1
|
Yang Y, Wei Y, Yin M, Liu E, Du X, Shen J, Dong M, Yan S. Efficient Polyamine-Based Nanodelivery System for Proline: Enhanced Uptake Improves the Drought Tolerance of Tobacco. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:1550-1560. [PMID: 38207102 DOI: 10.1021/acs.jafc.3c05636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Drought stress is one of the most unfavorable factors affecting plant growth and productivity among various environmental stresses. Nanotechnology is expected to enhance the effectiveness of conventional biostimulants. Herein, the current study constructed an efficient proline (Pro) nanodelivery system based on a star polyamine (SPc). The hydroxyl groups of Pro could assemble with carbonyl groups of SPc, and the self-assembly of Pro with SPc formed the nanoscale particles of the Pro/SPc complex. Compared to Pro alone, the contact angle of SPc-loaded Pro decreased, and its retentivity and plant uptake increased. Importantly, the tobacco (Nicotiana benthamiana) seeds and seedlings treated with Pro/SPc complex exhibited stronger drought tolerance. RNA-Seq analysis indicated that the SPc-loaded Pro could further upregulate photosynthesis-related genes and endocytosis-related genes. The current study constructed an efficient nanodelivery system for improving the bioactivity of biostimulants, which has broad application prospects in the agricultural field.
Collapse
Affiliation(s)
- Yanxiao Yang
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
- Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ying Wei
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
| | - Meizhen Yin
- State Key Laboratory of Chemical Resource Engineering, Beijing Lab of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Enliang Liu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, P. R. China
| | - Xiangge Du
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
| | - Jie Shen
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
| | - Min Dong
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
| | - Shuo Yan
- Department of Plant Biosecurity and MARA Key Laboratory of Surveillance and Management for Plant Quarantine Pests, College of Plant Protection, China Agricultural University, Beijing 100193, P. R. China
| |
Collapse
|
2
|
Guo Y, Li Q, Ji D, Tian L, Meurer J, Chi W. A Ubiquitin-Based Module Directing Protein-Protein Interactions in Chloroplasts. Int J Mol Sci 2023; 24:16673. [PMID: 38068997 PMCID: PMC10706609 DOI: 10.3390/ijms242316673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
A promising approach for the genetic engineering of multiprotein complexes in living cells involves designing and reconstructing the interaction between two proteins that lack native affinity. Thylakoid-embedded multiprotein complexes execute the light reaction of plant photosynthesis, but their engineering remains challenging, likely due to difficulties in accurately targeting heterologous membrane-bound proteins to various sub-compartments of thylakoids. In this study, we developed a ubiquitin-based module (Nub-Cub) capable of directing interactions in vivo between two chloroplast proteins lacking native affinities. We applied this module to genetically modify thylakoid multiprotein complexes. We demonstrated the functionality of the Nub-Cub module in the model organism Arabidopsis thaliana. Employing this system, we successfully modified the Photosystem II (PSII) complex by ectopically attaching an extrinsic subunit of PSII, PsbTn1, to CP26-a component of the antenna system of PSII. Surprisingly, this mandatory interaction between CP26 and PsbTn1 in plants impairs the efficiency of electron transport in PSII and unexpectedly results in noticeable defects in leaf development. Our study not only offers a general strategy to modify multiprotein complexes embedded in thylakoid membranes but it also sheds light on the possible interplay between two proteins without native interaction.
Collapse
Affiliation(s)
- Yinjie Guo
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Y.G.); (Q.L.); (D.J.); (L.T.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiuxin Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Y.G.); (Q.L.); (D.J.); (L.T.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daili Ji
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Y.G.); (Q.L.); (D.J.); (L.T.)
| | - Lijin Tian
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Y.G.); (Q.L.); (D.J.); (L.T.)
| | - Jörg Meurer
- Faculty of Biology, Plant Molecular Biology, Ludwig-Maximilians University, D-82152 Munich, Germany;
| | - Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; (Y.G.); (Q.L.); (D.J.); (L.T.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
3
|
Gross LE, Klinger A, Spies N, Ernst T, Flinner N, Simm S, Ladig R, Bodensohn U, Schleiff E. Insertion of plastidic β-barrel proteins into the outer envelopes of plastids involves an intermembrane space intermediate formed with Toc75-V/OEP80. THE PLANT CELL 2021; 33:1657-1681. [PMID: 33624803 PMCID: PMC8254496 DOI: 10.1093/plcell/koab052] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/03/2021] [Indexed: 06/12/2023]
Abstract
The insertion of organellar membrane proteins with the correct topology requires the following: First, the proteins must contain topogenic signals for translocation across and insertion into the membrane. Second, proteinaceous complexes in the cytoplasm, membrane, and lumen of organelles are required to drive this process. Many complexes required for the intracellular distribution of membrane proteins have been described, but the signals and components required for the insertion of plastidic β-barrel-type proteins into the outer membrane are largely unknown. The discovery of common principles is difficult, as only a few plastidic β-barrel proteins exist. Here, we provide evidence that the plastidic outer envelope β-barrel proteins OEP21, OEP24, and OEP37 from pea (Pisum sativum) and Arabidopsis thaliana contain information defining the topology of the protein. The information required for the translocation of pea proteins across the outer envelope membrane is present within the six N-terminal β-strands. This process requires the action of translocon of the outer chloroplast (TOC) membrane. After translocation into the intermembrane space, β-barrel proteins interact with TOC75-V, as exemplified by OEP37 and P39, and are integrated into the membrane. The membrane insertion of plastidic β-barrel proteins is affected by mutation of the last β-strand, suggesting that this strand contributes to the insertion signal. These findings shed light on the elements and complexes involved in plastidic β-barrel protein import.
Collapse
Affiliation(s)
- Lucia E Gross
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Anna Klinger
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Nicole Spies
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Theresa Ernst
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Nadine Flinner
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Stefan Simm
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
- Frankfurt Institute for Advanced Studies, D-60438 Frankfurt, Germany
| | - Roman Ladig
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Uwe Bodensohn
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
| | - Enrico Schleiff
- Department of Molecular Cell Biology of Plants, Goethe University, Max-von-Laue Str. 9; D-60438 Frankfurt, Germany
- Frankfurt Institute for Advanced Studies, D-60438 Frankfurt, Germany
| |
Collapse
|
4
|
Chen Z, Wang X, Li S, Yao J, Shao Z, Duan D. Verification of the Saccharina japonica Translocon Tic20 and its Localization in the Chloroplast Membrane in Diatoms. Int J Mol Sci 2019; 20:E4000. [PMID: 31426420 PMCID: PMC6720183 DOI: 10.3390/ijms20164000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/01/2019] [Accepted: 08/15/2019] [Indexed: 12/21/2022] Open
Abstract
Tic20 is an important translocon protein that plays a role in protein transport in the chloroplast. The sequence of Tic20 was determined in the lower brown alga Saccharina japonica. Structural analysis of SjTic20 revealed a noncanonical structure consisting of an N-terminal non-cyanobacterium-originated EF-hand domain (a helix-loop-helix structural domain) and a C-terminal cyanobacterium-originated Tic20 domain. Subcellular localization and transmembrane analysis indicated that SjTic20 featured an "M"-type Nin-Cin-terminal orientation, with four transmembrane domains in the innermost membrane of the chloroplast in the microalga Phaeodactylum tricornutum, and the EF-hand domain was entirely extruded into the chloroplast stroma. Our study provides information on the structure, localization, and topological features of SjTic20, and further functional analysis of SjTic20 in S. japonica is needed.
Collapse
Affiliation(s)
- Zhihang Chen
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100093, China
| | - Xiuliang Wang
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| | - Shuang Li
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100093, China
| | - Jianting Yao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Zhanru Shao
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Delin Duan
- Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
| |
Collapse
|
5
|
Cutolo E, Parvin N, Ruge H, Pirayesh N, Roustan V, Weckwerth W, Teige M, Grieco M, Larosa V, Vothknecht UC. The High Light Response in Arabidopsis Requires the Calcium Sensor Protein CAS, a Target of STN7- and STN8-Mediated Phosphorylation. FRONTIERS IN PLANT SCIENCE 2019; 10:974. [PMID: 31417591 PMCID: PMC6682602 DOI: 10.3389/fpls.2019.00974] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/11/2019] [Indexed: 05/18/2023]
Abstract
Reversible phosphorylation of thylakoid proteins contributes to photoacclimation responses in photosynthetic organisms, enabling the fine-tuning of light harvesting under changing light conditions and promoting the onset of photoprotective processes. However, the precise functional role of many of the described phosphorylation events on thylakoid proteins remains elusive. The calcium sensor receptor protein (CAS) has previously been indicated as one of the targets of the state transition kinase 8 (STN8). Here we show that in Arabidopsis thaliana, CAS is also phosphorylated by the state transition kinase 7 (STN7), as well as by another, so-far unknown, Ca2+-dependent kinase. Phosphoproteomics analysis and in vitro phosphorylation assays on CAS variants identified the phylogenetically conserved residues Thr-376, Ser-378, and Thr-380 as the major phosphorylation sites of the STN kinases. Spectroscopic analyses of chlorophyll fluorescence emission at 77K further showed that, while the cas mutant is not affected in state transition, it displays a persistent strong excitation of PSI under high light exposure, similar to the phenotype previously observed in other mutants defective in photoacclimation mechanisms. Together with the observation of a strong concomitant phosphorylation of light harvesting complex II (LHCII) and photosynthetic core proteins under high irradiance in the cas mutant this suggests a role for CAS in the STN7/STN8/TAP38 network of phosphorylation-mediated photoacclimation processes in Arabidopsis.
Collapse
Affiliation(s)
- Edoardo Cutolo
- Plant Cell Biology, Institut für Zelluläre und Molekulare Botanik, University of Bonn, Bonn, Germany
| | - Nargis Parvin
- Department of Plant Nutrition, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz, University of Bonn, Bonn, Germany
| | - Henning Ruge
- Department of Biology I, Ludwig Maximilian University of Munich, Munich, Germany
| | - Niloufar Pirayesh
- Plant Cell Biology, Institut für Zelluläre und Molekulare Botanik, University of Bonn, Bonn, Germany
| | - Valentin Roustan
- Department of Molecular Systems Biology, University of Vienna, Vienna, Austria
| | - Wolfram Weckwerth
- Department of Molecular Systems Biology, University of Vienna, Vienna, Austria
| | - Markus Teige
- Department of Molecular Systems Biology, University of Vienna, Vienna, Austria
| | - Michele Grieco
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Veronique Larosa
- Laboratory of Genetics and Physiology of Microalgae, InBios, University of Liège, Liège, Belgium
| | - Ute C. Vothknecht
- Plant Cell Biology, Institut für Zelluläre und Molekulare Botanik, University of Bonn, Bonn, Germany
| |
Collapse
|
6
|
Bodensohn US, Simm S, Fischer K, Jäschke M, Groß LE, Kramer K, Ehmann C, Rensing SA, Ladig R, Schleiff E. The intracellular distribution of the components of the GET system in vascular plants. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:1650-1662. [PMID: 31233800 DOI: 10.1016/j.bbamcr.2019.06.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 12/16/2022]
Abstract
The guided entry of tail-anchored proteins (GET) pathway facilitates targeting and insertion of tail-anchored proteins into membranes. In plants, such a protein insertion machinery for the endoplasmic reticulum as well as constituents within mitochondrial and chloroplasts were discovered. Previous phylogenetic analysis revealed that Get3 sequences of Embryophyta form two clades representing cytosolic ("a") and organellar ("bc") GET3 homologs, respectively. Cellular fractionation of Arabidopsis thaliana seedlings and usage of the self-assembly GFP system in protoplasts verified the cytosolic (ATGet3a), plastidic (ATGet3b) and mitochondrial (ATGet3c) localization of the different homologs. The identified plant homologs of Get1 and Get4 in A. thaliana are localized in ER and cytosol, respectively, implicating a degree of conservation of the GET pathway in A. thaliana. Transient expression of Get3 homologs of Solanum lycopersicum, Medicago × varia or Physcomitrella patens with the self-assembly GFP technique in homologous and heterologous systems verified that multiple Get3 homologs with differing subcellular localizations are common in plants. Chloroplast localized Get3 homologs were detected in all tested plant systems. In contrast, mitochondrial localized Get3 homologs were not identified in S. lycopersicum, or P. patens, while we confirmed on the example of A. thaliana proteins that mitochondrial localized Get3 proteins are properly targeted in S. lycopersicum as well.
Collapse
Affiliation(s)
- Uwe S Bodensohn
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Stefan Simm
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany; Frankfurt Institute of Advanced Studies, Ruth-Moufang-Straße 1, D-60438 Frankfurt, Germany
| | - Ken Fischer
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Michelle Jäschke
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Lucia E Groß
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Katharina Kramer
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Christian Ehmann
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Stefan A Rensing
- Faculty of Biology, University of Marburg, Karl-von-Frisch-Str. 8, D-35043 Marburg, Germany
| | - Roman Ladig
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany; Buchman Institute for Molecular Life Sciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 15, D-60438 Frankfurt, Germany; Frankfurt Institute of Advanced Studies, Ruth-Moufang-Straße 1, D-60438 Frankfurt, Germany.
| |
Collapse
|
7
|
Sharma M, Kretschmer C, Lampe C, Stuttmann J, Klösgen RB. Targeting specificity of nuclear-encoded organelle proteins with a self-assembling split-fluorescent protein toolkit. J Cell Sci 2019; 132:jcs230839. [PMID: 31085714 DOI: 10.1242/jcs.230839] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/01/2019] [Indexed: 12/21/2022] Open
Abstract
A large number of nuclear-encoded proteins are targeted to the organelles of endosymbiotic origin, namely mitochondria and plastids. To determine the targeting specificity of these proteins, fluorescent protein tagging is a popular approach. However, ectopic expression of fluorescent protein fusions commonly results in considerable background signals and often suffers from the large size and robust folding of the reporter protein, which may perturb membrane transport. Among the alternative approaches that have been developed in recent years, the self-assembling split-fluorescent protein (sasplit-FP) technology appears particularly promising to analyze protein targeting specificity in vivo Here, we improved the sensitivity of this technology and systematically evaluated its utilization to determine protein targeting to plastids and mitochondria. Furthermore, to facilitate high-throughput screening of candidate proteins we developed a Golden Gate-based vector toolkit (PlaMinGo). As a result of these improvements, dual targeting could be detected for a number of proteins that had earlier been characterized as being targeted to a single organelle only. These results were independently confirmed with a plant phenotype complementation approach based on the immutans mutant.This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Mayank Sharma
- Institute of Biology-Plant Physiology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle (Saale), Germany
| | - Carola Kretschmer
- Institute of Biology-Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle (Saale), Germany
| | - Christina Lampe
- Institute of Biology-Plant Physiology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle (Saale), Germany
| | - Johannes Stuttmann
- Institute of Biology-Genetics, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle (Saale), Germany
| | - Ralf Bernd Klösgen
- Institute of Biology-Plant Physiology, Martin Luther University Halle-Wittenberg, Weinbergweg 10, 06120 Halle (Saale), Germany
| |
Collapse
|
8
|
Klinger A, Gosch V, Bodensohn U, Ladig R, Schleiff E. The signal distinguishing between targeting of outer membrane β-barrel protein to plastids and mitochondria in plants. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:663-672. [PMID: 30633951 DOI: 10.1016/j.bbamcr.2019.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 12/03/2018] [Accepted: 01/07/2019] [Indexed: 12/15/2022]
Abstract
The proteome of the outer membrane of mitochondria and chloroplasts consists of membrane proteins anchored by α-helical or β-sheet elements. While proteins with α-helical transmembrane domains are present in all cellular membranes, proteins with β-barrel structure are specific for these two membranes. The organellar β-barrel proteins are encoded in the nuclear genome and thus, have to be targeted to the outer organellar membrane where they are recognized by surface exposed translocation complexes. In the last years, the signals that ensure proper targeting of these proteins have been investigated as essential base for an understanding of the regulation of cellular protein distribution. However, the organellar β-barrel proteins are unique as most of them do not contain a typical targeting information in form of an N-terminal cleavable targeting signal. Recently, it was discovered that targeting and surface recognition of mitochondrial β-barrel proteins in yeast, humans and plants depends on the hydrophobicity of the last β-hairpin of the β-barrel. However, we demonstrate that the hydrophobicity is not sufficient for the discrimination of targeting to chloroplasts or mitochondria. By domain swapping between mitochondrial and chloroplast targeted β-barrel proteins atVDAC1 and psOEP24 we demonstrate that the presence of a hydrophilic amino acid at the C-terminus of the penultimate β-strand is required for mitochondrial targeting. A mutation of the chloroplast β-barrel protein psOEP24 which mimics such profile is efficiently targeted to mitochondria. Thus, we present the properties of the signal for mitochondrial targeting of β-barrel proteins in plants.
Collapse
Affiliation(s)
- Anna Klinger
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Victoria Gosch
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Uwe Bodensohn
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Roman Ladig
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 9, D-60438 Frankfurt, Germany; Buchman Institute for Molecular Life Sciences, Goethe University Frankfurt am Main, Max-von-Laue Str. 15, D-60438 Frankfurt, Germany; Frankfurt Institute of Advanced Studies, Ruth-Moufang-Straße 1, D-60438 Frankfurt, Germany.
| |
Collapse
|
9
|
Hsueh YC, Flinner N, Gross LE, Haarmann R, Mirus O, Sommer MS, Schleiff E. Chloroplast outer envelope protein P39 in Arabidopsis thaliana belongs to the Omp85 protein family. Proteins 2017; 85:1391-1401. [PMID: 25401771 DOI: 10.1002/prot.24725] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/14/2014] [Accepted: 11/03/2014] [Indexed: 01/08/2023]
Abstract
Proteins of the Omp85 family chaperone the membrane insertion of β-barrel-shaped outer membrane proteins in bacteria, mitochondria, and probably chloroplasts and facilitate the transfer of nuclear-encoded cytosolically synthesized preproteins across the outer envelope of chloroplasts. This protein family is characterized by N-terminal polypeptide transport-associated (POTRA) domains and a C-terminal membrane-embedded β-barrel. We have investigated a recently identified Omp85 family member of Arabidopsis thaliana annotated as P39. We show by in vitro and in vivo experiments that P39 is localized in chloroplasts. The electrophysiological properties of P39 are consistent with those of other Omp85 family members confirming the sequence based assignment of P39 to this family. Bioinformatic analysis showed that P39 lacks any POTRA domain, while a complete 16 stranded β-barrel including the highly conserved L6 loop is proposed. The electrophysiological properties are most comparable to Toc75-V, which is consistent with the phylogenetic clustering of P39 in the Toc75-V rather than the Toc75-III branch of the Omp85 family tree. Taken together P39 forms a pore with Omp85 family protein characteristics. The bioinformatic comparison of the pore region of Toc75-III, Toc75-V, and P39 shows distinctions of the barrel region most likely related to function. Proteins 2017; 85:1391-1401. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yi-Ching Hsueh
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany
| | - Nadine Flinner
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany.,Center of Membrane Proteomics, Goethe University, D-60438, Frankfurt, Germany
| | - Lucia E Gross
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany
| | - Raimund Haarmann
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany
| | - Oliver Mirus
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany
| | - Maik S Sommer
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany
| | - Enrico Schleiff
- Department of Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt, Germany.,Center of Membrane Proteomics, Goethe University, D-60438, Frankfurt, Germany.,Cluster of Excellence Frankfurt, Goethe University, D-60438, Frankfurt, Germany.,Buchman Institute of Molecular Life Sciences, Goethe University, D-60438, Frankfurt, Germany
| |
Collapse
|
10
|
Ruge H, Flosdorff S, Ebersberger I, Chigri F, Vothknecht UC. The calmodulin-like proteins AtCML4 and AtCML5 are single-pass membrane proteins targeted to the endomembrane system by an N-terminal signal anchor sequence. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3985-96. [PMID: 27029353 PMCID: PMC4915527 DOI: 10.1093/jxb/erw101] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Calmodulins (CaMs) are important mediators of Ca(2+) signals that are found ubiquitously in all eukaryotic organisms. Plants contain a unique family of calmodulin-like proteins (CMLs) that exhibit greater sequence variance compared to canonical CaMs. The Arabidopsis thaliana proteins AtCML4 and AtCML5 are members of CML subfamily VII and possess a CaM domain comprising the characteristic double pair of EF-hands, but they are distinguished from other members of this subfamily and from canonical CaMs by an N-terminal extension of their amino acid sequence. Transient expression of yellow fluorescent protein-tagged AtCML4 and AtCML5 under a 35S-promoter in Nicotiana benthamiana leaf cells revealed a spherical fluorescence pattern. This pattern was confirmed by transient expression in Arabidopsis protoplasts under the native promoter. Co-localization analyses with various endomembrane marker proteins suggest that AtCML4 and AtCML5 are localized to vesicular structures in the interphase between Golgi and the endosomal system. Further studies revealed AtCML5 to be a single-pass membrane protein that is targeted into the endomembrane system by an N-terminal signal anchor sequence. Self-assembly green fluorescent protein and protease protection assays support a topology with the CaM domain exposed to the cytosolic surface and not the lumen of the vesicles, indicating that AtCML5 could sense Ca(2+) signals in the cytosol. Phylogenetic analysis suggests that AtCML4 and AtCML5 are closely related paralogues originating from a duplication event within the Brassicaceae family. CML4/5-like proteins seem to be universally present in eudicots but are absent in some monocots. Together these results show that CML4/5-like proteins represent a flowering plant-specific subfamily of CMLs with a potential function in vesicle transport within the plant endomembrane system.
Collapse
Affiliation(s)
- Henning Ruge
- Department of Biology I, Faculty of Biology, LMU Munich, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Sandra Flosdorff
- Department of Biology I, Faculty of Biology, LMU Munich, Großhaderner Straße 2-4, D-82152 Planegg, Germany
| | - Ingo Ebersberger
- Department for Applied Bioinformatics, Institute for Cell Biology and Neuroscience, Goethe-University Frankfurt, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
| | - Fatima Chigri
- Department of Biology I, Faculty of Biology, LMU Munich, Großhaderner Straße 2-4, D-82152 Planegg, Germany Center for Integrated Protein Science (Munich) at the Department of Biology I, Faculty of Biology, LMU Munich, D-81377 Munich, Germany
| | - Ute C Vothknecht
- Department of Biology I, Faculty of Biology, LMU Munich, Großhaderner Straße 2-4, D-82152 Planegg, Germany Center for Integrated Protein Science (Munich) at the Department of Biology I, Faculty of Biology, LMU Munich, D-81377 Munich, Germany
| |
Collapse
|
11
|
PBR1 selectively controls biogenesis of photosynthetic complexes by modulating translation of the large chloroplast gene Ycf1 in Arabidopsis. Cell Discov 2016; 2:16003. [PMID: 27462450 PMCID: PMC4870678 DOI: 10.1038/celldisc.2016.3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/27/2016] [Indexed: 11/14/2022] Open
Abstract
The biogenesis of photosystem I (PSI), cytochrome b6f (Cytb6f) and NADH dehydrogenase (NDH) complexes relies on the spatially and temporally coordinated expression and translation of both nuclear and chloroplast genes. Here we report the identification of photosystem biogenesis regulator 1 (PBR1), a nuclear-encoded chloroplast RNA-binding protein that regulates the concerted biogenesis of NDH, PSI and Cytb6f complexes. We identified Ycf1, one of the two largest chloroplast genome-encoded open reading frames as the direct downstream target protein of PBR1. Biochemical and molecular analyses reveal that PBR1 regulates Ycf1 translation by directly binding to its mRNA. Surprisingly, we further demonstrate that relocation of the chloroplast gene Ycf1 fused with a plastid-transit sequence to the nucleus bypasses the requirement of PBR1 for Ycf1 translation, which sufficiently complements the defects in biogenesis of NDH, PSI and Cytb6f complexes in PBR1-deficient plants. Remarkably, the nuclear-encoded PBR1 tightly controls the expression of the chloroplast gene Ycf1 at the translational level, which is sufficient to sustain the coordinated biogenesis of NDH, PSI and Cytb6f complexes as a whole. Our findings provide deep insights into better understanding of how a predominant nuclear-encoded factor can act as a migratory mediator and undergoes selective translational regulation of the target plastid gene in controlling biogenesis of photosynthetic complexes.
Collapse
|
12
|
Eilers U, Dietzel L, Breitenbach J, Büchel C, Sandmann G. Identification of genes coding for functional zeaxanthin epoxidases in the diatom Phaeodactylum tricornutum. JOURNAL OF PLANT PHYSIOLOGY 2016; 192:64-70. [PMID: 26851888 DOI: 10.1016/j.jplph.2016.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 05/21/2023]
Abstract
Phaeodactylum tricornutum like other diatoms synthesizes fucoxanthin and diadinoxanthin as major carotenoid end products. The genes involved have recently been assigned for early pathway steps. Beyond β-carotene, only gene candidates for β-carotene hydroxylase, zeaxanthin epoxidase and zeaxanthin de-epoxidase have been proposed from the available genome sequence. The two latter enzymes may be involved in the two different xanthophyll cycles which operate in P. tricornutum. The function of three putative zeaxanthin epoxidase genes (zep) was addressed by pathway complementation in the Arabidopsis thaliana Zep mutant npq2. Genes zep2 and zep3 were able to restore zeaxanthin epoxidation and a functional xanthophyll cycle but the corresponding enzymes exhibited different catalytic activities. Zep3 functioned as a zeaxanthin epoxidase whereas Zep2 exhibited a broader substrate specificity additionally converting lutein to lutein-5,6-epoxide. Although zep1 was transcribed and the protein could be identified after import into the chloroplast in A. thaliana, Zep1 was found not to be functional in zeaxanthin epoxidation. The non-photochemical quenching kinetics of wild type A. thaliana was only restored in transformant npq2-zep3.
Collapse
Affiliation(s)
- Ulrike Eilers
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Lars Dietzel
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Jürgen Breitenbach
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Claudia Büchel
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Gerhard Sandmann
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany.
| |
Collapse
|
13
|
Bionda T, Gross LE, Becker T, Papasotiriou DG, Leisegang MS, Karas M, Schleiff E. Eukaryotic Hsp70 chaperones in the intermembrane space of chloroplasts. PLANTA 2016; 243:733-47. [PMID: 26669598 DOI: 10.1007/s00425-015-2440-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
MAIN CONCLUSION Multiple eukaryotic Hsp70 typically localized in the cytoplasm are also distributed to the intermembrane space of chloroplasts and might thereby represent the missing link in energizing protein translocation. Protein translocation into organelles is a central cellular process that is tightly regulated. It depends on signals within the preprotein and on molecular machines catalyzing the process. Molecular chaperones participate in transport and translocation of preproteins into organelles to control folding and to provide energy for the individual steps. While most of the processes are explored and the components are identified, the transfer of preproteins into and across the intermembrane space of chloroplasts is not yet understood. The existence of an energy source in this compartment is discussed, because the required transit peptide length for successful translocation into chloroplasts is shorter than that found for mitochondria where energy is provided exclusively by matrix chaperones. Furthermore, a cytosolic-type Hsp70 homologue was proposed as component of the chloroplast translocon in the intermembrane space energizing the initial translocation. The molecular identity of such intermembrane space localized Hsp70 remained unknown, which led to a controversy concerning its existence. We identified multiple cytosolic Hsp70s by mass spectrometry on isolated, thermolysin-treated Medicago sativa chloroplasts. The localization of these Hsp70s of M. sativa or Arabidopsis thaliana in the intermembrane space was confirmed by a self-assembly GFP-based in vivo system. The localization of cytosolic Hsp70s in the stroma of chloroplasts or different mitochondrial compartments could not be observed. Similarly, we could not identify any cytosolic Hsp90 in the intermembrane space of chloroplast. With respect to our results we discuss the possible targeting and function of the Hsp70 found in the intermembrane space.
Collapse
Affiliation(s)
- Tihana Bionda
- Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
- Institute of Biochemistry II, Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Lucia E Gross
- Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
| | - Thomas Becker
- Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
- Biochemistry and Molecular Biology, ZBMZ, and BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University Freiburg, Stefan-Meier-Str. 17, 79104, Freiburg, Germany
| | - Dimitrios G Papasotiriou
- Pharmaceutical Chemistry, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
- Syngenta Ltd., Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK
| | - Matthias S Leisegang
- Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
- Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - Michael Karas
- Pharmaceutical Chemistry, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany
| | - Enrico Schleiff
- Molecular Cell Biology of Plants, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany.
- Molecular Cell Biology of Plants, Cluster of Excellence Frankfurt, Goethe University, Max von Laue Str. 9, 60438, Frankfurt, Germany.
- Buchmann Institut for Molecular Life Sciences, Max von Laue Str. 9, 60438, Frankfurt, Germany.
| |
Collapse
|
14
|
Evolution of a plant-specific copper chaperone family for chloroplast copper homeostasis. Proc Natl Acad Sci U S A 2014; 111:E5480-7. [PMID: 25468978 DOI: 10.1073/pnas.1421545111] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Metallochaperones traffic copper (Cu(+)) from its point of entry at the plasma membrane to its destination. In plants, one destination is the chloroplast, which houses plastocyanin, a Cu-dependent electron transfer protein involved in photosynthesis. We present a previously unidentified Cu(+) chaperone that evolved early in the plant lineage by an alternative-splicing event of the pre-mRNA encoding the chloroplast P-type ATPase in Arabidopsis 1 (PAA1). In several land plants, recent duplication events created a separate chaperone-encoding gene coincident with loss of alternative splicing. The plant-specific Cu(+) chaperone delivers Cu(+) with specificity for PAA1, which is flipped in the envelope relative to prototypical bacterial ATPases, compatible with a role in Cu(+) import into the stroma and consistent with the canonical catalytic mechanism of these enzymes. The ubiquity of the chaperone suggests conservation of this Cu(+)-delivery mechanism and provides a unique snapshot into the evolution of a Cu(+) distribution pathway. We also provide evidence for an interaction between PAA2, the Cu(+)-ATPase in thylakoids, and the Cu(+)-chaperone for Cu/Zn superoxide dismutase (CCS), uncovering a Cu(+) network that has evolved to fine-tune Cu(+) distribution.
Collapse
|
15
|
Li HM, Teng YS. Transit peptide design and plastid import regulation. TRENDS IN PLANT SCIENCE 2013; 18:360-6. [PMID: 23688728 DOI: 10.1016/j.tplants.2013.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/25/2013] [Accepted: 04/05/2013] [Indexed: 05/04/2023]
Abstract
Import of most nuclear encoded proteins into plastids is directed by an N-terminal transit peptide. Early studies suggested that transit peptides are interchangeable between precursor proteins. However, emerging evidence shows that different transit peptides contain different motifs specifying their preference for certain plastid types or ages. In this opinion article, we propose a 'multi-selection and multi-order' (M&M) model for transit peptide design, describing each transit peptide as an assembly of motifs for interacting with selected translocon components. These interactions determine the preference of the precursor for a particular plastid type or age. Furthermore, the order of the motifs varies among transit peptides, explaining why no consensus sequences have been identified through linear sequence comparison of all transit peptides as one group.
Collapse
Affiliation(s)
- Hsou-min Li
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.
| | | |
Collapse
|
16
|
Rudolf M, Machettira AB, Groß LE, Weber KL, Bolte K, Bionda T, Sommer MS, Maier UG, Weber APM, Schleiff E, Tripp J. In vivo function of Tic22, a protein import component of the intermembrane space of chloroplasts. MOLECULAR PLANT 2013. [PMID: 23204504 DOI: 10.1093/mp/sss114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Preprotein import into chloroplasts depends on macromolecular machineries in the outer and inner chloroplast envelope membrane (TOC and TIC). It was suggested that both machineries are interconnected by components of the intermembrane space (IMS). That is, amongst others, Tic22, of which two closely related isoforms exist in Arabidopsis thaliana, namely atTic22-III and atTic22-IV. We investigated the function of Tic22 in vivo by analyzing T-DNA insertion lines of the corresponding genes. While the T-DNA insertion in the individual genes caused only slight defects, a double mutant of both isoforms showed retarded growth, a pale phenotype under high-light conditions, a reduced import rate, and a reduction in the photosynthetic performance of the plants. The latter is supported by changes in the metabolite content of mutant plants when compared to wild-type. Thus, our results support the notion that Tic22 is directly involved in chloroplast preprotein import and might point to a particular importance of Tic22 in chloroplast biogenesis at times of high import rates.
Collapse
Affiliation(s)
- Mareike Rudolf
- Department of Biosciences, Molecular Cell Biology of Plants, Center of Membrane Proteomics and Cluster of Excellence Frankfurt, Goethe University, Max-von-Laue Str 9, D-60438 Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Sommer M, Rudolf M, Tillmann B, Tripp J, Sommer MS, Schleiff E. Toc33 and Toc64-III cooperate in precursor protein import into the chloroplasts of Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2013; 36:970-83. [PMID: 23131143 DOI: 10.1111/pce.12030] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 10/31/2012] [Indexed: 05/08/2023]
Abstract
The import of cytosolically synthesized precursor proteins into chloroplasts by the translocon at the outer envelope membrane of chloroplasts (TOC) is crucial for organelle function. The recognition of precursor proteins at the chloroplast surface precedes translocation and involves the membrane-inserted receptor subunits Toc34 and Toc159. A third receptor, Toc64, was discussed to recognize cytosolic complexes guiding precursor proteins to the membrane surface, but this function remains debated. We analysed Arabidopsis thaliana plants carrying a T-DNA insertion in the gene encoding the Toc64 homolog Toc64-III. We observed a light intensity-dependent growth phenotype, which is distinct from the phenotype of ppi1, the previously described mutant of the TOC34 homolog TOC33. Furthermore, chloroplast import of the model precursor proteins pOE33 and pSSU into chloroplasts is reduced in protoplasts isolated from plants with impaired Toc64-III function. This suggests that Toc64-III modulates the translocation efficiency in vivo. A ppi1 and toc64-III double mutant shows a significant increase in the transcript levels of HSP90 and TOC75-III, the latter coding for the pore-forming TOC component. Remarkably, the protein level of Toc75-III is significantly reduced, suggesting that Toc64-III and Toc33 cooperate in the insertion or stabilization of Toc75-III. Accordingly, the results presented support Toc64 as an import-relevant component of the TOC complex.
Collapse
Affiliation(s)
- Manuel Sommer
- Center of Membrane Proteomics, Cluster of Excellence Macromolecular Complexes Frankfurt, Department of Biosciences, Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University Frankfurt, D-60438 Frankfurt, Germany
| | | | | | | | | | | |
Collapse
|
18
|
Wiesemann K, Groß LE, Sommer M, Schleiff E, Sommer MS. self-assembling GFP: a versatile tool for plant (membrane) protein analyses. Methods Mol Biol 2013; 1033:131-144. [PMID: 23996175 DOI: 10.1007/978-1-62703-487-6_9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The investigation of cellular processes on the molecular level is important to understand the functional network within plant cells. self-assembling GFP has evolved to be a versatile tool for (membrane) protein analyses. Based on the autocatalytical reassembling property of the nonfluorescent strands 1-10 and 11, protein distribution and membrane protein topology can be analyzed in vivo. Here, we provide basic protocols to determine membrane protein topology in Arabidopsis thaliana protoplasts.
Collapse
Affiliation(s)
- Katharina Wiesemann
- Cluster of Excellence Frankfurt, Center for Membrane Proteomics, Department of Biosciences, Molecular Cell Biology, Goethe University, Frankfurt, Germany
| | | | | | | | | |
Collapse
|
19
|
Biogenic membranes of the chloroplast in Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2012; 109:19286-91. [PMID: 23129655 DOI: 10.1073/pnas.1209860109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The polypeptide subunits of the photosynthetic electron transport complexes in plants and algae are encoded by two genomes. Nuclear genome-encoded subunits are synthesized in the cytoplasm by 80S ribosomes, imported across the chloroplast envelope, and assembled with the subunits that are encoded by the plastid genome. Plastid genome-encoded subunits are synthesized by 70S chloroplast ribosomes directly into membranes that are widely believed to belong to the photosynthetic thylakoid vesicles. However, in situ evidence suggested that subunits of photosystem II are synthesized in specific regions within the chloroplast and cytoplasm of Chlamydomonas. Our results provide biochemical and in situ evidence of biogenic membranes that are localized to these translation zones. A "chloroplast translation membrane" is bound by the translation machinery and appears to be privileged for the synthesis of polypeptides encoded by the plastid genome. Membrane domains of the chloroplast envelope are located adjacent to the cytoplasmic translation zone and enriched in the translocons of the outer and inner chloroplast envelope membranes protein import complexes, suggesting a coordination of protein synthesis and import. Our findings contribute to a current realization that biogenic processes are compartmentalized within organelles and bacteria.
Collapse
|
20
|
Shi LX, Theg SM. The chloroplast protein import system: from algae to trees. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:314-31. [PMID: 23063942 DOI: 10.1016/j.bbamcr.2012.10.002] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/07/2012] [Accepted: 10/01/2012] [Indexed: 01/15/2023]
Abstract
Chloroplasts are essential organelles in the cells of plants and algae. The functions of these specialized plastids are largely dependent on the ~3000 proteins residing in the organelle. Although chloroplasts are capable of a limited amount of semiautonomous protein synthesis - their genomes encode ~100 proteins - they must import more than 95% of their proteins after synthesis in the cytosol. Imported proteins generally possess an N-terminal extension termed a transit peptide. The importing translocons are made up of two complexes in the outer and inner envelope membranes, the so-called Toc and Tic machineries, respectively. The Toc complex contains two precursor receptors, Toc159 and Toc34, a protein channel, Toc75, and a peripheral component, Toc64/OEP64. The Tic complex consists of as many as eight components, namely Tic22, Tic110, Tic40, Tic20, Tic21 Tic62, Tic55 and Tic32. This general Toc/Tic import pathway, worked out largely in pea chloroplasts, appears to operate in chloroplasts in all green plants, albeit with significant modifications. Sub-complexes of the Toc and Tic machineries are proposed to exist to satisfy different substrate-, tissue-, cell- and developmental requirements. In this review, we summarize our understanding of the functions of Toc and Tic components, comparing these components of the import machinery in green algae through trees. We emphasize recent findings that point to growing complexities of chloroplast protein import process, and use the evolutionary relationships between proteins of different species in an attempt to define the essential core translocon components and those more likely to be responsible for regulation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
Collapse
Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
| | | |
Collapse
|
21
|
Ulrich T, Gross LE, Sommer MS, Schleiff E, Rapaport D. Chloroplast β-barrel proteins are assembled into the mitochondrial outer membrane in a process that depends on the TOM and TOB complexes. J Biol Chem 2012; 287:27467-79. [PMID: 22745120 PMCID: PMC3431683 DOI: 10.1074/jbc.m112.382093] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/27/2012] [Indexed: 11/06/2022] Open
Abstract
Membrane-embedded β-barrel proteins are found in the outer membranes (OM) of Gram-negative bacteria, mitochondria and chloroplasts. In eukaryotic cells, precursors of these proteins are synthesized in the cytosol and have to be sorted to their corresponding organelle. Currently, the signal that ensures their specific targeting to either mitochondria or chloroplasts is ill-defined. To address this issue, we studied targeting of the chloroplast β-barrel proteins Oep37 and Oep24. We found that both proteins can be integrated in vitro into isolated plant mitochondria. Furthermore, upon their expression in yeast cells Oep37 and Oep24 were exclusively located in the mitochondrial OM. Oep37 partially complemented the growth phenotype of yeast cells lacking Porin, the general metabolite transporter of this membrane. Similarly to mitochondrial β-barrel proteins, Oep37 and Oep24 expressed in yeast cells were assembled into the mitochondrial OM in a pathway dependent on the TOM and TOB complexes. Taken together, this study demonstrates that the central mitochondrial components that mediate the import of yeast β-barrel proteins can deal with precursors of chloroplast β-barrel proteins. This implies that the mitochondrial import machinery does not recognize signals that are unique to mitochondrial β-barrel proteins. Our results further suggest that dedicated targeting factors had to evolve in plant cells to prevent mis-sorting of chloroplast β-barrel proteins to mitochondria.
Collapse
Affiliation(s)
- Thomas Ulrich
- From the Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen and
| | - Lucia E. Gross
- the Centre of Membrane Proteomics and Cluster of Excellence Frankfurt, Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, D-60438 Frankfurt, Germany
| | - Maik S. Sommer
- the Centre of Membrane Proteomics and Cluster of Excellence Frankfurt, Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, D-60438 Frankfurt, Germany
| | - Enrico Schleiff
- the Centre of Membrane Proteomics and Cluster of Excellence Frankfurt, Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, D-60438 Frankfurt, Germany
| | - Doron Rapaport
- From the Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen and
| |
Collapse
|
22
|
Machettira AB, Groß LE, Tillmann B, Weis BL, Englich G, Sommer MS, Königer M, Schleiff E. Protein-induced modulation of chloroplast membrane morphology. FRONTIERS IN PLANT SCIENCE 2012; 2:118. [PMID: 22639631 PMCID: PMC3355639 DOI: 10.3389/fpls.2011.00118] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 12/29/2011] [Indexed: 05/24/2023]
Abstract
Organelles are surrounded by membranes with a distinct lipid and protein composition. While it is well established that lipids affect protein functioning and vice versa, it has been only recently suggested that elevated membrane protein concentrations may affect the shape and organization of membranes. We therefore analyzed the effects of high chloroplast envelope protein concentrations on membrane structures using an in vivo approach with protoplasts. Transient expression of outer envelope proteins or protein domains such as CHUP1-TM-GFP, outer envelope protein of 7 kDa-GFP, or outer envelope protein of 24 kDa-GFP at high levels led to the formation of punctate, circular, and tubular membrane protrusions. Expression of inner membrane proteins such as translocase of inner chloroplast membrane 20, isoform II (Tic20-II)-GFP led to membrane protrusions including invaginations. Using increasing amounts of DNA for transfection, we could show that the frequency, size, and intensity of these protrusions increased with protein concentration. The membrane deformations were absent after cycloheximide treatment. Co-expression of CHUP1-TM-Cherry and Tic20-II-GFP led to membrane protrusions of various shapes and sizes including some stromule-like structures, for which several functions have been proposed. Interestingly, some structures seemed to contain both proteins, while others seem to contain one protein exclusively, indicating that outer and inner envelope dynamics might be regulated independently. While it was more difficult to investigate the effects of high expression levels of membrane proteins on mitochondrial membrane shapes using confocal imaging, it was striking that the expression of the outer membrane protein Tom20 led to more elongate mitochondria. We discuss that the effect of protein concentrations on membrane structure is possibly caused by an imbalance in the lipid to protein ratio and may be involved in a signaling pathway regulating membrane biogenesis. Finally, the observed phenomenon provides a valuable experimental approach to investigate the relationship between lipid synthesis and membrane protein expression in future studies.
Collapse
Affiliation(s)
- Anu B. Machettira
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Lucia E. Groß
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Bodo Tillmann
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Benjamin L. Weis
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Gisela Englich
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Maik S. Sommer
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| | - Martina Königer
- Department of Biological Sciences, Wellesley CollegeWellesley, MA, USA
| | - Enrico Schleiff
- Molecular Cell Biology of Plants, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
- Cluster of Excellence “Macromolecular Complexes”, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
- Department of Biosciences, Center of Membrane Proteomics, Johann-Wolfgang-Goethe University FrankfurtFrankfurt am Main, Germany
| |
Collapse
|