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Gaussmann S, Peschel R, Ott J, Zak KM, Sastre J, Delhommel F, Popowicz GM, Boekhoven J, Schliebs W, Erdmann R, Sattler M. Modulation of peroxisomal import by the PEX13 SH3 domain and a proximal FxxxF binding motif. Nat Commun 2024; 15:3317. [PMID: 38632234 PMCID: PMC11024197 DOI: 10.1038/s41467-024-47605-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/08/2024] [Indexed: 04/19/2024] Open
Abstract
Import of proteins into peroxisomes depends on PEX5, PEX13 and PEX14. By combining biochemical methods and structural biology, we show that the C-terminal SH3 domain of PEX13 mediates intramolecular interactions with a proximal FxxxF motif. The SH3 domain also binds WxxxF peptide motifs in the import receptor PEX5, demonstrating evolutionary conservation of such interactions from yeast to human. Strikingly, intramolecular interaction of the PEX13 FxxxF motif regulates binding of PEX5 WxxxF/Y motifs to the PEX13 SH3 domain. Crystal structures reveal how FxxxF and WxxxF/Y motifs are recognized by a non-canonical surface on the SH3 domain. The PEX13 FxxxF motif also mediates binding to PEX14. Surprisingly, the potential PxxP binding surface of the SH3 domain does not recognize PEX14 PxxP motifs, distinct from its yeast ortholog. Our data show that the dynamic network of PEX13 interactions with PEX5 and PEX14, mediated by diaromatic peptide motifs, modulates peroxisomal matrix import.
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Affiliation(s)
- Stefan Gaussmann
- Technical University of Munich, TUM School of Natural Sciences, Bavarian NMR Center and Department of Bioscience, Lichtenbergstr. 4, 85747, Garching, Germany
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Rebecca Peschel
- Institute of Biochemistry and Pathobiochemistry, Department of Systems Biology, Faculty of Medicine, Ruhr University Bochum, 44780, Bochum, Germany
| | - Julia Ott
- Institute of Biochemistry and Pathobiochemistry, Department of Systems Biology, Faculty of Medicine, Ruhr University Bochum, 44780, Bochum, Germany
| | - Krzysztof M Zak
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Judit Sastre
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Florent Delhommel
- Technical University of Munich, TUM School of Natural Sciences, Bavarian NMR Center and Department of Bioscience, Lichtenbergstr. 4, 85747, Garching, Germany
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Grzegorz M Popowicz
- Technical University of Munich, TUM School of Natural Sciences, Bavarian NMR Center and Department of Bioscience, Lichtenbergstr. 4, 85747, Garching, Germany
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Job Boekhoven
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstr. 4, 85747, Garching, Germany
| | - Wolfgang Schliebs
- Institute of Biochemistry and Pathobiochemistry, Department of Systems Biology, Faculty of Medicine, Ruhr University Bochum, 44780, Bochum, Germany
| | - Ralf Erdmann
- Institute of Biochemistry and Pathobiochemistry, Department of Systems Biology, Faculty of Medicine, Ruhr University Bochum, 44780, Bochum, Germany.
| | - Michael Sattler
- Technical University of Munich, TUM School of Natural Sciences, Bavarian NMR Center and Department of Bioscience, Lichtenbergstr. 4, 85747, Garching, Germany.
- Helmholtz Munich, Molecular Targets and Therapeutics Center, Institute of Structural Biology, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
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2
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Chen R, Lu K, Yang L, Jiang J, Li L. Peroxin MoPex22 Regulates the Import of Peroxisomal Matrix Proteins and Appressorium-Mediated Plant Infection in Magnaporthe oryzae. J Fungi (Basel) 2024; 10:143. [PMID: 38392815 PMCID: PMC10890347 DOI: 10.3390/jof10020143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 02/04/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024] Open
Abstract
Magnaporthe oryzae, the pathogen responsible for rice blast disease, utilizes specialized infection structures known as appressoria to breach the leaf cuticle and establish intracellular, infectious hyphae. Our study demonstrates that the peroxin MoPex22 is crucial for appressorium function, specifically for the development of primary penetration hyphae. The ∆Mopex22 mutant exhibited slow growth, reduced aerial hyphae, and almost complete loss of virulence. Specifically, despite the mutant's capability to form appressoria, it showed abnormalities during appressorium development, including reduced turgor, increased permeability of the appressorium wall, failure to form septin rings, and significantly decreased ability to penetrate host cells. Additionally, there was a delay in the degradation of lipid droplets during conidial germination and appressorium development. Consistent with these findings, the ΔMopex22 mutant showed an inefficient utilization of long-chain fatty acids and defects in cell wall integrity. Moreover, our findings indicate that MoPex22 acts as an anchor for MoPex4, facilitating the localization of MoPex4 to peroxisomes. Together with MoPex4, it affects the function of MoPex5, thus regulating the import of peroxisomal matrix proteins. Overall, these results highlight the essential role of MoPex22 in regulating the transport of peroxisomal matrix proteins, which affect fatty acid metabolism, glycerol accumulation, cell wall integrity, growth, appressorium development, and the pathogenicity of M. oryzae. This study provides valuable insights into the significance of peroxin functions in fungal biology and appressorium-mediated plant infection.
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Affiliation(s)
- Rangrang Chen
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Kailun Lu
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Lina Yang
- College of Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Jihong Jiang
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
| | - Lianwei Li
- The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China
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3
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Abstract
Peroxisomes are involved in a multitude of metabolic and catabolic pathways, as well as the innate immune system. Their dysfunction is linked to severe peroxisome-specific diseases, as well as cancer and neurodegenerative diseases. To ensure the ability of peroxisomes to fulfill their many roles in the organism, more than 100 different proteins are post-translationally imported into the peroxisomal membrane and matrix, and their functionality must be closely monitored. In this Review, we briefly discuss the import of peroxisomal membrane proteins, and we emphasize an updated view of both classical and alternative peroxisomal matrix protein import pathways. We highlight different quality control pathways that ensure the degradation of dysfunctional peroxisomal proteins. Finally, we compare peroxisomal matrix protein import with other systems that transport folded proteins across membranes, in particular the twin-arginine translocation (Tat) system and the nuclear pore.
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Affiliation(s)
- Markus Rudowitz
- Systems Biochemistry , Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Ralf Erdmann
- Systems Biochemistry , Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
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4
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Feng P, Skowyra ML, Rapoport TA. Structure and function of the peroxisomal ubiquitin ligase complex. Biochem Soc Trans 2022; 50:1921-1930. [PMID: 36421406 PMCID: PMC9788354 DOI: 10.1042/bst20221393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 09/26/2023]
Abstract
Peroxisomes are membrane-bounded organelles that exist in most eukaryotic cells and are involved in the oxidation of fatty acids and the destruction of reactive oxygen species. Depending on the organism, they house additional metabolic reactions that range from glycolysis in parasitic protozoa to the production of ether lipids in animals and antibiotics in fungi. The importance of peroxisomes for human health is revealed by various disorders - notably the Zellweger spectrum - that are caused by defects in peroxisome biogenesis and are often fatal. Most peroxisomal metabolic enzymes reside in the lumen, but are synthesized in the cytosol and imported into the organelle by mobile receptors. The receptors accompany cargo all the way into the lumen and must return to the cytosol to start a new import cycle. Recycling requires receptor monoubiquitination by a membrane-embedded ubiquitin ligase complex composed of three RING finger (RF) domain-containing proteins: PEX2, PEX10, and PEX12. A recent cryo-electron microscopy (cryo-EM) structure of the complex reveals its function as a retro-translocation channel for peroxisomal import receptors. Each subunit of the complex contributes five transmembrane segments that assemble into an open channel. The N terminus of a receptor likely inserts into the pore from the lumenal side, and is then monoubiquitinated by one of the RFs to enable extraction into the cytosol. If recycling is compromised, receptors are polyubiquitinated by the concerted action of the other two RFs and ultimately degraded. The new data provide mechanistic insight into a crucial step of peroxisomal protein import.
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Affiliation(s)
- Peiqiang Feng
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
| | - Michael L. Skowyra
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
| | - Tom A. Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, U.S.A
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5
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Gao Y, Skowyra ML, Feng P, Rapoport TA. Protein import into peroxisomes occurs through a nuclear pore-like phase. Science 2022; 378:eadf3971. [PMID: 36520918 PMCID: PMC9795577 DOI: 10.1126/science.adf3971] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Peroxisomes are ubiquitous organelles whose dysfunction causes fatal human diseases. Most peroxisomal proteins are imported from the cytosol in a folded state by the soluble receptor PEX5. How folded cargo crosses the membrane is unknown. Here, we show that peroxisomal import is similar to nuclear transport. The peroxisomal membrane protein PEX13 contains a conserved tyrosine (Y)- and glycine (G)-rich YG domain, which forms a selective phase resembling that formed by phenylalanine-glycine (FG) repeats within nuclear pores. PEX13 resides in the membrane in two orientations that oligomerize and suspend the YG meshwork within the lipid bilayer. Purified YG domains form hydrogels into which PEX5 selectively partitions, by using conserved aromatic amino acid motifs, bringing cargo along. The YG meshwork thus forms an aqueous conduit through which PEX5 delivers folded proteins into peroxisomes.
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Affiliation(s)
- Yuan Gao
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Michael L. Skowyra
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Peiqiang Feng
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Tom A. Rapoport
- Department of Cell Biology, Harvard Medical School, Boston, MA, 02115, USA.,Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, 02115, USA.,Corresponding author.
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6
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Fusarium verticillioides Pex7/20 mediates peroxisomal PTS2 pathway import, pathogenicity, and fumonisin B1 biosynthesis. Appl Microbiol Biotechnol 2022; 106:6595-6609. [PMID: 36121485 DOI: 10.1007/s00253-022-12167-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 11/02/2022]
Abstract
Fusarium verticillioides, a well-known fungal pathogen that causes severe disease in maize and contaminates the grains with fumonisin B1 (FB1) mycotoxin, affects the yield and quality of maize worldwide. The intrinsic roles of peroxisome targeting signal (PTS)-containing proteins in phytopathogens remain elusive. We therefore explored the regulatory role and other biological functions of the components of PTS2 receptor complex, FvPex7 and FvPex20, in F. verticillioides. We found that FvPex7 directly interacts with the carboxyl terminus of FvPex20 in F. verticillioides. PTS2-containing proteins are recognized and bound by the FvPex7 receptor or the FvPex7-Pex20 receptor complex in the cytoplasm, but the peroxisome localization of the PTS2-Pex7-Pex20 complex is only determined by Pex20 in F. verticillioides. However, we observed that some putative PTS2 proteins that interact with Pex7 are not transported into the peroxisomes, but a PTS1 protein that interacts with Pex5 was detected in the peroxisomes. Furthermore, ΔFvpex7pex20 as well as ΔFvpex7pex5 double mutants exhibited reduced pathogenicity and FB1 biosynthesis, along with defects in conidiation. The PTS2 receptor complex mutants (ΔFvpex7pex20) grew slowly on minimal media and showed reduced sensitivity to cell wall and cell membrane stress-inducing agents compared to the wild type. Taken together, we conclude that the PTS2 receptor complex mediates peroxisome matrix proteins import and contributes to pathogenicity and FB1 biosynthesis in F. verticillioides. KEY POINTS: • FvPex7 directly interacts with FvPex20 in F. verticillioides. • vThe PTS2 receptor complex is essential for the importation of PTS2-containing matrix protein into peroxisomes in F. verticillioides. • Fvpex7/pex20 is involved in pathogenicity and FB1 biosynthesis in F. verticillioides.
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7
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Bürgi J, Ekal L, Wilmanns M. Versatile allosteric properties in Pex5-like tetratricopeptide repeat proteins to induce diverse downstream function. Traffic 2021; 22:140-152. [PMID: 33580581 DOI: 10.1111/tra.12785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/30/2021] [Accepted: 02/10/2021] [Indexed: 01/11/2023]
Abstract
Proteins composed of tetratricopeptide repeat (TPR) arrays belong to the α-solenoid tandem-repeat family that have unique properties in terms of their overall conformational flexibility and ability to bind to multiple protein ligands. The peroxisomal matrix protein import receptor Pex5 comprises two TPR triplets that recognize protein cargos with a specific C-terminal Peroxisomal Targeting Signal (PTS) 1 motif. Import of PTS1-containing protein cargos into peroxisomes through a transient pore is mainly driven by allosteric binding, coupling and release mechanisms, without a need for external energy. A very similar TPR architecture is found in the functionally unrelated TRIP8b, a regulator of the hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channel. TRIP8b binds to the HCN ion channel via a C-terminal sequence motif that is nearly identical to the PTS1 motif of Pex5 receptor cargos. Pex5, Pex5-related Pex9, and TRIP8b also share a less conserved N-terminal domain. This domain provides a second protein cargo-binding site and plays a distinct role in allosteric coupling of initial cargo loading by PTS1 motif-mediated interactions and different downstream functional readouts. The data reviewed here highlight the overarching role of molecular allostery in driving the diverse functions of TPR array proteins, which could form a model for other α-solenoid tandem-repeat proteins involved in translocation processes across membranes.
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Affiliation(s)
- Jérôme Bürgi
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Lakhan Ekal
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Matthias Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany.,University Hamburg Clinical Center Hamburg-Eppendorf, Hamburg, Germany
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8
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Glycosome heterogeneity in kinetoplastids. Biochem Soc Trans 2021; 49:29-39. [PMID: 33439256 PMCID: PMC7925000 DOI: 10.1042/bst20190517] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/18/2020] [Accepted: 11/26/2020] [Indexed: 01/05/2023]
Abstract
Kinetoplastid parasites have essential organelles called glycosomes that are analogous to peroxisomes present in other eukaryotes. While many of the processes that regulate glycosomes are conserved, there are several unique aspects of their biology that are divergent from other systems and may be leveraged as therapeutic targets for the treatment of kinetoplastid diseases. Glycosomes are heterogeneous organelles that likely exist as sub-populations with different protein composition and function in a given cell, between individual cells, and between species. However, the limitations posed by the small size of these organelles makes the study of this heterogeneity difficult. Recent advances in the analysis of small vesicles by flow-cytometry provide an opportunity to overcome these limitations. In this review, we describe studies that document the diverse nature of glycosomes and propose an approach to using flow cytometry and organelle sorting to study the diverse composition and function of these organelles. Because the cellular machinery that regulates glycosome protein import and biogenesis is likely to contribute, at least in part, to glycosome heterogeneity we highlight some ways in which the glycosome protein import machinery differs from that of peroxisomes in other eukaryotes.
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9
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Reglinski K, Steinfort-Effelsberg L, Sezgin E, Klose C, Platta HW, Girzalsky W, Eggeling C, Erdmann R. Fluidity and Lipid Composition of Membranes of Peroxisomes, Mitochondria and the ER From Oleic Acid-Induced Saccharomyces cerevisiae. Front Cell Dev Biol 2020; 8:574363. [PMID: 33195209 PMCID: PMC7658010 DOI: 10.3389/fcell.2020.574363] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/05/2020] [Indexed: 01/08/2023] Open
Abstract
The maintenance of a fluid lipid bilayer is key for organelle function and cell viability. Given the critical role of lipid compositions in determining membrane properties and organelle identity, it is clear that cells must have elaborate mechanism for membrane maintenance during adaptive responses to environmental conditions. Emphasis of the presented study is on peroxisomes, oleic acid-inducible organelles that are essential for the growth of yeast under conditions of oleic acid as single carbon source. Here, we isolated peroxisomes, mitochondria and ER from oleic acid-induced Saccharomyces cerevisiae and determined the lipid composition of their membranes using shotgun lipidomics and compared it to lipid ordering using fluorescence microscopy. In comparison to mitochondrial and ER membranes, the peroxisomal membranes were slightly more disordered and characterized by a distinct enrichment of phosphaditylinositol, indicating an important role of this phospholipid in peroxisomal membrane associated processes.
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Affiliation(s)
- Katharina Reglinski
- Leibniz-Institute of Photonic Technologies, Jena, Germany
- Institute of Applied Optics and Biophysics, Friedrich-Schiller University Jena, Jena, Germany
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- University Hospital Jena, Jena, Germany
| | | | - Erdinc Sezgin
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Science for Life Laboratory, Department of Women’s and Children’s Health, Karolinska Institutet, Solna, Sweden
| | | | - Harald W. Platta
- Biochemistry of Intracelluar Transport, Ruhr-University Bochum, Bochum, Germany
| | - Wolfgang Girzalsky
- Systems Biochemistry, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Christian Eggeling
- Leibniz-Institute of Photonic Technologies, Jena, Germany
- Institute of Applied Optics and Biophysics, Friedrich-Schiller University Jena, Jena, Germany
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Jena Center for Soft Matter (JCSM), Jena, Germany
| | - Ralf Erdmann
- Systems Biochemistry, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
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10
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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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11
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Uncovering targeting priority to yeast peroxisomes using an in-cell competition assay. Proc Natl Acad Sci U S A 2020; 117:21432-21440. [PMID: 32817524 PMCID: PMC7474679 DOI: 10.1073/pnas.1920078117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Half of eukaryotic proteins reside in organelles to which they are directed by dedicated targeting pathways, each recognizing unique targeting signals. Multiple proteins compete for any targeting pathway and might have different priority of reaching an organelle. However, the proteins with targeting priority, and the mechanisms underlying it, have not been explored. We developed a systematic tool to study targeting priority. We expressed a competitor protein and examined how it affects the localization of all other proteins targeted by the same pathway. We found several proteins with high targeting priority, dissected the mechanism of priority, and suggest that priority is governed by different parameters. This approach can be modified to study targeting priority in various organelles, cell types, and organisms. Approximately half of eukaryotic proteins reside in organelles. To reach their correct destination, such proteins harbor targeting signals recognized by dedicated targeting pathways. It has been shown that differences in targeting signals alter the efficiency in which proteins are recognized and targeted. Since multiple proteins compete for any single pathway, such differences can affect the priority for which a protein is catered. However, to date the entire repertoire of proteins with targeting priority, and the mechanisms underlying it, have not been explored for any pathway. Here we developed a systematic tool to study targeting priority and used the Pex5-mediated targeting to yeast peroxisomes as a model. We titrated Pex5 out by expressing high levels of a Pex5-cargo protein and examined how the localization of each peroxisomal protein is affected. We found that while most known Pex5 cargo proteins were outcompeted, several cargo proteins were not affected, implying that they have high targeting priority. This priority group was dependent on metabolic conditions. We dissected the mechanism of priority for these proteins and suggest that targeting priority is governed by different parameters, including binding affinity of the targeting signal to the cargo factor, the number of binding interfaces to the cargo factor, and more. This approach can be modified to study targeting priority in various organelles, cell types, and organisms.
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12
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Abstract
Blobel and coworkers discovered in 1978 that peroxisomal proteins are synthesized on free ribosomes in the cytosol and thus provided the grounds for the conception of peroxisomes as self-containing organelles. Peroxisomes are highly adaptive and versatile organelles carrying out a wide variety of metabolic functions. A striking feature of the peroxisomal import machinery is that proteins can traverse the peroxisomal membrane in a folded and even oligomeric state via cycling receptors. We outline essential steps of peroxisomal matrix protein import, from targeting of the proteins to the peroxisomal membrane, their translocation via transient pores and export of the corresponding cycling import receptors with emphasis on the situation in yeast. Peroxisomes can contribute to the adaptation of cells to different environmental conditions. This is realized by changes in metabolic functions and thus the enzyme composition of the organelles is adopted according to the cellular needs. In recent years, it turned out that this organellar diversity is based on an elaborate regulation of gene expression and peroxisomal protein import. The latter is in the focus of this review that summarizes our knowledge on the composition and function of the peroxisomal protein import machinery with emphasis on novel alternative protein import pathways.
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Affiliation(s)
- Thomas Walter
- Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Universitätsstr. 150, 44780, Bochum, Germany
| | - Ralf Erdmann
- Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Universitätsstr. 150, 44780, Bochum, Germany.
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13
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Kunze M. The type-2 peroxisomal targeting signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118609. [PMID: 31751594 DOI: 10.1016/j.bbamcr.2019.118609] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.
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Affiliation(s)
- Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Spitalgasse 4, 1090 Vienna, Austria.
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14
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Chang J, Rachubinski RA. Pex20p functions as the receptor for non‐PTS1/non‐PTS2 acyl‐CoA oxidase import into peroxisomes of the yeast
Yarrowia lipolytica. Traffic 2019; 20:504-515. [DOI: 10.1111/tra.12652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Jinlan Chang
- Department of Cell BiologyUniversity of Alberta Edmonton Alberta Canada
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15
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Mukai S, Matsuzaki T, Fujiki Y. The cytosolic peroxisome-targeting signal (PTS)-receptors, Pex7p and Pex5pL, are sufficient to transport PTS2 proteins to peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:441-449. [PMID: 30296498 DOI: 10.1016/j.bbamcr.2018.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/14/2018] [Accepted: 10/02/2018] [Indexed: 12/28/2022]
Abstract
Proteins harboring peroxisome-targeting signal type-2 (PTS2) are recognized in the cytosol by mobile PTS2 receptor Pex7p and associate with a longer isoform Pex5pL of the PTS1 receptor. Trimeric PTS2 protein-Pex7p-Pex5pL complexes are translocated to peroxisomes in mammalian cells. However, it remains unclear whether Pex5pL and Pex7p are sufficient cytosolic components in transporting of PTS2 proteins to peroxisomes. Here, we construct a semi-intact cell import system to define the cytosolic components required for the peroxisomal PTS2 protein import and show that the PTS2 pre-import complexes comprising Pex7p, Pex5p, and Hsc70 isolated from the cytosol of pex14 Chinese hamster ovary cell mutant ZP161 is import-competent. PTS2 reporter proteins are transported to peroxisomes by recombinant Pex7p and Pex5pL in semi-intact cells devoid of the cytosol. Furthermore, PTS2 proteins are translocated to peroxisomes in the presence of a non-hydrolyzable ATP analogue, adenylyl imidodiphosphate, and N-ethylmaleimide, suggesting that ATP-dependent chaperones including Hsc70 are dispensable for PTS2 protein import. Taken together, we suggest that Pex7p and Pex5pL are the minimal cytosolic factors in the transport of PTS2 proteins to peroxisomes.
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Affiliation(s)
- Satoru Mukai
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Takashi Matsuzaki
- Department of Biology, Faculty of Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Yukio Fujiki
- Division of Organelle Homeostasis, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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16
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Rymer Ł, Kempiński B, Chełstowska A, Skoneczny M. The budding yeast Pex5p receptor directs Fox2p and Cta1p into peroxisomes via its N-terminal region near the FxxxW domain. J Cell Sci 2018; 131:jcs.216986. [PMID: 30131444 DOI: 10.1242/jcs.216986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 08/07/2018] [Indexed: 01/08/2023] Open
Abstract
The import of most of peroxisomal proteins into the lumen of their target organelle is driven by C-terminal (PTS1) or N-terminal (PTS2) signals recognized by the Pex5p or Pex7p receptors, respectively. However, some proteins in budding yeast, such as acyl-CoA oxidase (AOx) and carnitine acetyltransferase (Cat2p), are imported into peroxisomes via an alternative route that does not rely on known PTS signals and involves the Pex5p receptor N-terminal region. Here, we show that two other budding yeast peroxisomal proteins, a multifunctional enzyme from the β-oxidation pathway (Fox2p) and catalase A (Cta1p), both of which contain PTS1, can be imported independently of this signal. The I264K amino acid substitution in Pex5p adjacent to its FxxxW diaromatic motif, previously shown to abolish the import of AOx and Cat2p into peroxisomes, also affects Fox2p and Cta1p import. Moreover, we demonstrate that Pex9p, a newly discovered paralog of Pex5p that was recently implicated in the import of malate synthases in budding yeast, also exhibits weak receptor activity towards Fox2p and Cta1p. These findings indicate the need to re-evaluate the peroxisomal import paradigm.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Łukasz Rymer
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Błażej Kempiński
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Anna Chełstowska
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5A, 02-106 Warszawa, Poland
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17
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Chen X, Devarajan S, Danda N, Williams C. Insights into the Role of the Peroxisomal Ubiquitination Machinery in Pex13p Degradation in the Yeast Hansenula polymorpha. J Mol Biol 2018; 430:1545-1558. [PMID: 29694833 DOI: 10.1016/j.jmb.2018.03.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/15/2018] [Accepted: 03/16/2018] [Indexed: 12/13/2022]
Abstract
The import of matrix proteins into peroxisomes in yeast requires the action of the ubiquitin-conjugating enzyme Pex4p and a complex consisting of the ubiquitin E3 ligases Pex2p, Pex10p and Pex12p. Together, this peroxisomal ubiquitination machinery is thought to ubiquitinate the cycling receptor protein Pex5p and members of the Pex20p family of co-receptors, a modification that is required for receptor recycling. However, recent reports have demonstrated that this machinery plays a role in additional peroxisome-associated processes. Hence, our understanding of the function of these proteins in peroxisome biology is still incomplete. Here, we identify a role for the peroxisomal ubiquitination machinery in the degradation of the peroxisomal membrane protein Pex13p. Our data demonstrate that Pex13p levels build up in cells lacking members of this machinery and also establish that Pex13p undergoes rapid degradation in wild-type cells. Furthermore, we show that Pex13p is ubiquitinated in wild-type cells and also establish that Pex13p ubiquitination is reduced in cells lacking a functional peroxisomal E3 ligase complex. Finally, deletion of PEX2 causes Pex13p to build up at the peroxisomal membrane. Taken together, our data provide further evidence that the role of the peroxisomal ubiquitination machinery in peroxisome biology goes much deeper than receptor recycling alone.
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Affiliation(s)
- Xin Chen
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, the Netherlands
| | - Srishti Devarajan
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, the Netherlands
| | - Natasha Danda
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, the Netherlands
| | - Chris Williams
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747AG Groningen, the Netherlands.
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18
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Kao YT, Gonzalez KL, Bartel B. Peroxisome Function, Biogenesis, and Dynamics in Plants. PLANT PHYSIOLOGY 2018; 176:162-177. [PMID: 29021223 PMCID: PMC5761812 DOI: 10.1104/pp.17.01050] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/09/2017] [Indexed: 05/19/2023]
Abstract
Recent advances highlight understanding of the diversity of peroxisome contributions to plant biology and the mechanisms through which these essential organelles are generated.
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Affiliation(s)
- Yun-Ting Kao
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Kim L Gonzalez
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, Texas 77005
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19
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Chan A, Schummer A, Fischer S, Schröter T, Cruz-Zaragoza LD, Bender J, Drepper F, Oeljeklaus S, Kunau WH, Girzalsky W, Warscheid B, Erdmann R. Pex17p-dependent assembly of Pex14p/Dyn2p-subcomplexes of the peroxisomal protein import machinery. Eur J Cell Biol 2016; 95:585-597. [PMID: 27823812 DOI: 10.1016/j.ejcb.2016.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/30/2016] [Accepted: 10/10/2016] [Indexed: 01/10/2023] Open
Abstract
Peroxisomal matrix protein import is facilitated by cycling receptors that recognize their cargo proteins in the cytosol by peroxisomal targeting sequences (PTS). In the following, the assembled receptor-cargo complex is targeted to the peroxisomal membrane where it docks to the docking-complex as part of the peroxisomal translocation machinery. The docking-complex is composed of Pex13p, Pex14p and in yeast also Pex17p, whose function is still elusive. In order to characterize the function of Pex17p, we compared the composition and size of peroxisomal receptor-docking complexes from wild-type and pex17Δ cells. Our data demonstrate that the deficiency of Pex17p affects the stoichiometry of the constituents of an isolated 600kDa complex and that pex17Δ cells lack a high molecular weight complex (>900kDa) of unknown function. We identified the dynein light chain protein Dyn2p as an additional core component of the Pex14p/Pex17p-complex. Both, Pex14p and Pex17p interact directly with Dyn2p, but in vivo, Pex17p turned out to be prerequisite for an association of Dyn2p with Pex14p. Finally, like pex17Δ also dyn2Δ cells lack the high molecular weight complex. As dyn2Δ cells also display reduced peroxisomal function, our data indicate that Dyn2p-dependent formation of the high molecular weight Pex14p-complex is required to maintain peroxisomal function on wild-type level.
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Affiliation(s)
- Anna Chan
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Andreas Schummer
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Sven Fischer
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Thomas Schröter
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Luis Daniel Cruz-Zaragoza
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Julian Bender
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Friedel Drepper
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Wolf-H Kunau
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Wolfgang Girzalsky
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
| | - Ralf Erdmann
- Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, Bochum, Germany.
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20
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Emmanouilidis L, Gopalswamy M, Passon DM, Wilmanns M, Sattler M. Structural biology of the import pathways of peroxisomal matrix proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:804-13. [DOI: 10.1016/j.bbamcr.2015.09.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/29/2015] [Accepted: 09/30/2015] [Indexed: 11/28/2022]
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21
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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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22
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Effelsberg D, Cruz-Zaragoza LD, Tonillo J, Schliebs W, Erdmann R. Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae. J Biol Chem 2015; 290:25333-42. [PMID: 26276932 DOI: 10.1074/jbc.m115.653451] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Indexed: 01/30/2023] Open
Abstract
Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD(+) salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions.
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Affiliation(s)
- Daniel Effelsberg
- From the Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, and
| | | | - Jason Tonillo
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Wolfgang Schliebs
- From the Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, and
| | - Ralf Erdmann
- From the Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, and
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23
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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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24
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Woodward AW, Fleming WA, Burkhart SE, Ratzel SE, Bjornson M, Bartel B. A viable Arabidopsis pex13 missense allele confers severe peroxisomal defects and decreases PEX5 association with peroxisomes. PLANT MOLECULAR BIOLOGY 2014; 86:201-214. [PMID: 25008153 PMCID: PMC4142595 DOI: 10.1007/s11103-014-0223-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 07/01/2014] [Indexed: 05/29/2023]
Abstract
Peroxisomes are organelles that catabolize fatty acids and compartmentalize other oxidative metabolic processes in eukaryotes. Using a forward-genetic screen designed to recover severe peroxisome-defective mutants, we isolated a viable allele of the peroxisome biogenesis gene PEX13 with striking peroxisomal defects. The pex13-4 mutant requires an exogenous source of fixed carbon for pre-photosynthetic development and is resistant to the protoauxin indole-3-butyric acid. Delivery of peroxisome-targeted matrix proteins depends on the PEX5 receptor docking with PEX13 at the peroxisomal membrane, and we found severely reduced import of matrix proteins and less organelle-associated PEX5 in pex13-4 seedlings. Moreover, pex13-4 physiological and molecular defects were partially ameliorated when PEX5 was overexpressed, suggesting that PEX5 docking is partially compromised in this mutant and can be improved by increasing PEX5 levels. Because previously described Arabidopsis pex13 alleles either are lethal or confer only subtle defects, the pex13-4 mutant provides valuable insight into plant peroxisome receptor docking and matrix protein import.
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Affiliation(s)
- Andrew W. Woodward
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA. Department of Biology, University of Mary Hardin-Baylor, Belton, TX 76513, USA
| | - Wendell A. Fleming
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Sarah E. Burkhart
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Sarah E. Ratzel
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Marta Bjornson
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
| | - Bonnie Bartel
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77005, USA
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25
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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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26
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A PEX7-centered perspective on the peroxisomal targeting signal type 2-mediated protein import pathway. Mol Cell Biol 2014; 34:2917-28. [PMID: 24865970 DOI: 10.1128/mcb.01727-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and transported to the organelle by shuttling receptors. Matrix proteins containing a type 1 signal are carried to the peroxisome by PEX5, whereas those harboring a type 2 signal are transported by a PEX5-PEX7 complex. The pathway followed by PEX5 during the protein transport cycle has been characterized in detail. In contrast, not much is known regarding PEX7. In this work, we show that PEX7 is targeted to the peroxisome in a PEX5- and cargo-dependent manner, where it becomes resistant to exogenously added proteases. Entry of PEX7 and its cargo into the peroxisome occurs upstream of the first cytosolic ATP-dependent step of the PEX5-mediated import pathway, i.e., before monoubiquitination of PEX5. PEX7 passing through the peroxisome becomes partially, if not completely, exposed to the peroxisome matrix milieu, suggesting that cargo release occurs at the trans side of the peroxisomal membrane. Finally, we found that export of peroxisomal PEX7 back into the cytosol requires export of PEX5 but, strikingly, the two export events are not strictly coupled, indicating that the two proteins leave the peroxisome separately.
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27
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El Magraoui F, Brinkmeier R, Schrötter A, Girzalsky W, Müller T, Marcus K, Meyer HE, Erdmann R, Platta HW. Distinct Ubiquitination Cascades Act on the Peroxisomal Targeting Signal Type 2 Co-receptor Pex18p. Traffic 2013; 14:1290-301. [DOI: 10.1111/tra.12120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/09/2013] [Accepted: 09/11/2013] [Indexed: 01/29/2023]
Affiliation(s)
- Fouzi El Magraoui
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
- Systembiochemie; Ruhr-Universität Bochum; Bochum 44780 Germany
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
| | - Andreas Schrötter
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics; Medizinisches Proteom-Center; Bochum 44801 Germany
| | | | - Thorsten Müller
- Funktionelle Proteomik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Katrin Marcus
- Funktionelle Proteomik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Helmut E. Meyer
- Medizinische Proteomik/Bioanalytik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Ralf Erdmann
- Systembiochemie; Ruhr-Universität Bochum; Bochum 44780 Germany
| | - Harald W. Platta
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
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28
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Gualdrón-López M, Chevalier N, Van Der Smissen P, Courtoy PJ, Rigden DJ, Michels PAM. Ubiquitination of the glycosomal matrix protein receptor PEX5 in Trypanosoma brucei by PEX4 displays novel features. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3076-3092. [PMID: 23994617 DOI: 10.1016/j.bbamcr.2013.08.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/08/2013] [Accepted: 08/12/2013] [Indexed: 12/12/2022]
Abstract
Trypanosomatids contain peroxisome-like organelles called glycosomes. Peroxisomal biogenesis involves a cytosolic receptor, PEX5, which, after its insertion into the organellar membrane, delivers proteins to the matrix. In yeasts and mammalian cells, transient PEX5 monoubiquitination at the membrane serves as the signal for its retrieval from the organelle for re-use. When its recycling is impaired, PEX5 is polyubiquitinated for proteasomal degradation. Stably monoubiquitinated TbPEX5 was detected in cytosolic fractions of Trypanosoma brucei, indicative for its role as physiological intermediate in receptor recycling. This modification's resistance to dithiothreitol suggests ubiquitin conjugation of a lysine residue. T. brucei PEX4, the functional homologue of the ubiquitin-conjugating (UBC) enzyme responsible for PEX5 monoubiquitination in yeast, was identified. It is associated with the cytosolic face of the glycosomal membrane, probably anchored by an identified putative TbPEX22. The involvement of TbPEX4 in TbPEX5 ubiquitination was demonstrated using procyclic ∆PEX4 trypanosomes. Surprisingly, glycosomal matrix protein import was only mildly affected in this mutant. Since other UBC homologues were upregulated, it might be possible that these have partially rescued PEX4's function in PEX5 ubiquitination. In addition, the altered expression of UBCs, notably of candidates involved in cell-cycle control, could be responsible for observed morphological and motility defects of the ∆PEX4 mutant.
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Affiliation(s)
- Melisa Gualdrón-López
- Research Unit for Tropical Diseases, de Duve Institute, and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium
| | - Nathalie Chevalier
- Research Unit for Tropical Diseases, de Duve Institute, and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium
| | - Patrick Van Der Smissen
- Cell Biology Unit, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Pierre J Courtoy
- Cell Biology Unit, de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Daniel J Rigden
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Paul A M Michels
- Research Unit for Tropical Diseases, de Duve Institute, and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium.
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Lipid droplets and peroxisomes: key players in cellular lipid homeostasis or a matter of fat--store 'em up or burn 'em down. Genetics 2013; 193:1-50. [PMID: 23275493 PMCID: PMC3527239 DOI: 10.1534/genetics.112.143362] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Lipid droplets (LDs) and peroxisomes are central players in cellular lipid homeostasis: some of their main functions are to control the metabolic flux and availability of fatty acids (LDs and peroxisomes) as well as of sterols (LDs). Both fatty acids and sterols serve multiple functions in the cell—as membrane stabilizers affecting membrane fluidity, as crucial structural elements of membrane-forming phospholipids and sphingolipids, as protein modifiers and signaling molecules, and last but not least, as a rich carbon and energy source. In addition, peroxisomes harbor enzymes of the malic acid shunt, which is indispensable to regenerate oxaloacetate for gluconeogenesis, thus allowing yeast cells to generate sugars from fatty acids or nonfermentable carbon sources. Therefore, failure of LD and peroxisome biogenesis and function are likely to lead to deregulated lipid fluxes and disrupted energy homeostasis with detrimental consequences for the cell. These pathological consequences of LD and peroxisome failure have indeed sparked great biomedical interest in understanding the biogenesis of these organelles, their functional roles in lipid homeostasis, interaction with cellular metabolism and other organelles, as well as their regulation, turnover, and inheritance. These questions are particularly burning in view of the pandemic development of lipid-associated disorders worldwide.
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Tabak HF, Braakman I, Zand AVD. Peroxisome Formation and Maintenance Are Dependent on the Endoplasmic Reticulum. Annu Rev Biochem 2013; 82:723-44. [DOI: 10.1146/annurev-biochem-081111-125123] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Henk F. Tabak
- Section of Cellular Protein Chemistry, Faculty of Science, Utrecht University, NL-3584 CH Utrecht, the Netherlands;
| | - Ineke Braakman
- Section of Cellular Protein Chemistry, Faculty of Science, Utrecht University, NL-3584 CH Utrecht, the Netherlands;
| | - Adabella van der Zand
- Section of Cellular Protein Chemistry, Faculty of Science, Utrecht University, NL-3584 CH Utrecht, the Netherlands;
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Liu X, Subramani S. Unique requirements for mono- and polyubiquitination of the peroxisomal targeting signal co-receptor, Pex20. J Biol Chem 2013; 288:7230-40. [PMID: 23344950 DOI: 10.1074/jbc.m112.424911] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In Pichia pastoris, the peroxisomal targeting signal 2 (PTS2)-dependent peroxisomal matrix protein import pathway requires the receptor, Pex7, and its co-receptor Pex20. A conserved lysine (Lys(19)) near the N terminus of Pex20 is required for its polyubiquitination and proteasomal degradation, whereas a conserved cysteine (Cys(8)) is essential for its recycling. In this study, we found that Cys(8) is required for the DTT-sensitive mono- and diubiquitination of Pex20. We also show that the PTS2 cargo receptor, Pex7, is required for Pex20 polyubiquitination. Pex4, the E2 ubiquitin-conjugation enzyme, is required for monoubiquitination of Pex20. However, it is also necessary for polyubiquitination of Pex20, making its behavior distinct from the ubiquitination described for other PTS receptors. Unlike the roles of specific RING peroxins in Pex5 ubiquitination, we found that all the RING peroxins (Pex2, Pex10, and Pex12) are required as E3 ubiquitin ligases for Pex20 mono- and polyubiquitination. A model for Pex20 ubiquitination is proposed based on these observations. This is the first description of the complete ubiquitination pathway of Pex20, which provides a better understanding of the recycling and degradation of this PTS2 cargo co-receptor.
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Affiliation(s)
- Xueqian Liu
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0322, USA
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Pieuchot L, Jedd G. Peroxisome Assembly and Functional Diversity in Eukaryotic Microorganisms. Annu Rev Microbiol 2012; 66:237-63. [DOI: 10.1146/annurev-micro-092611-150126] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Laurent Pieuchot
- Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 117604 Singapore; ,
| | - Gregory Jedd
- Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 117604 Singapore; ,
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Faust JE, Verma A, Peng C, McNew JA. An inventory of peroxisomal proteins and pathways in Drosophila melanogaster. Traffic 2012; 13:1378-92. [PMID: 22758915 PMCID: PMC3443258 DOI: 10.1111/j.1600-0854.2012.01393.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 06/28/2012] [Accepted: 07/03/2012] [Indexed: 11/29/2022]
Abstract
Peroxisomes are ubiquitous organelles housing a variety of essential biochemical pathways. Peroxisome dysfunction causes a spectrum of human diseases known as peroxisome biogenesis disorders (PBD). Although much is known regarding the mechanism of peroxisome biogenesis, it is still unclear how peroxisome dysfunction leads to the disease state. Several recent studies have shown that mutations in Drosophila peroxin genes cause phenotypes similar to those seen in humans with PBDs suggesting that Drosophila might be a useful system to model PBDs. We have analyzed the proteome of Drosophila to identify the proteins involved in peroxisomal biogenesis and homeostasis as well as metabolic enzymes that function within the organelle. The subcellular localization of five of these predicted peroxisomal proteins was confirmed. Similar to Caenorhabditis elegans, Drosophila appears to only utilize the peroxisome targeting signal type 1 system for matrix protein import. This work will further our understanding of peroxisomes in Drosophila and add to the usefulness of this emerging model system.
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Affiliation(s)
- Joseph E. Faust
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - Avani Verma
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - Chengwei Peng
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
| | - James A. McNew
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street MS601, Houston, TX 77005
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Verplaetse E, Gualdrón-López M, Chevalier N, Michels PAM. Studies on the organization of the docking complex involved in matrix protein import into glycosomes of Trypanosoma brucei. Biochem Biophys Res Commun 2012; 424:781-5. [PMID: 22809509 DOI: 10.1016/j.bbrc.2012.07.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/09/2012] [Indexed: 10/28/2022]
Abstract
Trypanosoma brucei contains peroxisome-like organelles designated glycosomes because they sequester the major part of the glycolytic pathway. Import of proteins into the peroxisomal matrix involves a protein complex associated with the peroxisomal membrane of which PEX13 is a component. Two very different PEX13 isoforms have recently been identified in T. brucei. A striking feature of one of the isoforms, TbPEX13.1, is the presence of a C-terminal type 1 peroxisomal-targeting signal (PTS1), the tripeptide TKL, conserved in its orthologues in all members of the Trypanosomatidae family so far studied, but absent from TbPEX13.2 and the PEX13s in all other organisms. Despite their differences, both TbPEX13s function as part of a docking complex for cytosolic receptors with bound matrix proteins to be imported. We further characterized TbPEX13.1's function in glycosomal matrix-protein import. It provides a frame to anchor another docking complex component, PEX14, to the glycosomal membrane or information to correctly position it within the membrane. To investigate the possible function of the C-terminal TKL, we determined the topology of the C-terminal half of TbPEX13.1 in the membrane and show that its SH3 domain, located immediately adjacent to the PTS1, is at the cytosolic face.
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Affiliation(s)
- Emilie Verplaetse
- Research Unit for Tropical Diseases, de Duve Institute, Laboratory of Biochemistry, Université catholique de Louvain, Brussels, Belgium
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Recent advances in peroxisomal matrix protein import. Curr Opin Cell Biol 2012; 24:484-9. [PMID: 22683191 DOI: 10.1016/j.ceb.2012.05.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 05/14/2012] [Indexed: 11/22/2022]
Abstract
Peroxisomes are essential organelles responsible for many metabolic reactions, such as the oxidation of very long chain and branched fatty acids, D-amino acids and polyamines, as well as the production and turnover of hydrogen peroxide. They comprise a class of organelles called microbodies, including glycosomes, glyoxysomes and Woronin bodies. Dysfunction of human peroxisomes causes severe and often fatal peroxisome biogenesis disorders (PBDs). Peroxisomal matrix protein import is mediated by receptors that shuttle between the cytosol and peroxisomal matrix using ubiquitination/deubiquitination reactions and ATP hydrolysis for receptor recycling. We focus on the machinery involved in the peroxisomal matrix protein import cycle, highlighting recent advances in peroxisomal matrix protein import, cargo release and receptor recycling/degradation.
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Grimm I, Saffian D, Platta HW, Erdmann R. The AAA-type ATPases Pex1p and Pex6p and their role in peroxisomal matrix protein import in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:150-8. [DOI: 10.1016/j.bbamcr.2011.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 09/02/2011] [Accepted: 09/03/2011] [Indexed: 12/25/2022]
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Hensel A, Beck S, El Magraoui F, Platta HW, Girzalsky W, Erdmann R. Cysteine-dependent ubiquitination of Pex18p is linked to cargo translocation across the peroxisomal membrane. J Biol Chem 2011; 286:43495-505. [PMID: 22021076 DOI: 10.1074/jbc.m111.286104] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The peroxisomal matrix protein import is facilitated by cycling receptor molecules that shuttle between the cytosol and the peroxisomal membrane. In the yeast Saccharomyces cerevisiae, the import of proteins harboring a peroxisomal targeting signal of type II (PTS2) is mediated by the receptor Pex7p and its co-receptor Pex18p. Here we demonstrate that Pex18p undergoes two kinds of ubiquitin modifications. One of these ubiquitination events depends on lysines 13 and 20 and forces rapid Pex18p turnover by proteasomal degradation. A cysteine residue near the extreme Pex18p amino-terminus is required for the second type of ubiquitination. It turned out that this cysteine residue at position 6 is essential for the function of Pex18p in peroxisomal protein import but does not contribute to receptor-cargo association and binding to the peroxisomal import apparatus. However, in contrast to the wild-type protein, cysteine 6-mutated Pex18p is arrested in a membrane-protected state, whereas Pex7p is accessible in a protease protection assay. This finding indicates that Pex18p export is linked to cargo translocation, which supports the idea of an export-driven import of proteins into peroxisomes.
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Affiliation(s)
- Astrid Hensel
- Abteilung für Systembiochemie, Institut für Physiologische Chemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Monroe-Augustus M, Ramón NM, Ratzel SE, Lingard MJ, Christensen SE, Murali C, Bartel B. Matrix proteins are inefficiently imported into Arabidopsis peroxisomes lacking the receptor-docking peroxin PEX14. PLANT MOLECULAR BIOLOGY 2011; 77:1-15. [PMID: 21553312 PMCID: PMC3529590 DOI: 10.1007/s11103-011-9782-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 04/24/2011] [Indexed: 05/24/2023]
Abstract
Mutations in peroxisome biogenesis proteins (peroxins) can lead to developmental deficiencies in various eukaryotes. PEX14 and PEX13 are peroxins involved in docking cargo-receptor complexes at the peroxisomal membrane, thus aiding in the transport of the cargo into the peroxisomal matrix. Genetic screens have revealed numerous Arabidopsis thaliana peroxins acting in peroxisomal matrix protein import; the viable alleles isolated through these screens are generally partial loss-of-function alleles, whereas null mutations that disrupt delivery of matrix proteins to peroxisomes can confer embryonic lethality. In this study, we used forward and reverse genetics in Arabidopsis to isolate four pex14 alleles. We found that all four alleles conferred reduced PEX14 mRNA levels and displayed physiological and molecular defects suggesting reduced but not abolished peroxisomal matrix protein import. The least severe pex14 allele, pex14-3, accumulated low levels of a C-terminally truncated PEX14 product that retained partial function. Surprisingly, even the severe pex14-2 allele, which lacked detectable PEX14 mRNA and PEX14 protein, was viable, fertile, and displayed residual peroxisome matrix protein import. As pex14 plants matured, import improved. Together, our data indicate that PEX14 facilitates, but is not essential for peroxisomal matrix protein import in plants.
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Affiliation(s)
- Melanie Monroe-Augustus
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Naxhiely Martínez Ramón
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Sarah E. Ratzel
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Matthew J. Lingard
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA. 700 Chesterfield Parkway, Chesterfield, MO 63017, USA
| | - Sarah E. Christensen
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Chaya Murali
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
| | - Bonnie Bartel
- Department of Biochemistry and Cell Biology, Rice University, 6100 South Main Street, Houston, TX 77005, USA
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40
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Debelyy MO, Platta HW, Saffian D, Hensel A, Thoms S, Meyer HE, Warscheid B, Girzalsky W, Erdmann R. Ubp15p, a ubiquitin hydrolase associated with the peroxisomal export machinery. J Biol Chem 2011; 286:28223-34. [PMID: 21665945 DOI: 10.1074/jbc.m111.238600] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Peroxisomal matrix protein import is facilitated by cycling receptors shuttling between the cytosol and the peroxisomal membrane. One crucial step in this cycle is the ATP-dependent release of the receptors from the peroxisomal membrane. This step is facilitated by the peroxisomal AAA (ATPases associated with various cellular activities) proteins Pex1p and Pex6p with ubiquitination of the receptor being the main signal for its export. Here we report that the AAA complex contains dislocase as well as deubiquitinating activity. Ubp15p, a ubiquitin hydrolase, was identified as a novel constituent of the complex. Ubp15p partially localizes to peroxisomes and is capable of cleaving off ubiquitin moieties from the type I peroxisomal targeting sequence (PTS1) receptor Pex5p. Furthermore, Ubp15p-deficient cells are characterized by a stress-related PTS1 import defect. The results merge into a picture in which removal of ubiquitin from the PTS1 receptor Pex5p is a specific event and might represent a vital step in receptor recycling.
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Affiliation(s)
- Mykhaylo O Debelyy
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Bochum, Germany
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41
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The phosphoinositide 3-kinase Vps34p is required for pexophagy in Saccharomyces cerevisiae. Biochem J 2011; 434:161-70. [PMID: 21121900 DOI: 10.1042/bj20101115] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PIds (phosphoinositides) are phosphorylated derivatives of the membrane phospholipid PtdIns that have emerged as key regulators of many aspects of cellular physiology. We have discovered a PtdIns3P-synthesizing activity in peroxisomes of Saccharomyces cerevisiae and have demonstrated that the lipid kinase Vps34p is already associated with peroxisomes during biogenesis. However, although Vps34 is required, it is not essential for optimal peroxisome biogenesis. The function of Vps34p-containing complex I as well as a subset of PtdIns3P-binding proteins proved to be mandatory for the regulated degradation of peroxisomes. This demonstrates that PtdIns3P-mediated signalling is required for pexophagy.
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42
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Managadze D, Würtz C, Wiese S, Schneider M, Girzalsky W, Meyer HE, Erdmann R, Warscheid B, Rottensteiner H. Identification of PEX33, a novel component of the peroxisomal docking complex in the filamentous fungus Neurospora crassa. Eur J Cell Biol 2010; 89:955-64. [DOI: 10.1016/j.ejcb.2010.07.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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43
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Deckers M, Emmrich K, Girzalsky W, Awa WL, Kunau WH, Erdmann R. Targeting of Pex8p to the peroxisomal importomer. Eur J Cell Biol 2010; 89:924-31. [DOI: 10.1016/j.ejcb.2010.06.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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44
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Galland N, Michels PAM. Comparison of the peroxisomal matrix protein import system of different organisms. Exploration of possibilities for developing inhibitors of the import system of trypanosomatids for anti-parasite chemotherapy. Eur J Cell Biol 2010; 89:621-37. [PMID: 20435370 DOI: 10.1016/j.ejcb.2010.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/28/2010] [Accepted: 04/06/2010] [Indexed: 10/19/2022] Open
Abstract
In recent decades, research on peroxisome biogenesis has been particularly boosted since the role of these organelles in metabolism became unraveled. Indeed in plants, yeasts and fungi, peroxisomes play an important role in the adaptation of metabolism during developmental processes and/or altered environmental conditions. In mammals their importance is illustrated by the fact that several severe human inherited diseases have been identified as peroxisome biogenesis disorders (PBD). Particularly interesting are the glycosomes - peroxisome-like organelles in trypanosomatids where the major part of the glycolytic pathway is sequestered - because it was demonstrated that proper compartmentalization of matrix proteins inside glycosomes is essential for the parasite. Although the overall process of peroxisome biogenesis seems well conserved between species, careful study of the literature reveals nonetheless many differences at various steps. In this review, we present a comparison of the first two steps of peroxisome biogenesis - receptor loading and docking at the peroxisomal membrane - in yeasts, mammals, plants and trypanosomatids and highlight major differences in the import process between species despite the conservation of (some of) the proteins involved. Some of the unique features of the process as it occurs in trypanosomatids will be discussed with regard to the possibilities for exploiting them for the development of compounds that could specifically disturb interactions between trypanosomatid peroxins. This strategy could eventually lead to the discovery of drugs against the diseases caused by these parasites.
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Affiliation(s)
- Nathalie Galland
- Research Unit for Tropical Diseases, de Duve Institute, Brussels, Belgium
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45
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Rucktäschel R, Girzalsky W, Erdmann R. Protein import machineries of peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:892-900. [PMID: 20659419 DOI: 10.1016/j.bbamem.2010.07.020] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 07/19/2010] [Accepted: 07/20/2010] [Indexed: 10/19/2022]
Abstract
Peroxisomes are a class of structurally and functionally related organelles present in almost all eukaryotic cells. The importance of peroxisomes for human life is highlighted by severe inherited diseases which are caused by defects of peroxins, encoded by PEX genes. To date 32 peroxins are known to be involved in different aspects of peroxisome biogenesis. This review addresses two of these aspects, the translocation of soluble proteins into the peroxisomal matrix and the biogenesis of the peroxisomal membrane. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.
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Affiliation(s)
- Robert Rucktäschel
- Abteilung für Systembiochemie, Institut für Physiologische Chemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
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46
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Girzalsky W, Saffian D, Erdmann R. Peroxisomal protein translocation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:724-31. [DOI: 10.1016/j.bbamcr.2010.01.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/22/2009] [Accepted: 01/04/2010] [Indexed: 11/30/2022]
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Fujihara N, Sakaguchi A, Tanaka S, Fujii S, Tsuji G, Shiraishi T, O'Connell R, Kubo Y. Peroxisome biogenesis factor PEX13 is required for appressorium-mediated plant infection by the anthracnose fungus Colletotrichum orbiculare. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:436-445. [PMID: 20192831 DOI: 10.1094/mpmi-23-4-0436] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Peroxisomes are ubiquitous organelles of eukaryotic cells that fulfill a variety of biochemical functions, including beta-oxidation of fatty acids. Here, we report that an ortholog of the Saccharomyces cerevisiae peroxisome biogenesis gene PEX13 is required for pathogenicity of Colletotrichum orbiculare. CoPEX13 was identified by screening random insertional mutants for deficiency in fatty acid utilization. Targeted knockout mutants of CoPEX13 were unable to utilize fatty acids as a carbon source. Expression analysis using green fluorescent protein fused to the peroxisomal targeting signals PTS1 and PTS2 revealed that the import machinery for peroxisomal matrix proteins was impaired in copex13 mutants. Appressoria formed by the copex13 mutants were defective in both melanization and penetration ability on host plants, had thin cell walls, and lacked peroxisomes. Moreover, the concentration of intracellular glycerol was lower in copex13 appressoria than those of the wild type. These findings indicate that fatty acid oxidation in peroxisomes is required not only for appressorium melanization but also for cell wall biogenesis and metabolic processes involved in turgor generation, all of which are essential for appressorium penetration ability.
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Affiliation(s)
- Naoki Fujihara
- Laboratory of Plant Pathology, Graduate school of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
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48
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Getting a camel through the eye of a needle: the import of folded proteins by peroxisomes. Biol Cell 2010; 102:245-63. [PMID: 20146669 DOI: 10.1042/bc20090159] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Peroxisomes are a family of organelles which have many unusual features. They can arise de novo from the endoplasmic reticulum by a still poorly characterized process, yet possess a unique machinery for the import of their matrix proteins. As peroxisomes lack DNA, their function, which is highly variable and dependent on developmental and/or environmental conditions, is determined by the post-translational import of specific metabolic enzymes in folded or oligomeric states. The two classes of matrix targeting signals for peroxisomal proteins [PTS1 (peroxisomal targeting signal 1) and PTS2] are recognized by cytosolic receptors [PEX5 (peroxin 5) and PEX7 respectively] which escort their cargo proteins to, or possibly across, the peroxisome membrane. Although the membrane translocation mechanism remains unclear, it appears to be driven by thermodynamically favourable binding interactions. Recycling of the receptors from the peroxisome membrane requires ATP hydrolysis for two linked processes: ubiquitination of PEX5 (and the PEX7 co-receptors in yeast) and the function of two peroxisome-associated AAA (ATPase associated with various cellular activities) ATPases, which play a role in recycling or turnover of the ubiquitinated receptors. This review summarizes and integrates recent findings on peroxisome matrix protein import from yeast, plant and mammalian model systems, and discusses some of the gaps in our understanding of this remarkable protein transport system.
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Abstract
Peroxisomes play an important role in lipid metabolic pathways and are implicated in many human disorders. Their biogenesis has been studied over the last two decades using many uni and multi-cellular model systems and many aspects of the mechanisms and proteins involved in peroxisome biogenesis are conserved from yeast to humans. In this manuscript we review the recent progress made in our understanding of the mechanisms by which matrix and membrane proteins are sorted to and assembled into peroxisomes.
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Affiliation(s)
- Changle Ma
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0322, USA
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50
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Michels PAM, Moyersoen J, Krazy H, Galland N, Herman M, Hannaert V. Peroxisomes, glyoxysomes and glycosomes (Review). Mol Membr Biol 2009; 22:133-45. [PMID: 16092531 DOI: 10.1080/09687860400024186] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Peroxisomes, glyoxysomes and glycosomes are related organelles found in different organisms. The morphology and enzymic content of the different members of this organelle family differ considerably, and may also be highly dependent on the cell's environmental conditions or life cycle. However, all peroxisome-like organelles have in common a number of characteristic enzymes or enzyme systems, notably enzymes dealing with reactive oxygen species. All organelles of the family follow essentially the same route of biogenesis, but with species-specific differences. Sets of proteins called peroxins are involved in different aspects of the formation and proliferation of peroxisomes such as import of proteins in the organellar matrix, insertion of proteins in the membrane, etc. In different eukaryotic lineages these functions are carried out by often--but not always--homologous yet poorly conserved peroxins. The process of biogenesis and the nature of the proteins involved suggest that all members of the peroxisome family evolved from a single organelle in an ancestral eukaryotic cell. This original peroxisome was possibly derived from a cellular membrane system such as the endoplasmic reticulum. Most of the organism-specific functions of the extant organelles have been acquired later in evolution.
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Affiliation(s)
- Paul A M Michels
- Research Unit for Tropical Diseases, Christian de Duve Institute of Cellular Pathology and Laboratory of Biochemistry, Université Catholique de Louvain, Brussels, Belgium.
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