1
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Jiang J, Tang Y, Cao Z, Zhou C, Yu Z. Effects of hypo-osmotic stress on osmoregulation, antioxidant response, and energy metabolism in sea cucumber Holothuria moebii under desalination environment. ENVIRONMENTAL RESEARCH 2024; 252:118800. [PMID: 38555088 DOI: 10.1016/j.envres.2024.118800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/15/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
With global climate changing, hypo-salinity events are increasing in frequency and duration because of continuous rainfall and freshwater inflow, which causes reduced cytosolic osmolarity and cellular stress responses in aquatic animals. Sea cucumbers are considered stenohaline because they lack osmoregulatory organs and are vulnerable to salinity fluctuations. In this study, we performed multiple biochemical assays, de novo transcriptomics, and widely targeted metabolomics to comprehensively explore the osmoregulatory mechanisms and physiological responses of sea cucumber Holothuria moebii to hypo-osmotic stress, which is a representative specie that is frequently exposed to hypo-saline intertidal zones. Our results found that H. moebii contracted their ambulacral feet and oral tentacles, and the coelomic fluid ion concentrations were reduced to be consistent with the environment. The microvilli of intestines and respiratory trees underwent degeneration, and the cytoplasm exhibited swelling and vacuolation. Moreover, the Na+, K+, and Cl- concentrations and Na+/K+-ATPase activity were significantly reduced under hypo-osmotic stress. The decrease in protein kinase A activity and increase in 5'-AMP level indicated a significant inhibition of the cAMP signaling pathway to regulate ion concentrations. And small intracellular organic molecules (amino acids, nucleotides and their derivatives) also play crucial roles in osmoregulation through oxidative deamination of glutamate, nucleotide catabolism, and nucleic acid synthesis. Moreover, lysosomes and peroxisomes removed oxidative damage, whereas antioxidant metabolites, such as N-acetyl amino acids and glutathione, were increased to resist oxidative stress. With prolonged hypo-osmotic stress, glycerophospholipid metabolism was enhanced to maintain membrane stability. Furthermore, acyl-CoA-binding protein activity was significantly inhibited, and only a small amount of acylcarnitine was significantly accumulated, which indicated a disruption in energy metabolism. PPAR signaling pathway and choline content were up-regulated to promote fatty acid metabolism under hypo-osmotic stress. Overall, our results provide new insights into the osmoregulatory mechanisms and physiological responses of sea cucumbers to hypo-osmotic stress.
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Affiliation(s)
- Junyang Jiang
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Yanna Tang
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Zhaozhao Cao
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Cong Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Zonghe Yu
- College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, China.
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2
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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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3
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Fischer S, Bürgi J, Gabay-Maskit S, Maier R, Mastalski T, Yifrach E, Obarska-Kosinska A, Rudowitz M, Erdmann R, Platta HW, Wilmanns M, Schuldiner M, Zalckvar E, Oeljeklaus S, Drepper F, Warscheid B. Phosphorylation of the receptor protein Pex5p modulates import of proteins into peroxisomes. Biol Chem 2023; 404:135-155. [PMID: 36122347 PMCID: PMC9929924 DOI: 10.1515/hsz-2022-0168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/23/2022] [Indexed: 11/15/2022]
Abstract
Peroxisomes are organelles with vital functions in metabolism and their dysfunction is associated with human diseases. To fulfill their multiple roles, peroxisomes import nuclear-encoded matrix proteins, most carrying a peroxisomal targeting signal (PTS) 1. The receptor Pex5p recruits PTS1-proteins for import into peroxisomes; whether and how this process is posttranslationally regulated is unknown. Here, we identify 22 phosphorylation sites of Pex5p. Yeast cells expressing phospho-mimicking Pex5p-S507/523D (Pex5p2D) show decreased import of GFP with a PTS1. We show that the binding affinity between a PTS1-protein and Pex5p2D is reduced. An in vivo analysis of the effect of the phospho-mimicking mutant on PTS1-proteins revealed that import of most, but not all, cargos is affected. The physiological effect of the phosphomimetic mutations correlates with the binding affinity of the corresponding extended PTS1-sequences. Thus, we report a novel Pex5p phosphorylation-dependent mechanism for regulating PTS1-protein import into peroxisomes. In a broader view, this suggests that posttranslational modifications can function in fine-tuning the peroxisomal protein composition and, thus, cellular metabolism.
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Affiliation(s)
- Sven Fischer
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104Freiburg, Germany
| | - Jérôme Bürgi
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, D-22607Hamburg, Germany
- University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246Hamburg, Germany
| | - Shiran Gabay-Maskit
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Renate Maier
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104Freiburg, Germany
| | - Thomas Mastalski
- Biochemistry of Intracellular Transport, Medical Faculty, Ruhr University Bochum, D-44780Bochum, Germany
| | - Eden Yifrach
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Agnieszka Obarska-Kosinska
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, D-22607Hamburg, Germany
- University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246Hamburg, Germany
| | - Markus Rudowitz
- Systems Biochemistry, Medical Faculty, Ruhr-University Bochum, D-44780Bochum, Germany
| | - Ralf Erdmann
- Systems Biochemistry, Medical Faculty, Ruhr-University Bochum, D-44780Bochum, Germany
| | - Harald W. Platta
- Biochemistry of Intracellular Transport, Medical Faculty, Ruhr University Bochum, D-44780Bochum, Germany
| | - Matthias Wilmanns
- Hamburg Unit c/o DESY, European Molecular Biology Laboratory (EMBL), Notkestrasse 85, D-22607Hamburg, Germany
- University Medical Center Hamburg-Eppendorf, Martinistrasse 52, D-20246Hamburg, Germany
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104Freiburg, Germany
- Biochemistry II, Theodor Boveri-Institute, Biocenter, University of Würzburg, Am Hubland, D-97074, Würzburg, Germany
| | - Friedel Drepper
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104Freiburg, Germany
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104Freiburg, Germany
- Biochemistry II, Theodor Boveri-Institute, Biocenter, University of Würzburg, Am Hubland, D-97074, Würzburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, D-79104Freiburg, Germany
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Vasilev J, Mix AK, Heimerl T, Maier UG, Moog D. Inferred Subcellular Localization of Peroxisomal Matrix Proteins of Guillardia theta Suggests an Important Role of Peroxisomes in Cryptophytes. FRONTIERS IN PLANT SCIENCE 2022; 13:889662. [PMID: 35783940 PMCID: PMC9244630 DOI: 10.3389/fpls.2022.889662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
Peroxisomes participate in several important metabolic processes in eukaryotic cells, such as the detoxification of reactive oxygen species (ROS) or the degradation of fatty acids by β-oxidation. Recently, the presence of peroxisomes in the cryptophyte Guillardia theta and other "chromalveolates" was revealed by identifying proteins for peroxisomal biogenesis. Here, we investigated the subcellular localization of candidate proteins of G. theta in the diatom Phaeodactylum tricornutum, either possessing a putative peroxisomal targeting signal type 1 (PTS1) sequence or factors lacking a peroxisomal targeting signal but known to be involved in β-oxidation. Our results indicate important contributions of the peroxisomes of G. theta to the carbohydrate, ether phospholipid, nucleotide, vitamin K, ROS, amino acid, and amine metabolisms. Moreover, our results suggest that in contrast to many other organisms, the peroxisomes of G. theta are not involved in the β-oxidation of fatty acids, which exclusively seems to occur in the cryptophyte's mitochondria.
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Affiliation(s)
- Jana Vasilev
- Laboratory for Cell Biology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Ann-Kathrin Mix
- Laboratory for Cell Biology, Department of Biology, Philipps-University Marburg, Marburg, Germany
| | - Thomas Heimerl
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Uwe G. Maier
- Laboratory for Cell Biology, Department of Biology, Philipps-University Marburg, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
| | - Daniel Moog
- Laboratory for Cell Biology, Department of Biology, Philipps-University Marburg, Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-University Marburg, Marburg, Germany
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5
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Verner Z, Žárský V, Le T, Narayanasamy RK, Rada P, Rozbeský D, Makki A, Belišová D, Hrdý I, Vancová M, Lender C, König C, Bruchhaus I, Tachezy J. Anaerobic peroxisomes in Entamoeba histolytica metabolize myo-inositol. PLoS Pathog 2021; 17:e1010041. [PMID: 34780573 PMCID: PMC8629394 DOI: 10.1371/journal.ppat.1010041] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 11/29/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022] Open
Abstract
Entamoeba histolytica is believed to be devoid of peroxisomes, like most anaerobic protists. In this work, we provided the first evidence that peroxisomes are present in E. histolytica, although only seven proteins responsible for peroxisome biogenesis (peroxins) were identified (Pex1, Pex6, Pex5, Pex11, Pex14, Pex16, and Pex19). Targeting matrix proteins to peroxisomes is reduced to the PTS1-dependent pathway mediated via the soluble Pex5 receptor, while the PTS2 receptor Pex7 is absent. Immunofluorescence microscopy showed that peroxisomal markers (Pex5, Pex14, Pex16, Pex19) are present in vesicles distinct from mitosomes, the endoplasmic reticulum, and the endosome/phagosome system, except Pex11, which has dual localization in peroxisomes and mitosomes. Immunoelectron microscopy revealed that Pex14 localized to vesicles of approximately 90-100 nm in diameter. Proteomic analyses of affinity-purified peroxisomes and in silico PTS1 predictions provided datasets of 655 and 56 peroxisomal candidates, respectively; however, only six proteins were shared by both datasets, including myo-inositol dehydrogenase (myo-IDH). Peroxisomal NAD-dependent myo-IDH appeared to be a dimeric enzyme with high affinity to myo-inositol (Km 0.044 mM) and can utilize also scyllo-inositol, D-glucose and D-xylose as substrates. Phylogenetic analyses revealed that orthologs of myo-IDH with PTS1 are present in E. dispar, E. nutalli and E. moshkovskii but not in E. invadens, and form a monophyletic clade of mostly peroxisomal orthologs with free-living Mastigamoeba balamuthi and Pelomyxa schiedti. The presence of peroxisomes in E. histolytica and other archamoebae breaks the paradigm of peroxisome absence in anaerobes and provides a new potential target for the development of antiparasitic drugs.
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Affiliation(s)
- Zdeněk Verner
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Tien Le
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ravi Kumar Narayanasamy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Petr Rada
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Daniel Rozbeský
- Department of Cell Biology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Darja Belišová
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Marie Vancová
- Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Ceske Budejovice, Czech Republic
| | - Corinna Lender
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Constantin König
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
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6
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Jansen RLM, Santana-Molina C, van den Noort M, Devos DP, van der Klei IJ. Comparative Genomics of Peroxisome Biogenesis Proteins: Making Sense of the PEX Proteins. Front Cell Dev Biol 2021; 9:654163. [PMID: 34095119 PMCID: PMC8172628 DOI: 10.3389/fcell.2021.654163] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/21/2021] [Indexed: 11/29/2022] Open
Abstract
PEX genes encode proteins involved in peroxisome biogenesis and proliferation. Using a comparative genomics approach, we clarify the evolutionary relationships between the 37 known PEX proteins in a representative set of eukaryotes, including all common model organisms, pathogenic unicellular eukaryotes and human. A large number of previously unknown PEX orthologs were identified. We analyzed all PEX proteins, their conservation and domain architecture and defined the core set of PEX proteins that is required to make a peroxisome. The molecular processes in peroxisome biogenesis in different organisms were put into context, showing that peroxisomes are not static organelles in eukaryotic evolution. Organisms that lack peroxisomes still contain a few PEX proteins, which probably play a role in alternative processes. Finally, the relationships between PEX proteins of two large families, the Pex11 and Pex23 families, were analyzed, thereby contributing to the understanding of their complicated and sometimes incorrect nomenclature. We provide an exhaustive overview of this important eukaryotic organelle.
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Affiliation(s)
- Renate L M Jansen
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Carlos Santana-Molina
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Seville, Spain
| | - Marco van den Noort
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
| | - Damien P Devos
- Centro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide, Seville, Spain
| | - Ida J van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands
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7
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Schummer A, Maier R, Gabay-Maskit S, Hansen T, Mühlhäuser WWD, Suppanz I, Fadel A, Schuldiner M, Girzalsky W, Oeljeklaus S, Zalckvar E, Erdmann R, Warscheid B. Pex14p Phosphorylation Modulates Import of Citrate Synthase 2 Into Peroxisomes in Saccharomyces cerevisiae. Front Cell Dev Biol 2020; 8:549451. [PMID: 33042991 PMCID: PMC7522779 DOI: 10.3389/fcell.2020.549451] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/25/2020] [Indexed: 12/16/2022] Open
Abstract
The peroxisomal biogenesis factor Pex14p is an essential component of the peroxisomal matrix protein import machinery. Together with Pex13p and Pex17p, it is part of the membrane-associated peroxisomal docking complex in yeast, facilitating the binding of cargo-loaded receptor proteins for translocation of cargo proteins into the peroxisome. Furthermore, Pex14p is part of peroxisomal import pores. The central role of Pex14p in peroxisomal matrix protein import processes renders it an obvious target for regulatory mechanisms such as protein phosphorylation. To explore this possibility, we examined the state of Pex14p phosphorylation in Saccharomyces cerevisiae. Phos-tag-SDS-PAGE of Pex14p affinity-purified from solubilized membranes revealed Pex14p as multi-phosphorylated protein. Using mass spectrometry, we identified 16 phosphorylation sites, with phosphorylation hot spots located in the N- and C-terminal regions of Pex14p. Analysis of phosphomimicking and non-phosphorylatable variants of Pex14p revealed a decreased import of GFP carrying a peroxisomal targeting signal type 1, indicating a functional relevance of Pex14p phosphorylation in peroxisomal matrix protein import. We show that this effect can be ascribed to the phosphomimicking mutation at serine 266 of Pex14p (Pex14p-S266D). We further screened the subcellular distribution of 23 native GFP-tagged peroxisomal matrix proteins by high-content fluorescence microscopy. Only Cit2p, the peroxisomal isoform of citrate synthase, was affected in the Pex14p-S266D mutant, showing increased cytosolic localization. Cit2p is part of the glyoxylate cycle, which is required for the production of essential carbohydrates when yeast is grown on non-fermentable carbon sources. Pex14p-S266 phosphosite mutants showed reversed growth phenotypes in oleic acid and ethanol with acetyl-CoA formed in peroxisomes and the cytosol, respectively. Overexpression of Cit2p rescued the growth phenotype of yeast cells expressing Pex14p-S266D in oleic acid. Our data indicate that phosphorylation of Pex14p at S266 provides a mechanism for controlling the peroxisomal import of Cit2p, which helps S. cerevisiae cells to adjust their carbohydrate metabolism according to the nutritional conditions.
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Affiliation(s)
- Andreas Schummer
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Renate Maier
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Shiran Gabay-Maskit
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tobias Hansen
- Faculty of Medicine, System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Wignand W D Mühlhäuser
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Ida Suppanz
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany
| | - Amir Fadel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Wolfgang Girzalsky
- Faculty of Medicine, System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Silke Oeljeklaus
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ralf Erdmann
- Faculty of Medicine, System Biochemistry, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Bettina Warscheid
- Faculty of Biology, Biochemistry and Functional Proteomics, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
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8
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Patel KJ, Kao Y, Llinas RJ, Bartel B. A PEX5 missense allele preferentially disrupts PTS1 cargo import into Arabidopsis peroxisomes. PLANT DIRECT 2019; 3:e00128. [PMID: 31236542 PMCID: PMC6508846 DOI: 10.1002/pld3.128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/09/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
The sorting of eukaryotic proteins to various organellar destinations requires receptors that recognize cargo protein targeting signals and facilitate transport into the organelle. One such receptor is the peroxin PEX5, which recruits cytosolic cargo carrying a peroxisome-targeting signal (PTS) type 1 (PTS1) for delivery into the peroxisomal lumen (matrix). In plants and mammals, PEX5 is also indirectly required for peroxisomal import of proteins carrying a PTS2 signal because PEX5 binds the PTS2 receptor, bringing the associated PTS2 cargo to the peroxisome along with PTS1 cargo. Despite PEX5 being the PTS1 cargo receptor, previously identified Arabidopsis pex5 mutants display either impairment of both PTS1 and PTS2 import or defects only in PTS2 import. Here we report the first Arabidopsis pex5 mutant with an exclusive PTS1 import defect. In addition to markedly diminished GFP-PTS1 import and decreased pex5-2 protein accumulation, this pex5-2 mutant shows typical peroxisome-related defects, including inefficient β-oxidation and reduced growth. Growth at reduced or elevated temperatures ameliorated or exacerbated pex5-2 peroxisome-related defects, respectively, without markedly changing pex5-2 protein levels. In contrast to the diminished PTS1 import, PTS2 processing was only slightly impaired and PTS2-GFP import appeared normal in pex5-2. This finding suggests that even minor peroxisomal localization of the PTS1 protein DEG15, the PTS2-processing protease, is sufficient to maintain robust PTS2 processing.
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Affiliation(s)
- Khushali J. Patel
- Department of BioSciencesRice UniversityHoustonTexas
- Present address:
Graduate School of Biomedical SciencesBaylor College of MedicineHoustonTexas
| | - Yun‐Ting Kao
- Department of BioSciencesRice UniversityHoustonTexas
- Present address:
Department of Cell Biology and Molecular GeneticsUniversity of MarylandCollege ParkMaryland
| | | | - Bonnie Bartel
- Department of BioSciencesRice UniversityHoustonTexas
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9
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El Magraoui F, Brinkmeier R, Mastalski T, Hupperich A, Strehl C, Schwerter D, Girzalsky W, Meyer HE, Warscheid B, Erdmann R, Platta HW. The deubiquitination of the PTS1-import receptor Pex5p is required for peroxisomal matrix protein import. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:199-213. [PMID: 30408545 DOI: 10.1016/j.bbamcr.2018.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/13/2018] [Accepted: 11/02/2018] [Indexed: 12/28/2022]
Abstract
Peroxisomal biogenesis depends on the correct import of matrix proteins into the lumen of the organelle. Most peroxisomal matrix proteins harbor the peroxisomal targeting-type 1 (PTS1), which is recognized by the soluble PTS1-receptor Pex5p in the cytosol. Pex5p ferries the PTS1-proteins to the peroxisomal membrane and releases them into the lumen. Finally, the PTS1-receptor is monoubiquitinated on the conserved cysteine 6 in Saccharomyces cerevisiae. The monoubiquitinated Pex5p is recognized by the peroxisomal export machinery and is retrotranslocated into the cytosol for further rounds of protein import. However, the functional relevance of deubiquitination has not yet been addressed. In this study, we have analyzed a Pex5p-truncation lacking Cys6 [(Δ6)Pex5p], a construct with a ubiquitin-moiety genetically fused to the truncation [Ub-(Δ6)Pex5p], as well as a construct with a reduced susceptibility to deubiquitination [Ub(G75/76A)-(Δ6)Pex5p]. While the (Δ6)Pex5p-truncation is not functional, the Ub-(Δ6)Pex5p chimeric protein can facilitate matrix protein import. In contrast, the Ub(G75/76A)-(Δ6)Pex5p chimera exhibits a complete PTS1-import defect. The data show for the first time that not only ubiquitination but also deubiquitination rates are tightly regulated and that efficient deubiquitination of Pex5p is essential for peroxisomal biogenesis.
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Affiliation(s)
- Fouzi El Magraoui
- Biomedizinische Forschung, Leibniz-Insitute for Analytische Wissenschaften - ISAS e.V. - (ISAS e.V.), 44139 Dortmund, Germany; Systembiochemie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Thomas Mastalski
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Alexander Hupperich
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Christofer Strehl
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | | | | | - Helmut E Meyer
- Biomedizinische Forschung, Leibniz-Insitute for Analytische Wissenschaften - ISAS e.V. - (ISAS e.V.), 44139 Dortmund, Germany
| | - Bettina Warscheid
- Functional Proteomics, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Ralf Erdmann
- Systembiochemie, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
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10
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Guder P, Lotz-Havla AS, Woidy M, Reiß DD, Danecka MK, Schatz UA, Becker M, Ensenauer R, Pagel P, Büttner L, Muntau AC, Gersting SW. Isoform-specific domain organization determines conformation and function of the peroxisomal biogenesis factor PEX26. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:518-531. [PMID: 30366024 DOI: 10.1016/j.bbamcr.2018.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 10/11/2018] [Accepted: 10/18/2018] [Indexed: 10/28/2022]
Abstract
Peroxisomal biogenesis factor PEX26 is a membrane anchor for the multi-subunit PEX1-PEX6 protein complex that controls ubiquitination and dislocation of PEX5 cargo receptors for peroxisomal matrix protein import. PEX26 associates with the peroxisomal translocation pore via PEX14 and a splice variant (PEX26Δex5) of unknown function has been reported. Here, we demonstrate PEX26 homooligomerization mediated by two heptad repeat domains adjacent to the transmembrane domain. We show that isoform-specific domain organization determines PEX26 oligomerization and impacts peroxisomal β-oxidation and proliferation. PEX26 and PEX26Δex5 displayed different patterns of interaction with PEX2-PEX10 or PEX13-PEX14 complexes, which relate to distinct pre-peroxisomes in the de novo synthesis pathway. Our data support an alternative PEX14-dependent mechanism of peroxisomal membrane association for the splice variant, which lacks a transmembrane domain. Structure-function relationships of PEX26 isoforms explain an extended function in peroxisomal homeostasis and these findings may improve our understanding of the broad phenotype of PEX26-associated human disorders.
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Affiliation(s)
- Philipp Guder
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Children's Hospital, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Amelie S Lotz-Havla
- Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany
| | - Mathias Woidy
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Children's Hospital, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Dunja D Reiß
- Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany
| | - Marta K Danecka
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Ulrich A Schatz
- Department for Medical Genetics, Molecular and Clinical Pharmacology, Medical University Innsbruck, 6020 Innsbruck, Austria
| | - Marc Becker
- Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany; Labor Becker Olgemöller und Kollegen, 81671 Munich, Germany
| | - Regina Ensenauer
- Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany; Experimental Pediatrics, Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Philipp Pagel
- Lehrstuhl für Genomorientierte Bioinformatik, Technische Universität, 85350 Freising, Germany; numares GmbH, Josef-Engert-Str. 9, 93053 Regensburg, Germany
| | - Lars Büttner
- Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany
| | - Ania C Muntau
- Children's Hospital, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Søren W Gersting
- University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; Children's Hospital, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
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11
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Marcassa E, Kallinos A, Jardine J, Rusilowicz-Jones EV, Martinez A, Kuehl S, Islinger M, Clague MJ, Urbé S. Dual role of USP30 in controlling basal pexophagy and mitophagy. EMBO Rep 2018; 19:embr.201745595. [PMID: 29895712 PMCID: PMC6030704 DOI: 10.15252/embr.201745595] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 12/20/2022] Open
Abstract
USP30 is an integral protein of the outer mitochondrial membrane that counteracts PINK1 and Parkin‐dependent mitophagy following acute mitochondrial depolarisation. Here, we use two distinct mitophagy reporter systems to reveal tonic suppression by USP30, of a PINK1‐dependent component of basal mitophagy in cells lacking detectable Parkin. We propose that USP30 acts upstream of PINK1 through modulation of PINK1‐substrate availability and thereby determines the potential for mitophagy initiation. We further show that a fraction of endogenous USP30 is independently targeted to peroxisomes where it regulates basal pexophagy in a PINK1‐ and Parkin‐independent manner. Thus, we reveal a critical role of USP30 in the clearance of the two major sources of ROS in mammalian cells and in the regulation of both a PINK1‐dependent and a PINK1‐independent selective autophagy pathway.
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Affiliation(s)
- Elena Marcassa
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Andreas Kallinos
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Jane Jardine
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Emma V Rusilowicz-Jones
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Aitor Martinez
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Sandra Kuehl
- Institute of Neuroanatomy, Centre for Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Markus Islinger
- Institute of Neuroanatomy, Centre for Biomedicine and Medical Technology Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Michael J Clague
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Sylvie Urbé
- Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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12
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Suaste-Olmos F, Zirión-Martínez C, Takano-Rojas H, Peraza-Reyes L. Meiotic development initiation in the fungus Podospora anserina requires the peroxisome receptor export machinery. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:572-586. [DOI: 10.1016/j.bbamcr.2018.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 12/29/2017] [Accepted: 01/03/2018] [Indexed: 01/19/2023]
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13
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Law KB, Bronte-Tinkew D, Di Pietro E, Snowden A, Jones RO, Moser A, Brumell JH, Braverman N, Kim PK. The peroxisomal AAA ATPase complex prevents pexophagy and development of peroxisome biogenesis disorders. Autophagy 2018; 13:868-884. [PMID: 28521612 PMCID: PMC5446072 DOI: 10.1080/15548627.2017.1291470] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Peroxisome biogenesis disorders (PBDs) are metabolic disorders caused by the loss of peroxisomes. The majority of PBDs result from mutation in one of 3 genes that encode for the peroxisomal AAA ATPase complex (AAA-complex) required for cycling PEX5 for peroxisomal matrix protein import. Mutations in these genes are thought to result in a defect in peroxisome assembly by preventing the import of matrix proteins. However, we show here that loss of the AAA-complex does not prevent matrix protein import, but instead causes an upregulation of peroxisome degradation by macroautophagy, or pexophagy. The loss of AAA-complex function in cells results in the accumulation of ubiquitinated PEX5 on the peroxisomal membrane that signals pexophagy. Inhibiting autophagy by genetic or pharmacological approaches rescues peroxisome number, protein import and function. Our findings suggest that the peroxisomal AAA-complex is required for peroxisome quality control, whereas its absence results in the selective degradation of the peroxisome. Thus the loss of peroxisomes in PBD patients with mutations in their peroxisomal AAA-complex is a result of increased pexophagy. Our study also provides a framework for the development of novel therapeutic treatments for PBDs.
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Affiliation(s)
- Kelsey B Law
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,b Department of Biochemistry , University of Toronto , Toronto , ON , Canada
| | - Dana Bronte-Tinkew
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada
| | - Erminia Di Pietro
- c Research Institute of the MUHC and McGill University , Montreal , QC , Canada
| | - Ann Snowden
- d Kennedy Krieger Institute , Baltimore , MD , USA
| | | | - Ann Moser
- d Kennedy Krieger Institute , Baltimore , MD , USA
| | - John H Brumell
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,e Department of Molecular Genetics , University of Toronto , Toronto , ON , Canada.,f Institute of Medical Science, University of Toronto , Toronto , ON , Canada.,g SickKids IBD Centre , Hospital for Sick Children , Toronto , ON , Canada
| | - Nancy Braverman
- c Research Institute of the MUHC and McGill University , Montreal , QC , Canada
| | - Peter K Kim
- a Cell Biology Program , Hospital for Sick Children, Peter Gilgan Centre for Research and Learning , Toronto , ON , Canada.,b Department of Biochemistry , University of Toronto , Toronto , ON , Canada
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14
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Moog D, Przyborski JM, Maier UG. Genomic and Proteomic Evidence for the Presence of a Peroxisome in the Apicomplexan Parasite Toxoplasma gondii and Other Coccidia. Genome Biol Evol 2018; 9:3108-3121. [PMID: 29126146 PMCID: PMC5737649 DOI: 10.1093/gbe/evx231] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2017] [Indexed: 02/06/2023] Open
Abstract
Apicomplexans are successful parasites responsible for severe human diseases including malaria, toxoplasmosis, and cryptosporidiosis. For many years, it has been discussed whether these parasites are in possession of peroxisomes, highly variable eukaryotic organelles usually involved in fatty acid degradation and cellular detoxification. Conflicting experimental data has been published. With the age of genomics, ever more high quality apicomplexan genomes have become available, that now allow a new assessment of the dispute. Here, we provide bioinformatic evidence for the presence of peroxisomes in Toxoplasma gondii and other coccidians. For these organisms, we have identified a complete set of peroxins, probably responsible for peroxisome biogenesis, division, and protein import. Moreover, via a global screening for peroxisomal targeting signals, we were able to show that a complete set of fatty acid β-oxidation enzymes is equipped with either PTS1 or PTS2 sequences, most likely mediating transport of these factors to putative peroxisomes in all investigated Coccidia. Our results further imply a life cycle stage-specific presence of peroxisomes in T. gondii and suggest several independent losses of peroxisomes during the evolution of apicomplexan parasites.
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Affiliation(s)
- Daniel Moog
- Laboratory for Cell Biology, Philipps University Marburg, Germany
| | - Jude M Przyborski
- Laboratory for Parasitology, Philipps University Marburg, Germany.,Centre for Infectious Diseases, Parasitology, Heidelberg University Medical School, INF324, Heidelberg, Germany
| | - Uwe G Maier
- Laboratory for Cell Biology, Philipps University Marburg, Germany.,LOEWE Center for Synthetic Microbiology (Synmikro), Philipps University, Marburg, Germany
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15
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Cho DH, Kim YS, Jo DS, Choe SK, Jo EK. Pexophagy: Molecular Mechanisms and Implications for Health and Diseases. Mol Cells 2018; 41:55-64. [PMID: 29370694 PMCID: PMC5792714 DOI: 10.14348/molcells.2018.2245] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an intracellular degradation pathway for large protein aggregates and damaged organelles. Recent studies have indicated that autophagy targets cargoes through a selective degradation pathway called selective autophagy. Peroxisomes are dynamic organelles that are crucial for health and development. Pexophagy is selective autophagy that targets peroxisomes and is essential for the maintenance of homeostasis of peroxisomes, which is necessary in the prevention of various peroxisome-related disorders. However, the mechanisms by which pexophagy is regulated and the key players that induce and modulate pexophagy are largely unknown. In this review, we focus on our current understanding of how pexophagy is induced and regulated, and the selective adaptors involved in mediating pexophagy. Furthermore, we discuss current findings on the roles of pexophagy in physiological and pathological responses, which provide insight into the clinical relevance of pexophagy regulation. Understanding how pexophagy interacts with various biological functions will provide fundamental insights into the function of pexophagy and facilitate the development of novel therapeutics against peroxisomal dysfunction-related diseases.
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Affiliation(s)
- Dong-Hyung Cho
- Graduate School of East-West Medical Science, Kyung Hee University, Yongin 17104,
Korea
| | - Yi Sak Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon 35015,
Korea
| | - Doo Sin Jo
- Graduate School of East-West Medical Science, Kyung Hee University, Yongin 17104,
Korea
| | - Seong-Kyu Choe
- Department of Microbiology and Center for Metabolic Function Regulation, Wonkwang University School of Medicine, Iksan 54538,
Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon 35015,
Korea
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16
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Walker CL, Pomatto LCD, Tripathi DN, Davies KJA. Redox Regulation of Homeostasis and Proteostasis in Peroxisomes. Physiol Rev 2018; 98:89-115. [PMID: 29167332 PMCID: PMC6335096 DOI: 10.1152/physrev.00033.2016] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 06/19/2017] [Accepted: 06/21/2017] [Indexed: 02/08/2023] Open
Abstract
Peroxisomes are highly dynamic intracellular organelles involved in a variety of metabolic functions essential for the metabolism of long-chain fatty acids, d-amino acids, and many polyamines. A byproduct of peroxisomal metabolism is the generation, and subsequent detoxification, of reactive oxygen and nitrogen species, particularly hydrogen peroxide (H2O2). Because of its relatively low reactivity (as a mild oxidant), H2O2 has a comparatively long intracellular half-life and a high diffusion rate, all of which makes H2O2 an efficient signaling molecule. Peroxisomes also have intricate connections to mitochondria, and both organelles appear to play important roles in regulating redox signaling pathways. Peroxisomal proteins are also subject to oxidative modification and inactivation by the reactive oxygen and nitrogen species they generate, but the peroxisomal LonP2 protease can selectively remove such oxidatively damaged proteins, thus prolonging the useful lifespan of the organelle. Peroxisomal homeostasis must adapt to the metabolic state of the cell, by a combination of peroxisome proliferation, the removal of excess or badly damaged organelles by autophagy (pexophagy), as well as by processes of peroxisome inheritance and motility. More recently the tumor suppressors ataxia telangiectasia mutate (ATM) and tuberous sclerosis complex (TSC), which regulate mTORC1 signaling, have been found to regulate pexophagy in response to variable levels of certain reactive oxygen and nitrogen species. It is now clear that any significant loss of peroxisome homeostasis can have devastating physiological consequences. Peroxisome dysregulation has been implicated in several metabolic diseases, and increasing evidence highlights the important role of diminished peroxisomal functions in aging processes.
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Affiliation(s)
- Cheryl L Walker
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Laura C D Pomatto
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Durga Nand Tripathi
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Kelvin J A Davies
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
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17
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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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18
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Gonzalez KL, Fleming WA, Kao YT, Wright ZJ, Venkova SV, Ventura MJ, Bartel B. Disparate peroxisome-related defects in Arabidopsis pex6 and pex26 mutants link peroxisomal retrotranslocation and oil body utilization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:110-128. [PMID: 28742939 PMCID: PMC5605450 DOI: 10.1111/tpj.13641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/22/2017] [Accepted: 07/18/2017] [Indexed: 05/29/2023]
Abstract
Catabolism of fatty acids stored in oil bodies is essential for seed germination and seedling development in Arabidopsis. This fatty acid breakdown occurs in peroxisomes, organelles that sequester oxidative reactions. Import of peroxisomal enzymes is facilitated by peroxins including PEX5, a receptor that delivers cargo proteins from the cytosol to the peroxisomal matrix. After cargo delivery, a complex of the PEX1 and PEX6 ATPases and the PEX26 tail-anchored membrane protein removes ubiquitinated PEX5 from the peroxisomal membrane. We identified Arabidopsis pex6 and pex26 mutants by screening for inefficient seedling β-oxidation phenotypes. The mutants displayed distinct defects in growth, response to a peroxisomally metabolized auxin precursor, and peroxisomal protein import. The low PEX5 levels in these mutants were increased by treatment with a proteasome inhibitor or by combining pex26 with peroxisome-associated ubiquitination machinery mutants, suggesting that ubiquitinated PEX5 is degraded by the proteasome when the function of PEX6 or PEX26 is reduced. Combining pex26 with mutations that increase PEX5 levels either worsened or improved pex26 physiological and molecular defects, depending on the introduced lesion. Moreover, elevating PEX5 levels via a 35S:PEX5 transgene exacerbated pex26 defects and ameliorated the defects of only a subset of pex6 alleles, implying that decreased PEX5 is not the sole molecular deficiency in these mutants. We found peroxisomes clustered around persisting oil bodies in pex6 and pex26 seedlings, suggesting a role for peroxisomal retrotranslocation machinery in oil body utilization. The disparate phenotypes of these pex alleles may reflect unanticipated functions of the peroxisomal ATPase complex.
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Affiliation(s)
| | | | | | | | | | | | - Bonnie Bartel
- Corresponding author: Bonnie Bartel, Department of Biosciences, MS-140, Rice University, 6100 Main St., Houston TX, USA. Phone: 713-348-5602, Fax: 713-348-5154;
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19
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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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20
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Effelsberg D, Cruz-Zaragoza LD, Schliebs W, Erdmann R. Pex9p is a new yeast peroxisomal import receptor for PTS1-containing proteins. J Cell Sci 2016; 129:4057-4066. [PMID: 27678487 DOI: 10.1242/jcs.195271] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 07/27/2016] [Indexed: 11/20/2022] Open
Abstract
Peroxisomal proteins carrying a type 1 peroxisomal targeting signal (PTS1) are recognized by the well-conserved cycling import receptor Pex5p. The yeast YMR018W gene encodes a Pex5p paralog and newly identified peroxin that is involved in peroxisomal import of a subset of matrix proteins. The new peroxin was designated Pex9p, and it interacts with the docking protein Pex14p and a subclass of PTS1-containing peroxisomal matrix enzymes. Unlike Pex5p, Pex9p is not expressed in glucose- or ethanol-grown cells, but it is strongly induced by oleate. Under these conditions, Pex9p acts as a cytosolic and membrane-bound peroxisome import receptor for both malate synthase isoenzymes, Mls1p and Mls2p. The inducible Pex9p-dependent import pathway provides a mechanism for the oleate-inducible peroxisomal targeting of malate synthases. The existence of two distinct PTS1 receptors, in addition to two PTS2-dependent import routes, contributes to the adaptive metabolic capacity of peroxisomes in response to environmental changes and underlines the role of peroxisomes as multi-purpose organelles. The identification of different import routes into peroxisomes contributes to the molecular understanding of how regulated protein targeting can alter the function of organelles according to cellular needs.
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Affiliation(s)
- Daniel Effelsberg
- Abteilung Systembiochemie, Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Luis Daniel Cruz-Zaragoza
- Abteilung Systembiochemie, Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Wolfgang Schliebs
- Abteilung Systembiochemie, Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, Ruhr-Universität Bochum, Bochum D-44780, Germany
| | - Ralf Erdmann
- Abteilung Systembiochemie, Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, Ruhr-Universität Bochum, Bochum D-44780, Germany
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21
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Nordgren M, Francisco T, Lismont C, Hennebel L, Brees C, Wang B, Van Veldhoven PP, Azevedo JE, Fransen M. Export-deficient monoubiquitinated PEX5 triggers peroxisome removal in SV40 large T antigen-transformed mouse embryonic fibroblasts. Autophagy 2016; 11:1326-40. [PMID: 26086376 DOI: 10.1080/15548627.2015.1061846] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Peroxisomes are ubiquitous cell organelles essential for human health. To maintain a healthy cellular environment, dysfunctional and superfluous peroxisomes need to be selectively removed. Although emerging evidence suggests that peroxisomes are mainly degraded by pexophagy, little is known about the triggers and molecular mechanisms underlying this process in mammalian cells. In this study, we show that PEX5 proteins fused to a bulky C-terminal tag trigger peroxisome degradation in SV40 large T antigen-transformed mouse embryonic fibroblasts. In addition, we provide evidence that this process is autophagy-dependent and requires monoubiquitination of the N-terminal cysteine residue that marks PEX5 for recycling. As our findings also demonstrate that the addition of a bulky tag to the C terminus of PEX5 does not interfere with PEX5 monoubiquitination but strongly inhibits its export from the peroxisomal membrane, we hypothesize that such a tag mimics a cargo protein that cannot be released from PEX5, thus keeping monoubiquitinated PEX5 at the membrane for a sufficiently long time to be recognized by the autophagic machinery. This in turn suggests that monoubiquitination of the N-terminal cysteine of peroxisome-associated PEX5 not only functions to recycle the peroxin back to the cytosol, but also serves as a quality control mechanism to eliminate peroxisomes with a defective protein import machinery.
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Affiliation(s)
- Marcus Nordgren
- a Laboratory of Lipid Biochemistry and Protein Interactions; Department of Cellular and Molecular Medicine; University of Leuven - KU Leuven ; Leuven , Belgium
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22
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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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23
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Zientara-Rytter K, Subramani S. Autophagic degradation of peroxisomes in mammals. Biochem Soc Trans 2016; 44:431-40. [PMID: 27068951 PMCID: PMC4958620 DOI: 10.1042/bst20150268] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 12/21/2022]
Abstract
Peroxisomes are essential organelles required for proper cell function in all eukaryotic organisms. They participate in a wide range of cellular processes including the metabolism of lipids and generation, as well as detoxification, of hydrogen peroxide (H2O2). Therefore, peroxisome homoeostasis, manifested by the precise and efficient control of peroxisome number and functionality, must be tightly regulated in response to environmental changes. Due to the existence of many physiological disorders and diseases associated with peroxisome homoeostasis imbalance, the dynamics of peroxisomes have been widely examined. The increasing volume of reports demonstrating significant involvement of the autophagy machinery in peroxisome removal leads us to summarize current knowledge of peroxisome degradation in mammalian cells. In this review we present current models of peroxisome degradation. We particularly focus on pexophagy-the selective clearance of peroxisomes through autophagy. We also critically discuss concepts of peroxisome recognition for pexophagy, including signalling and selectivity factors. Finally, we present examples of the pathological effects of pexophagy dysfunction and suggest promising future directions.
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Affiliation(s)
- Katarzyna Zientara-Rytter
- Section of Molecular Biology, Division of Biological Sciences, University California, San Diego, CA 92093-0322, U.S.A
| | - Suresh Subramani
- Section of Molecular Biology, Division of Biological Sciences, University California, San Diego, CA 92093-0322, U.S.A.
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Takano-Rojas H, Zickler D, Peraza-Reyes L. Peroxisome dynamics during development of the fungus Podospora anserina. Mycologia 2016; 108:590-602. [PMID: 26908647 DOI: 10.3852/15-112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 07/07/2015] [Indexed: 11/10/2022]
Abstract
Peroxisomes are versatile and dynamic organelles that are required for the development of diverse eukaryotic organisms. We demonstrated previously that in the fungus Podospora anserina different peroxisomal functions are required at distinct stages of sexual development, including the initiation and progression of meiocyte (ascus) development and the differentiation and germination of sexual spores (ascospores). Peroxisome assembly during these processes relies on the differential activity of the protein machinery that drives the import of proteins into the organelle, indicating a complex developmental regulation of peroxisome formation and activity. Here we demonstrate that peroxisome dynamics is also highly regulated during development. We show that peroxisomes in P. anserina are highly dynamic and respond to metabolic and environmental cues by undergoing changes in size, morphology and number. In addition, peroxisomes of vegetative and sexual cell types are structurally different. During sexual development peroxisome number increases at two stages: at early ascus differentiation and during ascospore formation. These processes are accompanied by changes in peroxisome structure and distribution, which include a cell-polarized concentration of peroxisomes at the beginning of ascus development, as well as a morphological transition from predominantly spherical to elongated shapes at the end of the first meiotic division. Further, the mostly tubular peroxisomes present from second meiotic division to early ascospore formation again become rounded during ascospore differentiation. Ultimately the number of peroxisomes dramatically decreases upon ascospore maturation. Our results reveal a precise regulation of peroxisome dynamics during sexual development and suggest that peroxisome constitution and function during development is defined by the coordinated regulation of the proteins that control peroxisome assembly and dynamics.
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Affiliation(s)
- Harumi Takano-Rojas
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, México DF, Mexico
| | - Denise Zickler
- Univ. Paris-Sud, CNRS UMR8621, Institut de Génétique et Microbiologie, 91405 Orsay, France
| | - Leonardo Peraza-Reyes
- Departamento de Bioquímica y Biología Estructural, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, México DF, Mexico
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25
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The Early-Acting Peroxin PEX19 Is Redundantly Encoded, Farnesylated, and Essential for Viability in Arabidopsis thaliana. PLoS One 2016; 11:e0148335. [PMID: 26824478 PMCID: PMC4733102 DOI: 10.1371/journal.pone.0148335] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 01/15/2016] [Indexed: 11/20/2022] Open
Abstract
Peroxisomes are single-membrane bound organelles that are essential for normal development in plants and animals. In mammals and yeast, the peroxin (PEX) proteins PEX3 and PEX19 facilitate the early steps of peroxisome membrane protein (PMP) insertion and pre-peroxisome budding from the endoplasmic reticulum. The PEX3 membrane protein acts as a docking site for PEX19, a cytosolic chaperone for PMPs that delivers PMPs to the endoplasmic reticulum or peroxisomal membrane. PEX19 is farnesylated in yeast and mammals, and we used immunoblotting with prenylation mutants to show that PEX19 also is fully farnesylated in wild-type Arabidopsis thaliana plants. We examined insertional alleles disrupting either of the two Arabidopsis PEX19 isoforms, PEX19A or PEX19B, and detected similar levels of PEX19 protein in the pex19a-1 mutant and wild type; however, PEX19 protein was nearly undetectable in the pex19b-1 mutant. Despite the reduction in PEX19 levels in pex19b-1, both pex19a-1 and pex19b-1 single mutants lacked notable peroxisomal β-oxidation defects and displayed normal levels and localization of peroxisomal matrix and membrane proteins. The pex19a-1 pex19b-1 double mutant was embryo lethal, indicating a redundantly encoded critical role for PEX19 during embryogenesis. Expressing YFP-tagged versions of either PEX19 isoform rescued this lethality, confirming that PEX19A and PEX19B act redundantly in Arabidopsis. We observed that pex19b-1 enhanced peroxisome-related defects of a subset of peroxin-defective mutants, supporting a role for PEX19 in peroxisome function. Together, our data indicate that Arabidopsis PEX19 promotes peroxisome function and is essential for viability.
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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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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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Targeting and insertion of peroxisomal membrane proteins: ER trafficking versus direct delivery to peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:870-80. [PMID: 26392202 DOI: 10.1016/j.bbamcr.2015.09.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 09/11/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
The importance of peroxisomes is highlighted by severe inherited human disorders linked to impaired peroxisomal biogenesis. Besides the simple architecture of these ubiquitous and dynamic organelles, their biogenesis is surprisingly complex and involves specialized proteins, termed peroxins, which mediate targeting and insertion of peroxisomal membrane proteins (PMPs) into the peroxisomal bilayer, and the import of soluble proteins into the protein-dense matrix of the organelle. The long-standing paradigm that all peroxisomal proteins are imported directly into preexisting peroxisomes has been challenged by the detection of PMPs inside the endoplasmic reticulum (ER). New models propose that the ER originates peroxisomal biogenesis by mediating PMP trafficking to the peroxisomes via budding vesicles. However, the relative contribution of this ER-derived pathway to the total peroxisome population in vivo, and the detailed mechanisms of ER entry and exit of PMPs are controversially discussed. This review aims to summarize present knowledge about how PMPs are targeted to the ER, instead of being inserted directly into preexisting peroxisomes. Moreover, molecular mechanisms that facilitate bilayer insertion of PMPs among different species are discussed.
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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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30
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Haanstra JR, González-Marcano EB, Gualdrón-López M, Michels PAM. Biogenesis, maintenance and dynamics of glycosomes in trypanosomatid parasites. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1038-48. [PMID: 26384872 DOI: 10.1016/j.bbamcr.2015.09.015] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/31/2022]
Abstract
Peroxisomes of organisms belonging to the protist group Kinetoplastea, which include trypanosomatid parasites of the genera Trypanosoma and Leishmania, are unique in playing a crucial role in glycolysis and other parts of intermediary metabolism. They sequester the majority of the glycolytic enzymes and hence are called glycosomes. Their glycosomal enzyme content can vary strongly, particularly quantitatively, between different trypanosomatid species, and within each species during its life cycle. Turnover of glycosomes by autophagy of redundant ones and biogenesis of a new population of organelles play a pivotal role in the efficient adaptation of the glycosomal metabolic repertoire to the sudden, major nutritional changes encountered during the transitions in their life cycle. The overall mechanism of glycosome biogenesis is similar to that of peroxisomes in other organisms, but the homologous peroxins involved display low sequence conservation as well as variations in motifs mediating crucial protein-protein interactions in the process. The correct compartmentalisation of enzymes is essential for the regulation of the trypanosomatids' metabolism and consequently for their viability. For Trypanosoma brucei it was shown that glycosomes also play a crucial role in its life-cycle regulation: a crucial developmental control switch involves the translocation of a protein phosphatase from the cytosol into the organelles. Many glycosomal proteins are differentially phosphorylated in different life-cycle stages, possibly indicative of regulation of enzyme activities as an additional means to adapt the metabolic network to the different environmental conditions encountered.
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Affiliation(s)
- Jurgen R Haanstra
- Systems Bioinformatics, Vrije Universiteit Amsterdam, The Netherlands
| | - Eglys B González-Marcano
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Melisa Gualdrón-López
- Federal University of Minas Gerais, Laboratory of Immunoregulation of Infectious Diseases, Department of Biochemistry and Immunology, Institute for Biological Sciences, Belo Horizonte, Brazil
| | - Paul A M Michels
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela; Centre for Translational and Chemical Biology, Institute of Structural and Molecular Biology, School of Biological Sciences, University of Edinburgh, United Kingdom.
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Kao YT, Bartel B. Elevated growth temperature decreases levels of the PEX5 peroxisome-targeting signal receptor and ameliorates defects of Arabidopsis mutants with an impaired PEX4 ubiquitin-conjugating enzyme. BMC PLANT BIOLOGY 2015; 15:224. [PMID: 26377801 PMCID: PMC4574000 DOI: 10.1186/s12870-015-0605-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 09/06/2015] [Indexed: 05/29/2023]
Abstract
BACKGROUND Peroxisomes house critical metabolic reactions. For example, fatty acid β-oxidation enzymes, which are essential during early seedling development, are peroxisomal. Peroxins (PEX proteins) are needed to bring proteins into peroxisomes. Most matrix proteins are delivered to peroxisomes by PEX5, a receptor that forms transient pores to escort proteins across the peroxisomal membrane. After cargo delivery, a peroxisome-tethered ubiquitin-conjugating enzyme (PEX4) and peroxisomal ubiquitin-protein ligases mono- or polyubiquitinate PEX5 for recycling back to the cytosol or for degradation, respectively. Arabidopsis pex mutants β-oxidize fatty acids inefficiently and therefore fail to germinate or grow less vigorously. These defects can be partially alleviated by providing a fixed carbon source, such as sucrose, in the growth medium. Despite extensive characterization of peroxisome biogenesis in Arabidopsis grown in non-challenged conditions, the effects of environmental stressors on peroxisome function and pex mutant dysfunction are largely unexplored. RESULTS We surveyed the impact of growth temperature on a panel of pex mutants and found that elevated temperature ameliorated dependence on external sucrose and reduced PEX5 levels in the pex4-1 mutant. Conversely, growth at low temperature exacerbated pex4-1 physiological defects and increased PEX5 levels. Overexpressing PEX5 also worsened pex4-1 defects, implying that PEX5 lingering on the peroxisomal membrane when recycling is impaired impedes peroxisome function. Growth at elevated temperature did not reduce the fraction of membrane-associated PEX5 in pex4-1, suggesting that elevated temperature did not restore PEX4 enzymatic function in the mutant. Moreover, preventing autophagy in pex4-1 did not restore PEX5 levels at high temperature. In contrast, MG132 treatment increased PEX5 levels, implicating the proteasome in degrading PEX5, especially at high temperature. CONCLUSIONS We conclude that growth at elevated temperature increases proteasomal degradation of PEX5 to reduce overall PEX5 levels and ameliorate pex4-1 physiological defects. Our results support the hypothesis that efficient retrotranslocation of PEX5 after cargo delivery is needed not only to make PEX5 available for further rounds of cargo delivery, but also to prevent the peroxisome dysfunction that results from PEX5 lingering in the peroxisomal membrane.
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Affiliation(s)
- Yun-Ting Kao
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, TX, USA.
| | - Bonnie Bartel
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, TX, USA.
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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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Young PG, Bartel B. Pexophagy and peroxisomal protein turnover in plants. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:999-1005. [PMID: 26348128 DOI: 10.1016/j.bbamcr.2015.09.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/26/2015] [Accepted: 09/02/2015] [Indexed: 01/21/2023]
Abstract
Peroxisomes are dynamic, vital organelles that sequester a variety of oxidative reactions and their toxic byproducts from the remainder of the cell. The oxidative nature of peroxisomal metabolism predisposes the organelle to self-inflicted damage, highlighting the need for a mechanism to dispose of damaged peroxisomes. In addition, the metabolic requirements of plant peroxisomes change during development, and obsolete peroxisomal proteins are degraded. Although pexophagy, the selective autophagy of peroxisomes, is an obvious mechanism for executing such degradation, pexophagy has only recently been described in plants. Several recent studies in the reference plant Arabidopsis thaliana implicate pexophagy in the turnover of peroxisomal proteins, both for quality control and during functional transitions of peroxisomal content. In this review, we describe our current understanding of the occurrence, roles, and mechanisms of pexophagy in plants.
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Affiliation(s)
- Pierce G Young
- Department of BioSciences, Rice University, Houston, TX 77005, USA.
| | - Bonnie Bartel
- Department of BioSciences, Rice University, Houston, TX 77005, USA.
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Wanders RJA, Ferdinandusse S, Ebberink MS, Waterham HR. Phytanoyl-CoA Hydroxylase: A 2-Oxoglutarate-Dependent Dioxygenase Crucial for Fatty Acid Alpha-Oxidation in Humans. 2-OXOGLUTARATE-DEPENDENT OXYGENASES 2015. [DOI: 10.1039/9781782621959-00338] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Phytanoyl-CoA hydroxylase belongs to the family of 2-oxoglutarate-dependent dioxygenases and plays a crucial role in the α-oxidation of fatty acids. The complete α-oxidation pathway involves five different enzymes localized in peroxisomes. Thus far, phytanoyl-CoA hydroxylase deficiency has remained the only genetically determined inborn error of metabolism affecting the α-oxidation pathway. In this chapter we describe the current state of knowledge on fatty acid α-oxidation with special emphasis on phytanoyl-CoA hydroxylase and its deficiency in Refsum disease.
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Affiliation(s)
- Ronald J. A. Wanders
- Laboratory Genetic Metabolic Diseases, Departments of Paediatrics, Emma Children’s Hospital, and Clinical Chemistry, Academic Medical Center, University of Amsterdam Meibergdreef 9 1105 AZ Amsterdam the Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Departments of Paediatrics, Emma Children’s Hospital, and Clinical Chemistry, Academic Medical Center, University of Amsterdam Meibergdreef 9 1105 AZ Amsterdam the Netherlands
| | - Merel S. Ebberink
- Laboratory Genetic Metabolic Diseases, Departments of Paediatrics, Emma Children’s Hospital, and Clinical Chemistry, Academic Medical Center, University of Amsterdam Meibergdreef 9 1105 AZ Amsterdam the Netherlands
| | - Hans R. Waterham
- Laboratory Genetic Metabolic Diseases, Departments of Paediatrics, Emma Children’s Hospital, and Clinical Chemistry, Academic Medical Center, University of Amsterdam Meibergdreef 9 1105 AZ Amsterdam the Netherlands
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35
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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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Gardner BM, Chowdhury S, Lander GC, Martin A. The Pex1/Pex6 complex is a heterohexameric AAA+ motor with alternating and highly coordinated subunits. J Mol Biol 2015; 427:1375-1388. [PMID: 25659908 DOI: 10.1016/j.jmb.2015.01.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 01/23/2015] [Accepted: 01/24/2015] [Indexed: 12/13/2022]
Abstract
Pex1 and Pex6 are Type-2 AAA+ ATPases required for the de novo biogenesis of peroxisomes. Mutations in Pex1 and Pex6 account for the majority of the most severe forms of peroxisome biogenesis disorders in humans. Here, we show that the ATP-dependent complex of Pex1 and Pex6 from Saccharomyces cerevisiae is a heterohexamer with alternating subunits. Within the Pex1/Pex6 complex, only the D2 ATPase ring hydrolyzes ATP, while nucleotide binding in the D1 ring promotes complex assembly. ATP hydrolysis by Pex1 is highly coordinated with that of Pex6. Furthermore, Pex15, the membrane anchor required for Pex1/Pex6 recruitment to peroxisomes, inhibits the ATP-hydrolysis activity of Pex1/Pex6.
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Affiliation(s)
- Brooke M Gardner
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA; Miller Institute for Basic Research in Science, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Saikat Chowdhury
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Andreas Martin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720-3220, USA.
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Reidick C, El Magraoui F, Meyer HE, Stenmark H, Platta HW. Regulation of the Tumor-Suppressor Function of the Class III Phosphatidylinositol 3-Kinase Complex by Ubiquitin and SUMO. Cancers (Basel) 2014; 7:1-29. [PMID: 25545884 PMCID: PMC4381249 DOI: 10.3390/cancers7010001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/08/2014] [Indexed: 12/19/2022] Open
Abstract
The occurrence of cancer is often associated with a dysfunction in one of the three central membrane-involution processes—autophagy, endocytosis or cytokinesis. Interestingly, all three pathways are controlled by the same central signaling module: the class III phosphatidylinositol 3-kinase (PI3K-III) complex and its catalytic product, the phosphorylated lipid phosphatidylinositol 3-phosphate (PtdIns3P). The activity of the catalytic subunit of the PI3K-III complex, the lipid-kinase VPS34, requires the presence of the membrane-targeting factor VPS15 as well as the adaptor protein Beclin 1. Furthermore, a growing list of regulatory proteins associates with VPS34 via Beclin 1. These accessory factors define distinct subunit compositions and thereby guide the PI3K-III complex to its different cellular and physiological roles. Here we discuss the regulation of the PI3K-III complex components by ubiquitination and SUMOylation. Especially Beclin 1 has emerged as a highly regulated protein, which can be modified with Lys11-, Lys48- or Lys63-linked polyubiquitin chains catalyzed by distinct E3 ligases from the RING-, HECT-, RBR- or Cullin-type. We also point out other cross-links of these ligases with autophagy in order to discuss how these data might be merged into a general concept.
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Affiliation(s)
- Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum 44801, Germany.
| | - Fouzi El Magraoui
- Biomedical Research, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften-ISAS, Dortmund 44139, Germany.
| | - Helmut E Meyer
- Biomedical Research, Human Brain Proteomics II, Leibniz-Institut für Analytische Wissenschaften-ISAS, Dortmund 44139, Germany.
| | - Harald Stenmark
- Department of Biochemistry, Institute for Cancer Research, Oslo University Hospital, Montebello, Oslo 0310, Norway.
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum 44801, Germany.
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Wang X, Li S, Liu Y, Ma C. Redox regulated peroxisome homeostasis. Redox Biol 2014; 4:104-8. [PMID: 25545794 PMCID: PMC4309859 DOI: 10.1016/j.redox.2014.12.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/13/2014] [Accepted: 12/15/2014] [Indexed: 11/15/2022] Open
Abstract
Peroxisomes are ubiquitous organelles present in nearly all eukaryotic cells. Conserved functions of peroxisomes encompass beta-oxidation of fatty acids and scavenging of reactive oxygen species generated from diverse peroxisomal metabolic pathways. Peroxisome content, number, and size can change quickly in response to environmental and/or developmental cues. To achieve efficient peroxisome homeostasis, peroxisome biogenesis and degradation must be orchestrated. We review the current knowledge on redox regulated peroxisome biogenesis and degradation with an emphasis on yeasts and plants. Conserved functions of peroxisomes include β-oxidation of fatty acids and scavenging of ROS. Peroxisome homeostasis is achieved by coordinating biogenesis and degradation. Repression of peroxisome biogenesis under oxidative stress. Superfluous and oxidative damaged peroxisomes are degraded by pexophagy.
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Affiliation(s)
- Xiaofeng Wang
- College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan, Shandong 250014, China
| | - Shuo Li
- College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan, Shandong 250014, China
| | - Yu Liu
- College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan, Shandong 250014, China
| | - Changle Ma
- College of Life Sciences, Shandong Normal University, Wenhua East Road 88, Jinan, Shandong 250014, China.
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39
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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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Choudhry SK, Kawałek A, van der Klei IJ. Peroxisomal quality control mechanisms. Curr Opin Microbiol 2014; 22:30-7. [PMID: 25305535 DOI: 10.1016/j.mib.2014.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/08/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
Abstract
Peroxisomes are ubiquitous organelles that harbor diverse metabolic pathways, which are essential for normal cell performance. Conserved functions of these organelles are hydrogen peroxide metabolism and β-oxidation. Cells employ multiple quality control mechanisms to ensure proper peroxisome function and to protect peroxisomes from damage. These involve the function of molecular chaperones, a peroxisomal Lon protease and autophagic removal of dysfunctional organelles. In addition, multiple mechanisms exist to combat peroxisomal oxidative stress. Here, we outline recent advances in our understanding of peroxisomal quality control, focussing on yeast and filamentous fungi.
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Affiliation(s)
- Sanjeev K Choudhry
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, Systems Biology Centre for Energy Metabolism and Ageing, University of Groningen, P.O. Box 11103, 9300CC Groningen, The Netherlands
| | - Adam Kawałek
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, Systems Biology Centre for Energy Metabolism and Ageing, University of Groningen, P.O. Box 11103, 9300CC Groningen, The Netherlands
| | - Ida J van der Klei
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, Systems Biology Centre for Energy Metabolism and Ageing, University of Groningen, P.O. Box 11103, 9300CC Groningen, The Netherlands.
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41
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Callis J. The ubiquitination machinery of the ubiquitin system. THE ARABIDOPSIS BOOK 2014; 12:e0174. [PMID: 25320573 PMCID: PMC4196676 DOI: 10.1199/tab.0174] [Citation(s) in RCA: 216] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The protein ubiquitin is a covalent modifier of proteins, including itself. The ubiquitin system encompasses the enzymes required for catalysing attachment of ubiquitin to substrates as well as proteins that bind to ubiquitinated proteins leading them to their final fate. Also included are activities that remove ubiquitin independent of, or in concert with, proteolysis of the substrate, either by the proteasome or proteases in the vacuole. In addition to ubiquitin encoded by a family of fusion proteins, there are proteins with ubiquitin-like domains, likely forming ubiquitin's β-grasp fold, but incapable of covalent modification. However, they serve as protein-protein interaction platforms within the ubiquitin system. Multi-gene families encode all of these types of activities. Within the ubiquitination machinery "half" of the ubiquitin system are redundant, partially redundant, and unique components affecting diverse developmental and environmental responses in plants. Notably, multiple aspects of biotic and abiotic stress responses require, or are modulated by, ubiquitination. Finally, aspects of the ubiquitin system have broad utility: as components to enhance gene expression or to regulate protein abundance. This review focuses on the ubiquitination machinery: ubiquitin, unique aspects about the synthesis of ubiquitin and organization of its gene family, ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2) and ubiquitin ligases, or E3s. Given the large number of E3s in Arabidopsis this review covers the U box, HECT and RING type E3s, with the exception of the cullin-based E3s.
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Affiliation(s)
- Judy Callis
- Department of Molecular and Cellular Biology, University of California-Davis, Davis CA 95616
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El Magraoui F, Schrötter A, Brinkmeier R, Kunst L, Mastalski T, Müller T, Marcus K, Meyer HE, Girzalsky W, Erdmann R, Platta HW. The cytosolic domain of Pex22p stimulates the Pex4p-dependent ubiquitination of the PTS1-receptor. PLoS One 2014; 9:e105894. [PMID: 25162638 PMCID: PMC4146569 DOI: 10.1371/journal.pone.0105894] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 07/25/2014] [Indexed: 01/08/2023] Open
Abstract
Peroxisomal biogenesis is an ubiquitin-dependent process because the receptors required for the import of peroxisomal matrix proteins are controlled via their ubiquitination status. A key step is the monoubiquitination of the import receptor Pex5p by the ubiquitin-conjugating enzyme (E2) Pex4p. This monoubiquitination is supposed to take place after Pex5p has released the cargo into the peroxisomal matrix and primes Pex5p for the extraction from the membrane by the mechano-enzymes Pex1p/Pex6p. These two AAA-type ATPases export Pex5p back to the cytosol for further rounds of matrix protein import. Recently, it has been reported that the soluble Pex4p requires the interaction to its peroxisomal membrane-anchor Pex22p to display full activity. Here we demonstrate that the soluble C-terminal domain of Pex22p harbours its biological activity and that this activity is independent from its function as membrane-anchor of Pex4p. We show that Pex4p can be functionally fused to the trans-membrane segment of the membrane protein Pex3p, which is not directly involved in Pex5p-ubiquitination and matrix protein import. However, this Pex3(N)-Pex4p chimera can only complement the double-deletion strain pex4Δ/pex22Δ and ensure optimal Pex5p-ubiquitination when the C-terminal part of Pex22p is additionally expressed in the cell. Thus, while the membrane-bound portion Pex22(N)p is not required when Pex4p is fused to Pex3(N)p, the soluble Pex22(C)p is essential for peroxisomal biogenesis and efficient monoubiquitination of the import receptor Pex5p by the E3-ligase Pex12p in vivo and in vitro. The results merge into a picture of an ubiquitin-conjugating complex at the peroxisomal membrane consisting of three domains: the ubiquitin-conjugating domain (Pex4p), a membrane-anchor domain (Pex22(N)p) and an enhancing domain (Pex22(C)p), with the membrane-anchor domain being mutually exchangeable, while the Ubc- and enhancer-domains are essential.
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Affiliation(s)
- Fouzi El Magraoui
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum, Germany
- Systembiochemie, Ruhr-Universität Bochum, Bochum, Germany
- Biomedizinische Forschung, Leibniz-Institut für Analytische Wissenschaften - ISAS -e.V., Dortmund, Germany
| | - Andreas Schrötter
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics, Medizinisches Proteom-Center, Bochum, Germany
- Biomedizinische Forschung, Leibniz-Institut für Analytische Wissenschaften - ISAS -e.V., Dortmund, Germany
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum, Germany
| | - Lena Kunst
- Systembiochemie, Ruhr-Universität Bochum, Bochum, Germany
| | - Thomas Mastalski
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics, Medizinisches Proteom-Center, Bochum, Germany
| | - Thorsten Müller
- Funktionelle Proteomik, Medizinisches Proteom-Center, Bochum, Germany
| | - Katrin Marcus
- Funktionelle Proteomik, Medizinisches Proteom-Center, Bochum, Germany
| | - Helmut E. Meyer
- Biomedizinische Forschung, Leibniz-Institut für Analytische Wissenschaften - ISAS -e.V., Dortmund, Germany
| | | | - Ralf Erdmann
- Systembiochemie, Ruhr-Universität Bochum, Bochum, Germany
- * E-mail: (RE); (HWP)
| | - Harald W. Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Bochum, Germany
- * E-mail: (RE); (HWP)
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43
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Williams C. Going against the flow: A case for peroxisomal protein export. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1386-92. [DOI: 10.1016/j.bbamcr.2014.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 04/03/2014] [Accepted: 04/07/2014] [Indexed: 10/25/2022]
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