1
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Fu X, Zhu X. Key homeobox transcription factors regulate the development of the firefly's adult light organ and bioluminescence. Nat Commun 2024; 15:1736. [PMID: 38443352 PMCID: PMC10914744 DOI: 10.1038/s41467-024-45559-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 01/26/2024] [Indexed: 03/07/2024] Open
Abstract
Adult fireflies exhibit unique flashing courtship signals, emitted by specialized light organs, which develop mostly independently from larval light organs during the pupal stage. The mechanisms of adult light organ development have not been thoroughly studied until now. Here we show that key homeobox transcription factors AlABD-B and AlUNC-4 regulate the development of adult light organs and bioluminescence in the firefly Aquatica leii. Interference with the expression of AlAbd-B and AlUnc-4 genes results in undeveloped or non-luminescent adult light organs. AlABD-B regulates AlUnc-4, and they interact with each other. AlABD-B and AlUNC-4 activate the expression of the luciferase gene AlLuc1 and some peroxins. Four peroxins are involved in the import of AlLUC1 into peroxisomes. Our study provides key insights into the development of adult light organs and flash signal control in fireflies.
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Affiliation(s)
- Xinhua Fu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Xinlei Zhu
- Firefly Conservation Research Centre, Wuhan, 430070, China
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2
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Martin de Fourchambault E, Callens N, Saliou JM, Fourcot M, Delos O, Barois N, Thorel Q, Ramirez S, Bukh J, Cocquerel L, Bertrand-Michel J, Marot G, Sebti Y, Dubuisson J, Rouillé Y. Hepatitis C virus alters the morphology and function of peroxisomes. Front Microbiol 2023; 14:1254728. [PMID: 37808318 PMCID: PMC10551450 DOI: 10.3389/fmicb.2023.1254728] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023] Open
Abstract
Despite the introduction of effective treatments for hepatitis C in clinics, issues remain regarding the liver disease induced by chronic hepatitis C virus (HCV) infection. HCV is known to disturb the metabolism of infected cells, especially lipid metabolism and redox balance, but the mechanisms leading to HCV-induced pathogenesis are still poorly understood. In an APEX2-based proximity biotinylation screen, we identified ACBD5, a peroxisome membrane protein, as located in the vicinity of HCV replication complexes. Confocal microscopy confirmed the relocation of peroxisomes near HCV replication complexes and indicated that their morphology and number are altered in approximately 30% of infected Huh-7 cells. Peroxisomes are small versatile organelles involved among other functions in lipid metabolism and ROS regulation. To determine their importance in the HCV life cycle, we generated Huh-7 cells devoid of peroxisomes by inactivating the PEX5 and PEX3 genes using CRISPR/Cas9 and found that the absence of peroxisomes had no impact on replication kinetics or infectious titers of HCV strains JFH1 and DBN3a. The impact of HCV on peroxisomal functions was assessed using sub-genomic replicons. An increase of ROS was measured in peroxisomes of replicon-containing cells, correlated with a significant decrease of catalase activity with the DBN3a strain. In contrast, HCV replication had little to no impact on cytoplasmic and mitochondrial ROS, suggesting that the redox balance of peroxisomes is specifically impaired in cells replicating HCV. Our study provides evidence that peroxisome function and morphology are altered in HCV-infected cells.
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Affiliation(s)
- Esther Martin de Fourchambault
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
| | - Nathalie Callens
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
| | - Jean-Michel Saliou
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, UAR CNRS 2014 - US Inserm 41 - PLBS, Lille, France
| | - Marie Fourcot
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, UAR CNRS 2014 - US Inserm 41 - PLBS, Lille, France
| | - Oceane Delos
- MetaToul-MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
- I2MC, Université de Toulouse, Inserm, Université Toulouse III – Paul Sabatier (UPS), Toulouse, France
| | - Nicolas Barois
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, UAR CNRS 2014 - US Inserm 41 - PLBS, Lille, France
| | - Quentin Thorel
- Université de Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Lille, France
| | - Santseharay Ramirez
- Faculty of Health and Medical Sciences, Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital Hvidovre and Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Faculty of Health and Medical Sciences, Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital Hvidovre and Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Laurence Cocquerel
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
| | - Justine Bertrand-Michel
- MetaToul-MetaboHUB, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
- I2MC, Université de Toulouse, Inserm, Université Toulouse III – Paul Sabatier (UPS), Toulouse, France
| | - Guillemette Marot
- Université de Lille, Inria, CHU Lille, ULR 2694 - METRICS: Évaluation des technologies de santé et des pratiques médicales, Lille, France
| | - Yasmine Sebti
- Université de Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011 - EGID, Lille, France
| | - Jean Dubuisson
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
| | - Yves Rouillé
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U 1019 – UMR9017 – CIIL – Center for Infection and Immunity of Lille, Lille, France
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3
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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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4
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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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5
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Baker A, Lin CC, Lett C, Karpinska B, Wright MH, Foyer CH. Catalase: A critical node in the regulation of cell fate. Free Radic Biol Med 2023; 199:56-66. [PMID: 36775107 DOI: 10.1016/j.freeradbiomed.2023.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/19/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
Catalase (CAT) is an extensively studied if somewhat enigmatic enzyme that is at the heart of eukaryotic antioxidant systems with a canonical role in peroxisomal function. The CAT family of proteins exert control over a wide range of plant growth and defence processes. CAT proteins are subject to many types of post-translational modification (PTM), which modify activity, ligand binding, stability, compartmentation and function. The CAT interactome involves many cytosolic and nuclear proteins that appear to be essential for protein functions. Hence, the CAT network of roles extends far beyond those associated with peroxisomal metabolism. Some pathogen effector proteins are able to redirect CAT to the nucleus and recent evidence indicates CAT can traffic to the nucleus in the absence of exogenous proteins. While the mechanisms that target CAT to the nucleus are not understood, CAT activity in the cytosol and nucleus is promoted by interactions with nucleoredoxin. Here we discuss recent findings that have been pivotal in generating a step change in our understanding of CAT functions in plant cells.
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Affiliation(s)
- Alison Baker
- Centre for Plant Sciences and School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
| | - Chi-Chuan Lin
- Centre for Plant Sciences and School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Casey Lett
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Barbara Karpinska
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Megan H Wright
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK
| | - Christine H Foyer
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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6
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Rüttermann M, Gatsogiannis C. Good things come to those who bait: the peroxisomal docking complex. Biol Chem 2023; 404:107-119. [PMID: 36117327 DOI: 10.1515/hsz-2022-0161] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/25/2022] [Indexed: 11/15/2022]
Abstract
Peroxisomal integrity and function are highly dependent on its membrane and soluble (matrix) components. Matrix enzymes are imported post-translationally in a folded or even oligomeric state, via a still mysterious protein translocation mechanism. They are guided to peroxisomes via the Peroxisomal Targeting Signal (PTS) sequences which are recognized by specific cytosolic receptors, Pex5, Pex7 and Pex9. Subsequently, cargo-loaded receptors bind to the docking complex in an initial step, followed by channel formation, cargo-release, receptor-recycling and -quality control. The docking complexes of different species share Pex14 as their core component but differ in composition and oligomeric state of Pex14. Here we review and highlight the latest insights on the structure and function of the peroxisomal docking complex. We summarize differences between yeast and mammals and then we integrate this knowledge into our current understanding of the import machinery.
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Affiliation(s)
- Maximilian Rüttermann
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, D-48149 Münster, Germany
| | - Christos Gatsogiannis
- Institute for Medical Physics and Biophysics and Center for Soft Nanoscience, Westfälische Wilhelms Universität Münster, D-48149 Münster, Germany
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7
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Melicher P, Dvořák P, Šamaj J, Takáč T. Protein-protein interactions in plant antioxidant defense. FRONTIERS IN PLANT SCIENCE 2022; 13:1035573. [PMID: 36589041 PMCID: PMC9795235 DOI: 10.3389/fpls.2022.1035573] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/14/2022] [Indexed: 06/17/2023]
Abstract
The regulation of reactive oxygen species (ROS) levels in plants is ensured by mechanisms preventing their over accumulation, and by diverse antioxidants, including enzymes and nonenzymatic compounds. These are affected by redox conditions, posttranslational modifications, transcriptional and posttranscriptional modifications, Ca2+, nitric oxide (NO) and mitogen-activated protein kinase signaling pathways. Recent knowledge about protein-protein interactions (PPIs) of antioxidant enzymes advanced during last decade. The best-known examples are interactions mediated by redox buffering proteins such as thioredoxins and glutaredoxins. This review summarizes interactions of major antioxidant enzymes with regulatory and signaling proteins and their diverse functions. Such interactions are important for stability, degradation and activation of interacting partners. Moreover, PPIs of antioxidant enzymes may connect diverse metabolic processes with ROS scavenging. Proteins like receptor for activated C kinase 1 may ensure coordination of antioxidant enzymes to ensure efficient ROS regulation. Nevertheless, PPIs in antioxidant defense are understudied, and intensive research is required to define their role in complex regulation of ROS scavenging.
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8
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Hochreiter B, Malagon-Vina H, Schmid JA, Berger J, Kunze M. Studying the interaction between PEX5 and its full-length cargo proteins in living cells by a novel Försteŕs resonance energy transfer-based competition assay. Front Cell Dev Biol 2022; 10:1026388. [PMID: 36407094 PMCID: PMC9669585 DOI: 10.3389/fcell.2022.1026388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
The import of the majority of soluble peroxisomal proteins is initiated by the interaction between type-1 peroxisomal targeting signals (PTS1) and their receptor PEX5. PTS1 motifs reside at the extreme C-terminus of proteins and consist of a characteristic tripeptide and a modulatory upstream region. Various PTS1-PEX5 interactions have been studied by biophysical methods using isolated proteins or in heterologous systems such as two-hybrid assays, but a recently established approach based on Försters resonance energy transfer (FRET) allows a quantifying investigation in living cells. FRET is the radiation-free energy transfer between two fluorophores in close proximity and can be used to estimate the fraction of acceptor molecules bound to a donor molecule. For PTS1-PEX5 this method relies on the measurement of FRET-efficiency between the PTS1-binding TPR-domain of PEX5 tagged with mCherry and EGFP fused to a PTS1 peptide. However, this method is less suitable for binding partners with low affinity and protein complexes involving large proteins such as the interaction between full-length PTS1-carrying cargo proteins and PEX5. To overcome this limitation, we introduce a life-cell competition assay based on the same FRET approach but including a fusion protein of Cerulean with the protein of interest as a competitor. After implementing the mathematical description of competitive binding experiments into a fitting algorithm, we demonstrate the functionality of this approach using known interaction partners, its ability to circumvent previous limitations of FRET-measurements and its ability to study the interaction between PEX5 and its full-length cargo proteins. We find that some proteins (SCP2 and AGXT) bind PEX5 with higher affinity than their PTS1-peptides alone, but other proteins (ACOX3, DAO, PerCR-SRL) bind with lower but reasonable affinity, whereas GSTK1 binds with very low affinity. This binding strength was not increased upon elongating the PEX5 TPR-domain at its N-terminus, PEX5(N-TPR), although it interacts specifically with the N-terminal domain of PEX14. Finally, we demonstrate that the latter reduces the interaction strength between PEX5(N-TPR) and PTS1 by a dose-dependent but apparently non-competitive mechanism. Altogether, this demonstrates the power of this novel FRET-based competition approach for studying cargo recognition by PEX5 and protein complexes including large proteins in general.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hugo Malagon-Vina
- Department of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Johannes A. Schmid
- Institute for Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, 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
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
- *Correspondence: Markus Kunze,
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9
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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: 11] [Impact Index Per Article: 5.5] [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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10
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Judy RM, Sheedy CJ, Gardner BM. Insights into the Structure and Function of the Pex1/Pex6 AAA-ATPase in Peroxisome Homeostasis. Cells 2022; 11:2067. [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] [MESH Headings] [Grants] [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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Affiliation(s)
| | | | - Brooke M. Gardner
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA; (R.M.J.); (C.J.S.)
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11
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Galiani S, Reglinski K, Carravilla P, Barbotin A, Urbančič I, Ott J, Sehr J, Sezgin E, Schneider F, Waithe D, Hublitz P, Schliebs W, Erdmann R, Eggeling C. Diffusion and interaction dynamics of the cytosolic peroxisomal import receptor PEX5. BIOPHYSICAL REPORTS 2022; 2:None. [PMID: 36299769 PMCID: PMC9586885 DOI: 10.1016/j.bpr.2022.100055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/24/2022] [Indexed: 11/18/2022]
Abstract
Cellular functions rely on proper actions of organelles such as peroxisomes. These organelles rely on the import of proteins from the cytosol. The peroxisomal import receptor PEX5 takes up target proteins in the cytosol and transports them to the peroxisomal matrix. However, its cytosolic molecular interactions have so far not directly been disclosed. Here, we combined advanced optical microscopy and spectroscopy techniques such as fluorescence correlation spectroscopy and stimulated emission depletion microscopy with biochemical tools to present a detailed characterization of the cytosolic diffusion and interaction dynamics of PEX5. Among other features, we highlight a slow diffusion of PEX5, independent of aggregation or target binding, but associated with cytosolic interaction partners via its N-terminal domain. This sheds new light on the functionality of the receptor in the cytosol as well as highlighting the potential of using complementary microscopy tools to decipher molecular interactions in the cytosol by studying their diffusion dynamics.
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Affiliation(s)
- S. Galiani
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Wolfson Imaging Centre, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - K. Reglinski
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Leibniz-Institute of Photonic Technologies e.V., Jena, Germany
- Institute of Applied Optic and Biophysics, Friedrich-Schiller University Jena, Jena, Germany
- University Hospital Jena, Jena, Germany
| | - P. Carravilla
- Leibniz-Institute of Photonic Technologies e.V., Jena, Germany
- Institute of Applied Optic and Biophysics, Friedrich-Schiller University Jena, Jena, Germany
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
- Instituto Biofisika (UPV/EHU, CSIC), University of the Basque Country, Leioa, Spain
| | - A. Barbotin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - I. Urbančič
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Laboratory of Biophysics, Condensed Matter Physics Department, Jožef Stefan Institute, Ljubljana, Slovenia
| | - J. Ott
- Institute of Biochemistry and Pathobiochemistry, Systems Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - J. Sehr
- Institute of Biochemistry and Pathobiochemistry, Systems Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - E. Sezgin
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Science for Life Laboratory, Department of Women’s and Children’s Health, Karolinska Institutet, Solna, Sweden
| | - F. Schneider
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, UK
| | - D. Waithe
- Wolfson Imaging Centre, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- WIMM Centre for Computational Biology , MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - P. Hublitz
- WIMM Genome Engineering Services, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - W. Schliebs
- Institute of Biochemistry and Pathobiochemistry, Systems Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - R. Erdmann
- Institute of Biochemistry and Pathobiochemistry, Systems Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - C. Eggeling
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Wolfson Imaging Centre, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Leibniz-Institute of Photonic Technologies e.V., Jena, Germany
- Institute of Applied Optic and Biophysics, Friedrich-Schiller University Jena, Jena, Germany
- Jena Center for Soft Matter (JCSM), Jena, Germany
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12
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Al‐Hajaya Y, Karpinska B, Foyer CH, Baker A. Nuclear and peroxisomal targeting of catalase. PLANT, CELL & ENVIRONMENT 2022; 45:1096-1108. [PMID: 35040158 PMCID: PMC9305541 DOI: 10.1111/pce.14262] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 06/14/2023]
Abstract
Catalase is a well-known component of the cellular antioxidant network, but there have been conflicting conclusions reached regarding the nature of its peroxisome targeting signal. It has also been reported that catalase can be hijacked to the nucleus by effector proteins of plant pathogens. Using a physiologically relevant system where native untagged catalase variants are expressed in a cat2-1 mutant background, the C terminal most 18 amino acids could be deleted without affecting activity, peroxisomal targeting or ability to complement multiple phenotypes of the cat2-1 mutant. In contrast, converting the native C terminal tripeptide PSI to the canonical PTS1 sequence ARL resulted in lower catalase specific activity. Localisation experiments using split superfolder green fluorescent protein revealed that catalase can be targeted to the nucleus in the absence of any pathogen effectors, and that C terminal tagging in combination with alterations of the native C terminus can interfere with nuclear localisation. These findings provide fundamental new insights into catalase targeting and pave the way for exploration of the mechanism of catalase targeting to the nucleus and its role in non-infected plants.
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Affiliation(s)
- Yousef Al‐Hajaya
- Centre for Plant Sciences and School of Molecular and Cellular BiologyUniversity of LeedsLeedsUK
- Present address:
Department of Laboratory Medical SciencesMutah UniversityKarakJordan
| | - Barbara Karpinska
- Centre for Plant Sciences and School of BiologyUniversity of LeedsLeedsUK
| | - Christine H. Foyer
- Centre for Plant Sciences and School of BiologyUniversity of LeedsLeedsUK
- Present address:
School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamEdgbastonUK
| | - Alison Baker
- Centre for Plant Sciences and School of Molecular and Cellular BiologyUniversity of LeedsLeedsUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsLeedsUK
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13
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Dindo M, Ambrosini G, Oppici E, Pey AL, O’Toole PJ, Marrison JL, Morrison IEG, Butturini E, Grottelli S, Costantini C, Cellini B. Dimerization Drives Proper Folding of Human Alanine:Glyoxylate Aminotransferase But Is Dispensable for Peroxisomal Targeting. J Pers Med 2021; 11:jpm11040273. [PMID: 33917320 PMCID: PMC8067440 DOI: 10.3390/jpm11040273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 12/15/2022] Open
Abstract
Peroxisomal matrix proteins are transported into peroxisomes in a fully-folded state, but whether multimeric proteins are imported as monomers or oligomers is still disputed. Here, we used alanine:glyoxylate aminotransferase (AGT), a homodimeric pyridoxal 5′-phosphate (PLP)-dependent enzyme, whose deficit causes primary hyperoxaluria type I (PH1), as a model protein and compared the intracellular behavior and peroxisomal import of native dimeric and artificial monomeric forms. Monomerization strongly reduces AGT intracellular stability and increases its aggregation/degradation propensity. In addition, monomers are partly retained in the cytosol. To assess possible differences in import kinetics, we engineered AGT to allow binding of a membrane-permeable dye and followed its intracellular trafficking without interfering with its biochemical properties. By fluorescence recovery after photobleaching, we measured the import rate in live cells. Dimeric and monomeric AGT displayed a similar import rate, suggesting that the oligomeric state per se does not influence import kinetics. However, when dimerization is compromised, monomers are prone to misfolding events that can prevent peroxisomal import, a finding crucial to predicting the consequences of PH1-causing mutations that destabilize the dimer. Treatment with pyridoxine of cells expressing monomeric AGT promotes dimerization and folding, thus, demonstrating the chaperone role of PLP. Our data support a model in which dimerization represents a potential key checkpoint in the cytosol at the crossroad between misfolding and correct targeting, a possible general mechanism for other oligomeric peroxisomal proteins.
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Affiliation(s)
- Mirco Dindo
- Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (M.D.); (S.G.); (C.C.)
| | - Giulia Ambrosini
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (G.A.); (E.O.); (E.B.)
| | - Elisa Oppici
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (G.A.); (E.O.); (E.B.)
| | - Angel L. Pey
- Departamento de Química Física, Unidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain;
| | - Peter J. O’Toole
- Bioscience Technology Facility, Department of Biology, University of York, York YO23 3GE, UK; (P.J.O.); (J.L.M.); (I.E.G.M.)
| | - Joanne L. Marrison
- Bioscience Technology Facility, Department of Biology, University of York, York YO23 3GE, UK; (P.J.O.); (J.L.M.); (I.E.G.M.)
| | - Ian E. G. Morrison
- Bioscience Technology Facility, Department of Biology, University of York, York YO23 3GE, UK; (P.J.O.); (J.L.M.); (I.E.G.M.)
| | - Elena Butturini
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy; (G.A.); (E.O.); (E.B.)
| | - Silvia Grottelli
- Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (M.D.); (S.G.); (C.C.)
| | - Claudio Costantini
- Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (M.D.); (S.G.); (C.C.)
| | - Barbara Cellini
- Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (M.D.); (S.G.); (C.C.)
- Correspondence: ; Tel.: +39-075-585-8339
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14
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Bürgi J, Ekal L, Wilmanns M. Versatile allosteric properties in Pex5-like tetratricopeptide repeat proteins to induce diverse downstream function. Traffic 2021; 22:140-152. [PMID: 33580581 DOI: 10.1111/tra.12785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/30/2021] [Accepted: 02/10/2021] [Indexed: 01/11/2023]
Abstract
Proteins composed of tetratricopeptide repeat (TPR) arrays belong to the α-solenoid tandem-repeat family that have unique properties in terms of their overall conformational flexibility and ability to bind to multiple protein ligands. The peroxisomal matrix protein import receptor Pex5 comprises two TPR triplets that recognize protein cargos with a specific C-terminal Peroxisomal Targeting Signal (PTS) 1 motif. Import of PTS1-containing protein cargos into peroxisomes through a transient pore is mainly driven by allosteric binding, coupling and release mechanisms, without a need for external energy. A very similar TPR architecture is found in the functionally unrelated TRIP8b, a regulator of the hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channel. TRIP8b binds to the HCN ion channel via a C-terminal sequence motif that is nearly identical to the PTS1 motif of Pex5 receptor cargos. Pex5, Pex5-related Pex9, and TRIP8b also share a less conserved N-terminal domain. This domain provides a second protein cargo-binding site and plays a distinct role in allosteric coupling of initial cargo loading by PTS1 motif-mediated interactions and different downstream functional readouts. The data reviewed here highlight the overarching role of molecular allostery in driving the diverse functions of TPR array proteins, which could form a model for other α-solenoid tandem-repeat proteins involved in translocation processes across membranes.
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Affiliation(s)
- Jérôme Bürgi
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Lakhan Ekal
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany.,University Hamburg Clinical Center Hamburg-Eppendorf, Hamburg, Germany
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15
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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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16
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Kunze M. The type-2 peroxisomal targeting signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118609. [PMID: 31751594 DOI: 10.1016/j.bbamcr.2019.118609] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.
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Affiliation(s)
- Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Spitalgasse 4, 1090 Vienna, Austria.
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17
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A Mechanistic Perspective on PEX1 and PEX6, Two AAA+ Proteins of the Peroxisomal Protein Import Machinery. Int J Mol Sci 2019; 20:ijms20215246. [PMID: 31652724 PMCID: PMC6862443 DOI: 10.3390/ijms20215246] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022] Open
Abstract
In contrast to many protein translocases that use ATP or GTP hydrolysis as the driving force to transport proteins across biological membranes, the peroxisomal matrix protein import machinery relies on a regulated self-assembly mechanism for this purpose and uses ATP hydrolysis only to reset its components. The ATP-dependent protein complex in charge of resetting this machinery—the Receptor Export Module (REM)—comprises two members of the “ATPases Associated with diverse cellular Activities” (AAA+) family, PEX1 and PEX6, and a membrane protein that anchors the ATPases to the organelle membrane. In recent years, a large amount of data on the structure/function of the REM complex has become available. Here, we discuss the main findings and their mechanistic implications.
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18
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Barros-Barbosa A, Rodrigues TA, Ferreira MJ, Pedrosa AG, Teixeira NR, Francisco T, Azevedo JE. The intrinsically disordered nature of the peroxisomal protein translocation machinery. FEBS J 2018; 286:24-38. [PMID: 30443986 DOI: 10.1111/febs.14704] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/14/2018] [Indexed: 12/18/2022]
Abstract
Despite having a membrane that is impermeable to all but the smallest of metabolites, peroxisomes acquire their newly synthesized (cytosolic) matrix proteins in an already folded conformation. In some cases, even oligomeric proteins have been reported to translocate the organelle membrane. The protein sorting machinery that accomplishes this feat must be rather flexible and, unsurprisingly, several of its key components have large intrinsically disordered domains. Here, we provide an overview on these domains and their interactions trying to infer their functional roles in this protein sorting pathway.
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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, 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, 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, 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, Portugal
| | - Nélson R Teixeira
- 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, Portugal
| | - 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, 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, Portugal
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19
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Rymer Ł, Kempiński B, Chełstowska A, Skoneczny M. The budding yeast Pex5p receptor directs Fox2p and Cta1p into peroxisomes via its N-terminal region near the FxxxW domain. J Cell Sci 2018; 131:jcs.216986. [PMID: 30131444 DOI: 10.1242/jcs.216986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 08/07/2018] [Indexed: 01/08/2023] Open
Abstract
The import of most of peroxisomal proteins into the lumen of their target organelle is driven by C-terminal (PTS1) or N-terminal (PTS2) signals recognized by the Pex5p or Pex7p receptors, respectively. However, some proteins in budding yeast, such as acyl-CoA oxidase (AOx) and carnitine acetyltransferase (Cat2p), are imported into peroxisomes via an alternative route that does not rely on known PTS signals and involves the Pex5p receptor N-terminal region. Here, we show that two other budding yeast peroxisomal proteins, a multifunctional enzyme from the β-oxidation pathway (Fox2p) and catalase A (Cta1p), both of which contain PTS1, can be imported independently of this signal. The I264K amino acid substitution in Pex5p adjacent to its FxxxW diaromatic motif, previously shown to abolish the import of AOx and Cat2p into peroxisomes, also affects Fox2p and Cta1p import. Moreover, we demonstrate that Pex9p, a newly discovered paralog of Pex5p that was recently implicated in the import of malate synthases in budding yeast, also exhibits weak receptor activity towards Fox2p and Cta1p. These findings indicate the need to re-evaluate the peroxisomal import paradigm.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Łukasz Rymer
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Błażej Kempiński
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Anna Chełstowska
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
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20
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Kao YT, Gonzalez KL, Bartel B. Peroxisome Function, Biogenesis, and Dynamics in Plants. PLANT PHYSIOLOGY 2018; 176:162-177. [PMID: 29021223 PMCID: PMC5761812 DOI: 10.1104/pp.17.01050] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/09/2017] [Indexed: 05/19/2023]
Abstract
Recent advances highlight understanding of the diversity of peroxisome contributions to plant biology and the mechanisms through which these essential organelles are generated.
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Affiliation(s)
- Yun-Ting Kao
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Kim L Gonzalez
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, Texas 77005
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21
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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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22
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Lyman KA, Han Y, Heuermann RJ, Cheng X, Kurz JE, Lyman RE, Van Veldhoven PP, Chetkovich DM. Allostery between two binding sites in the ion channel subunit TRIP8b confers binding specificity to HCN channels. J Biol Chem 2017; 292:17718-17730. [PMID: 28887304 DOI: 10.1074/jbc.m117.802256] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/05/2017] [Indexed: 12/20/2022] Open
Abstract
Tetratricopeptide repeat (TPR) domains are ubiquitous structural motifs that mediate protein-protein interactions. For example, the TPR domains in the peroxisomal import receptor PEX5 enable binding to a range of type 1 peroxisomal targeting signal motifs. A homolog of PEX5, tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b), binds to and functions as an auxiliary subunit of hyperpolarization-activated cyclic nucleotide (HCN)-gated channels. Given the similarity between TRIP8b and PEX5, this difference in function raises the question of what mechanism accounts for their binding specificity. In this report, we found that the cyclic nucleotide-binding domain and the C terminus of the HCN channel are critical for conferring specificity to TRIP8b binding. We show that TRIP8b binds the HCN cyclic nucleotide-binding domain through a 37-residue domain and the HCN C terminus through the TPR domains. Using a combination of fluorescence polarization- and co-immunoprecipitation-based assays, we establish that binding at either site increases affinity at the other. Thus, allosteric coupling of the TRIP8b TPR domains both promotes binding to HCN channels and limits binding to type 1 peroxisomal targeting signal substrates. These results raise the possibility that other TPR domains may be similarly influenced by allosteric mechanisms as a general feature of protein-protein interactions.
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Affiliation(s)
- Kyle A Lyman
- From the Davee Department of Neurology and Clinical Neurosciences and
| | - Ye Han
- From the Davee Department of Neurology and Clinical Neurosciences and
| | | | - Xiangying Cheng
- From the Davee Department of Neurology and Clinical Neurosciences and
| | | | - Reagan E Lyman
- From the Davee Department of Neurology and Clinical Neurosciences and
| | - Paul P Van Veldhoven
- the Laboratory of Lipid Biochemistry and Protein Interactions, Campus Gasthuisberg, KU Leuven, 3000 Leuven, Belgium
| | - Dane M Chetkovich
- From the Davee Department of Neurology and Clinical Neurosciences and .,Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and
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23
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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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24
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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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25
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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: 14] [Impact Index Per Article: 2.0] [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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26
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Cipolla CM, Lodhi IJ. Peroxisomal Dysfunction in Age-Related Diseases. Trends Endocrinol Metab 2017; 28:297-308. [PMID: 28063767 PMCID: PMC5366081 DOI: 10.1016/j.tem.2016.12.003] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/04/2016] [Accepted: 12/07/2016] [Indexed: 12/21/2022]
Abstract
Peroxisomes carry out many key functions related to lipid and reactive oxygen species (ROS) metabolism. The fundamental importance of peroxisomes for health in humans is underscored by the existence of devastating genetic disorders caused by impaired peroxisomal function or lack of peroxisomes. Emerging studies suggest that peroxisomal function may also be altered with aging and contribute to the pathogenesis of a variety of diseases, including diabetes and its related complications, neurodegenerative disorders, and cancer. With increasing evidence connecting peroxisomal dysfunction to the pathogenesis of these acquired diseases, the possibility of targeting peroxisomal function in disease prevention or treatment becomes intriguing. Here, we review recent developments in understanding the pathophysiological implications of peroxisomal dysfunctions outside the context of inherited peroxisomal disorders.
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Affiliation(s)
- Cynthia M Cipolla
- Division of Endocrinology, Metabolism & Lipid Research, Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Irfan J Lodhi
- Division of Endocrinology, Metabolism & Lipid Research, Department of Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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27
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Saryi NAA, Hutchinson JD, Al-Hejjaj MY, Sedelnikova S, Baker P, Hettema EH. Pnc1 piggy-back import into peroxisomes relies on Gpd1 homodimerisation. Sci Rep 2017; 7:42579. [PMID: 28209961 PMCID: PMC5314374 DOI: 10.1038/srep42579] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 12/29/2016] [Indexed: 12/17/2022] Open
Abstract
Peroxisomes are eukaryotic organelles that posttranslationally import proteins via one of two conserved peroxisomal targeting signal (PTS1 or 2) mediated pathways. Oligomeric proteins can be imported via these pathways but evidence is accumulating that at least some PTS1-containing monomers enter peroxisomes before they assemble into oligomers. Some proteins lacking a PTS are imported by piggy-backing onto PTS-containing proteins. One of these proteins is the nicotinamidase Pnc1, that is co-imported with the PTS2-containing enzyme Glycerol-3-phosphate dehydrogenase 1, Gpd1. Here we show that Pnc1 co-import requires Gpd1 to form homodimers. A mutation that interferes with Gpd1 homodimerisation does not prevent Gpd1 import but prevents Pnc1 co-import. A suppressor mutation that restores Gpd1 homodimerisation also restores Pnc1 co-import. In line with this, Pnc1 interacts with Gpd1 in vivo only when Gpd1 can form dimers. Redirection of Gpd1 from the PTS2 import pathway to the PTS1 import pathway supports Gpd1 monomer import but not Gpd1 homodimer import and Pnc1 co-import. Our results support a model whereby Gpd1 may be imported as a monomer or a dimer but only the Gpd1 dimer facilitates co-transport of Pnc1 into peroxisomes.
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Affiliation(s)
- Nadal A Al Saryi
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
| | - John D Hutchinson
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
| | - Murtakab Y Al-Hejjaj
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
| | - Svetlana Sedelnikova
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
| | - Patrick Baker
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
| | - Ewald H Hettema
- Department of Molecular Biology and Biotechnology University of Sheffield Firth Court, Western Bank Sheffield S10 2TN United Kingdom
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28
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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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29
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Affiliation(s)
| | - Maria Daniela D'Agostino
- McGill University Department of Human Genetics and McGill University Health Center, Department of Medical Genetics, Montreal, QC, Canada
| | - Nancy Braverman
- McGill University Department of Human Genetics and Pediatrics, and The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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30
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Kao YT, Fleming WA, Ventura MJ, Bartel B. Genetic Interactions between PEROXIN12 and Other Peroxisome-Associated Ubiquitination Components. PLANT PHYSIOLOGY 2016; 172:1643-1656. [PMID: 27650450 PMCID: PMC5100787 DOI: 10.1104/pp.16.01211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/15/2016] [Indexed: 05/28/2023]
Abstract
Most eukaryotic cells require peroxisomes, organelles housing fatty acid β-oxidation and other critical metabolic reactions. Peroxisomal matrix proteins carry peroxisome-targeting signals that are recognized by one of two receptors, PEX5 or PEX7, in the cytosol. After delivering the matrix proteins to the organelle, these receptors are removed from the peroxisomal membrane or matrix. Receptor retrotranslocation not only facilitates further rounds of matrix protein import but also prevents deleterious PEX5 retention in the membrane. Three peroxisome-associated ubiquitin-protein ligases in the Really Interesting New Gene (RING) family, PEX2, PEX10, and PEX12, facilitate PEX5 retrotranslocation. However, the detailed mechanism of receptor retrotranslocation remains unclear in plants. We identified an Arabidopsis (Arabidopsis thaliana) pex12 Glu-to-Lys missense allele that conferred severe peroxisomal defects, including impaired β-oxidation, inefficient matrix protein import, and decreased growth. We compared this pex12-1 mutant to other peroxisome-associated ubiquitination-related mutants and found that RING peroxin mutants displayed elevated PEX5 and PEX7 levels, supporting the involvement of RING peroxins in receptor ubiquitination in Arabidopsis. Also, we observed that disruption of any Arabidopsis RING peroxin led to decreased PEX10 levels, as seen in yeast and mammals. Peroxisomal defects were exacerbated in RING peroxin double mutants, suggesting distinct roles of individual RING peroxins. Finally, reducing function of the peroxisome-associated ubiquitin-conjugating enzyme PEX4 restored PEX10 levels and partially ameliorated the other molecular and physiological defects of the pex12-1 mutant. Future biochemical analyses will be needed to determine whether destabilization of the RING peroxin complex observed in pex12-1 stems from PEX4-dependent ubiquitination on the pex12-1 ectopic Lys residue.
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Affiliation(s)
- Yun-Ting Kao
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Wendell A Fleming
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Meredith J Ventura
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Bonnie Bartel
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
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31
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Abstract
The import of proteins into peroxisomes possesses many unusual features such as the ability to import folded proteins, and a surprising diversity of targeting signals with differing affinities that can be recognized by the same receptor. As understanding of the structure and function of many components of the protein import machinery has grown, an increasingly complex network of factors affecting each step of the import pathway has emerged. Structural studies have revealed the presence of additional interactions between cargo proteins and the PEX5 receptor that affect import potential, with a subtle network of cargo-induced conformational changes in PEX5 being involved in the import process. Biochemical studies have also indicated an interdependence of receptor-cargo import with release of unloaded receptor from the peroxisome. Here, we provide an update on recent literature concerning mechanisms of protein import into peroxisomes.
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Affiliation(s)
- Alison Baker
- School of Molecular and Cellular Biology, Astbury Centre for Structural Molecular Biology and Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Thomas Lanyon-Hogg
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, London SW7 2AZ, U.K
| | - Stuart L Warriner
- School of Chemistry, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
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32
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Emmanouilidis L, Gopalswamy M, Passon DM, Wilmanns M, Sattler M. Structural biology of the import pathways of peroxisomal matrix proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:804-13. [DOI: 10.1016/j.bbamcr.2015.09.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 11/28/2022]
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33
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Reumann S, Chowdhary G, Lingner T. Characterization, prediction and evolution of plant peroxisomal targeting signals type 1 (PTS1s). BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1863:790-803. [PMID: 26772785 DOI: 10.1016/j.bbamcr.2016.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/01/2016] [Accepted: 01/04/2016] [Indexed: 12/22/2022]
Abstract
Our knowledge of the proteome of plant peroxisomes and their functional plasticity is far from being complete, primarily due to major technical challenges in experimental proteome research of the fragile cell organelle. Several unexpected novel plant peroxisome functions, for instance in biotin and phylloquinone biosynthesis, have been uncovered recently. Nevertheless, very few regulatory and membrane proteins of plant peroxisomes have been identified and functionally described up to now. To define the matrix proteome of plant peroxisomes, computational methods have emerged as important powerful tools. Novel prediction approaches of high sensitivity and specificity have been developed for peroxisome targeting signals type 1 (PTS1) and have been validated by in vivo subcellular targeting analyses and thermodynamic binding studies with the cytosolic receptor, PEX5. Accordingly, the algorithms allow the correct prediction of many novel peroxisome-targeted proteins from plant genome sequences and the discovery of additional organelle functions. In this review, we provide an overview of methodologies, capabilities and accuracies of available prediction algorithms for PTS1 carrying proteins. We also summarize and discuss recent quantitative, structural and mechanistic information of the interaction of PEX5 with PTS1 carrying proteins in relation to in vivo import efficiency. With this knowledge, we develop a model of how proteins likely evolved peroxisomal targeting signals in the past and still nowadays, in which order the two import pathways might have evolved in the ancient eukaryotic cell, and how the secondary loss of the PTS2 pathway probably happened in specific organismal groups.
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Affiliation(s)
- S Reumann
- Department of Plant Biochemistry and Infection Biology, Biocentre Klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany; Centre for Organelle Research, University of Stavanger, N-4036 Stavanger, Norway.
| | - G Chowdhary
- Centre for Organelle Research, University of Stavanger, N-4036 Stavanger, Norway; KIIT School of Biotechnology, Campus XI, KIIT University, I-751024 Bhubaneswar, India.
| | - T Lingner
- Department of Bioinformatics, Institute for Microbiology and Genetics, D-37077 Goettingen, Germany.
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34
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Neuhaus A, Eggeling C, Erdmann R, Schliebs W. Why do peroxisomes associate with the cytoskeleton? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1019-26. [DOI: 10.1016/j.bbamcr.2015.11.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/16/2015] [Accepted: 11/20/2015] [Indexed: 12/20/2022]
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35
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Peroxisomal protein import pores. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:821-7. [DOI: 10.1016/j.bbamcr.2015.10.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/14/2015] [Accepted: 10/16/2015] [Indexed: 02/06/2023]
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36
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Freitas MO, Francisco T, Rodrigues TA, Lismont C, Domingues P, Pinto MP, Grou CP, Fransen M, Azevedo JE. The peroxisomal protein import machinery displays a preference for monomeric substrates. Open Biol 2016; 5:140236. [PMID: 25854684 PMCID: PMC4422123 DOI: 10.1098/rsob.140236] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and transported by the shuttling receptor PEX5 to the peroxisomal membrane docking/translocation machinery, where they are translocated into the organelle matrix. Under certain experimental conditions this protein import machinery has the remarkable capacity to accept already oligomerized proteins, a property that has heavily influenced current models on the mechanism of peroxisomal protein import. However, whether or not oligomeric proteins are really the best and most frequent clients of this machinery remain unclear. In this work, we present three lines of evidence suggesting that the peroxisomal import machinery displays a preference for monomeric proteins. First, in agreement with previous findings on catalase, we show that PEX5 binds newly synthesized (monomeric) acyl-CoA oxidase 1 (ACOX1) and urate oxidase (UOX), potently inhibiting their oligomerization. Second, in vitro import experiments suggest that monomeric ACOX1 and UOX are better peroxisomal import substrates than the corresponding oligomeric forms. Finally, we provide data strongly suggesting that although ACOX1 lacking a peroxisomal targeting signal can be imported into peroxisomes when co-expressed with ACOX1 containing its targeting signal, this import pathway is inefficient.
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Affiliation(s)
- Marta O Freitas
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal
| | - Tânia Francisco
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal
| | - Tony A Rodrigues
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Celien Lismont
- Departement Cellulaire en Moleculaire Geneeskunde, KU Leuven-Universiteit Leuven, Leuven, Belgium
| | - Pedro Domingues
- Departamento de Química, Universidade de Aveiro, Aveiro, Portugal
| | - Manuel P Pinto
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal
| | - Cláudia P Grou
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal
| | - Marc Fransen
- Departement Cellulaire en Moleculaire Geneeskunde, KU Leuven-Universiteit Leuven, Leuven, Belgium
| | - Jorge E Azevedo
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, Porto, Portugal Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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37
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Oeljeklaus S, Schummer A, Mastalski T, Platta HW, Warscheid B. Regulation of peroxisome dynamics by phosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1027-37. [PMID: 26775584 DOI: 10.1016/j.bbamcr.2015.12.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/22/2015] [Accepted: 12/24/2015] [Indexed: 12/31/2022]
Abstract
Peroxisomes are highly dynamic organelles that can rapidly change in size, abundance, and protein content in response to alterations in nutritional and other environmental conditions. These dynamic changes in peroxisome features, referred to as peroxisome dynamics, rely on the coordinated action of several processes of peroxisome biogenesis. Revealing the regulatory mechanisms of peroxisome dynamics is an emerging theme in cell biology. These mechanisms are inevitably linked to and synchronized with the biogenesis and degradation of peroxisomes. To date, the key players and basic principles of virtually all steps in the peroxisomal life cycle are known, but regulatory mechanisms remained largely elusive. A number of recent studies put the spotlight on reversible protein phosphorylation for the control of peroxisome dynamics and highlighted peroxisomes as hubs for cellular signal integration and regulation. Here, we will present and discuss the results of several studies performed using yeast and mammalian cells that convey a sense of the impact protein phosphorylation may have on the modulation of peroxisome dynamics by regulating peroxisomal matrix and membrane protein import, proliferation, inheritance, and degradation. We further put forward the idea to make use of current data on phosphorylation sites of peroxisomal and peroxisome-associated proteins reported in advanced large-scale phosphoproteomic studies.
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Affiliation(s)
- Silke Oeljeklaus
- Faculty of Biology, Department of Biochemistry and Functional Proteomics, University of Freiburg, 79104 Freiburg, Germany
| | - Andreas Schummer
- Faculty of Biology, Department of Biochemistry and Functional Proteomics, University of Freiburg, 79104 Freiburg, Germany
| | - Thomas Mastalski
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Bettina Warscheid
- Faculty of Biology, Department of Biochemistry and Functional Proteomics, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
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38
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Bhogal MS, Lanyon-Hogg T, Johnston KA, Warriner SL, Baker A. Covalent Label Transfer between Peroxisomal Importomer Components Reveals Export-driven Import Interactions. J Biol Chem 2015; 291:2460-8. [PMID: 26567336 PMCID: PMC4732227 DOI: 10.1074/jbc.m115.686501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 11/06/2022] Open
Abstract
Peroxisomes are vital metabolic organelles found in almost all eukaryotic organisms, and they rely exclusively on import of their matrix protein content from the cytosol. In vitro import of proteins into isolated peroxisomal fractions has provided a wealth of knowledge on the import process. However, the common method of protease protection garnered no information on the import of an N-terminally truncated PEX5 (PEX5C) receptor construct or peroxisomal malate dehydrogenase 1 (pMDH1) cargo protein into sunflower peroxisomes because of high degrees of protease susceptibility or resistance, respectively. Here we present a means for analysis of in vitro import through a covalent biotin label transfer and employ this method to the import of PEX5C. Label transfer demonstrates that the PEX5C construct is monomeric under the conditions of the import assay. This technique was capable of identifying the PEX5-PEX14 interaction as the first interaction of the import process through competition experiments. Labeling of the peroxisomal protein import machinery by PEX5C demonstrated that this interaction was independent of added cargo protein, and, strikingly, the interaction between PEX5C and the import machinery was shown to be ATP-dependent. These important mechanistic insights highlight the power of label transfer in studying interactions, rather than proteins, of interest and demonstrate that this technique should be applied to future studies of peroxisomal in vitro import.
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Affiliation(s)
- Moninder S Bhogal
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
| | - Thomas Lanyon-Hogg
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and School of Chemistry and Astbury Centre, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Katherine A Johnston
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
| | - Stuart L Warriner
- School of Chemistry and Astbury Centre, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Alison Baker
- From the Centre for Plant Sciences and School of Molecular and Cellular Biology and
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Hojjat H, Jardim A. The Leishmania donovani peroxin 14 binding domain accommodates a high degeneracy in the pentapeptide motifs present on peroxin 5. Biochim Biophys Acta Gen Subj 2015; 1850:2203-12. [DOI: 10.1016/j.bbagen.2015.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 06/22/2015] [Accepted: 07/21/2015] [Indexed: 12/12/2022]
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40
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The first minutes in the life of a peroxisomal matrix protein. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:814-20. [PMID: 26408939 DOI: 10.1016/j.bbamcr.2015.09.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 01/30/2023]
Abstract
In the field of intracellular protein sorting, peroxisomes are most famous by their capacity to import oligomeric proteins. The data supporting this remarkable property are abundant and, understandably, have inspired a variety of hypothetical models on how newly synthesized (cytosolic) proteins reach the peroxisome matrix. However, there is also accumulating evidence suggesting that many peroxisomal oligomeric proteins actually arrive at the peroxisome still as monomers. In support of this idea, recent data suggest that PEX5, the shuttling receptor for peroxisomal matrix proteins, is also a chaperone/holdase, binding newly synthesized peroxisomal proteins in the cytosol and blocking their oligomerization. Here we review the data behind these two different perspectives and discuss their mechanistic implications on this protein sorting pathway.
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41
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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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42
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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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43
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Revisiting the intraperoxisomal pathway of mammalian PEX7. Sci Rep 2015; 5:11806. [PMID: 26138649 PMCID: PMC4490337 DOI: 10.1038/srep11806] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 06/08/2015] [Indexed: 02/07/2023] Open
Abstract
Newly synthesized peroxisomal proteins containing a cleavable type 2 targeting signal (PTS2) are transported to the peroxisome by a cytosolic PEX5-PEX7 complex. There, the trimeric complex becomes inserted into the peroxisomal membrane docking/translocation machinery (DTM), a step that leads to the translocation of the cargo into the organelle matrix. Previous work suggests that PEX5 is retained at the DTM during all the steps occurring at the peroxisome but whether the same applies to PEX7 was unknown. By subjecting different pre-assembled trimeric PEX5-PEX7-PTS2 complexes to in vitro co-import/export assays we found that the export competence of peroxisomal PEX7 is largely determined by the PEX5 molecule that transported it to the peroxisome. This finding suggests that PEX7 is also retained at the DTM during the peroxisomal steps and implies that cargo proteins are released into the organelle matrix by DTM-embedded PEX7. The release step does not depend on PTS2 cleavage. Rather, our data suggest that insertion of the trimeric PEX5-PEX7-PTS2 protein complex into the DTM is probably accompanied by conformational alterations in PEX5 to allow release of the PTS2 protein into the organelle matrix.
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44
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Chakravarti R, Gupta K, Majors A, Ruple L, Aronica M, Stuehr DJ. Novel insights in mammalian catalase heme maturation: effect of NO and thioredoxin-1. Free Radic Biol Med 2015; 82:105-13. [PMID: 25659933 PMCID: PMC5030845 DOI: 10.1016/j.freeradbiomed.2015.01.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 01/07/2015] [Accepted: 01/13/2015] [Indexed: 12/29/2022]
Abstract
Catalase is a tetrameric heme-containing enzyme with essential antioxidant functions in biology. Multiple factors including nitric oxide (NO) have been shown to attenuate its activity. However, the possible impact of NO in relation to the maturation of active catalase, including its heme acquisition and tetramer formation, has not been investigated. We found that NO attenuates heme insertion into catalase in both short-term and long-term incubations. The NO inhibition in catalase heme incorporation was associated with defective oligomerization of catalase, such that inactive catalase monomers and dimers accumulated in place of the mature tetrameric enzyme. We also found that GAPDH plays a key role in mediating these NO effects on the structure and activity of catalase. Moreover, the NO sensitivity of catalase maturation could be altered up or down by manipulating the cellular expression level or activity of thioredoxin-1, a known protein-SNO denitrosylase enzyme. In a mouse model of allergic inflammatory asthma, we found that lungs from allergen-challenged mice contained a greater percentage of dimeric catalase relative to tetrameric catalase in the unchallenged control, suggesting that the mechanisms described here are in play in the allergic asthma model. Together, our study shows how maturation of active catalase can be influenced by NO, S-nitrosylated GAPDH, and thioredoxin-1, and how maturation may become compromised in inflammatory conditions such as asthma.
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Affiliation(s)
- Ritu Chakravarti
- Department of Pathobiology, Lerner Research Institute, 9500 Euclid Avenue, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Karishma Gupta
- School of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
| | - Alana Majors
- Department of Pathobiology, Lerner Research Institute, 9500 Euclid Avenue, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Lisa Ruple
- Department of Pathobiology, Lerner Research Institute, 9500 Euclid Avenue, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Mark Aronica
- Department of Pathobiology, Lerner Research Institute, 9500 Euclid Avenue, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Dennis J Stuehr
- Department of Pathobiology, Lerner Research Institute, 9500 Euclid Avenue, Cleveland Clinic, Cleveland, OH 44195, USA.
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45
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Kim PK, Hettema EH. Multiple pathways for protein transport to peroxisomes. J Mol Biol 2015; 427:1176-90. [PMID: 25681696 PMCID: PMC4726662 DOI: 10.1016/j.jmb.2015.02.005] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 02/05/2015] [Accepted: 02/06/2015] [Indexed: 12/15/2022]
Abstract
Peroxisomes are unique among the organelles of the endomembrane system. Unlike other organelles that derive most if not all of their proteins from the ER (endoplasmic reticulum), peroxisomes contain dedicated machineries for import of matrix proteins and insertion of membrane proteins. However, peroxisomes are also able to import a subset of their membrane proteins from the ER. One aspect of peroxisome biology that has remained ill defined is the role the various import pathways play in peroxisome maintenance. In this review, we discuss the available data on matrix and membrane protein import into peroxisomes. Peroxisomal membrane and matrix proteins require distinct factors for their transport. Matrix proteins fold in the cytosol prior to their import. Loaded targeting receptors form part of the matrix protein translocation pore. Many membrane proteins are directly inserted into the peroxisomal membrane. Some peroxisomal membrane proteins are transported via the ER to peroxisomes.
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Affiliation(s)
- P K Kim
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - E H Hettema
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, South Yorkshire S10 2TN, United Kingdom.
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Skoulding NS, Chowdhary G, Deus MJ, Baker A, Reumann S, Warriner SL. Experimental validation of plant peroxisomal targeting prediction algorithms by systematic comparison of in vivo import efficiency and in vitro PTS1 binding affinity. J Mol Biol 2014; 427:1085-101. [PMID: 25498386 DOI: 10.1016/j.jmb.2014.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/30/2014] [Accepted: 12/04/2014] [Indexed: 01/19/2023]
Abstract
Most peroxisomal matrix proteins possess a C-terminal targeting signal type 1 (PTS1). Accurate prediction of functional PTS1 sequences and their relative strength by computational methods is essential for determination of peroxisomal proteomes in silico but has proved challenging due to high levels of sequence variability of non-canonical targeting signals, particularly in higher plants, and low levels of availability of experimentally validated non-canonical examples. In this study, in silico predictions were compared with in vivo targeting analyses and in vitro thermodynamic binding of mutated variants within the context of one model targeting sequence. There was broad agreement between the methods for entire PTS1 domains and position-specific single amino acid residues, including residues upstream of the PTS1 tripeptide. The hierarchy Leu>Met>Ile>Val at the C-terminal position was determined for all methods but both experimental approaches suggest that Tyr is underweighted in the prediction algorithm due to the absence of this residue in the positive training dataset. A combination of methods better defines the score range that discriminates a functional PTS1. In vitro binding to the PEX5 receptor could discriminate among strong targeting signals while in vivo targeting assays were more sensitive, allowing detection of weak functional import signals that were below the limit of detection in the binding assay. Together, the data provide a comprehensive assessment of the factors driving PTS1 efficacy and provide a framework for the more quantitative assessment of the protein import pathway in higher plants.
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Affiliation(s)
- Nicola S Skoulding
- School of Chemistry and the Astbury Centre, University of Leeds, Leeds LS2 9JT, UK
| | - Gopal Chowdhary
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway; KIIT School of Biotechnology, Campus XI, KIIT University, I-751024 Bhubaneswar, India
| | - Mara J Deus
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway
| | - Alison Baker
- Centre for Plant Sciences, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Sigrun Reumann
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway; Department of Biology, Biocentre Klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany
| | - Stuart L Warriner
- School of Chemistry and the Astbury Centre, University of Leeds, Leeds LS2 9JT, UK.
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47
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Baker A, Paudyal R. The life of the peroxisome: from birth to death. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:39-47. [PMID: 25261594 DOI: 10.1016/j.pbi.2014.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 07/24/2014] [Accepted: 09/05/2014] [Indexed: 06/03/2023]
Abstract
Peroxisomes are dynamic and metabolically plastic organelles. Their multiplicity of functions impacts on many aspects of plant development and survival. New functions for plant peroxisomes such as in the synthesis of biotin, ubiquinone and phylloquinone are being uncovered and their role in generating reactive oxygen species (ROS) and reactive nitrogen species (RNS) as signalling hubs in defence and development is becoming appreciated. Understanding of the biogenesis of peroxisomes, mechanisms of import and turnover of their protein complement, and the wholesale destruction of the organelle by specific autophagic processes is giving new insight into the ways that plants can adjust peroxisome function in response to changing needs.
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Affiliation(s)
- Alison Baker
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Rupesh Paudyal
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, UK
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48
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Lanyon-Hogg T, Hooper J, Gunn S, Warriner SL, Baker A. PEX14 binding to Arabidopsis PEX5 has differential effects on PTS1 and PTS2 cargo occupancy of the receptor. FEBS Lett 2014; 588:2223-9. [PMID: 24879895 PMCID: PMC4065332 DOI: 10.1016/j.febslet.2014.05.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/16/2014] [Accepted: 05/15/2014] [Indexed: 12/11/2022]
Abstract
The interaction between Arabidopsis PEX5 and PEX14N is independent of cargo binding. The affinity of a PTS1 peptide for PEX5 is unaffected by PEX14N binding. Arabidopsis PEX5 complexes PTS1 and PTS2 cargoes. PEX5 and 7 co-isolate with PEX14N, but the PTS2 cargo thiolase does not. PEX14N does not unload canonical PTS1 cargo peptide in vitro but may play a role in PTS2 release.
PEX5 acts as a cycling receptor for import of PTS1 proteins into peroxisomes and as a co-receptor for PEX7, the PTS2 receptor, but the mechanism of cargo unloading has remained obscure. Using recombinant protein domains we show PEX5 binding to the PEX14N-terminal domain (PEX14N) has no effect on the affinity of PEX5 for a PTS1 containing peptide. PEX5 can form a complex containing both recombinant PTS1 cargo and endogenous PEX7-thiolase simultaneously but isolation of the complex via the PEX14 construct resulted in an absence of thiolase, suggesting a possible role for PEX14 in the unloading of PTS2 cargos. pMDH1physically interacts with PEX5 by pull down (View interaction) PEX5Cbinds to PEX14N by filter binding (View interaction) PEX14Nbinds to PEX5C by pull down (View interaction) PEX14Nphysically interacts with PEX7 by pull down (View interaction) PEX5physically interacts with PEX7 by pull down (View interaction) DCI1physically interacts with PEX5 by pull down (View interaction) PEX5physically interacts with thiolase PTS2-cargo by pull down (View interaction) pMDH1physically interacts with PEX7 by pull down (View interaction) DCI1physically interacts with thiolase PTS2-cargo by pull down (View interaction) DCI1physically interacts with PEX7 by pull down (View interaction) PEX14Nphysically interacts with PEX5 by pull down (View interaction)
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Affiliation(s)
- Thomas Lanyon-Hogg
- Centre for Plant Sciences, Irene Manton Building, University of Leeds, Leeds LS2 9JT, UK; School of Chemistry, University of Leeds, Leeds LS2 9JT, UK
| | - Jacob Hooper
- School of Chemistry, University of Leeds, Leeds LS2 9JT, UK
| | - Sarah Gunn
- Centre for Plant Sciences, Irene Manton Building, University of Leeds, Leeds LS2 9JT, UK; School of Chemistry, University of Leeds, Leeds LS2 9JT, UK
| | | | - Alison Baker
- Centre for Plant Sciences, Irene Manton Building, University of Leeds, Leeds LS2 9JT, UK.
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49
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A PEX7-centered perspective on the peroxisomal targeting signal type 2-mediated protein import pathway. Mol Cell Biol 2014; 34:2917-28. [PMID: 24865970 DOI: 10.1128/mcb.01727-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and transported to the organelle by shuttling receptors. Matrix proteins containing a type 1 signal are carried to the peroxisome by PEX5, whereas those harboring a type 2 signal are transported by a PEX5-PEX7 complex. The pathway followed by PEX5 during the protein transport cycle has been characterized in detail. In contrast, not much is known regarding PEX7. In this work, we show that PEX7 is targeted to the peroxisome in a PEX5- and cargo-dependent manner, where it becomes resistant to exogenously added proteases. Entry of PEX7 and its cargo into the peroxisome occurs upstream of the first cytosolic ATP-dependent step of the PEX5-mediated import pathway, i.e., before monoubiquitination of PEX5. PEX7 passing through the peroxisome becomes partially, if not completely, exposed to the peroxisome matrix milieu, suggesting that cargo release occurs at the trans side of the peroxisomal membrane. Finally, we found that export of peroxisomal PEX7 back into the cytosol requires export of PEX5 but, strikingly, the two export events are not strictly coupled, indicating that the two proteins leave the peroxisome separately.
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50
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Hettema EH, Erdmann R, van der Klei I, Veenhuis M. Evolving models for peroxisome biogenesis. Curr Opin Cell Biol 2014; 29:25-30. [PMID: 24681485 PMCID: PMC4148619 DOI: 10.1016/j.ceb.2014.02.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 02/18/2014] [Accepted: 02/21/2014] [Indexed: 12/11/2022]
Abstract
Significant progress has been made towards our understanding of the mechanism of peroxisome formation, in particular concerning sorting of peroxisomal membrane proteins, matrix protein import and organelle multiplication. Here we evaluate the progress made in recent years. We focus mainly on progress made in yeasts. We indicate the gaps in our knowledge and discuss conflicting models.
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Affiliation(s)
- Ewald H Hettema
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| | - Ralf Erdmann
- System Biochie, Ruhr Universitat Bochum, Universitatstr. 150, D-44780, Bochum, Germany
| | - Ida van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology institute, University of Groningen, 11 103, 9700CC, Groningen, The Netherlands
| | - Marten Veenhuis
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology institute, University of Groningen, 11 103, 9700CC, Groningen, The Netherlands
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