation, and/or preferential orientation of particles can be introduced. Here, we report how we solved these problems in the case of CDC48A, a hexameric AAA ATPase from Arabidopsis thaliana. CDC48A hexamers are well preserved under negative staining conditions but disassemble during grid freezing using the classical blotting method. Vitrification of grids using the blot-free Chameleon method preserved the integrity of particles but resulted in their strong preferential orientation. We then used a strategy where we improved in parallel the purification of CDC48A and the conditions for cryo-EM data acquisition. Indeed, we noted that images taken from thicker ice presented an even distribution of intact particles with random orientations, but resulted in a lower image resolution. Consequently, in our case, distribution, orientation, image resolution, and the integrity of particles were tightly correlated with ice thickness. By combining the more homogeneous and stable CDC48A hexamers resulting from our improved purification protocol with an iterative search across different ice thicknesses, we identified an intermediate thickness that retained sufficiently high-resolution structural information while maintaining a complete distribution of particle orientations. Our approach may provide a simple, fast, and generally applicable strategy to record data of sufficient quality under standard laboratory and microscope settings. This method may be of particular value when time and resources are limited.
Collapse
Affiliation(s)
- Brandon Huntington
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Lingyun Zhao
- Imaging and Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Patrick Bron
- Centre de Biologie Structurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Umar F. Shahul Hameed
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
| | - Stefan T. Arold
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Centre de Biologie Structurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
| | - Bilal M. Qureshi
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Division of Structural Biology (Strubi), University of Oxford, Oxford, United Kingdom
- Scientific Center of Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, Switzerland
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
| |
Collapse
|