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Francisco T, Pedrosa AG, Rodrigues TA, Abalkhail T, Li H, Ferreira MJ, van der Heden van Noort GJ, Fransen M, Hettema EH, Azevedo JE. Noncanonical and reversible cysteine ubiquitination prevents the overubiquitination of PEX5 at the peroxisomal membrane. PLoS Biol 2024; 22:e3002567. [PMID: 38470934 PMCID: PMC10959387 DOI: 10.1371/journal.pbio.3002567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 03/22/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
PEX5, the peroxisomal protein shuttling receptor, binds newly synthesized proteins in the cytosol and transports them to the organelle. During its stay at the peroxisomal protein translocon, PEX5 is monoubiquitinated at its cysteine 11 residue, a mandatory modification for its subsequent ATP-dependent extraction back into the cytosol. The reason why a cysteine and not a lysine residue is the ubiquitin acceptor is unknown. Using an established rat liver-based cell-free in vitro system, we found that, in contrast to wild-type PEX5, a PEX5 protein possessing a lysine at position 11 is polyubiquitinated at the peroxisomal membrane, a modification that negatively interferes with the extraction process. Wild-type PEX5 cannot retain a polyubiquitin chain because ubiquitination at cysteine 11 is a reversible reaction, with the E2-mediated deubiquitination step presenting faster kinetics than PEX5 polyubiquitination. We propose that the reversible nonconventional ubiquitination of PEX5 ensures that neither the peroxisomal protein translocon becomes obstructed with polyubiquitinated PEX5 nor is PEX5 targeted for proteasomal degradation.
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Affiliation(s)
- Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana G. Pedrosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Tony A. Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Tarad Abalkhail
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Hongli Li
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Maria J. Ferreira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | | | - Marc Fransen
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Ewald H. Hettema
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Jorge E. Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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Hunt LC, Nyamkondiwa K, Stephan A, Jiao J, Kavdia K, Pagala V, Peng J, Demontis F. The ubiquitin-conjugating enzyme UBE2D/eff maintains a youthful proteome and ensures protein quality control during aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.12.571303. [PMID: 38168249 PMCID: PMC10759998 DOI: 10.1101/2023.12.12.571303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Ubiquitin-conjugating enzymes (E2s) are key for regulating protein function and turnover via ubiquitination but it remains undetermined which E2s maintain proteostasis during aging. Here, we find that E2s have diverse roles in handling a model aggregation-prone protein (huntingtin-polyQ) in the Drosophila retina: while some E2s mediate aggregate assembly, UBE2D/effete (eff) and other E2s are required for huntingtin-polyQ degradation. UBE2D/eff is key for proteostasis also in skeletal muscle: eff protein levels decline with aging, and muscle-specific eff knockdown causes an accelerated buildup in insoluble poly-ubiquitinated proteins (which progressively accumulate with aging) and shortens lifespan. Transgenic expression of human UBE2D2, homologous to eff, partially rescues the lifespan and proteostasis deficits caused by muscle-specific effRNAi by re-establishing the physiological levels of effRNAi-regulated proteins, which include several regulators of proteostasis. Interestingly, UBE2D/eff knockdown in young age reproduces part of the proteomic changes that normally occur in old muscles, suggesting that the decrease in UBE2D/eff protein levels that occurs with aging contributes to reshaping the composition of the muscle proteome. Altogether, these findings indicate that UBE2D/eff is a key E2 ubiquitin-conjugating enzyme that ensures protein quality control and helps maintain a youthful proteome composition during aging.
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Affiliation(s)
- Liam C. Hunt
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Kudzai Nyamkondiwa
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Anna Stephan
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Jianqin Jiao
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Kanisha Kavdia
- Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Vishwajeeth Pagala
- Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Junmin Peng
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
- Department of Structural Biology, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - Fabio Demontis
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
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3
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van Overbeek NK, Aguirre T, van der Heden van Noort GJ, Blagoev B, Vertegaal ACO. Deciphering non-canonical ubiquitin signaling: biology and methodology. Front Mol Biosci 2024; 10:1332872. [PMID: 38414868 PMCID: PMC10897730 DOI: 10.3389/fmolb.2023.1332872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 12/20/2023] [Indexed: 02/29/2024] Open
Abstract
Ubiquitination is a dynamic post-translational modification that regulates virtually all cellular processes by modulating function, localization, interactions and turnover of thousands of substrates. Canonical ubiquitination involves the enzymatic cascade of E1, E2 and E3 enzymes that conjugate ubiquitin to lysine residues giving rise to monomeric ubiquitination and polymeric ubiquitination. Emerging research has established expansion of the ubiquitin code by non-canonical ubiquitination of N-termini and cysteine, serine and threonine residues. Generic methods for identifying ubiquitin substrates using mass spectrometry based proteomics often overlook non-canonical ubiquitinated substrates, suggesting that numerous undiscovered substrates of this modification exist. Moreover, there is a knowledge gap between in vitro studies and comprehensive understanding of the functional consequence of non-canonical ubiquitination in vivo. Here, we discuss the current knowledge about non-lysine ubiquitination, strategies to map the ubiquitinome and their applicability for studying non-canonical ubiquitination substrates and sites. Furthermore, we elucidate the available chemical biology toolbox and elaborate on missing links required to further unravel this less explored subsection of the ubiquitin system.
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Affiliation(s)
- Nila K. van Overbeek
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Tim Aguirre
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Blagoy Blagoev
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Alfred C. O. Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
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4
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Hunt LC, Pagala V, Stephan A, Xie B, Kodali K, Kavdia K, Wang YD, Shirinifard A, Curley M, Graca FA, Fu Y, Poudel S, Li Y, Wang X, Tan H, Peng J, Demontis F. An adaptive stress response that confers cellular resilience to decreased ubiquitination. Nat Commun 2023; 14:7348. [PMID: 37963875 PMCID: PMC10646096 DOI: 10.1038/s41467-023-43262-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 11/02/2023] [Indexed: 11/16/2023] Open
Abstract
Ubiquitination is a post-translational modification initiated by the E1 enzyme UBA1, which transfers ubiquitin to ~35 E2 ubiquitin-conjugating enzymes. While UBA1 loss is cell lethal, it remains unknown how partial reduction in UBA1 activity is endured. Here, we utilize deep-coverage mass spectrometry to define the E1-E2 interactome and to determine the proteins that are modulated by knockdown of UBA1 and of each E2 in human cells. These analyses define the UBA1/E2-sensitive proteome and the E2 specificity in protein modulation. Interestingly, profound adaptations in peroxisomes and other organelles are triggered by decreased ubiquitination. While the cargo receptor PEX5 depends on its mono-ubiquitination for binding to peroxisomal proteins and importing them into peroxisomes, we find that UBA1/E2 knockdown induces the compensatory upregulation of other PEX proteins necessary for PEX5 docking to the peroxisomal membrane. Altogether, this study defines a homeostatic mechanism that sustains peroxisomal protein import in cells with decreased ubiquitination capacity.
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Affiliation(s)
- Liam C Hunt
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
- Department of Biology, Rhodes College, 2000 North Pkwy, Memphis, TN, 38112, USA
| | - Vishwajeeth Pagala
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Anna Stephan
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Boer Xie
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Kiran Kodali
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Kanisha Kavdia
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Abbas Shirinifard
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Michelle Curley
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Flavia A Graca
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Yingxue Fu
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Suresh Poudel
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Yuxin Li
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Xusheng Wang
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Haiyan Tan
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Junmin Peng
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Fabio Demontis
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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You X, Zhu S, Sheng H, Liu Z, Wang D, Wang M, Xu X, He F, Fang H, Zhang F, Wang D, Hao Z, Wang R, Xiao Y, Wan J, Wang GL, Ning Y. The rice peroxisomal receptor PEX5 negatively regulates resistance to rice blast fungus Magnaporthe oryzae. Cell Rep 2023; 42:113315. [PMID: 37862164 DOI: 10.1016/j.celrep.2023.113315] [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: 07/21/2022] [Revised: 08/22/2023] [Accepted: 10/06/2023] [Indexed: 10/22/2023] Open
Abstract
The receptor protein PEX5, an important component of peroxisomes, regulates growth, development, and immunity in yeast and mammals. PEX5 also influences growth and development in plants, but whether it participates in plant immunity has remained unclear. Here, we report that knockdown of OsPEX5 enhances resistance to the rice blast fungus Magnaporthe oryzae. We demonstrate that OsPEX5 interacts with the E3 ubiquitin ligase APIP6, a positive regulator of plant immunity. APIP6 ubiquitinates OsPEX5 in vitro and promotes its degradation in vivo via the 26S proteasome pathway. In addition, OsPEX5 interacts with the aldehyde dehydrogenase OsALDH2B1, which functions in growth-defense trade-offs in rice. OsPEX5 stabilizes OsALDH2B1 to enhance its repression of the defense-related gene OsAOS2. Our study thus uncovers a previously unrecognized hierarchical regulatory mechanism in which an E3 ubiquitin ligase targets a peroxisome receptor protein that negatively regulates immunity in rice by stabilizing an aldehyde dehydrogenase that suppresses defense gene expression.
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Affiliation(s)
- Xiaoman You
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shanshan Zhu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
| | - Haowen Sheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Zheng Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Dan Wang
- College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Min Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiao Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Feng He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Hong Fang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Debao Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zeyun Hao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ruyi Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yinghui Xiao
- College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Jianmin Wan
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA
| | - Yuese Ning
- 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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Abstract
Peroxisomes are involved in a multitude of metabolic and catabolic pathways, as well as the innate immune system. Their dysfunction is linked to severe peroxisome-specific diseases, as well as cancer and neurodegenerative diseases. To ensure the ability of peroxisomes to fulfill their many roles in the organism, more than 100 different proteins are post-translationally imported into the peroxisomal membrane and matrix, and their functionality must be closely monitored. In this Review, we briefly discuss the import of peroxisomal membrane proteins, and we emphasize an updated view of both classical and alternative peroxisomal matrix protein import pathways. We highlight different quality control pathways that ensure the degradation of dysfunctional peroxisomal proteins. Finally, we compare peroxisomal matrix protein import with other systems that transport folded proteins across membranes, in particular the twin-arginine translocation (Tat) system and the nuclear pore.
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Affiliation(s)
- Markus Rudowitz
- Systems Biochemistry , Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Ralf Erdmann
- Systems Biochemistry , Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
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Traver MS, Bartel B. The ubiquitin-protein ligase MIEL1 localizes to peroxisomes to promote seedling oleosin degradation and lipid droplet mobilization. Proc Natl Acad Sci U S A 2023; 120:e2304870120. [PMID: 37410814 PMCID: PMC10629534 DOI: 10.1073/pnas.2304870120] [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: 03/28/2023] [Accepted: 06/02/2023] [Indexed: 07/08/2023] Open
Abstract
Lipid droplets are organelles conserved across eukaryotes that store and release neutral lipids to regulate energy homeostasis. In oilseed plants, fats stored in seed lipid droplets provide fixed carbon for seedling growth before photosynthesis begins. As fatty acids released from lipid droplet triacylglycerol are catabolized in peroxisomes, lipid droplet coat proteins are ubiquitinated, extracted, and degraded. In Arabidopsis seeds, the predominant lipid droplet coat protein is OLEOSIN1 (OLE1). To identify genes modulating lipid droplet dynamics, we mutagenized a line expressing mNeonGreen-tagged OLE1 expressed from the OLE1 promoter and isolated mutants with delayed oleosin degradation. From this screen, we identified four miel1 mutant alleles. MIEL1 (MYB30-interacting E3 ligase 1) targets specific MYB transcription factors for degradation during hormone and pathogen responses [D. Marino et al., Nat. Commun. 4, 1476 (2013); H. G. Lee and P. J. Seo, Nat. Commun. 7, 12525 (2016)] but had not been implicated in lipid droplet dynamics. OLE1 transcript levels were unchanged in miel1 mutants, indicating that MIEL1 modulates oleosin levels posttranscriptionally. When overexpressed, fluorescently tagged MIEL1 reduced oleosin levels, causing very large lipid droplets. Unexpectedly, fluorescently tagged MIEL1 localized to peroxisomes. Our data suggest that MIEL1 ubiquitinates peroxisome-proximal seed oleosins, targeting them for degradation during seedling lipid mobilization. The human MIEL1 homolog (PIRH2; p53-induced protein with a RING-H2 domain) targets p53 and other proteins for degradation and promotes tumorigenesis [A. Daks et al., Cells 11, 1515 (2022)]. When expressed in Arabidopsis, human PIRH2 also localized to peroxisomes, hinting at a previously unexplored role for PIRH2 in lipid catabolism and peroxisome biology in mammals.
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Affiliation(s)
- Melissa S. Traver
- Department of Biosciences, Biochemistry and Cell Biology Program, Rice University, Houston, TX77005
| | - Bonnie Bartel
- Department of Biosciences, Biochemistry and Cell Biology Program, Rice University, Houston, TX77005
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Sahu I, Zhu H, Buhrlage SJ, Marto JA. Proteomic approaches to study ubiquitinomics. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194940. [PMID: 37121501 PMCID: PMC10612121 DOI: 10.1016/j.bbagrm.2023.194940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/21/2023] [Accepted: 04/20/2023] [Indexed: 05/02/2023]
Abstract
As originally described some 40 years ago, protein ubiquitination was thought to serve primarily as a static mark for protein degradation. In the ensuing years, it has become clear that 'ubiquitination' is a structurally diverse and dynamic post-translational modification and is intricately involved in a myriad of signaling pathways in all eukaryote cells. And like other key pathways in the functional proteome, ubiquitin signaling is often disrupted, sometimes severely so, in human pathophysiology. As a result of its central role in normal physiology and human disease, the ubiquitination field is now represented across the full landscape of biomedical research from fundamental structural and biochemical studies to translational and clinical research. In recent years, mass spectrometry has emerged as a powerful technology for the detection and characterization of protein ubiquitination. Herein we detail qualitative and quantitative proteomic methods using a compare/contrast approach to highlight their strengths and weaknesses.
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Affiliation(s)
- Indrajit Sahu
- Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - He Zhu
- Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Sara J Buhrlage
- Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA; Center for Emergent Drug Targets, USA.
| | - Jarrod A Marto
- Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA; Center for Emergent Drug Targets, USA.
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9
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Ferreira MJ, Rodrigues TA, Pedrosa AG, Gales L, Salvador A, Francisco T, Azevedo JE. The mammalian peroxisomal membrane is permeable to both GSH and GSSG - Implications for intraperoxisomal redox homeostasis. Redox Biol 2023; 63:102764. [PMID: 37257275 DOI: 10.1016/j.redox.2023.102764] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/14/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023] Open
Abstract
Despite the large amounts of H2O2 generated in mammalian peroxisomes, cysteine residues of intraperoxisomal proteins are maintained in a reduced state. The biochemistry behind this phenomenon remains unexplored, and simple questions such as "is the peroxisomal membrane permeable to glutathione?" or "is there a thiol-disulfide oxidoreductase in the organelle matrix?" still have no answer. We used a cell-free in vitro system to equip rat liver peroxisomes with a glutathione redox sensor. The organelles were then incubated with glutathione solutions of different redox potentials and the oxidation/reduction kinetics of the redox sensor was monitored. The data suggest that the mammalian peroxisomal membrane is promptly permeable to both reduced and oxidized glutathione. No evidence for the presence of a robust thiol-disulfide oxidoreductase in the peroxisomal matrix could be found. Also, prolonged incubation of organelle suspensions with glutaredoxin 1 did not result in the internalization of the enzyme. To explore a potential role of glutathione in intraperoxisomal redox homeostasis we performed kinetic simulations. The results suggest that even in the absence of a glutaredoxin, glutathione is more important in protecting cysteine residues of matrix proteins from oxidation by H2O2 than peroxisomal catalase itself.
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Affiliation(s)
- Maria J Ferreira
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Ana G Pedrosa
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Luís Gales
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Armindo Salvador
- Coimbra Chemistry Center-Institute of Molecular Sciences (CQC-IMS), University of Coimbra, 3004-535, Coimbra, Portugal; CNC-Center for Neuroscience and Cell Biology, 3004-504, Coimbra, Portugal; Institute for Interdisciplinary Research, University of Coimbra, 3030-789, Coimbra, Portugal
| | - Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
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10
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Skowyra ML, Rapoport TA. Cell-free reconstitution of peroxisomal matrix protein import using Xenopus egg extract. STAR Protoc 2023; 4:102111. [PMID: 36853666 PMCID: PMC9947420 DOI: 10.1016/j.xpro.2023.102111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/08/2022] [Accepted: 01/20/2023] [Indexed: 02/13/2023] Open
Abstract
Peroxisomes are vital metabolic organelles whose matrix enzymes are imported from the cytosol in a folded state by the soluble receptor PEX5. The import mechanism has been challenging to decipher because of the lack of suitable in vitro systems. Here, we present a protocol for reconstituting matrix protein import using Xenopus egg extract. We describe how extract is prepared, how to replace endogenous PEX5 with recombinant versions, and how to perform and interpret a peroxisomal import reaction using a fluorescent cargo. For complete details on the use and execution of this protocol, please refer to Skowyra and Rapoport (2022).1.
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Affiliation(s)
- Michael L Skowyra
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
| | - Tom A Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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11
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Ghosh M, Denkert N, Reuter M, Klümper J, Reglinski K, Peschel R, Schliebs W, Erdmann R, Meinecke M. Dynamics of the translocation pore of the human peroxisomal protein import machinery. Biol Chem 2023; 404:169-178. [PMID: 35977096 DOI: 10.1515/hsz-2022-0170] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 07/05/2022] [Indexed: 01/15/2023]
Abstract
Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and imported in a posttranslational manner. Intricate protein import machineries have evolved that catalyze the different stages of translocation. In humans, PEX5L was found to be an essential component of the peroxisomal translocon. PEX5L is the main receptor for substrate proteins carrying a peroxisomal targeting signal (PTS). Substrates are bound by soluble PEX5L in the cytosol after which the cargo-receptor complex is recruited to peroxisomal membranes. Here, PEX5L interacts with the docking protein PEX14 and becomes part of an integral membrane protein complex that facilitates substrate translocation into the peroxisomal lumen in a still unknown process. In this study, we show that PEX5L containing complexes purified from human peroxisomal membranes constitute water-filled pores when reconstituted into planar-lipid membranes. Channel characteristics were highly dynamic in terms of conductance states, selectivity and voltage- and substrate-sensitivity. Our results show that a PEX5L associated pore exists in human peroxisomes, which can be activated by receptor-cargo complexes.
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Affiliation(s)
- Mausumi Ghosh
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany.,Institute for Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Niels Denkert
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany.,Institute for Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
| | - Maren Reuter
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Jessica Klümper
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Katharina Reglinski
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Rebecca Peschel
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Wolfgang Schliebs
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Ralf Erdmann
- Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, D-44780 Bochum, Germany
| | - Michael Meinecke
- Biochemistry Center (BZH), Heidelberg University, D-69120 Heidelberg, Germany.,Institute for Cellular Biochemistry, University Medical Center Göttingen, D-37073 Göttingen, Germany
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12
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Akhter D, Zhang Y, Hu J, Pan R. Protein ubiquitination in plant peroxisomes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:371-380. [PMID: 35975710 DOI: 10.1111/jipb.13346] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Protein ubiquitination regulates diverse cellular processes in eukaryotic organisms, from growth and development to stress response. Proteins subjected to ubiquitination can be found in virtually all subcellular locations and organelles, including peroxisomes, single-membrane and highly dynamic organelles ubiquitous in eukaryotes. Peroxisomes contain metabolic functions essential to plants and animals such as lipid catabolism, detoxification of reactive oxygen species (ROS), biosynthesis of vital hormones and cofactors, and photorespiration. Plant peroxisomes possess a complex proteome with functions varying among different tissue types and developmental stages, and during plant response to distinct environmental cues. However, how these diverse functions are regulated at the post-translational level is poorly understood, especially in plants. In this review, we summarized current knowledge of the involvement of protein ubiquitination in peroxisome protein import, remodeling, pexophagy, and metabolism, focusing on plants, and referencing discoveries from other eukaryotic systems when relevant. Based on previous ubiquitinomics studies, we compiled a list of 56 ubiquitinated Arabidopsis peroxisomal proteins whose functions are associated with all the major plant peroxisomal metabolic pathways. This discovery suggests a broad impact of protein ubiquitination on plant peroxisome functions, therefore substantiating the need to investigate this significant regulatory mechanism in peroxisomes at more depths.
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Affiliation(s)
- Delara Akhter
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
- Department of Genetics and Plant Breeding, Sylhet Agricultural University, Sylhet, 3100, Bangladesh
| | - Yuchan Zhang
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
| | - Jianping Hu
- Department of Energy Plant Research Laboratory and Plant Biology Department, Michigan State University, East Lansing,, Michigan, USA
- Department of Plant Biology, Michigan State University, East Lansing,, Michigan, USA
| | - Ronghui Pan
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
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13
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Pedrosa AG, Francisco T, Rodrigues TA, Ferreira MJ, van der Heden van Noort GJ, Azevedo JE. The Extraction Mechanism of Monoubiquitinated PEX5 from the Peroxisomal Membrane. J Mol Biol 2023; 435:167896. [PMID: 36442669 DOI: 10.1016/j.jmb.2022.167896] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022]
Abstract
The AAA ATPases PEX1•PEX6 extract PEX5, the peroxisomal protein shuttling receptor, from the peroxisomal membrane so that a new protein transport cycle can start. Extraction requires ubiquitination of PEX5 at residue 11 and involves a threading mechanism, but how exactly this occurs is unclear. We used a cell-free in vitro system and a variety of engineered PEX5 and ubiquitin molecules to challenge the extraction machinery. We show that PEX5 modified with a single ubiquitin is a substrate for extraction and extend previous findings proposing that neither the N- nor the C-terminus of PEX5 are required for extraction. Chimeric PEX5 molecules possessing a branched polypeptide structure at their C-terminal domains can still be extracted from the peroxisomal membrane thus suggesting that the extraction machinery can thread more than one polypeptide chain simultaneously. Importantly, we found that the PEX5-linked monoubiquitin is unfolded at a pre-extraction stage and, accordingly, an intra-molecularly cross-linked ubiquitin blocked extraction when conjugated to residue 11 of PEX5. Collectively, our data suggest that the PEX5-linked monoubiquitin is the extraction initiator and that the complete ubiquitin-PEX5 conjugate is threaded by PEX1•PEX6.
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Affiliation(s)
- Ana G Pedrosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Maria J Ferreira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Gerbrand J van der Heden van Noort
- Oncode Institute and Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
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14
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Feng P, Skowyra ML, Rapoport TA. Structure and function of the peroxisomal ubiquitin ligase complex. Biochem Soc Trans 2022; 50:1921-1930. [PMID: 36421406 PMCID: PMC9788354 DOI: 10.1042/bst20221393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 09/26/2023]
Abstract
Peroxisomes are membrane-bounded organelles that exist in most eukaryotic cells and are involved in the oxidation of fatty acids and the destruction of reactive oxygen species. Depending on the organism, they house additional metabolic reactions that range from glycolysis in parasitic protozoa to the production of ether lipids in animals and antibiotics in fungi. The importance of peroxisomes for human health is revealed by various disorders - notably the Zellweger spectrum - that are caused by defects in peroxisome biogenesis and are often fatal. Most peroxisomal metabolic enzymes reside in the lumen, but are synthesized in the cytosol and imported into the organelle by mobile receptors. The receptors accompany cargo all the way into the lumen and must return to the cytosol to start a new import cycle. Recycling requires receptor monoubiquitination by a membrane-embedded ubiquitin ligase complex composed of three RING finger (RF) domain-containing proteins: PEX2, PEX10, and PEX12. A recent cryo-electron microscopy (cryo-EM) structure of the complex reveals its function as a retro-translocation channel for peroxisomal import receptors. Each subunit of the complex contributes five transmembrane segments that assemble into an open channel. The N terminus of a receptor likely inserts into the pore from the lumenal side, and is then monoubiquitinated by one of the RFs to enable extraction into the cytosol. If recycling is compromised, receptors are polyubiquitinated by the concerted action of the other two RFs and ultimately degraded. The new data provide mechanistic insight into a crucial step of peroxisomal protein import.
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Affiliation(s)
- Peiqiang Feng
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
| | - Michael L. Skowyra
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
| | - Tom A. Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
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15
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Rusilowicz-Jones EV, Brazel AJ, Frigenti F, Urbé S, Clague MJ. Membrane compartmentalisation of the ubiquitin system. Semin Cell Dev Biol 2022; 132:171-184. [PMID: 34895815 DOI: 10.1016/j.semcdb.2021.11.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 12/15/2022]
Abstract
We now have a comprehensive inventory of ubiquitin system components. Understanding of any system also needs an appreciation of how components are organised together. Quantitative proteomics has provided us with a census of their relative populations in several model cell types. Here, by examining large scale unbiased data sets, we seek to identify and map those components, which principally reside on the major organelles of the endomembrane system. We present the consensus distribution of > 50 ubiquitin modifying enzymes, E2s, E3s and DUBs, that possess transmembrane domains. This analysis reveals that the ER and endosomal compartments have a diverse cast of resident E3s, whilst the Golgi and mitochondria operate with a more restricted palette. We describe key functions of ubiquitylation that are specific to each compartment and relate this to their signature complement of ubiquitin modifying components.
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Affiliation(s)
- Emma V Rusilowicz-Jones
- Dept. of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK
| | - Ailbhe J Brazel
- Dept. of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK; Department of Biology, Maynooth University, Maynooth W23 F2K6, Ireland
| | - Francesca Frigenti
- Dept. of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK
| | - Sylvie Urbé
- Dept. of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK.
| | - Michael J Clague
- Dept. of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 3BX, UK.
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16
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Fujiki Y, Okumoto K, Honsho M, Abe Y. Molecular insights into peroxisome homeostasis and peroxisome biogenesis disorders. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119330. [PMID: 35917894 DOI: 10.1016/j.bbamcr.2022.119330] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Peroxisomes are single-membrane organelles essential for cell metabolism including the β-oxidation of fatty acids, synthesis of etherlipid plasmalogens, and redox homeostasis. Investigations into peroxisome biogenesis and the human peroxisome biogenesis disorders (PBDs) have identified 14 PEX genes encoding peroxins involved in peroxisome biogenesis and the mutation of PEX genes is responsible for the PBDs. Many recent findings have further advanced our understanding of the biology, physiology, and consequences of a functional deficit of peroxisomes. In this Review, we discuss cell defense mechanisms that counteract oxidative stress by 1) a proapoptotic Bcl-2 factor BAK-mediated release to the cytosol of H2O2-degrading catalase from peroxisomes and 2) peroxisomal import suppression of catalase by Ser232-phosphorylation of Pex14, a docking protein for the Pex5-PTS1 complex. With respect to peroxisome division, the important issue of how the energy-rich GTP is produced and supplied for the division process was recently addressed by the discovery of a nucleoside diphosphate kinase-like protein, termed DYNAMO1 in a lower eukaryote, which has a mammalian homologue NME3. In regard to the mechanisms underlying the pathogenesis of PBDs, a new PBD model mouse defective in Pex14 manifests a dysregulated brain-derived neurotrophic factor (BDNF)-TrkB pathway, an important signaling pathway for cerebellar morphogenesis. Communications between peroxisomes and other organelles are also addressed.
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Affiliation(s)
- Yukio Fujiki
- Medical Institute of Bioregulation, Institute of Rheological Functions of Food, Collaboration Program, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan.
| | - Kanji Okumoto
- Department of Biology and Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
| | - Masanori Honsho
- Medical Institute of Bioregulation, Institute of Rheological Functions of Food, Collaboration Program, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan
| | - Yuichi Abe
- Faculty of Arts and Science, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan
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17
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Kelsall IR. Non-lysine ubiquitylation: Doing things differently. Front Mol Biosci 2022; 9:1008175. [PMID: 36200073 PMCID: PMC9527308 DOI: 10.3389/fmolb.2022.1008175] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/01/2022] [Indexed: 11/23/2022] Open
Abstract
The post-translational modification of proteins with ubiquitin plays a central role in nearly all aspects of eukaryotic biology. Historically, studies have focused on the conjugation of ubiquitin to lysine residues in substrates, but it is now clear that ubiquitylation can also occur on cysteine, serine, and threonine residues, as well as on the N-terminal amino group of proteins. Paradigm-shifting reports of non-proteinaceous substrates have further extended the reach of ubiquitylation beyond the proteome to include intracellular lipids and sugars. Additionally, results from bacteria have revealed novel ways to ubiquitylate (and deubiquitylate) substrates without the need for any of the enzymatic components of the canonical ubiquitylation cascade. Focusing mainly upon recent findings, this review aims to outline the current understanding of non-lysine ubiquitylation and speculate upon the molecular mechanisms and physiological importance of this non-canonical modification.
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18
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Feng P, Wu X, Erramilli SK, Paulo JA, Knejski P, Gygi SP, Kossiakoff AA, Rapoport TA. A peroxisomal ubiquitin ligase complex forms a retrotranslocation channel. Nature 2022; 607:374-380. [PMID: 35768507 PMCID: PMC9279156 DOI: 10.1038/s41586-022-04903-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/25/2022] [Indexed: 01/04/2023]
Abstract
Peroxisomes are ubiquitous organelles that house various metabolic reactions and are essential for human health1–4. Luminal peroxisomal proteins are imported from the cytosol by mobile receptors, which then recycle back to the cytosol by a poorly understood process1–4. Recycling requires receptor modification by a membrane-embedded ubiquitin ligase complex comprising three RING finger domain-containing proteins (Pex2, Pex10 and Pex12)5,6. Here we report a cryo-electron microscopy structure of the ligase complex, which together with biochemical and in vivo experiments reveals its function as a retrotranslocation channel for peroxisomal import receptors. Each subunit of the complex contributes five transmembrane segments that co-assemble into an open channel. The three ring finger domains form a cytosolic tower, with ring finger 2 (RF2) positioned above the channel pore. We propose that the N terminus of a recycling receptor is inserted from the peroxisomal lumen into the pore and monoubiquitylated by RF2 to enable extraction into the cytosol. If recycling is compromised, receptors are polyubiquitylated by the concerted action of RF10 and RF12 and degraded. This polyubiquitylation pathway also maintains the homeostasis of other peroxisomal import factors. Our results clarify a crucial step during peroxisomal protein import and reveal why mutations in the ligase complex cause human disease. The cryo-electron microscopy structure of the membrane-embedded ubiquitin ligase complex reveals its function as a retrotranslocation channel for shuttling mobile receptors out of peroxisomes.
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Affiliation(s)
- Peiqiang Feng
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
| | - Xudong Wu
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Pawel Knejski
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.,Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - Tom A Rapoport
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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19
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Insights into the Structure and Function of the Pex1/Pex6 AAA-ATPase in Peroxisome Homeostasis. Cells 2022; 11:cells11132067. [PMID: 35805150 PMCID: PMC9265785 DOI: 10.3390/cells11132067] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/25/2022] [Accepted: 06/26/2022] [Indexed: 02/01/2023] Open
Abstract
The AAA-ATPases Pex1 and Pex6 are required for the formation and maintenance of peroxisomes, membrane-bound organelles that harbor enzymes for specialized metabolism. Together, Pex1 and Pex6 form a heterohexameric AAA-ATPase capable of unfolding substrate proteins via processive threading through a central pore. Here, we review the proposed roles for Pex1/Pex6 in peroxisome biogenesis and degradation, discussing how the unfolding of potential substrates contributes to peroxisome homeostasis. We also consider how advances in cryo-EM, computational structure prediction, and mechanisms of related ATPases are improving our understanding of how Pex1/Pex6 converts ATP hydrolysis into mechanical force. Since mutations in PEX1 and PEX6 cause the majority of known cases of peroxisome biogenesis disorders such as Zellweger syndrome, insights into Pex1/Pex6 structure and function are important for understanding peroxisomes in human health and disease.
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20
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Traver MS, Bradford SE, Olmos JL, Wright ZJ, Miller MD, Xu W, Phillips GN, Bartel B. The Structure of the Arabidopsis PEX4-PEX22 Peroxin Complex-Insights Into Ubiquitination at the Peroxisomal Membrane. Front Cell Dev Biol 2022; 10:838923. [PMID: 35300425 PMCID: PMC8922245 DOI: 10.3389/fcell.2022.838923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 01/28/2022] [Indexed: 01/11/2023] Open
Abstract
Peroxisomes are eukaryotic organelles that sequester critical oxidative reactions and process the resulting reactive oxygen species into less toxic byproducts. Peroxisome function and formation are coordinated by peroxins (PEX proteins) that guide peroxisome biogenesis and division and shuttle proteins into the lumen and membrane of the organelle. Despite the importance of peroxins in plant metabolism and development, no plant peroxin structures have been reported. Here we report the X-ray crystal structure of the PEX4-PEX22 peroxin complex from the reference plant Arabidopsis thaliana. PEX4 is a ubiquitin-conjugating enzyme (UBC) that ubiquitinates proteins associated with the peroxisomal membrane, and PEX22 is a peroxisomal membrane protein that anchors PEX4 to the peroxisome and facilitates PEX4 activity. We co-expressed Arabidopsis PEX4 as a translational fusion with the soluble PEX4-interacting domain of PEX22 in E. coli. The fusion was linked via a protease recognition site, allowing us to separate PEX4 and PEX22 following purification and solve the structure of the complex. We compared the structure of the PEX4-PEX22 complex to the previously published structures of yeast orthologs. Arabidopsis PEX4 displays the typical UBC structure expected from its sequence. Although Arabidopsis PEX22 lacks notable sequence identity to yeast PEX22, it maintains a similar Rossmann fold-like structure. Several salt bridges are positioned to contribute to the specificity of PEX22 for PEX4 versus other Arabidopsis UBCs, and the long unstructured PEX22 tether would allow PEX4-mediated ubiquitination of distant peroxisomal membrane targets without dissociation from PEX22. The Arabidopsis PEX4-PEX22 structure also revealed that the residue altered in pex4-1 (P123L), a mutant previously isolated via a forward-genetic screen for peroxisomal dysfunction, is near the active site cysteine of PEX4. We demonstrated in vitro UBC activity for the PEX4-PEX22 complex and found that the pex4-1 enzyme has reduced in vitro ubiquitin-conjugating activity and altered specificity compared to PEX4. Our findings illuminate the role of PEX4 and PEX22 in peroxisome structure and function and provide tools for future exploration of ubiquitination at the peroxisome surface.
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Affiliation(s)
- Melissa S. Traver
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Sarah E. Bradford
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Jose Luis Olmos
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Zachary J. Wright
- Department of Biosciences, Rice University, Houston, TX, United States
| | | | - Weijun Xu
- Department of Biosciences, Rice University, Houston, TX, United States
| | - George N. Phillips
- Department of Biosciences, Rice University, Houston, TX, United States
- Department of Chemistry, Rice University, Houston, TX, United States
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, TX, United States
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21
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Non-proteolytic ubiquitylation in cellular signaling and human disease. Commun Biol 2022; 5:114. [PMID: 35136173 PMCID: PMC8826416 DOI: 10.1038/s42003-022-03060-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 01/18/2022] [Indexed: 12/18/2022] Open
Abstract
Ubiquitylation is one of the most common post-translational modifications (PTMs) of proteins that frequently targets substrates for proteasomal degradation. However it can also result in non-proteolytic events which play important functions in cellular processes such as intracellular signaling, membrane trafficking, DNA repair and cell cycle. Emerging evidence demonstrates that dysfunction of non-proteolytic ubiquitylation is associated with the development of multiple human diseases. In this review, we summarize the current knowledge and the latest concepts on how non-proteolytic ubiquitylation pathways are involved in cellular signaling and in disease-mediating processes. Our review, may advance our understanding of the non-degradative ubiquitylation process. Evanthia Pangou and co-authors review recent insights into the important roles of non-proteolytic ubiquitylation in cellular signaling as well as in physiology and disease.
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22
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Verner Z, Žárský V, Le T, Narayanasamy RK, Rada P, Rozbeský D, Makki A, Belišová D, Hrdý I, Vancová M, Lender C, König C, Bruchhaus I, Tachezy J. Anaerobic peroxisomes in Entamoeba histolytica metabolize myo-inositol. PLoS Pathog 2021; 17:e1010041. [PMID: 34780573 PMCID: PMC8629394 DOI: 10.1371/journal.ppat.1010041] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 11/29/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022] Open
Abstract
Entamoeba histolytica is believed to be devoid of peroxisomes, like most anaerobic protists. In this work, we provided the first evidence that peroxisomes are present in E. histolytica, although only seven proteins responsible for peroxisome biogenesis (peroxins) were identified (Pex1, Pex6, Pex5, Pex11, Pex14, Pex16, and Pex19). Targeting matrix proteins to peroxisomes is reduced to the PTS1-dependent pathway mediated via the soluble Pex5 receptor, while the PTS2 receptor Pex7 is absent. Immunofluorescence microscopy showed that peroxisomal markers (Pex5, Pex14, Pex16, Pex19) are present in vesicles distinct from mitosomes, the endoplasmic reticulum, and the endosome/phagosome system, except Pex11, which has dual localization in peroxisomes and mitosomes. Immunoelectron microscopy revealed that Pex14 localized to vesicles of approximately 90-100 nm in diameter. Proteomic analyses of affinity-purified peroxisomes and in silico PTS1 predictions provided datasets of 655 and 56 peroxisomal candidates, respectively; however, only six proteins were shared by both datasets, including myo-inositol dehydrogenase (myo-IDH). Peroxisomal NAD-dependent myo-IDH appeared to be a dimeric enzyme with high affinity to myo-inositol (Km 0.044 mM) and can utilize also scyllo-inositol, D-glucose and D-xylose as substrates. Phylogenetic analyses revealed that orthologs of myo-IDH with PTS1 are present in E. dispar, E. nutalli and E. moshkovskii but not in E. invadens, and form a monophyletic clade of mostly peroxisomal orthologs with free-living Mastigamoeba balamuthi and Pelomyxa schiedti. The presence of peroxisomes in E. histolytica and other archamoebae breaks the paradigm of peroxisome absence in anaerobes and provides a new potential target for the development of antiparasitic drugs.
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Affiliation(s)
- Zdeněk Verner
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Tien Le
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ravi Kumar Narayanasamy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Petr Rada
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Daniel Rozbeský
- Department of Cell Biology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Darja Belišová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Marie Vancová
- Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Ceske Budejovice, Czech Republic
| | - Corinna Lender
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Constantin König
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
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23
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Ubiquitin-Conjugating Enzymes in Cancer. Cells 2021; 10:cells10061383. [PMID: 34199813 PMCID: PMC8227520 DOI: 10.3390/cells10061383] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/28/2021] [Accepted: 05/30/2021] [Indexed: 12/22/2022] Open
Abstract
The ubiquitin-mediated degradation system is responsible for controlling various tumor-promoting processes, including DNA repair, cell cycle arrest, cell proliferation, apoptosis, angiogenesis, migration and invasion, metastasis, and drug resistance. The conjugation of ubiquitin to a target protein is mediated sequentially by the E1 (activating)‒E2 (conjugating)‒E3 (ligating) enzyme cascade. Thus, E2 enzymes act as the central players in the ubiquitination system, modulating various pathophysiological processes in the tumor microenvironment. In this review, we summarize the types and functions of E2s in various types of cancer and discuss the possibility of E2s as targets of anticancer therapeutic strategies.
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24
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Jansen RLM, Santana-Molina C, van den Noort M, Devos DP, van der Klei IJ. Comparative Genomics of Peroxisome Biogenesis Proteins: Making Sense of the PEX Proteins. Front Cell Dev Biol 2021; 9:654163. [PMID: 34095119 PMCID: PMC8172628 DOI: 10.3389/fcell.2021.654163] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/21/2021] [Indexed: 11/29/2022] Open
Abstract
PEX genes encode proteins involved in peroxisome biogenesis and proliferation. Using a comparative genomics approach, we clarify the evolutionary relationships between the 37 known PEX proteins in a representative set of eukaryotes, including all common model organisms, pathogenic unicellular eukaryotes and human. A large number of previously unknown PEX orthologs were identified. We analyzed all PEX proteins, their conservation and domain architecture and defined the core set of PEX proteins that is required to make a peroxisome. The molecular processes in peroxisome biogenesis in different organisms were put into context, showing that peroxisomes are not static organelles in eukaryotic evolution. Organisms that lack peroxisomes still contain a few PEX proteins, which probably play a role in alternative processes. Finally, the relationships between PEX proteins of two large families, the Pex11 and Pex23 families, were analyzed, thereby contributing to the understanding of their complicated and sometimes incorrect nomenclature. We provide an exhaustive overview of this important eukaryotic organelle.
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Affiliation(s)
- Renate L M Jansen
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Carlos Santana-Molina
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Seville, Spain
| | - Marco van den Noort
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Damien P Devos
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Seville, Spain
| | - Ida J van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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25
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Mechanisms and Functions of Pexophagy in Mammalian Cells. Cells 2021; 10:cells10051094. [PMID: 34063724 PMCID: PMC8147788 DOI: 10.3390/cells10051094] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/28/2021] [Accepted: 05/01/2021] [Indexed: 12/17/2022] Open
Abstract
Peroxisomes play essential roles in diverse cellular metabolism functions, and their dynamic homeostasis is maintained through the coordination of peroxisome biogenesis and turnover. Pexophagy, selective autophagic degradation of peroxisomes, is a major mechanism for removing damaged and/or superfluous peroxisomes. Dysregulation of pexophagy impairs the physiological functions of peroxisomes and contributes to the progression of many human diseases. However, the mechanisms and functions of pexophagy in mammalian cells remain largely unknown compared to those in yeast. This review focuses on mammalian pexophagy and aims to advance the understanding of the roles of pexophagy in human health and diseases. Increasing evidence shows that ubiquitination can serve as a signal for pexophagy, and ubiquitin-binding receptors, substrates, and E3 ligases/deubiquitinases involved in pexophagy have been described. Alternatively, pexophagy can be achieved in a ubiquitin-independent manner. We discuss the mechanisms of these ubiquitin-dependent and ubiquitin-independent pexophagy pathways and summarize several inducible conditions currently used to study pexophagy. We highlight several roles of pexophagy in human health and how its dysregulation may contribute to diseases.
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26
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Jo DS, Park NY, Cho DH. Peroxisome quality control and dysregulated lipid metabolism in neurodegenerative diseases. Exp Mol Med 2020; 52:1486-1495. [PMID: 32917959 PMCID: PMC8080768 DOI: 10.1038/s12276-020-00503-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/11/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022] Open
Abstract
In recent decades, the role of the peroxisome in physiology and disease conditions has become increasingly important. Together with the mitochondria and other cellular organelles, peroxisomes support key metabolic platforms for the oxidation of various fatty acids and regulate redox conditions. In addition, peroxisomes contribute to the biosynthesis of essential lipid molecules, such as bile acid, cholesterol, docosahexaenoic acid, and plasmalogen. Therefore, the quality control mechanisms that regulate peroxisome biogenesis and degradation are important for cellular homeostasis. Current evidence indicates that peroxisomal function is often reduced or dysregulated in various human disease conditions, such as neurodegenerative diseases. Here, we review the recent progress that has been made toward understanding the quality control systems that regulate peroxisomes and their pathological implications. Systematic studies of cellular organelles called peroxisomes are needed to determine their influence on the progression of neurodegenerative diseases. Peroxisomes play vital roles in biological processes including the metabolism of lipids and reactive oxygen species, and the synthesis of key molecules, including bile acid and cholesterol. Disruption to peroxisome activity has been linked to metabolic disorders, cancers and neurodegenerative conditions. Dong-Hyung Cho at Kyungpook National University in Daegu, South Korea, and coworkers reviewed current understanding of peroxisome regulation, with a particular focus on brain disorders. The quantity and activity of peroxisomes alter according to environmental and stress cues. The brain is lipid-rich, and even small changes in fatty acid composition may influence neuronal function. Changes in fatty acid metabolism are found in early stage Alzheimer’s and Parkinson’s diseases, but whether peroxisome disruption is responsible requires clarification.
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Affiliation(s)
- Doo Sin Jo
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Na Yeon Park
- School of Life Sciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Dong-Hyung Cho
- Brain Science and Engineering Institute, Kyungpook National University, Daegu, 41566, Republic of Korea. .,School of Life Sciences, Kyungpook National University, Daegu, 41566, Republic of Korea.
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27
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Abstract
Blobel and coworkers discovered in 1978 that peroxisomal proteins are synthesized on free ribosomes in the cytosol and thus provided the grounds for the conception of peroxisomes as self-containing organelles. Peroxisomes are highly adaptive and versatile organelles carrying out a wide variety of metabolic functions. A striking feature of the peroxisomal import machinery is that proteins can traverse the peroxisomal membrane in a folded and even oligomeric state via cycling receptors. We outline essential steps of peroxisomal matrix protein import, from targeting of the proteins to the peroxisomal membrane, their translocation via transient pores and export of the corresponding cycling import receptors with emphasis on the situation in yeast. Peroxisomes can contribute to the adaptation of cells to different environmental conditions. This is realized by changes in metabolic functions and thus the enzyme composition of the organelles is adopted according to the cellular needs. In recent years, it turned out that this organellar diversity is based on an elaborate regulation of gene expression and peroxisomal protein import. The latter is in the focus of this review that summarizes our knowledge on the composition and function of the peroxisomal protein import machinery with emphasis on novel alternative protein import pathways.
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Affiliation(s)
- Thomas Walter
- Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Ralf Erdmann
- Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Universitätsstr. 150, 44780, Bochum, Germany.
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28
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Le T, Žárský V, Nývltová E, Rada P, Harant K, Vancová M, Verner Z, Hrdý I, Tachezy J. Anaerobic peroxisomes in Mastigamoeba balamuthi. Proc Natl Acad Sci U S A 2020; 117:2065-2075. [PMID: 31932444 PMCID: PMC6994998 DOI: 10.1073/pnas.1909755117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The adaptation of eukaryotic cells to anaerobic conditions is reflected by substantial changes to mitochondrial metabolism and functional reduction. Hydrogenosomes belong among the most modified mitochondrial derivative and generate molecular hydrogen concomitant with ATP synthesis. The reduction of mitochondria is frequently associated with loss of peroxisomes, which compartmentalize pathways that generate reactive oxygen species (ROS) and thus protect against cellular damage. The biogenesis and function of peroxisomes are tightly coupled with mitochondria. These organelles share fission machinery components, oxidative metabolism pathways, ROS scavenging activities, and some metabolites. The loss of peroxisomes in eukaryotes with reduced mitochondria is thus not unexpected. Surprisingly, we identified peroxisomes in the anaerobic, hydrogenosome-bearing protist Mastigamoeba balamuthi We found a conserved set of peroxin (Pex) proteins that are required for protein import, peroxisomal growth, and division. Key membrane-associated Pexs (MbPex3, MbPex11, and MbPex14) were visualized in numerous vesicles distinct from hydrogenosomes, the endoplasmic reticulum (ER), and Golgi complex. Proteomic analysis of cellular fractions and prediction of peroxisomal targeting signals (PTS1/PTS2) identified 51 putative peroxisomal matrix proteins. Expression of selected proteins in Saccharomyces cerevisiae revealed specific targeting to peroxisomes. The matrix proteins identified included components of acyl-CoA and carbohydrate metabolism and pyrimidine and CoA biosynthesis, whereas no components related to either β-oxidation or catalase were present. In conclusion, we identified a subclass of peroxisomes, named "anaerobic" peroxisomes that shift the current paradigm and turn attention to the reductive evolution of peroxisomes in anaerobic organisms.
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Affiliation(s)
- Tien Le
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Eva Nývltová
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Petr Rada
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Karel Harant
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Marie Vancová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czech Republic
| | - Zdeněk Verner
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, BIOCEV, Charles University, 25242 Vestec, Czech Republic;
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29
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Baldauf S, Ogunkoya AO, Boross GN, Bode JW. Aspartic Acid Forming α-Ketoacid–Hydroxylamine (KAHA) Ligations with (S)-4,4-Difluoro-5-oxaproline. J Org Chem 2019; 85:1352-1364. [DOI: 10.1021/acs.joc.9b02271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Simon Baldauf
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Ayodele O. Ogunkoya
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Gábor N. Boross
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
| | - Jeffrey W. Bode
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland
- Institute of Transformative Bio-Molecules (WPI−ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
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30
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McClellan AJ, Laugesen SH, Ellgaard L. Cellular functions and molecular mechanisms of non-lysine ubiquitination. Open Biol 2019; 9:190147. [PMID: 31530095 PMCID: PMC6769291 DOI: 10.1098/rsob.190147] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Protein ubiquitination is of great cellular importance through its central role in processes such as degradation, DNA repair, endocytosis and inflammation. Canonical ubiquitination takes place on lysine residues, but in the past 15 years non-lysine ubiquitination on serine, threonine and cysteine has been firmly established. With the emerging importance of non-lysine ubiquitination, it is crucial to identify the responsible molecular machinery and understand the mechanistic basis for non-lysine ubiquitination. Here, we first provide an overview of the literature that has documented non-lysine ubiquitination. Informed by these examples, we then discuss the molecular mechanisms and cellular implications of non-lysine ubiquitination, and conclude by outlining open questions and future perspectives in the field.
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Affiliation(s)
- Amie J McClellan
- Division of Science and Mathematics, Bennington College, 1 College Drive, Bennington, VT 05201, USA
| | - Sophie Heiden Laugesen
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Lars Ellgaard
- Department of Biology, Linderstrøm-Lang Centre for Protein Science, University of Copenhagen, 2200 Copenhagen N, Denmark
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31
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Baldauf S, Schauenburg D, Bode JW. A Threonine‐Forming Oxazetidine Amino Acid for the Chemical Synthesis of Proteins through KAHA Ligation. Angew Chem Int Ed Engl 2019; 58:12599-12603. [DOI: 10.1002/anie.201906486] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Simon Baldauf
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang Pauli Strasse 10 8093 Zürich Switzerland
| | - Dominik Schauenburg
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang Pauli Strasse 10 8093 Zürich Switzerland
| | - Jeffrey W. Bode
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang Pauli Strasse 10 8093 Zürich Switzerland
- Institute of Transformative Bio-Molecules (WPI-ITbM)Nagoya University, Chisuka Nagoya 464-8602 Japan
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32
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Baldauf S, Schauenburg D, Bode JW. Eine Threonin‐bildende Oxazetidinaminosäure für die chemische Synthese von Proteinen mittels KAHA‐Ligation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201906486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Simon Baldauf
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang-Pauli-Strasse 10 8093 Zürich Schweiz
| | - Dominik Schauenburg
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang-Pauli-Strasse 10 8093 Zürich Schweiz
| | - Jeffrey W. Bode
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied biosciencesETH Zürich Wolfgang-Pauli-Strasse 10 8093 Zürich Schweiz
- Institute of Transformative Bio-Molecules (WPI-ITbM)Nagoya University, Chisuka Nagoya 464-8602 Japan
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33
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Barros-Barbosa A, Ferreira MJ, Rodrigues TA, Pedrosa AG, Grou CP, Pinto MP, Fransen M, Francisco T, Azevedo JE. Membrane topologies of PEX13 and PEX14 provide new insights on the mechanism of protein import into peroxisomes. FEBS J 2018; 286:205-222. [PMID: 30414318 DOI: 10.1111/febs.14697] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/19/2018] [Accepted: 11/07/2018] [Indexed: 01/19/2023]
Abstract
PEX13 and PEX14 are two core components of the so-called peroxisomal docking/translocation module, the transmembrane hydrophilic channel through which newly synthesized peroxisomal proteins are translocated into the organelle matrix. The two proteins interact with each other and with PEX5, the peroxisomal matrix protein shuttling receptor, through relatively well characterized domains. However, the topologies of these membrane proteins are still poorly defined. Here, we subjected proteoliposomes containing PEX13 or PEX14 and purified rat liver peroxisomes to protease-protection assays and analyzed the protected protein fragments by mass spectrometry, Edman degradation and western blotting using antibodies directed to specific domains of the proteins. Our results indicate that PEX14 is a bona fide intrinsic membrane protein with a Nin -Cout topology, and that PEX13 adopts a Nout -Cin topology, thus exposing its carboxy-terminal Src homology 3 [SH3] domain into the organelle matrix. These results reconcile several enigmatic findings previously reported on PEX13 and PEX14 and provide new insights into the organization of the peroxisomal protein import machinery. ENZYMES: Trypsin, EC3.4.21.4; Proteinase K, EC3.4.21.64; Tobacco etch virus protease, EC3.4.22.44.
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Affiliation(s)
- Aurora Barros-Barbosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Maria J Ferreira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana G Pedrosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Cláudia P Grou
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal
| | - Manuel P Pinto
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal
| | - Marc Fransen
- Departement Cellulaire en Moleculaire Geneeskunde, KU Leuven - Universiteit Leuven, Belgium
| | - Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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34
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Chemically monoubiquitinated PEX5 binds to the components of the peroxisomal docking and export machinery. Sci Rep 2018; 8:16014. [PMID: 30375424 PMCID: PMC6207756 DOI: 10.1038/s41598-018-34200-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/12/2018] [Indexed: 02/05/2023] Open
Abstract
Peroxisomal matrix proteins contain either a peroxisomal targeting sequence 1 (PTS1) or a PTS2 that are recognized by the import receptors PEX5 and PEX7, respectively. PEX5 transports the PTS1 proteins and the PEX7/PTS2 complex to the docking translocation module (DTM) at the peroxisomal membrane. After cargo release PEX5 is monoubiquitinated and extracted from the peroxisomal membrane by the receptor export machinery (REM) comprising PEX26 and the AAA ATPases PEX1 and PEX6. Here, we investigated the protein interactions of monoubiquitinated PEX5 with the docking proteins PEX13, PEX14 and the REM. “Click” chemistry was used to synthesise monoubiquitinated recombinant PEX5. We found that monoubiquitinated PEX5 binds the PEX7/PTS2 complex and restores PTS2 protein import in vivo in ΔPEX5 fibroblasts. In vitro pull-down assays revealed an interaction of recombinant PEX5 and monoubiquitinated PEX5 with PEX13, PEX14 and with the REM components PEX1, PEX6 and PEX26. The interactions with the docking proteins were independent of the PEX5 ubiquitination status whereas the interactions with the REM components were increased when PEX5 is ubiquitinated.
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35
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UBE2D1 RNA Expression Was an Independent Unfavorable Prognostic Indicator in Lung Adenocarcinoma, but Not in Lung Squamous Cell Carcinoma. DISEASE MARKERS 2018; 2018:4108919. [PMID: 30420903 PMCID: PMC6215576 DOI: 10.1155/2018/4108919] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/02/2018] [Indexed: 01/28/2023]
Abstract
In this study, we investigated the potential prognostic value of ubiquitin-conjugating enzyme E2D1 (UBE2D1) RNA expression in different histological subtypes of non-small-cell lung cancer (NSCLC). A retrospective study was performed by using molecular, clinicopathological, and survival data in the Cancer Genome Atlas (TCGA)—Lung Cancer. Results showed that both lung adenocarcinoma (LUAD) (N = 514) and lung squamous cell carcinoma (LUSC) (N = 502) tissues had significantly elevated UBE2D1 RNA expression compared to the normal tissues (p < 0.001 and p = 0.036, respectively). UBE2D1 RNA expression was significantly higher in LUAD than in LUSC tissues. Increased UBE2D1 RNA expression was independently associated with shorter OS (HR: 1.359, 95% CI: 1.031–1.791, p = 0.029) and RFS (HR: 1.842, 95% CI: 1.353–2.508, p < 0.001) in LUAD patients, but not in LUSC patients. DNA amplification was common in LUAD patients (88/551, 16.0%) and was associated with significantly upregulated UBE2D1 RNA expression. Based on these findings, we infer that UBE2D1 RNA expression might only serve as an independent prognostic indicator of unfavorable OS and RFS in LUAD, but not in LUSC.
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Pedrosa AG, Francisco T, Bicho D, Dias AF, Barros-Barbosa A, Hagmann V, Dodt G, Rodrigues TA, Azevedo JE. Peroxisomal monoubiquitinated PEX5 interacts with the AAA ATPases PEX1 and PEX6 and is unfolded during its dislocation into the cytosol. J Biol Chem 2018; 293:11553-11563. [PMID: 29884772 DOI: 10.1074/jbc.ra118.003669] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/28/2018] [Indexed: 11/06/2022] Open
Abstract
PEX1 and PEX6 are two members of the ATPases associated with diverse cellular activities (AAA) family and the core components of the receptor export module of the peroxisomal matrix protein import machinery. Their role is to extract monoubiquitinated PEX5, the peroxisomal protein-shuttling receptor, from the peroxisomal membrane docking/translocation module (DTM), so that a new cycle of protein transportation can start. Recent data have shown that PEX1 and PEX6 form a heterohexameric complex that unfolds substrates by processive threading. However, whether the natural substrate of the PEX1-PEX6 complex is monoubiquitinated PEX5 (Ub-PEX5) itself or some Ub-PEX5-interacting component(s) of the DTM remains unknown. In this work, we used an established cell-free in vitro system coupled with photoaffinity cross-linking and protein PEGylation assays to address this problem. We provide evidence suggesting that DTM-embedded Ub-PEX5 interacts directly with both PEX1 and PEX6 through its ubiquitin moiety and that the PEX5 polypeptide chain is globally unfolded during the ATP-dependent extraction event. These findings strongly suggest that DTM-embedded Ub-PEX5 is a bona fide substrate of the PEX1-PEX6 complex.
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Affiliation(s)
- Ana G Pedrosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Diana Bicho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Ana F Dias
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Aurora Barros-Barbosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Vera Hagmann
- Interfakultäres Institut für Biochemie, Universität Tübingen, Hoppe Seyler Strasse 4, 72076 Tübingen, Germany
| | - Gabriele Dodt
- Interfakultäres Institut für Biochemie, Universität Tübingen, Hoppe Seyler Strasse 4, 72076 Tübingen, Germany
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.
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37
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Using Pull Down Strategies to Analyze the Interactome of Peroxisomal Membrane Proteins in Human Cells. Subcell Biochem 2018; 89:261-285. [PMID: 30378027 DOI: 10.1007/978-981-13-2233-4_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Different pull-down strategies were successfully applied to gain novel insight into the interactome of human membrane-associated proteins. Here, we compare the outcome, efficiency and potential of pull-down strategies applied to human peroxisomal membrane proteins. Stable membrane-bound protein complexes can be affinity-purified from genetically engineered human cells or subfractions thereof after detergent solubilization, followed by size exclusion chromatography and analysis by mass spectrometry (MS). As exemplified for Protein A-tagged human PEX14, one of the central constituents of the peroxisomal matrix protein import machinery, MS analyses of the affinity-purified complexes revealed an unexpected association of PEX14 with other protein assemblies like the microtubular network or the insertion apparatus for peroxisomal membrane proteins comprising PEX3, PEX16 and PEX19. The latter association was recently supported by using a different pull-down strategy following in vivo proximity labeling with biotin, named BioID, which enabled the identification of various membrane proteins in close proximity of PEX16 in living cells.
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Kalel VC, Erdmann R. Unraveling of the Structure and Function of Peroxisomal Protein Import Machineries. Subcell Biochem 2018; 89:299-321. [PMID: 30378029 DOI: 10.1007/978-981-13-2233-4_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Peroxisomes are dynamic organelles of eukaryotic cells performing a wide range of functions including fatty acid oxidation, peroxide detoxification and ether-lipid synthesis in mammals. Peroxisomes lack their own DNA and therefore have to import proteins post-translationally. Peroxisomes can import folded, co-factor bound and even oligomeric proteins. The involvement of cycling receptors is a special feature of peroxisomal protein import. Complex machineries of peroxin (PEX) proteins mediate peroxisomal matrix and membrane protein import. Identification of PEX genes was dominated by forward genetic techniques in the early 90s. However, recent developments in proteomic techniques has revolutionized the detailed characterization of peroxisomal protein import. Here, we summarize the current knowledge on peroxisomal protein import with emphasis on the contribution of proteomic approaches to our understanding of the composition and function of the peroxisomal protein import machineries.
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Affiliation(s)
- Vishal C Kalel
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany.
| | - Ralf Erdmann
- Department of Systems Biochemistry, Faculty of Medicine, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Universitätsstr. 150, 44801, Bochum, Germany
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39
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Wang W, Subramani S. Role of PEX5 ubiquitination in maintaining peroxisome dynamics and homeostasis. Cell Cycle 2017; 16:2037-2045. [PMID: 28933989 PMCID: PMC5731411 DOI: 10.1080/15384101.2017.1376149] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 08/24/2017] [Accepted: 09/01/2017] [Indexed: 12/15/2022] Open
Abstract
Peroxisomes are essential and dynamic organelles that allow cells to rapidly adapt and cope with changing environments and/or physiological conditions by modulation of both peroxisome biogenesis and turnover. Peroxisome biogenesis involves the assembly of peroxisome membranes and the import of peroxisomal matrix proteins. The latter depends on the receptor, PEX5, which recognizes peroxisomal matrix proteins in the cytosol directly or indirectly, and transports them to the peroxisomal lumen. In this review, we discuss the role of PEX5 ubiquitination in both peroxisome biogenesis and turnover, specifically in PEX5 receptor recycling, stability and abundance, as well as its role in pexophagy (autophagic degradation of peroxisomes).
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Affiliation(s)
- Wei Wang
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Suresh Subramani
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
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40
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Francisco T, Rodrigues TA, Dias AF, Barros-Barbosa A, Bicho D, Azevedo JE. Protein transport into peroxisomes: Knowns and unknowns. Bioessays 2017; 39. [PMID: 28787099 DOI: 10.1002/bies.201700047] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and rapidly transported into the organelle by a complex machinery. The data gathered in recent years suggest that this machinery operates through a syringe-like mechanism, in which the shuttling receptor PEX5 - the "plunger" - pushes a newly synthesized protein all the way through a peroxisomal transmembrane protein complex - the "barrel" - into the matrix of the organelle. Notably, insertion of cargo-loaded receptor into the "barrel" is an ATP-independent process, whereas extraction of the receptor back into the cytosol requires its monoubiquitination and the action of ATP-dependent mechanoenzymes. Here, we review the main data behind this model.
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Affiliation(s)
- Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana F Dias
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Aurora Barros-Barbosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Diana Bicho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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41
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Dias AF, Rodrigues TA, Pedrosa AG, Barros-Barbosa A, Francisco T, Azevedo JE. The peroxisomal matrix protein translocon is a large cavity-forming protein assembly into which PEX5 protein enters to release its cargo. J Biol Chem 2017; 292:15287-15300. [PMID: 28765278 DOI: 10.1074/jbc.m117.805044] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 07/26/2017] [Indexed: 12/18/2022] Open
Abstract
A remarkable property of the machinery for import of peroxisomal matrix proteins is that it can accept already folded proteins as substrates. This import involves binding of newly synthesized proteins by cytosolic peroxisomal biogenesis factor 5 (PEX5) followed by insertion of the PEX5-cargo complex into the peroxisomal membrane at the docking/translocation module (DTM). However, how these processes occur remains largely unknown. Here, we used truncated PEX5 molecules to probe the DTM architecture. We found that the DTM can accommodate a larger number of truncated PEX5 molecules comprising amino acid residues 1-197 than full-length PEX5 molecules. A shorter PEX5 version (PEX5(1-125)) still interacted correctly with the DTM; however, this species was largely accessible to exogenously added proteinase K, suggesting that this protease can access the DTM occupied by a small PEX5 protein. Interestingly, the PEX5(1-125)-DTM interaction was inhibited by a polypeptide comprising PEX5 residues 138-639. Apparently, the DTM can recruit soluble PEX5 through interactions with different PEX5 domains, suggesting that the PEX5-DTM interactions are to some degree fuzzy. Finally, we found that the interaction between PEX5 and PEX14, a major DTM component, is stable at pH 11.5. Thus, there is no reason to assume that the hitherto intriguing resistance of DTM-bound PEX5 to alkaline extraction reflects its direct contact with the peroxisomal lipid bilayer. Collectively, these results suggest that the DTM is best described as a large cavity-forming protein assembly into which cytosolic PEX5 can enter to release its cargo.
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Affiliation(s)
- Ana F Dias
- From the Instituto de Investigação e Inovação em Saúde (i3S) and.,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Tony A Rodrigues
- From the Instituto de Investigação e Inovação em Saúde (i3S) and.,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Ana G Pedrosa
- From the Instituto de Investigação e Inovação em Saúde (i3S) and.,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Aurora Barros-Barbosa
- From the Instituto de Investigação e Inovação em Saúde (i3S) and.,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and
| | - Tânia Francisco
- From the Instituto de Investigação e Inovação em Saúde (i3S) and.,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and
| | - Jorge E Azevedo
- From the Instituto de Investigação e Inovação em Saúde (i3S) and .,the Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal and.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
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42
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Schwerter DP, Grimm I, Platta HW, Erdmann R. ATP-driven processes of peroxisomal matrix protein import. Biol Chem 2017; 398:607-624. [PMID: 27977397 DOI: 10.1515/hsz-2016-0293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022]
Abstract
In peroxisomal matrix protein import two processes directly depend on the binding and hydrolysis of ATP, both taking place at the late steps of the peroxisomal import cycle. First, ATP hydrolysis is required to initiate a ubiquitin-transfer cascade to modify the import (co-)receptors. These receptors display a dual localization in the cytosol and at the peroxisomal membrane, whereas only the membrane bound fraction receives the ubiquitin modification. The second ATP-dependent process of the import cycle is carried out by the two AAA+-proteins Pex1p and Pex6p. These ATPases form a heterohexameric complex, which is recruited to the peroxisomal import machinery by the membrane anchor protein Pex15p. The Pex1p/Pex6p complex recognizes the ubiquitinated import receptors, pulls them out of the membrane and releases them into the cytosol. There the deubiquitinated receptors are provided for further rounds of import. ATP binding and hydrolysis are required for Pex1p/Pex6p complex formation and receptor export. In this review, we summarize the current knowledge on the peroxisomal import cascade. In particular, we will focus on the ATP-dependent processes, which are so far best understood in the model organism Saccharomyces cerevisiae.
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Affiliation(s)
- Daniel P Schwerter
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Immanuel Grimm
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
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Wang W, Xia ZJ, Farré JC, Subramani S. TRIM37, a novel E3 ligase for PEX5-mediated peroxisomal matrix protein import. J Cell Biol 2017; 216:2843-2858. [PMID: 28724525 PMCID: PMC5584156 DOI: 10.1083/jcb.201611170] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 04/14/2017] [Accepted: 06/13/2017] [Indexed: 12/22/2022] Open
Abstract
Most proteins destined for the peroxisomal matrix depend on the peroxisomal targeting signals (PTSs), which require the PTS receptor PEX5, whose deficiency causes fatal human peroxisomal biogenesis disorders (PBDs). TRIM37 gene mutations cause muscle-liver-brain-eye (mulibrey) nanism. We found that TRIM37 localizes in peroxisomal membranes and ubiquitylates PEX5 at K464 by interacting with its C-terminal 51 amino acids (CT51), which is required for PTS protein import. PEX5 mutations (K464A or ΔCT51), or TRIM37 depletion or mutation, reduce PEX5 abundance by promoting its proteasomal degradation, thereby impairing its functions in cargo binding and PTS protein import in human cells. TRIM37 or PEX5 depletion induces apoptosis and enhances sensitivity to oxidative stress, underscoring the cellular requirement for functional peroxisomes. Therefore, TRIM37-mediated ubiquitylation stabilizes PEX5 and promotes peroxisomal matrix protein import, suggesting that mulibrey nanism is a new PBD.
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Affiliation(s)
- Wei Wang
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Zhi-Jie Xia
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Jean-Claude Farré
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Suresh Subramani
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
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A cell-free organelle-based in vitro system for studying the peroxisomal protein import machinery. Nat Protoc 2016; 11:2454-2469. [PMID: 27831570 DOI: 10.1038/nprot.2016.147] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Here we describe a protocol to dissect the peroxisomal matrix protein import pathway using a cell-free in vitro system. The system relies on a postnuclear supernatant (PNS), which is prepared from rat/mouse liver, to act as a source of peroxisomes and cytosolic components. A typical in vitro assay comprises the following steps: (i) incubation of the PNS with an in vitro-synthesized 35S-labeled reporter protein; (ii) treatment of the organelle suspension with a protease that degrades reporter proteins that have not associated with peroxisomes; and (iii) SDS-PAGE/autoradiography analysis. To study transport of proteins into peroxisomes, it is possible to use organelle-resident proteins that contain a peroxisomal targeting signal (PTS) as reporters in the assay. In addition, a receptor (PEX5L/S or PEX5L.PEX7) can be used to report the dynamics of shuttling proteins that mediate the import process. Thus, different but complementary perspectives on the mechanism of this pathway can be obtained. We also describe strategies to fortify the system with recombinant proteins to increase import yields and block specific parts of the machinery at a number of steps. The system recapitulates all the steps of the pathway, including mono-ubiquitination of PEX5L/S at the peroxisome membrane and its ATP-dependent export back into the cytosol by PEX1/PEX6. An in vitro import(/export) experiment can be completed in 24 h.
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45
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McDowell G, Philpott A. New Insights Into the Role of Ubiquitylation of Proteins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 325:35-88. [DOI: 10.1016/bs.ircmb.2016.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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46
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Evaluation of the activity and substrate specificity of the human SENP family of SUMO proteases. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:139-47. [PMID: 26522917 DOI: 10.1016/j.bbamcr.2015.10.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 10/05/2015] [Accepted: 10/28/2015] [Indexed: 11/24/2022]
Abstract
Protein modification with the small ubiquitin-like modifier (SUMO) is a reversible process regulating many central biological pathways. The reversibility of SUMOylation is ensured by SUMO proteases many of which belong to the sentrin/SUMO-specific protease (SENP) family. In recent years, many advances have been made in allocating SENPs to specific biological pathways. However, due to difficulties in obtaining recombinant full-length active SENPs for thorough enzymatic characterization, our knowledge on these proteases is still limited. In this work, we used in vitro synthesized full-length human SENPs to perform a side-by-side comparison of their activities and substrate specificities. ProSUMO1/2/3, RanGAP1-SUMO1/2/3 and polySUMO2/3 chains were used as substrates in these analyses. We found that SENP1 is by far the most versatile and active SENP whereas SENP3 stands out as the least active of these enzymes. Finally, a comparison between the activities of full-length SENPs and their catalytic domains suggests that in some cases their non-catalytic regions influence their activity.
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Grimm I, Erdmann R, Girzalsky W. Role of AAA(+)-proteins in peroxisome biogenesis and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:828-37. [PMID: 26453804 DOI: 10.1016/j.bbamcr.2015.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/30/2015] [Accepted: 10/03/2015] [Indexed: 11/16/2022]
Abstract
Mutations in the PEX1 gene, which encodes a protein required for peroxisome biogenesis, are the most common cause of the Zellweger spectrum diseases. The recognition that Pex1p shares a conserved ATP-binding domain with p97 and NSF led to the discovery of the extended family of AAA+-type ATPases. So far, four AAA+-type ATPases are related to peroxisome function. Pex6p functions together with Pex1p in peroxisome biogenesis, ATAD1/Msp1p plays a role in membrane protein targeting and a member of the Lon-family of proteases is associated with peroxisomal quality control. This review summarizes the current knowledge on the AAA+-proteins involved in peroxisome biogenesis and function.
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Affiliation(s)
- Immanuel Grimm
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany.
| | - Wolfgang Girzalsky
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany.
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48
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The Design and Structure of Outer Membrane Receptors from Peroxisomes, Mitochondria, and Chloroplasts. Structure 2015; 23:1783-1800. [DOI: 10.1016/j.str.2015.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/20/2015] [Accepted: 08/10/2015] [Indexed: 01/03/2023]
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Kunze M, Berger J. The similarity between N-terminal targeting signals for protein import into different organelles and its evolutionary relevance. Front Physiol 2015; 6:259. [PMID: 26441678 PMCID: PMC4585086 DOI: 10.3389/fphys.2015.00259] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/04/2015] [Indexed: 12/04/2022] Open
Abstract
The proper distribution of proteins between the cytosol and various membrane-bound compartments is crucial for the functionality of eukaryotic cells. This requires the cooperation between protein transport machineries that translocate diverse proteins from the cytosol into these compartments and targeting signal(s) encoded within the primary sequence of these proteins that define their cellular destination. The mechanisms exerting protein translocation differ remarkably between the compartments, but the predominant targeting signals for mitochondria, chloroplasts and the ER share the N-terminal position, an α-helical structural element and the removal from the core protein by intraorganellar cleavage. Interestingly, similar properties have been described for the peroxisomal targeting signal type 2 mediating the import of a fraction of soluble peroxisomal proteins, whereas other peroxisomal matrix proteins encode the type 1 targeting signal residing at the extreme C-terminus. The structural similarity of N-terminal targeting signals poses a challenge to the specificity of protein transport, but allows the generation of ambiguous targeting signals that mediate dual targeting of proteins into different compartments. Dual targeting might represent an advantage for adaptation processes that involve a redistribution of proteins, because it circumvents the hierarchy of targeting signals. Thus, the co-existence of two equally functional import pathways into peroxisomes might reflect a balance between evolutionary constant and flexible transport routes.
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Affiliation(s)
- Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna Vienna, Austria
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Platta HW, Brinkmeier R, Reidick C, Galiani S, Clausen MP, Eggeling C. Regulation of peroxisomal matrix protein import by ubiquitination. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:838-49. [PMID: 26367801 DOI: 10.1016/j.bbamcr.2015.09.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 02/02/2023]
Abstract
Peroxisomes are organelles that play an important role in many cellular tasks. The functionality of peroxisomes depends on the proper import of their matrix proteins. Peroxisomal matrix proteins are imported posttranslationally in a folded, sometimes even oligomeric state. They harbor a peroxisomal targeting sequence (PTS), which is recognized by dynamic PTS-receptors in the cytosol. The PTS-receptors ferry the cargo to the peroxisomal membrane, where they become part of a transient import pore and then release the cargo into the peroxisomal lumen. Subsequentially, the PTS-receptors are ubiquitinated in order to mark them for the export-machinery, which releases them back to the cytosol. Upon deubiquitination, the PTS-receptors can facilitate further rounds of cargo import. Because the ubiquitination of the receptors is an essential step in the import cycle, it also represents a central regulatory element that governs peroxisomal dynamics. In this review we want to give an introduction to the functional role played by ubiquitination during peroxisomal protein import and highlight the mechanistic concepts that have emerged based on data derived from different species since the discovery of the first ubiquitinated peroxin 15years ago. Moreover, we discuss future tasks and the potential of using advanced technologies for investigating further details of peroxisomal protein transport.
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Affiliation(s)
- Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Silvia Galiani
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Mathias P Clausen
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom.
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