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Ye C, Hong H, Gao J, Li M, Gou Y, Gao D, Dong C, Huang L, Xu Z, Lian J. Characterization and engineering of peroxisome targeting sequences for compartmentalization engineering in Pichia pastoris. Biotechnol Bioeng 2024; 121:2091-2105. [PMID: 38568751 DOI: 10.1002/bit.28706] [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: 12/27/2023] [Revised: 03/03/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024]
Abstract
Peroxisomal compartmentalization has emerged as a highly promising strategy for reconstituting intricate metabolic pathways. In recent years, significant progress has been made in the peroxisomes through harnessing precursor pools, circumventing metabolic crosstalk, and minimizing the cytotoxicity of exogenous pathways. However, it is important to note that in methylotrophic yeasts (e.g. Pichia pastoris), the abundance and protein composition of peroxisomes are highly variable, particularly when peroxisome proliferation is induced by specific carbon sources. The intricate subcellular localization of native proteins, the variability of peroxisomal metabolic pathways, and the lack of systematic characterization of peroxisome targeting signals have limited the applications of peroxisomal compartmentalization in P. pastoris. Accordingly, this study established a high-throughput screening method based on β-carotene biosynthetic pathway to evaluate the targeting efficiency of PTS1s (Peroxisome Targeting Signal Type 1) in P. pastoris. First, 25 putative endogenous PTS1s were characterized and 3 PTS1s with high targeting efficiency were identified. Then, directed evolution of PTS1s was performed by constructing two PTS1 mutant libraries, and a total of 51 PTS1s (29 classical and 22 noncanonical PTS1s) with presumably higher peroxisomal targeting efficiency were identified, part of which were further characterized via confocal microscope. Finally, the newly identified PTS1s were employed for peroxisomal compartmentalization of the geraniol biosynthetic pathway, resulting in more than 30% increase in the titer of monoterpene compared with when the pathway was localized to the cytosol. The present study expands the synthetic biology toolkit and lays a solid foundation for peroxisomal compartmentalization in P. pastoris.
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Affiliation(s)
- Cuifang Ye
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Haosen Hong
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Jucan Gao
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Mengxin Li
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Yuanwei Gou
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Di Gao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Chang Dong
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Lei Huang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Zhinan Xu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, National Key Laboratory of Biobased Transportation Fuel Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
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Hochreiter B, Malagon-Vina H, Schmid JA, Berger J, Kunze M. Studying the interaction between PEX5 and its full-length cargo proteins in living cells by a novel Försteŕs resonance energy transfer-based competition assay. Front Cell Dev Biol 2022; 10:1026388. [PMID: 36407094 PMCID: PMC9669585 DOI: 10.3389/fcell.2022.1026388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
The import of the majority of soluble peroxisomal proteins is initiated by the interaction between type-1 peroxisomal targeting signals (PTS1) and their receptor PEX5. PTS1 motifs reside at the extreme C-terminus of proteins and consist of a characteristic tripeptide and a modulatory upstream region. Various PTS1-PEX5 interactions have been studied by biophysical methods using isolated proteins or in heterologous systems such as two-hybrid assays, but a recently established approach based on Försters resonance energy transfer (FRET) allows a quantifying investigation in living cells. FRET is the radiation-free energy transfer between two fluorophores in close proximity and can be used to estimate the fraction of acceptor molecules bound to a donor molecule. For PTS1-PEX5 this method relies on the measurement of FRET-efficiency between the PTS1-binding TPR-domain of PEX5 tagged with mCherry and EGFP fused to a PTS1 peptide. However, this method is less suitable for binding partners with low affinity and protein complexes involving large proteins such as the interaction between full-length PTS1-carrying cargo proteins and PEX5. To overcome this limitation, we introduce a life-cell competition assay based on the same FRET approach but including a fusion protein of Cerulean with the protein of interest as a competitor. After implementing the mathematical description of competitive binding experiments into a fitting algorithm, we demonstrate the functionality of this approach using known interaction partners, its ability to circumvent previous limitations of FRET-measurements and its ability to study the interaction between PEX5 and its full-length cargo proteins. We find that some proteins (SCP2 and AGXT) bind PEX5 with higher affinity than their PTS1-peptides alone, but other proteins (ACOX3, DAO, PerCR-SRL) bind with lower but reasonable affinity, whereas GSTK1 binds with very low affinity. This binding strength was not increased upon elongating the PEX5 TPR-domain at its N-terminus, PEX5(N-TPR), although it interacts specifically with the N-terminal domain of PEX14. Finally, we demonstrate that the latter reduces the interaction strength between PEX5(N-TPR) and PTS1 by a dose-dependent but apparently non-competitive mechanism. Altogether, this demonstrates the power of this novel FRET-based competition approach for studying cargo recognition by PEX5 and protein complexes including large proteins in general.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hugo Malagon-Vina
- Department of Cognitive Neurobiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Johannes A. Schmid
- Institute for Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
- *Correspondence: Markus Kunze,
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Hochreiter B, Chong CS, Hartig A, Maurer-Stroh S, Berger J, Schmid JA, Kunze M. A Novel FRET Approach Quantifies the Interaction Strength of Peroxisomal Targeting Signals and Their Receptor in Living Cells. Cells 2020; 9:cells9112381. [PMID: 33143123 PMCID: PMC7693011 DOI: 10.3390/cells9112381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/22/2020] [Accepted: 10/25/2020] [Indexed: 02/02/2023] Open
Abstract
Measuring Förster–resonance–energy–transfer (FRET) efficiency allows the investigation of protein–protein interactions (PPI), but extracting quantitative measures of affinity necessitates highly advanced technical equipment or isolated proteins. We demonstrate the validity of a recently suggested novel approach to quantitatively analyze FRET-based experiments in living mammalian cells using standard equipment using the interaction between different type-1 peroxisomal targeting signals (PTS1) and their soluble receptor peroxin 5 (PEX5) as a model system. Large data sets were obtained by flow cytometry coupled FRET measurements of cells expressing PTS1-tagged EGFP together with mCherry fused to the PTS1-binding domain of PEX5, and were subjected to a fitting algorithm extracting a quantitative measure of the interaction strength. This measure correlates with results obtained by in vitro techniques and a two-hybrid assay, but is unaffected by the distance between the fluorophores. Moreover, we introduce a live cell competition assay based on this approach, capable of depicting dose- and affinity-dependent modulation of the PPI. Using this system, we demonstrate the relevance of a sequence element next to the core tripeptide in PTS1 motifs for the interaction strength between PTS1 and PEX5, which is supported by a structure-based computational prediction of the binding energy indicating a direct involvement of this sequence in the interaction.
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Affiliation(s)
- Bernhard Hochreiter
- Center for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, 1090 Vienna, Austria;
| | - Cheng-Shoong Chong
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore 138671, Singapore; (C.-S.C.); (S.M.-S.)
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore
| | - Andreas Hartig
- Department of Biochemistry and Cell Biology, Max Perutz Laboratories, University of Vienna, 1030 Vienna, Austria;
| | - Sebastian Maurer-Stroh
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore 138671, Singapore; (C.-S.C.); (S.M.-S.)
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Johannes Berger
- Center for Brain Research, Department of Pathobiology of the Nervous System, Medical University of Vienna, 1090 Vienna, Austria;
| | - Johannes A. Schmid
- Center for Physiology and Pharmacology, Institute of Vascular Biology and Thrombosis Research, Medical University of Vienna, 1090 Vienna, Austria;
- Correspondence: (J.A.S.); (M.K.)
| | - Markus Kunze
- Center for Brain Research, Department of Pathobiology of the Nervous System, Medical University of Vienna, 1090 Vienna, Austria;
- Correspondence: (J.A.S.); (M.K.)
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Abstract
Our knowledge of the proteome of plant peroxisomes is far from being complete, and the functional complexity and plasticity of this cell organelle are amazingly high particularly in plants, as exemplified by the model species Arabidopsis thaliana. Plant-specific peroxisome functions that have been uncovered only recently include, for instance, the participation of peroxisomes in phylloquinone and biotin biosynthesis. Experimental proteome studies have been proved very successful in defining the proteome of Arabidopsis peroxisomes but this approach also faces significant challenges and limitations. Complementary to experimental approaches, computational methods have emerged as important powerful tools to define the proteome of soluble matrix proteins of plant peroxisomes. Compared to other cell organelles such as mitochondria, plastids and the ER, the simultaneous operation of two major import pathways for soluble proteins in peroxisomes is rather atypical. Novel machine learning prediction approaches have been developed for peroxisome targeting signals type 1 (PTS1) and revealed high sensitivity and specificity, as validated by in vivo subcellular targeting analyses in diverse transient plant expression systems. Accordingly, the algorithms allow the correct prediction of many novel peroxisome-targeted proteins from plant genome sequences and the discovery of additional organelle functions. In contrast, the prediction of PTS2 proteins largely remains restricted to genome searches by conserved patterns contrary to more advanced machine learning methods. Here, we summarize and discuss the capabilities and accuracies of available prediction algorithms for PTS1 and PTS2 carrying proteins.
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Affiliation(s)
- Sigrun Reumann
- Department of Plant Biochemistry and Infection Biology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr. 18, 22609, Hamburg, Germany.
| | - Gopal Chowdhary
- KIIT School of Biotechnology, Campus XI, KIIT University, Bhubaneswar, 751024, India
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5
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Reumann S, Chowdhary G, Lingner T. Characterization, prediction and evolution of plant peroxisomal targeting signals type 1 (PTS1s). BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1863:790-803. [PMID: 26772785 DOI: 10.1016/j.bbamcr.2016.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 01/01/2016] [Accepted: 01/04/2016] [Indexed: 12/22/2022]
Abstract
Our knowledge of the proteome of plant peroxisomes and their functional plasticity is far from being complete, primarily due to major technical challenges in experimental proteome research of the fragile cell organelle. Several unexpected novel plant peroxisome functions, for instance in biotin and phylloquinone biosynthesis, have been uncovered recently. Nevertheless, very few regulatory and membrane proteins of plant peroxisomes have been identified and functionally described up to now. To define the matrix proteome of plant peroxisomes, computational methods have emerged as important powerful tools. Novel prediction approaches of high sensitivity and specificity have been developed for peroxisome targeting signals type 1 (PTS1) and have been validated by in vivo subcellular targeting analyses and thermodynamic binding studies with the cytosolic receptor, PEX5. Accordingly, the algorithms allow the correct prediction of many novel peroxisome-targeted proteins from plant genome sequences and the discovery of additional organelle functions. In this review, we provide an overview of methodologies, capabilities and accuracies of available prediction algorithms for PTS1 carrying proteins. We also summarize and discuss recent quantitative, structural and mechanistic information of the interaction of PEX5 with PTS1 carrying proteins in relation to in vivo import efficiency. With this knowledge, we develop a model of how proteins likely evolved peroxisomal targeting signals in the past and still nowadays, in which order the two import pathways might have evolved in the ancient eukaryotic cell, and how the secondary loss of the PTS2 pathway probably happened in specific organismal groups.
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Affiliation(s)
- S Reumann
- Department of Plant Biochemistry and Infection Biology, Biocentre Klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany; Centre for Organelle Research, University of Stavanger, N-4036 Stavanger, Norway.
| | - G Chowdhary
- Centre for Organelle Research, University of Stavanger, N-4036 Stavanger, Norway; KIIT School of Biotechnology, Campus XI, KIIT University, I-751024 Bhubaneswar, India.
| | - T Lingner
- Department of Bioinformatics, Institute for Microbiology and Genetics, D-37077 Goettingen, Germany.
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DeLoache WC, Russ ZN, Dueber JE. Towards repurposing the yeast peroxisome for compartmentalizing heterologous metabolic pathways. Nat Commun 2016; 7:11152. [PMID: 27025684 PMCID: PMC5476825 DOI: 10.1038/ncomms11152] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 02/23/2016] [Indexed: 11/29/2022] Open
Abstract
Compartmentalization of enzymes into organelles is a promising strategy for limiting metabolic crosstalk and improving pathway efficiency, but improved tools and design rules are needed to make this strategy available to more engineered pathways. Here we focus on the Saccharomyces cerevisiae peroxisome and develop a sensitive high-throughput assay for peroxisomal cargo import. We identify an enhanced peroxisomal targeting signal type 1 (PTS1) for rapidly sequestering non-native cargo proteins. Additionally, we perform the first systematic in vivo measurements of nonspecific metabolite permeability across the peroxisomal membrane using a polymer exclusion assay. Finally, we apply these new insights to compartmentalize a two-enzyme pathway in the peroxisome and characterize the expression regimes where compartmentalization leads to improved product titre. This work builds a foundation for using the peroxisome as a synthetic organelle, highlighting both promise and future challenges on the way to realizing this goal. Compartmentalization of enzymes into cellular organelles is a promising strategy for improving pathway efficiency. Here, the authors use a high-throughput assay to identify enhanced peroxisomal targeting signals in yeast, and study the effects of peroxisomal compartmentalization on the performance of a model pathway.
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Affiliation(s)
- William C DeLoache
- UC Berkeley and UCSF Graduate Program in Bioengineering, University of California, Berkeley (UC Berkeley), Berkeley, California 94720, USA.,Department of Bioengineering, UC Berkeley, Berkeley, California 94720, USA
| | - Zachary N Russ
- UC Berkeley and UCSF Graduate Program in Bioengineering, University of California, Berkeley (UC Berkeley), Berkeley, California 94720, USA.,Department of Bioengineering, UC Berkeley, Berkeley, California 94720, USA
| | - John E Dueber
- Department of Bioengineering, UC Berkeley, Berkeley, California 94720, USA
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Hagen S, Drepper F, Fischer S, Fodor K, Passon D, Platta HW, Zenn M, Schliebs W, Girzalsky W, Wilmanns M, Warscheid B, Erdmann R. Structural insights into cargo recognition by the yeast PTS1 receptor. J Biol Chem 2015; 290:26610-26. [PMID: 26359497 DOI: 10.1074/jbc.m115.657973] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 11/06/2022] Open
Abstract
The peroxisomal matrix protein import is facilitated by cycling import receptors that shuttle between the cytosol and the peroxisomal membrane. The import receptor Pex5p mediates the import of proteins harboring a peroxisomal targeting signal of type I (PTS1). Purified recombinant Pex5p forms a dimeric complex with the PTS1-protein Pcs60p in vitro with a KD of 0.19 μm. To analyze the structural basis for receptor-cargo recognition, the PTS1 and adjacent amino acids of Pcs60p were systematically scanned for Pex5p binding by an in vitro site-directed photo-cross-linking approach. The cross-linked binding regions of the receptor were subsequently identified by high resolution mass spectrometry. Most cross-links were found with TPR6, TPR7, as well as the 7C-loop of Pex5p. Surface plasmon resonance analysis revealed a bivalent interaction mode for Pex5p and Pcs60p. Interestingly, Pcs60p lacking its C-terminal tripeptide sequence was efficiently cross-linked to the same regions of Pex5p. The KD value of the interaction of truncated Pcs60p and Pex5p was in the range of 7.7 μm. Isothermal titration calorimetry and surface plasmon resonance measurements revealed a monovalent binding mode for the interaction of Pex5p and Pcs60p lacking the PTS1. Our data indicate that Pcs60p contains a second contact site for its receptor Pex5p, beyond the C-terminal tripeptide. The physiological relevance of the ancillary binding region was supported by in vivo import studies. The bivalent binding mode might be explained by a two-step concept as follows: first, cargo recognition and initial tethering by the PTS1-receptor Pex5p; second, lock-in of receptor and cargo.
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Affiliation(s)
- Stefanie Hagen
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Friedel Drepper
- the Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
| | - Sven Fischer
- the Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
| | - Krisztian Fodor
- the Department of Biochemistry, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Daniel Passon
- the European Molecular Biology Laboratory at Hamburg, D-22607 Hamburg, Germany
| | - Harald W Platta
- the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Biochemistry of Intracellular Transport Mechanism, Ruhr-University Bochum, D-44781 Bochum, Germany, and
| | - Michael Zenn
- the Biaffin GmbH and Co., KG, D-34132 Kassel, Germany
| | - Wolfgang Schliebs
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Wolfgang Girzalsky
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany
| | - Matthias Wilmanns
- the European Molecular Biology Laboratory at Hamburg, D-22607 Hamburg, Germany
| | - Bettina Warscheid
- the Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
| | - Ralf Erdmann
- From the Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, System Biochemistry, Ruhr-University Bochum, D-44780 Bochum, Germany,
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Skoulding NS, Chowdhary G, Deus MJ, Baker A, Reumann S, Warriner SL. Experimental validation of plant peroxisomal targeting prediction algorithms by systematic comparison of in vivo import efficiency and in vitro PTS1 binding affinity. J Mol Biol 2014; 427:1085-101. [PMID: 25498386 DOI: 10.1016/j.jmb.2014.12.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/30/2014] [Accepted: 12/04/2014] [Indexed: 01/19/2023]
Abstract
Most peroxisomal matrix proteins possess a C-terminal targeting signal type 1 (PTS1). Accurate prediction of functional PTS1 sequences and their relative strength by computational methods is essential for determination of peroxisomal proteomes in silico but has proved challenging due to high levels of sequence variability of non-canonical targeting signals, particularly in higher plants, and low levels of availability of experimentally validated non-canonical examples. In this study, in silico predictions were compared with in vivo targeting analyses and in vitro thermodynamic binding of mutated variants within the context of one model targeting sequence. There was broad agreement between the methods for entire PTS1 domains and position-specific single amino acid residues, including residues upstream of the PTS1 tripeptide. The hierarchy Leu>Met>Ile>Val at the C-terminal position was determined for all methods but both experimental approaches suggest that Tyr is underweighted in the prediction algorithm due to the absence of this residue in the positive training dataset. A combination of methods better defines the score range that discriminates a functional PTS1. In vitro binding to the PEX5 receptor could discriminate among strong targeting signals while in vivo targeting assays were more sensitive, allowing detection of weak functional import signals that were below the limit of detection in the binding assay. Together, the data provide a comprehensive assessment of the factors driving PTS1 efficacy and provide a framework for the more quantitative assessment of the protein import pathway in higher plants.
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Affiliation(s)
- Nicola S Skoulding
- School of Chemistry and the Astbury Centre, University of Leeds, Leeds LS2 9JT, UK
| | - Gopal Chowdhary
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway; KIIT School of Biotechnology, Campus XI, KIIT University, I-751024 Bhubaneswar, India
| | - Mara J Deus
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway
| | - Alison Baker
- Centre for Plant Sciences, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Sigrun Reumann
- Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, Richard Johansens Gate 4, N-4021 Stavanger, Norway; Department of Biology, Biocentre Klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany
| | - Stuart L Warriner
- School of Chemistry and the Astbury Centre, University of Leeds, Leeds LS2 9JT, UK.
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Otera H, Fujiki Y. Pex5p imports folded tetrameric catalase by interaction with Pex13p. Traffic 2012; 13:1364-77. [PMID: 22747494 DOI: 10.1111/j.1600-0854.2012.01391.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 06/26/2012] [Accepted: 07/02/2012] [Indexed: 11/28/2022]
Abstract
Human catalase forms a 240-kDa tetrameric complex and degrades H(2) O(2) in peroxisomes. Human catalase is targeted to peroxisomes by the interaction of its peroxisomal targeting signal type 1 (PTS1)-like KANL sequence with the cytosolic PTS1 receptor Pex5p. We show herein that human catalase tetramers are formed in the cytoplasm and that the expression of a PTS signal on each of the four subunits is not necessary for peroxisomal transport. We previously demonstrated that a Pex5p mutant defective in binding to Pex13p, designated Pex5p(Mut234), imports typical PTS1-type proteins but not catalase. This impaired catalase import is not rescued by replacing its C-terminal KANL sequence with a typical PTS1 sequence, SKL, indicating that the failure of catalase import in Mut234-expressing cells is not due to its weak PTS1. In contrast, several enzymatically inactive and monomeric mutants of catalase are efficiently imported in Mut234-expressing cells. Moreover, trimeric chloramphenicol acetyltransferase (CAT) harboring SKL is not imported in Pex5p(Mut234)-expressing cells, but CAT-SKL trimers are transported to peroxisomes in the wild-type cells. These findings suggest that the Pex5p-Pex13p interaction likely plays a pivotal role in the peroxisomal import of folded and oligomeric proteins.
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Affiliation(s)
- Hidenori Otera
- Department of Biology, Faculty of Sciences, Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, 812-8581, Japan
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Ghosh D, Berg JM. A proteome-wide perspective on peroxisome targeting signal 1(PTS1)-Pex5p affinities. J Am Chem Soc 2010; 132:3973-9. [PMID: 20178365 DOI: 10.1021/ja9109049] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Most proteins are targeted to the peroxisomal matrix by virtue of a peroxisomal targeting signal-1 (PTS1), a short carboxy-terminal sequence specifically recognized by the PTS1 receptor Pex5p. We had previously developed a model that allowed the estimation of the affinities of many PTS1 sequences within the human proteome for Pex5p that revealed a wide range of predicted affinities. We have now experimentally determined the affinities of the PTS1-containing peptides from 42 proteins from the human proteome for Pex5p and show that these range over 4 orders of magnitude. These affinities correlate reasonably well with the predicted values and are substantially more precise. In an attempt to provide a possible explanation for the wide range of PTS1-Pex5p affinities, we compared these affinities with mRNA levels (as a proxy for rates of protein production) of the genes encoding these proteins in 79 human tissues and cell types. We note that high affinity PTS1-Pex5p interactions tend to correspond to proteins encoded by genes expressed at relatively low levels, whereas lower affinity PTS1-Pex5p interactions tend to correspond to proteins encoded by genes exhibiting higher levels and wider ranges of expression. Further analysis revealed that these relationships are consistent with the notion that a relatively uniform pool of protein-Pex5p complexes is maintained for appropriate peroxisome assembly.
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Affiliation(s)
- Debdip Ghosh
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA
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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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Kiel JAKW, van den Berg MA, Fusetti F, Poolman B, Bovenberg RAL, Veenhuis M, van der Klei IJ. Matching the proteome to the genome: the microbody of penicillin-producing Penicillium chrysogenum cells. Funct Integr Genomics 2009; 9:167-84. [PMID: 19156454 DOI: 10.1007/s10142-009-0110-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/05/2009] [Accepted: 01/05/2009] [Indexed: 10/21/2022]
Abstract
In the filamentous fungus Penicillium chrysogenum, microbodies are essential for penicillin biosynthesis. To better understand the role of these organelles in antibiotics production, we determined the matrix enzyme contents of P. chrysogenum microbodies. Using a novel in silico approach, we first obtained a catalogue of 200 P. chrysogenum proteins with putative microbody targeting signals (PTSs). This included two orthologs of proteins involved in cephalosporin biosynthesis, which we demonstrate to be bona fide microbody matrix constituents. Subsequently, we performed a proteomics based inventory of P. chrysogenum microbody matrix proteins using nano-LC-MS/MS analysis. We identified 89 microbody proteins, 79 with a PTS, including the two known microbody-borne penicillin biosynthesis enzymes, isopenicillin N:acyl CoA acyltransferase and phenylacetyl-CoA ligase. Comparative analysis revealed that 69 out of 79 PTS proteins identified experimentally were in the reference list. A prominent microbody protein was identified as a novel fumarate reductase-cytochrome b5 fusion protein, which contains an internal PTS2 between the two functional domains. We show that this protein indeed localizes to P. chrysogenum microbodies.
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Affiliation(s)
- Jan A K W Kiel
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, AA Haren, The Netherlands.
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Mizuno Y, Kurochkin IV, Herberth M, Okazaki Y, Schönbach C. Predicted mouse peroxisome-targeted proteins and their actual subcellular locations. BMC Bioinformatics 2008; 9 Suppl 12:S16. [PMID: 19091015 PMCID: PMC2638156 DOI: 10.1186/1471-2105-9-s12-s16] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The import of most intraperoxisomal proteins is mediated by peroxisome targeting signals at their C-termini (PTS1) or N-terminal regions (PTS2). Both signals have been integrated in subcellular location prediction programs. However their present performance, particularly of PTS2-targeting did not seem fitting for large-scale screening of sequences. RESULTS We modified an earlier reported PTS1 screening method to identify PTS2-containing mouse candidates using a combination of computational and manual annotation. For rapid confirmation of five new PTS2- and two previously identified PTS1-containing candidates we developed the new cell line CHO-perRed which stably expresses the peroxisomal marker dsRed-PTS1. Using CHO-perRed we confirmed the peroxisomal localization of PTS1-targeted candidate Zadh2. Preliminary characterization of Zadh2 expression suggested non-PPARalpha mediated activation. Notably, none of the PTS2 candidates located to peroxisomes. CONCLUSION In a few cases the PTS may oscillate from "silent" to "functional" depending on its surface accessibility indicating the potential for context-dependent conditional subcellular sorting. Overall, PTS2-targeting predictions are unlikely to improve without generation and integration of new experimental data from location proteomics, protein structures and quantitative Pex7 PTS2 peptide binding assays.
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Affiliation(s)
- Yumi Mizuno
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka, Saitama 350-1241, Japan.
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Fransen M, Amery L, Hartig A, Brees C, Rabijns A, Mannaerts GP, Van Veldhoven PP. Comparison of the PTS1- and Rab8b-binding properties of Pex5p and Pex5Rp/TRIP8b. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:864-73. [PMID: 18346465 DOI: 10.1016/j.bbamcr.2008.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 02/11/2008] [Accepted: 02/13/2008] [Indexed: 11/26/2022]
Abstract
Tetratricopeptide (TPR)-domain proteins are involved in various cellular processes. The TPR domain is known to be responsible for interaction with other proteins commonly recognizing sequence motifs at the C-termini. One such TPR-protein, TRIP8b, was originally identified in rat as an interaction partner of Rab8b, and its human orthologue as a protein related to the peroxisomal targeting signal 1 (PTS1) receptor Pex5p (Pex5Rp). Somewhat later, the mouse orthologue was reported to bind the hyperpolarization-activated, cyclic nucleotide-regulated HCN channels, and, very recently, the rat orthologue was shown to interact with latrophilin 1, the calcium-independent receptor of alpha-latrotoxin. Here we employed various methodological approaches to investigate and compare the binding specificities of the human PTS1 receptor Pex5p and the related protein Pex5Rp/TRIP8b towards a subset of targets, including Rab8b and various C-termini resembling PTS1. The results show that the TPR domains of Pex5p and Pex5Rp/TRIP8b have distinct but overlapping substrate specificities. This suggests that selectivity in the recognition of substrates by the TPR domains of Pex5p and Pex5Rp/TRIP8b is a matter of considerable complexity, and that no single determinant appears to be sufficient in unambiguously defining a binding target for either protein. This idea is further corroborated by our observations that changes in the surrounding residues or the conformational state of one of the binding partners can profoundly alter their binding activities. The implications of these findings for the possible peroxisome-related functions of Pex5Rp/TRIP8b are discussed.
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Affiliation(s)
- Marc Fransen
- Katholieke Universiteit Leuven, Campus Gasthuisberg (O&N 1), Departement Moleculaire Celbiologie, LIPIT, Leuven, Belgium.
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