51
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Mass spectrometry approaches to study plant endomembrane trafficking. Semin Cell Dev Biol 2017; 80:123-132. [PMID: 29042236 DOI: 10.1016/j.semcdb.2017.10.014] [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: 08/11/2017] [Accepted: 10/12/2017] [Indexed: 01/08/2023]
Abstract
Intracellular proteins reside in highly controlled microenvironments in which they perform context specific functions. Trafficking pathways have evolved that enable proteins to be precisely delivered to the correct location but also to re-locate in response to environmental perturbation. Trafficking of membrane proteins to their correct endomembrane location is especially important to enable them to carry out their function. Although a considerable amount of knowledge about membrane protein trafficking in plants has been delivered by years of dedicated research, there are still significant gaps in our understanding of this process. Further knowledge of endomembrane trafficking is dependent on thorough characterization of the subcellular components that constitute the endomembrane system. Such studies are challenging for a number of reasons including the complexity of the plant endomembrane system, inability to purify individual constituents, discrimination protein cargo for full time residents of compartments, and the fact that many proteins function at more than one location. In this review, we describe the components of the secretory pathway and focus on how mass spectrometry based proteomics methods have helped elucidation of this pathway. We demonstrate that the combination of targeted and untargeted approaches is allowing research into new areas of the secretory pathway investigation. Finally we describe new enabling technologies that will impact future studies in this area.
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52
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Singh MK, Jürgens G. Specificity of plant membrane trafficking - ARFs, regulators and coat proteins. Semin Cell Dev Biol 2017; 80:85-93. [PMID: 29024759 DOI: 10.1016/j.semcdb.2017.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 09/29/2017] [Accepted: 10/09/2017] [Indexed: 11/27/2022]
Abstract
Approximately one-third of all eukaryotic proteins are delivered to their destination by trafficking within the endomembrane system. Such cargo proteins are incorporated into forming membrane vesicles on donor compartments and delivered to acceptor compartments by vesicle fusion. How cargo proteins are sorted into forming vesicles is still largely unknown. Here we review the roles of small GTPases of the ARF/SAR1 family, their regulators designated ARF guanine-nucleotide exchange factors (ARF-GEFs) and ARF GTPase-activating proteins (ARF-GAPs) as well as coat protein complexes during membrane vesicle formation. Although conserved across eukaryotes, these four functional groups of proteins display plant-specific modifications in composition, structure and function.
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Affiliation(s)
- Manoj K Singh
- Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Gerd Jürgens
- Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
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53
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Identifying Novel Regulators of Vacuolar Trafficking by Combining Fluorescence Imaging-Based Forward Genetic Screening and In Vitro Pollen Germination. Methods Mol Biol 2017. [PMID: 28861829 DOI: 10.1007/978-1-4939-7262-3_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Subcellular targeting of vacuolar proteins depends on cellular machinery regulating vesicular trafficking. Plant-specific vacuolar trafficking routes have been reported. However, regulators mediating these processes are obscure. By combining a fluorescence imaging-based forward genetic approach and in vitro pollen germination system, we show an efficient protocol of identifying regulators of plant-specific vacuolar trafficking routes.
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54
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Feng QN, Li S, Zhang Y. Update on adaptor protein-3 in Arabidopsis. PLANT SIGNALING & BEHAVIOR 2017; 12:e1356969. [PMID: 28786748 PMCID: PMC5616146 DOI: 10.1080/15592324.2017.1356969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
Adaptor proteins (APs) mediate protein sorting within endomembrane compartments in eukaryotic cells. AP-3 is an ancient AP complex mediating vacuolar trafficking in different phyla. Only recently, a few tonoplast proteins have been identified as AP-3 cargos in Arabidopsis whereas the function of AP-3 was largely unexplored. Here, we summarize recent advances on AP-3 in Arabidopsis, pointing at the potential roles of AP-3 in plant development and cellular processes.
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Affiliation(s)
- Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
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55
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Feng QN, Song SJ, Yu SX, Wang JG, Li S, Zhang Y. Adaptor Protein-3-Dependent Vacuolar Trafficking Involves a Subpopulation of COPII and HOPS Tethering Proteins. PLANT PHYSIOLOGY 2017; 174:1609-1620. [PMID: 28559361 PMCID: PMC5490925 DOI: 10.1104/pp.17.00584] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/25/2017] [Indexed: 05/20/2023]
Abstract
Plant vacuoles are versatile organelles critical for plant growth and responses to environment. Vacuolar proteins are transported from the endoplasmic reticulum via multiple routes in plants. Two classic routes bear great similarity to other phyla with major regulators known, such as COPII and Rab5 GTPases. By contrast, vacuolar trafficking mediated by adaptor protein-3 (AP-3) or that independent of the Golgi has few recognized cargos and none of the regulators. In search of novel regulators for vacuolar trafficking routes and by using a fluorescence-based forward genetic screen, we demonstrated that the multispan transmembrane protein, Arabidopsis (Arabidopsis thaliana) PROTEIN S-ACYL TRANSFERASE10 (PAT10), is an AP-3-mediated vacuolar cargo. We show that the tonoplast targeting of PAT10 is mediated by the AP-3 complex but independent of the Rab5-mediated post-Golgi trafficking route. We also report that AP-3-mediated vacuolar trafficking involves a subpopulation of COPII and requires the vacuolar tethering complex HOPS. In addition, we have identified two novel mutant alleles of AP-3δ, whose point mutations interfered with the formation of the AP-3 complex as well as its membrane targeting. The results presented here shed new light on the vacuolar trafficking route mediated by AP-3 in plant cells.
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Affiliation(s)
- Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Shi-Jian Song
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Shi-Xia Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Jia-Gang Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
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56
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Kaur H, Sparvoli D, Osakada H, Iwamoto M, Haraguchi T, Turkewitz AP. An endosomal syntaxin and the AP-3 complex are required for formation and maturation of candidate lysosome-related secretory organelles (mucocysts) in Tetrahymena thermophila. Mol Biol Cell 2017; 28:1551-1564. [PMID: 28381425 PMCID: PMC5449153 DOI: 10.1091/mbc.e17-01-0018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/22/2017] [Accepted: 03/28/2017] [Indexed: 12/14/2022] Open
Abstract
Lysosome-related organelles (LROs) are secretory organelles formed by convergence between secretory and endosomal trafficking pathways. In Tetrahymena, secretory vesicles that resemble dense core granules are a new class of LROs whose synthesis depends on a conserved syntaxin required for heterotypic fusion and AP-3 for maturation. The ciliate Tetrahymena thermophila synthesizes large secretory vesicles called mucocysts. Mucocyst biosynthesis shares features with dense core granules (DCGs) in animal cells, including proteolytic processing of cargo proteins during maturation. However, other molecular features have suggested relatedness to lysosome-related organelles (LROs). LROs, which include diverse organelles in animals, are formed via convergence of secretory and endocytic trafficking. Here we analyzed Tetrahymena syntaxin 7-like 1 (Stx7l1p), a Qa-SNARE whose homologues in other lineages are linked with vacuoles/LROs. Stx7l1p is targeted to both immature and mature mucocysts and is essential in mucocyst formation. In STX7L1-knockout cells, the two major classes of mucocyst cargo proteins localize independently, accumulating in largely nonoverlapping vesicles. Thus initial formation of immature mucocysts involves heterotypic fusion, in which a subset of mucocyst proteins is delivered via an endolysosomal compartment. Further, we show that subsequent maturation requires AP-3, a complex widely implicated in LRO formation. Knockout of the µ-subunit gene does not impede delivery of any known mucocyst cargo but nonetheless arrests mucocyst maturation. Our data argue that secretory organelles in ciliates may represent a new class of LROs and reveal key roles of an endosomal syntaxin and AP-3 in the assembly of this complex compartment.
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Affiliation(s)
- Harsimran Kaur
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Daniela Sparvoli
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Hiroko Osakada
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Masaaki Iwamoto
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Tokuko Haraguchi
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan.,Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan
| | - Aaron P Turkewitz
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
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57
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Feng QN, Zhang Y, Li S. Tonoplast targeting of VHA-a3 relies on a Rab5-mediated but Rab7-independent vacuolar trafficking route. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:230-233. [PMID: 28198146 DOI: 10.1111/jipb.12526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/09/2017] [Indexed: 06/06/2023]
Abstract
Vacuolar trafficking routes and their regulators have recently drawn lots of attention in plant cell biology. A recent study reported the discovery of a plant-specific vacuolar trafficking route, i.e., a direct ER-to-vacuole route, through analysis of VHA-a3 subcellular targeting, a key component for the tonoplast V-ATPases. Our recent findings showed that VHA-a3 targets to the tonoplast through a Rab5-mediated but Rab7-independent pathway, shedding new lights on the unconventional vacuolar trafficking route in plant cells.
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Affiliation(s)
- Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, China
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58
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Wendrich JR, Boeren S, Möller BK, Weijers D, De Rybel B. In Vivo Identification of Plant Protein Complexes Using IP-MS/MS. Methods Mol Biol 2017; 1497:147-158. [PMID: 27864765 DOI: 10.1007/978-1-4939-6469-7_14] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Individual proteins often function as part of a protein complex. The identification of interacting proteins is therefore vital to understand the biological role and function of the studied protein. Here we describe a method for the in vivo identification of nuclear, cytoplasmic, and membrane-associated protein complexes from plant tissues using a strategy of immunoprecipitation followed by tandem mass spectrometry. By performing quantitative mass spectrometry measurements on biological triplicates, relative abundance of proteins in GFP-tagged complexes compared to background controls can be statistically evaluated to identify high-confidence interactors. We detail the entire workflow of this approach.
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Affiliation(s)
- Jos R Wendrich
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Barbara K Möller
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands.,Department of Plant Systems Biology, VIB Ghent University, 9052, Ghent, Belgium
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands.
| | - Bert De Rybel
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands.,Department of Plant Systems Biology, Flemish Institute of Biotechnology, VIB Ghent University, 9052, Ghent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
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59
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Chu YJ, Chen X, Xue HW. Ins(1,4,5)P 3 Suppresses Protein Degradation in Plant Vacuoles by Regulating SNX-Mediated Protein Sorting. MOLECULAR PLANT 2016; 9:1440-1443. [PMID: 27477682 DOI: 10.1016/j.molp.2016.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/10/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Yu-Jia Chu
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China
| | - Xu Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China
| | - Hong-Wei Xue
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
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60
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Marcote MJ, Sancho-Andrés G, Soriano-Ortega E, Aniento F. Sorting signals for PIN1 trafficking and localization. PLANT SIGNALING & BEHAVIOR 2016; 11:e1212801. [PMID: 27603315 PMCID: PMC5155414 DOI: 10.1080/15592324.2016.1212801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 05/24/2023]
Abstract
PIN-FORMED (PIN) family proteins direct polar auxin transport based on their asymmetric (polar) localization at the plasma membrane. In the case of PIN1, it mainly localizes to the basal (rootward) plasma membrane domain of stele cells in root meristems. Vesicular trafficking events, such as clathrin-dependent PIN1 endocytosis and polar recycling, are probably the main determinants for PIN1 polar localization. However, very little is known about the signals which may be involved in binding the μ-adaptin subunit of clathrin adaptor complexes (APs) for sorting of PIN1 within clathrin-coated vesicles, which can determine its trafficking and localization. We have performed a systematic mutagenesis analysis to investigate putative sorting motifs in the hydrophilic loop of PIN1. We have found that a non-canonical motif, based in a phenylalanine residue, through the binding of μA(μ2)- and μD(μ3)-adaptin, is important for PIN1 endocytosis and for PIN1 traffcking along the secretory pathway, respectively. In addition, tyrosine-based motifs, which also bind different μ-adaptins, could also contribute to PIN1 trafficking and localization.
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Affiliation(s)
- María Jesús Marcote
- Departamento de Bioquímica y Biología Molecular,
Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED),
Universitat de València, Burjassot, Spain
| | - Gloria Sancho-Andrés
- Departamento de Bioquímica y Biología Molecular,
Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED),
Universitat de València, Burjassot, Spain
| | - Esther Soriano-Ortega
- Departamento de Bioquímica y Biología Molecular,
Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED),
Universitat de València, Burjassot, Spain
| | - Fernando Aniento
- Departamento de Bioquímica y Biología Molecular,
Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED),
Universitat de València, Burjassot, Spain
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61
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Pertl-Obermeyer H, Wu XN, Schrodt J, Müdsam C, Obermeyer G, Schulze WX. Identification of Cargo for Adaptor Protein (AP) Complexes 3 and 4 by Sucrose Gradient Profiling. Mol Cell Proteomics 2016; 15:2877-89. [PMID: 27371946 DOI: 10.1074/mcp.m116.060129] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Indexed: 11/06/2022] Open
Abstract
Intracellular vesicle trafficking is a fundamental process in eukaryotic cells. It enables cellular polarity and exchange of proteins between subcellular compartments such as the plasma membrane or the vacuole. Adaptor protein complexes participate in the vesicle formation by specific selection of the transported cargo. We investigated the role of the adaptor protein complex 3 (AP-3) and adaptor protein complex 4 (AP-4) in this selection process by screening for AP-3 and AP-4 dependent cargo proteins. Specific cargo proteins are expected to be mis-targeted in knock-out mutants of adaptor protein complex components. Thus, we screened for altered distribution profiles across a density gradient of membrane proteins in wild type versus ap-3β and ap-4β knock-out mutants. In ap-3β mutants, especially proteins with transport functions, such as aquaporins and plasma membrane ATPase, as well as vesicle trafficking proteins showed differential protein distribution profiles across the density gradient. In the ap-4β mutant aquaporins but also proteins from lipid metabolism were differentially distributed. These proteins also showed differential phosphorylation patterns in ap-3β and ap-4β compared with wild type. Other proteins, such as receptor kinases were depleted from the AP-3 mutant membrane system, possibly because of degradation after mis-targeting. In AP-4 mutants, membrane fractions were depleted for cytochrome P450 proteins, cell wall proteins and receptor kinases. Analysis of water transport capacity in wild type and mutant mesophyll cells confirmed aquaporins as cargo proteins of AP-3 and AP-4. The combination of organelle density gradients with proteome analysis turned out as a suitable experimental strategy for large-scale analyses of protein trafficking.
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Affiliation(s)
- Heidi Pertl-Obermeyer
- From the ‡Department of Plant Systems Biology, University of Hohenheim, 70593 Stuttgart, Germany
| | - Xu Na Wu
- From the ‡Department of Plant Systems Biology, University of Hohenheim, 70593 Stuttgart, Germany
| | - Jens Schrodt
- From the ‡Department of Plant Systems Biology, University of Hohenheim, 70593 Stuttgart, Germany
| | - Christina Müdsam
- ¶Molecular Plant Physiology, University of Erlangen, Staudtstraβe 5, 91058 Erlangen, Germany
| | - Gerhard Obermeyer
- §Molecular Plant Biophysics and Biochemistry, Department of Molecular Biology, University of Salzburg, Billrothstraβe 11, 5020 Salzburg, Austria
| | - Waltraud X Schulze
- From the ‡Department of Plant Systems Biology, University of Hohenheim, 70593 Stuttgart, Germany;
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62
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Sancho-Andrés G, Soriano-Ortega E, Gao C, Bernabé-Orts JM, Narasimhan M, Müller AO, Tejos R, Jiang L, Friml J, Aniento F, Marcote MJ. Sorting Motifs Involved in the Trafficking and Localization of the PIN1 Auxin Efflux Carrier. PLANT PHYSIOLOGY 2016; 171:1965-82. [PMID: 27208248 PMCID: PMC4936568 DOI: 10.1104/pp.16.00373] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/11/2016] [Indexed: 05/21/2023]
Abstract
In contrast with the wealth of recent reports about the function of μ-adaptins and clathrin adaptor protein (AP) complexes, there is very little information about the motifs that determine the sorting of membrane proteins within clathrin-coated vesicles in plants. Here, we investigated putative sorting signals in the large cytosolic loop of the Arabidopsis (Arabidopsis thaliana) PIN-FORMED1 (PIN1) auxin transporter, which are involved in binding μ-adaptins and thus in PIN1 trafficking and localization. We found that Phe-165 and Tyr-280, Tyr-328, and Tyr-394 are involved in the binding of different μ-adaptins in vitro. However, only Phe-165, which binds μA(μ2)- and μD(μ3)-adaptin, was found to be essential for PIN1 trafficking and localization in vivo. The PIN1:GFP-F165A mutant showed reduced endocytosis but also localized to intracellular structures containing several layers of membranes and endoplasmic reticulum (ER) markers, suggesting that they correspond to ER or ER-derived membranes. While PIN1:GFP localized normally in a μA (μ2)-adaptin mutant, it accumulated in big intracellular structures containing LysoTracker in a μD (μ3)-adaptin mutant, consistent with previous results obtained with mutants of other subunits of the AP-3 complex. Our data suggest that Phe-165, through the binding of μA (μ2)- and μD (μ3)-adaptin, is important for PIN1 endocytosis and for PIN1 trafficking along the secretory pathway, respectively.
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Affiliation(s)
- Gloria Sancho-Andrés
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Esther Soriano-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Caiji Gao
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Joan Miquel Bernabé-Orts
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Madhumitha Narasimhan
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Anna Ophelia Müller
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Ricardo Tejos
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Liwen Jiang
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Jiří Friml
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - Fernando Aniento
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
| | - María Jesús Marcote
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universitat de Valencia, 46100 Burjassot, Spain (G.S.-A., E.S.-O., J.M.B.-O., F.A., M.J.M.);Institute of Science and Technology Austria, 3400 Klostenburg, Austria (M.N., A.O.M., R.T., J.F.); andSchool of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Hong Kong, China (C.G., L.J.)
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Pei X, Fan F, Lin L, Chen Y, Sun W, Zhang S, Tian C. Involvement of the adaptor protein 3 complex in lignocellulase secretion in Neurospora crassa revealed by comparative genomic screening. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:124. [PMID: 26300971 PMCID: PMC4545925 DOI: 10.1186/s13068-015-0302-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/30/2015] [Indexed: 06/02/2023]
Abstract
BACKGROUND Lignocellulase hypersecretion has been achieved in industrial fungal workhorses such as Trichoderma reesei, but the underlying mechanism associated with this process is not well understood. Although previous comparative genomic studies have revealed that the mutagenic T. reesei strain RUT-C30 harbors hundreds of mutations compared with its parental strain QM6a, how these mutations actually contribute to the hypersecretion phenotype remains to be elucidated. RESULTS In this study, we systematically screened gene knockout (KO) mutants in the cellulolytic fungus Neurospora crassa, which contains orthologs of potentially defective T. reesei RUT-C30 mutated genes. Of the 86 deletion mutants screened in N. crassa, 12 exhibited lignocellulase production more than 25% higher than in the wild-type (WT) strain and 4 showed nearly 25% lower secretion. We observed that the deletion of Ncap3m (NCU03998), which encodes the μ subunit of the adaptor protein 3 (AP-3) complex in N. crassa, led to the most significant increase in lignocellulase secretion under both Avicel and xylan culture conditions. Moreover, strains lacking the β subunit of the AP-3 complex, encoded by Ncap3b (NCU06569), had a similar phenotype to ΔNcap3m, suggesting that the AP-3 complex is involved in lignocellulase secretion in N. crassa. We also found that the transcriptional abundance of major lignocellulase genes in ΔNcap3m was maintained at a relatively higher level during the late stage of fermentation compared with the WT, which might add to the hypersecretion phenotype. Finally, we found that importation of the T. reesei ap3m ortholog Trap3m into ΔNcap3m can genetically restore secretion of lignocellulases to normal levels, which suggests that the effect of the AP-3 complex on lignocellulase secretion is conserved in cellulolytic ascomycetes. CONCLUSIONS Using the model cellulolytic fungus N. crassa, we explored potential hypersecretion-related mutations in T. reesei strain RUT-C30. Through systematic genetic screening of 86 corresponding orthologous KO mutants in N. crassa, we identified several genes, particularly those encoding the AP-3 complex that contribute to lignocellulase secretion. These findings will be useful for strain improvement in future lignocellulase and biomass-based chemical production.
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Affiliation(s)
- Xue Pei
- />College of Plant Sciences, Jilin University, Changchun, 130062 China
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Feiyu Fan
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Liangcai Lin
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Yong Chen
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Wenliang Sun
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Shihong Zhang
- />College of Plant Sciences, Jilin University, Changchun, 130062 China
| | - Chaoguang Tian
- />Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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Hedrich R, Sauer N, Neuhaus HE. Sugar transport across the plant vacuolar membrane: nature and regulation of carrier proteins. CURRENT OPINION IN PLANT BIOLOGY 2015; 25:63-70. [PMID: 26000864 DOI: 10.1016/j.pbi.2015.04.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 04/16/2015] [Accepted: 04/30/2015] [Indexed: 05/06/2023]
Abstract
The ability of higher plants to store sugars is of crucial importance for plant development, adaption to endogenous or environmental cues and for the economic value of crop species. Sugar storage and accumulation, and its homeostasis in plant cells are managed by the vacuole. Although transport of sugars across the vacuolar membrane has been monitored for about four decades, the molecular entities of the transporters involved have been identified in the last 10 years only. Thus, it is just recently that our pictures of the transporters that channel the sugar load across the tonoplast have gained real shape. Here we describe the molecular nature and regulation of an important group of tonoplast sugar transporter (TST) allowing accumulation of sugars against large concentration gradients. In addition, we report on proton-driven tonoplast sugar exporters and on facilitators, which are also involved in balancing cytosolic and vacuolar sugar levels.
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Affiliation(s)
- Rainer Hedrich
- Molecular Plant Physiology and Biophysics, University of Würzburg, Germany
| | - Norbert Sauer
- Molecular Plant Physiology, University of Erlangen-Nuremberg, Germany
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Teh OK, Hatsugai N, Tamura K, Fuji K, Tabata R, Yamaguchi K, Shingenobu S, Yamada M, Hasebe M, Sawa S, Shimada T, Hara-Nishimura I. BEACH-domain proteins act together in a cascade to mediate vacuolar protein trafficking and disease resistance in Arabidopsis. MOLECULAR PLANT 2015; 8:389-98. [PMID: 25618824 DOI: 10.1016/j.molp.2014.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 10/21/2014] [Accepted: 11/12/2014] [Indexed: 05/08/2023]
Abstract
Membrane trafficking to the protein storage vacuole (PSV) is a specialized process in seed plants. However, this trafficking mechanism to PSV is poorly understood. Here, we show that three types of Beige and Chediak-Higashi (BEACH)-domain proteins contribute to both vacuolar protein transport and effector-triggered immunity (ETI). We screened a green fluorescent seed (GFS) library of Arabidopsis mutants with defects in vesicle trafficking and isolated two allelic mutants gfs3 and gfs12 with a defect in seed protein transport to PSV. The gene responsible for the mutant phenotype was found to encode a putative protein belonging to group D of BEACH-domain proteins, which possess kinase domains. Disruption of other BEACH-encoding loci in the gfs12 mutant showed that BEACH homologs acted in a cascading manner for PSV trafficking. The epistatic genetic interactions observed among BEACH homologs were also found in the ETI responses of the gfs12 and gfs12 bchb-1 mutants, which showed elevated avirulent bacterial growth. The GFS12 kinase domain interacted specifically with the pleckstrin homology domain of BchC1. These results suggest that a cascade of multiple BEACH-domain proteins contributes to vacuolar protein transport and plant defense.
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Affiliation(s)
- Ooi-kock Teh
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Noriyuki Hatsugai
- Research Centre for Cooperative Projects, Hokkaido University, Kita-ku, Sapporo 060-8638, Japan
| | - Kentaro Tamura
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kentaro Fuji
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Ryo Tabata
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Katsushi Yamaguchi
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Shuji Shingenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Masashi Yamada
- Department of Biology and IGSP Center for Systems Biology, Duke University, Durham, NC 27708, USA
| | - Mitsuyasu Hasebe
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; School of Life Science, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
| | - Shinichiro Sawa
- Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
| | - Tomoo Shimada
- Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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Adamowski M, Friml J. PIN-dependent auxin transport: action, regulation, and evolution. THE PLANT CELL 2015; 27:20-32. [PMID: 25604445 PMCID: PMC4330589 DOI: 10.1105/tpc.114.134874] [Citation(s) in RCA: 489] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 12/01/2014] [Accepted: 01/05/2015] [Indexed: 05/18/2023]
Abstract
Auxin participates in a multitude of developmental processes, as well as responses to environmental cues. Compared with other plant hormones, auxin exhibits a unique property, as it undergoes directional, cell-to-cell transport facilitated by plasma membrane-localized transport proteins. Among them, a prominent role has been ascribed to the PIN family of auxin efflux facilitators. PIN proteins direct polar auxin transport on account of their asymmetric subcellular localizations. In this review, we provide an overview of the multiple developmental roles of PIN proteins, including the atypical endoplasmic reticulum-localized members of the family, and look at the family from an evolutionary perspective. Next, we cover the cell biological and molecular aspects of PIN function, in particular the establishment of their polar subcellular localization. Hormonal and environmental inputs into the regulation of PIN action are summarized as well.
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Affiliation(s)
- Maciek Adamowski
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Jiří Friml
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
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67
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Zouhar J, Sauer M. Helping hands for budding prospects: ENTH/ANTH/VHS accessory proteins in endocytosis, vacuolar transport, and secretion. THE PLANT CELL 2014; 26:4232-44. [PMID: 25415979 PMCID: PMC4277227 DOI: 10.1105/tpc.114.131680] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/31/2014] [Accepted: 11/13/2014] [Indexed: 05/18/2023]
Abstract
Coated vesicles provide a major mechanism for the transport of proteins through the endomembrane system of plants. Transport between the endoplasmic reticulum and the Golgi involves vesicles with COPI and COPII coats, whereas clathrin is the predominant coat in endocytosis and post-Golgi trafficking. Sorting of cargo, coat assembly, budding, and fission are all complex and tightly regulated processes that involve many proteins. The mechanisms and responsible factors are largely conserved in eukaryotes, and increasing organismal complexity tends to be associated with a greater numbers of individual family members. Among the key factors is the class of ENTH/ANTH/VHS domain-containing proteins, which link membrane subdomains, clathrin, and other adapter proteins involved in early steps of clathrin coated vesicle formation. More than 30 Arabidopsis thaliana proteins contain this domain, but their generally low sequence conservation has made functional classification difficult. Reports from the last two years have greatly expanded our knowledge of these proteins and suggest that ENTH/ANTH/VHS domain proteins are involved in various instances of clathrin-related endomembrane trafficking in plants. This review aims to summarize these new findings and discuss the broader context of clathrin-dependent plant vesicular transport.
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Affiliation(s)
- Jan Zouhar
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, 28223 Madrid, Spain
| | - Michael Sauer
- Institute for Bichemistry and Biology, University of Potsdam, 10627 Potsdam, Germany
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68
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Wang X, Cai Y, Wang H, Zeng Y, Zhuang X, Li B, Jiang L. Trans-Golgi network-located AP1 gamma adaptins mediate dileucine motif-directed vacuolar targeting in Arabidopsis. THE PLANT CELL 2014; 26:4102-18. [PMID: 25351491 PMCID: PMC4247576 DOI: 10.1105/tpc.114.129759] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/17/2014] [Accepted: 09/29/2014] [Indexed: 05/18/2023]
Abstract
Membrane proteins on the tonoplast are indispensible for vacuolar functions in plants. However, how these proteins are transported to the vacuole and how they become separated from plasma membrane proteins remain largely unknown. In this study, we used Arabidopsis thaliana vacuolar ion transporter1 (VIT1) as a reporter to study the mechanisms of tonoplast targeting. We showed that VIT1 reached the tonoplast through a pathway involving the endoplasmic reticulum (ER), Golgi, trans-Golgi network (TGN), prevacuolar compartment, and tonoplast. VIT1 contains a putative N-terminal dihydrophobic type ER export signal, and its N terminus has a conserved dileucine motif (EKQTLL), which is responsible for tonoplast targeting. In vitro peptide binding assays with synthetic VIT1 N terminus identified adaptor protein complex-1 (AP1) subunits that interacted with the dileucine motif. A deficiency of AP1 gamma adaptins in Arabidopsis cells caused relocation of tonoplast proteins containing the dileucine motif, such as VIT1 and inositol transporter1, to the plasma membrane. The dileucine motif also effectively rerouted the plasma membrane protein SCAMP1 to the tonoplast. Together with subcellular localization studies showing that AP1 gamma adaptins localize to the TGN, we propose that the AP1 complex on the TGN mediates tonoplast targeting of membrane proteins with the dileucine motif.
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Affiliation(s)
- Xiangfeng Wang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yi Cai
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Hao Wang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Yonglun Zeng
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Xiaohong Zhuang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Baiying Li
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Liwen Jiang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen 518057, China
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69
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Zhang C, Hicks GR, Raikhel NV. Plant vacuole morphology and vacuolar trafficking. FRONTIERS IN PLANT SCIENCE 2014; 5:476. [PMID: 25309565 PMCID: PMC4173805 DOI: 10.3389/fpls.2014.00476] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/29/2014] [Indexed: 05/23/2023]
Abstract
Plant vacuoles are essential organelles for plant growth and development, and have multiple functions. Vacuoles are highly dynamic and pleiomorphic, and their size varies depending on the cell type and growth conditions. Vacuoles compartmentalize different cellular components such as proteins, sugars, ions and other secondary metabolites and play critical roles in plants response to different biotic/abiotic signaling pathways. In this review, we will summarize the patterns of changes in vacuole morphology in certain cell types, our understanding of the mechanisms of plant vacuole biogenesis, and the role of SNAREs and Rab GTPases in vacuolar trafficking.
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Affiliation(s)
- Chunhua Zhang
- *Correspondence: Chunhua Zhang, Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California at Riverside, 900 University Avenue, Riverside, CA 92521, USA e-mail:
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70
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Paul P, Simm S, Mirus O, Scharf KD, Fragkostefanakis S, Schleiff E. The complexity of vesicle transport factors in plants examined by orthology search. PLoS One 2014; 9:e97745. [PMID: 24844592 PMCID: PMC4028247 DOI: 10.1371/journal.pone.0097745] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/24/2014] [Indexed: 11/18/2022] Open
Abstract
Vesicle transport is a central process to ensure protein and lipid distribution in eukaryotic cells. The current knowledge on the molecular components and mechanisms of this process is majorly based on studies in Saccharomyces cerevisiae and Arabidopsis thaliana, which revealed 240 different proteinaceous factors either experimentally proven or predicted to be involved in vesicle transport. In here, we performed an orthologue search using two different algorithms to identify the components of the secretory pathway in yeast and 14 plant genomes by using the 'core-set' of 240 factors as bait. We identified 4021 orthologues and (co-)orthologues in the discussed plant species accounting for components of COP-II, COP-I, Clathrin Coated Vesicles, Retromers and ESCRTs, Rab GTPases, Tethering factors and SNAREs. In plants, we observed a significantly higher number of (co-)orthologues than yeast, while only 8 tethering factors from yeast seem to be absent in the analyzed plant genomes. To link the identified (co-)orthologues to vesicle transport, the domain architecture of the proteins from yeast, genetic model plant A. thaliana and agriculturally relevant crop Solanum lycopersicum has been inspected. For the orthologous groups containing (co-)orthologues from yeast, A. thaliana and S. lycopersicum, we observed the same domain architecture for 79% (416/527) of the (co-)orthologues, which documents a very high conservation of this process. Further, publically available tissue-specific expression profiles for a subset of (co-)orthologues found in A. thaliana and S. lycopersicum suggest that some (co-)orthologues are involved in tissue-specific functions. Inspection of localization of the (co-)orthologues based on available proteome data or localization predictions lead to the assignment of plastid- as well as mitochondrial localized (co-)orthologues of vesicle transport factors and the relevance of this is discussed.
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Affiliation(s)
- Puneet Paul
- Department of Biosciences Molecular Cell Biology of Plants
| | - Stefan Simm
- Department of Biosciences Molecular Cell Biology of Plants
| | - Oliver Mirus
- Department of Biosciences Molecular Cell Biology of Plants
| | | | | | - Enrico Schleiff
- Department of Biosciences Molecular Cell Biology of Plants
- Cluster of Excellence Frankfurt
- Center of Membrane Proteomics; Goethe University Frankfurt, Frankfurt/Main, Germany
- * E-mail:
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71
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Kania U, Fendrych M, Friml J. Polar delivery in plants; commonalities and differences to animal epithelial cells. Open Biol 2014; 4:140017. [PMID: 24740985 PMCID: PMC4043115 DOI: 10.1098/rsob.140017] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Although plant and animal cells use a similar core mechanism to deliver proteins
to the plasma membrane, their different lifestyle, body organization and
specific cell structures resulted in the acquisition of regulatory mechanisms
that vary in the two kingdoms. In particular, cell polarity regulators do not
seem to be conserved, because genes encoding key components are absent in plant
genomes. In plants, the broad knowledge on polarity derives from the study of
auxin transporters, the PIN-FORMED proteins, in the model plant
Arabidopsis thaliana. In animals, much information is
provided from the study of polarity in epithelial cells that exhibit basolateral
and luminal apical polarities, separated by tight junctions. In this review, we
summarize the similarities and differences of the polarization mechanisms
between plants and animals and survey the main genetic approaches that have been
used to characterize new genes involved in polarity establishment in plants,
including the frequently used forward and reverse genetics screens as well as a
novel chemical genetics approach that is expected to overcome the limitation of
classical genetics methods.
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Affiliation(s)
- Urszula Kania
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
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72
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Robinson DG, Pimpl P. Clathrin and post-Golgi trafficking: a very complicated issue. TRENDS IN PLANT SCIENCE 2014; 19:134-9. [PMID: 24263003 DOI: 10.1016/j.tplants.2013.10.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/18/2013] [Accepted: 10/21/2013] [Indexed: 05/21/2023]
Abstract
Clathrin-coated vesicles (CCVs) are formed at the plasma membrane and act as vectors for endocytosis. They also assemble at the trans-Golgi network (TGN), but their exact function at this organelle is unclear. Recent studies have examined the effects on vacuolar and secretory protein transport of knockout mutations of the adaptor protein 1 (AP1) μ-adaptin subunit AP1M, but these investigations do not clarify the situation. These mutations lead to the abrogation of multiple trafficking pathways at the TGN and cannot be used as evidence in favour of CCVs being agents for receptor-mediated export of vacuolar proteins out of the TGN. This transport process could just as easily occur through the maturation of the TGN into intermediate compartments that subsequently fuse with the vacuole.
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Affiliation(s)
- David G Robinson
- Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg, Germany.
| | - Peter Pimpl
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
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73
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SAC phosphoinositide phosphatases at the tonoplast mediate vacuolar function in Arabidopsis. Proc Natl Acad Sci U S A 2014; 111:2818-23. [PMID: 24550313 DOI: 10.1073/pnas.1324264111] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Phosphatidylinositol (PtdIns) is a structural phospholipid that can be phosphorylated into various lipid signaling molecules, designated polyphosphoinositides (PPIs). The reversible phosphorylation of PPIs on the 3, 4, or 5 position of inositol is performed by a set of organelle-specific kinases and phosphatases, and the characteristic head groups make these molecules ideal for regulating biological processes in time and space. In yeast and mammals, PtdIns3P and PtdIns(3,5)P2 play crucial roles in trafficking toward the lytic compartments, whereas the role in plants is not yet fully understood. Here we identified the role of a land plant-specific subgroup of PPI phosphatases, the suppressor of actin 2 (SAC2) to SAC5, during vacuolar trafficking and morphogenesis in Arabidopsis thaliana. SAC2-SAC5 localize to the tonoplast along with PtdIns3P, the presumable product of their activity. In SAC gain- and loss-of-function mutants, the levels of PtdIns monophosphates and bisphosphates were changed, with opposite effects on the morphology of storage and lytic vacuoles, and the trafficking toward the vacuoles was defective. Moreover, multiple sac knockout mutants had an increased number of smaller storage and lytic vacuoles, whereas extralarge vacuoles were observed in the overexpression lines, correlating with various growth and developmental defects. The fragmented vacuolar phenotype of sac mutants could be mimicked by treating wild-type seedlings with PtdIns(3,5)P2, corroborating that this PPI is important for vacuole morphology. Taken together, these results provide evidence that PPIs, together with their metabolic enzymes SAC2-SAC5, are crucial for vacuolar trafficking and for vacuolar morphology and function in plants.
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74
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Gadeyne A, Sánchez-Rodríguez C, Vanneste S, Di Rubbo S, Zauber H, Vanneste K, Van Leene J, De Winne N, Eeckhout D, Persiau G, Van De Slijke E, Cannoot B, Vercruysse L, Mayers J, Adamowski M, Kania U, Ehrlich M, Schweighofer A, Ketelaar T, Maere S, Bednarek S, Friml J, Gevaert K, Witters E, Russinova E, Persson S, De Jaeger G, Van Damme D. The TPLATE Adaptor Complex Drives Clathrin-Mediated Endocytosis in Plants. Cell 2014; 156:691-704. [DOI: 10.1016/j.cell.2014.01.039] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 10/28/2013] [Accepted: 01/16/2014] [Indexed: 10/25/2022]
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Uehara M, Wang S, Kamiya T, Shigenobu S, Yamaguchi K, Fujiwara T, Naito S, Takano J. Identification and Characterization of an Arabidopsis Mutant with Altered Localization of NIP5;1, a Plasma Membrane Boric Acid Channel, Reveals the Requirement for d-Galactose in Endomembrane Organization. ACTA ACUST UNITED AC 2014; 55:704-14. [DOI: 10.1093/pcp/pct191] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Viotti C. ER and vacuoles: never been closer. FRONTIERS IN PLANT SCIENCE 2014; 5:20. [PMID: 24550928 PMCID: PMC3913007 DOI: 10.3389/fpls.2014.00020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 01/17/2014] [Indexed: 05/02/2023]
Abstract
The endoplasmic reticulum (ER) represents the gateway for intracellular trafficking of membrane proteins, soluble cargoes and lipids. In all eukaryotes, the best described mechanism of exiting the ER is via COPII-coated vesicles, which transport both membrane proteins and soluble cargoes to the cis-Golgi. The vacuole, together with the plasma membrane, is the most distal point of the secretory pathway, and many vacuolar proteins are transported from the ER through intermediate compartments. However, past results and recent findings demonstrate the presence of alternative transport routes from the ER towards the tonoplast, which are independent of Golgi- and post-Golgi trafficking. Moreover, the transport mechanism of the vacuolar proton pumps VHA-a3 and AVP1 challenges the current model of vacuole biogenesis, pointing to the endoplasmic reticulum for being the main membrane source for the biogenesis of the plant lytic compartment. This review gives an overview of the current knowledge on the transport routes towards the vacuole and discusses the possible mechanism of vacuole biogenesis in plants.
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Affiliation(s)
- Corrado Viotti
- *Correspondence: Corrado Viotti, Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Linnéusväg 6, 90187 Umeå, Sweden e-mail:
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Baisa GA, Mayers JR, Bednarek SY. Budding and braking news about clathrin-mediated endocytosis. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:718-25. [PMID: 24139529 DOI: 10.1016/j.pbi.2013.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 05/07/2023]
Abstract
Clathrin-mediated endocytosis (CME) is the predominate mechanism of endocytosis in eukaryotes, but an understanding of this mechanism in plants has lagged behind yeast and mammalian systems. The generation of Arabidopsis mutant libraries, and the development of the molecular tools and equipment necessary to characterize these plant lines has led to an astonishing number of new insights into the mechanisms of membrane trafficking in plants. Over the past few years progress has been made on identifying, and in some instances confirming, the core components of CME in plants. This review focuses on the recent progress made in the understanding of the mechanism and regulation of CME in plants.
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Affiliation(s)
- Gary A Baisa
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
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Kansup J, Tsugama D, Liu S, Takano T. The Arabidopsis adaptor protein AP-3μ interacts with the G-protein β subunit AGB1 and is involved in abscisic acid regulation of germination and post-germination development. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:5611-21. [PMID: 24098050 PMCID: PMC3871816 DOI: 10.1093/jxb/ert327] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Heterotrimeric G-proteins (G-proteins) have been implicated in ubiquitous signalling mechanisms in eukaryotes. In plants, G-proteins modulate hormonal and stress responses and regulate diverse developmental processes. However, the molecular mechanisms of their functions are largely unknown. A yeast two-hybrid screen was performed to identify interacting partners of the Arabidopsis G-protein β subunit AGB1. One of the identified AGB1-interacting proteins is the Arabidopsis adaptor protein AP-3µ. The interaction between AGB1 and AP-3µ was confirmed by an in vitro pull-down assay and bimolecular fluorescence complementation assay. Two ap-3µ T-DNA insertional mutants were found to be hyposensitive to abscisic acid (ABA) during germination and post-germination growth, whereas agb1 mutants were hypersensitive to ABA. During seed germination, agb1/ap-3µ double mutants were more sensitive to ABA than the wild type but less sensitive than agb1 mutants. However, in post-germination growth, the double mutants were as sensitive to ABA as agb1 mutants. These data suggest that AP-3µ positively regulates the ABA responses independently of AGB1 in seed germination, while AP-3µ does require AGB1 to regulate ABA responses during post-germination growth.
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Affiliation(s)
- Jeeraporn Kansup
- Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan
| | - Daisuke Tsugama
- Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan
- Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113–8657, Japan
- * Present address: Biology Department, 208 Mueller Laboratory, Pennsylvania State University, University Park, PA 16802, USA
| | - Shenkui Liu
- Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin 150040, China
| | - Tetsuo Takano
- Asian Natural Environmental Science Center, The University of Tokyo, Nishitokyo, Tokyo 188-0002, Japan
- To whom correspondence should be addressed. E-mail:
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Nodzynski T, Feraru MI, Hirsch S, De Rycke R, Niculaes C, Boerjan W, Van Leene J, De Jaeger G, Vanneste S, Friml J. Retromer subunits VPS35A and VPS29 mediate prevacuolar compartment (PVC) function in Arabidopsis. MOLECULAR PLANT 2013; 6:1849-62. [PMID: 23770835 DOI: 10.1093/mp/sst044] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Intracellular protein routing is mediated by vesicular transport which is tightly regulated in eukaryotes. The protein and lipid homeostasis depends on coordinated delivery of de novo synthesized or recycled cargoes to the plasma membrane by exocytosis and their subsequent removal by rerouting them for recycling or degradation. Here, we report the characterization of protein affected trafficking 3 (pat3) mutant that we identified by an epifluorescence-based forward genetic screen for mutants defective in subcellular distribution of Arabidopsis auxin transporter PIN1-GFP. While pat3 displays largely normal plant morphology and development in nutrient-rich conditions, it shows strong ectopic intracellular accumulations of different plasma membrane cargoes in structures that resemble prevacuolar compartments (PVC) with an aberrant morphology. Genetic mapping revealed that pat3 is defective in vacuolar protein sorting 35A (VPS35A), a putative subunit of the retromer complex that mediates retrograde trafficking between the PVC and trans-Golgi network. Similarly, a mutant defective in another retromer subunit, vps29, shows comparable subcellular defects in PVC morphology and protein accumulation. Thus, our data provide evidence that the retromer components VPS35A and VPS29 are essential for normal PVC morphology and normal trafficking of plasma membrane proteins in plants. In addition, we show that, out of the three VPS35 retromer subunits present in Arabidopsis thaliana genome, the VPS35 homolog A plays a prevailing role in trafficking to the lytic vacuole, presenting another level of complexity in the retromer-dependent vacuolar sorting.
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Affiliation(s)
- Tomasz Nodzynski
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University (MU), Kamenice 5, CZ-625 00, Brno, Czech Republic
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80
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Rojas-Pierce M. Targeting of tonoplast proteins to the vacuole. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 211:132-136. [PMID: 23987818 DOI: 10.1016/j.plantsci.2013.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/08/2013] [Accepted: 07/10/2013] [Indexed: 06/02/2023]
Abstract
Vacuoles are essential for plant growth and development, and are dynamic compartments that require constant deposition of integral membrane proteins. These membrane proteins carry out many critical functions of the vacuole such as transporting ions and metabolites for vacuolar storage. Understanding the mechanisms for targeting proteins to the vacuolar membrane, or tonoplast, is important for developing novel applications for biotechnology. The mechanisms to target tonoplast proteins to the vacuole are quite complex. Multiple routes, including both Golgi-dependent and Golgi-independent mechanisms, have been implicated in tonoplast protein trafficking. A few endomembrane proteins that regulate this traffic at the level of the endoplasmic reticulum, the pre-vacuolar compartment and the tonoplast are now known. Recent reports indicate that the Golgi-dependent and independent pathways may merge at the level of the pre-vacuolar compartment. Finally, the small GTP-binding protein Rab7 and the SNARE protein SYP21 have been implicated in the traffic of tonoplast proteins from the pre-vacuolar compartment to the tonoplast. With multiple cargo proteins being analyzed under a variety of experimental systems, a clearer picture for targeting mechanisms for tonoplast proteins is starting to emerge.
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Affiliation(s)
- Marcela Rojas-Pierce
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, United States.
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81
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Fan L, Hao H, Xue Y, Zhang L, Song K, Ding Z, Botella MA, Wang H, Lin J. Dynamic analysis of Arabidopsis AP2 σ subunit reveals a key role in clathrin-mediated endocytosis and plant development. Development 2013; 140:3826-37. [DOI: 10.1242/dev.095711] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Clathrin-mediated endocytosis, which depends on the AP2 complex, plays an essential role in many cellular and developmental processes in mammalian cells. However, the function of the AP2 complex in plants remains largely unexplored. Here, we show in Arabidopsis that the AP2 σ subunit mutant (ap2 σ) displays various developmental defects that are similar to those of mutants defective in auxin transport and/or signaling, including single, trumpet-shaped and triple cotyledons, impaired vascular pattern, reduced vegetative growth, defective silique development and drastically reduced fertility. We demonstrate that AP2 σ is closely associated and physically interacts with the clathrin light chain (CLC) in vivo using fluorescence cross-correlation spectroscopy (FCCS), protein proximity analyses and co-immunoprecipitation assays. Using variable-angle total internal reflection fluorescence microscopy (VA-TIRFM), we show that AP2 σ-mCherry spots colocalize with CLC-EGFP at the plasma membrane, and that AP2 σ-mCherry fluorescence appears and disappears before CLC-EGFP fluorescence. The density and turnover rate of the CLC-EGFP spots are significantly reduced in the ap2 σ mutant. The internalization and recycling of the endocytic tracer FM4-64 and the auxin efflux carrier protein PIN1 are also significantly reduced in the ap2 σ mutant. Further, the polar localization of PIN1-GFP is significantly disrupted during embryogenesis in the ap2 σ mutant. Taken together, our results support an essential role of AP2 σ in the assembly of a functional AP2 complex in plants, which is required for clathrin-mediated endocytosis, polar auxin transport and plant growth regulation.
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Affiliation(s)
- Lusheng Fan
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huaiqing Hao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Yiqun Xue
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liang Zhang
- College of Life Science, Henan Normal University, Xinxiang 453007, China
| | - Kai Song
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaojun Ding
- School of Life Sciences, Shandong University, Jinan 250100, China
| | - Miguel A. Botella
- Departamento de Biología Celular, Genética y Fisiología, Universidad de Málaga, 29071 Malaga, Spain
| | - Haiyang Wang
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520-8104, USA
| | - Jinxing Lin
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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82
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Offringa R, Huang F. Phosphorylation-dependent trafficking of plasma membrane proteins in animal and plant cells. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:789-808. [PMID: 23945267 DOI: 10.1111/jipb.12096] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/02/2013] [Indexed: 05/27/2023]
Abstract
In both unicellular and multicellular organisms, transmembrane (TM) proteins are sorted to and retained at specific membrane domains by endomembrane trafficking mechanisms that recognize sorting signals in the these proteins. The trafficking and distribution of plasma membrane (PM)-localized TM proteins (PM proteins), especially of those PM proteins that show an asymmetric distribution over the PM, has received much attention, as their proper PM localization is crucial for elementary signaling and transport processes, and defects in their localization often lead to severe disease symptoms or developmental defects. The subcellular localization of PM proteins is dynamically regulated by post-translational modifications, such as phosphorylation and ubiquitination. These modificaitons mostly occur on sorting signals that are located in the larger cytosolic domains of the cargo proteins. Here we review the effects of phosphorylation of PM proteins on their trafficking, and present the key examples from the animal field that have been subject to studies for already several decades, such as that of aquaporin 2 and the epidermal growth factor receptor. Our knowledge on cargo trafficking in plants is largely based on studies of the family of PIN FORMED (PIN) carriers that mediate the efflux of the plant hormone auxin. We will review what is known on the subcellular distribution and trafficking of PIN proteins, with a focus on how this is modulated by phosphorylation, and identify and discuss analogies and differences in trafficking with the well-studied animal examples.
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Affiliation(s)
- Remko Offringa
- Molecular and Developmental Genetics, Institute Biology Leiden, Sylvius Laboratory, Sylviusweg 72, 2333 BE Leiden, Leiden University, The Netherlands
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83
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Wang JG, Li S, Zhao XY, Zhou LZ, Huang GQ, Feng C, Zhang Y. HAPLESS13, the Arabidopsis μ1 adaptin, is essential for protein sorting at the trans-Golgi network/early endosome. PLANT PHYSIOLOGY 2013; 162:1897-910. [PMID: 23766365 PMCID: PMC3729769 DOI: 10.1104/pp.113.221051] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/11/2013] [Indexed: 05/20/2023]
Abstract
In plant cells, secretory and endocytic routes intersect at the trans-Golgi network (TGN)/early endosome (EE), where cargos are further sorted correctly and in a timely manner. Cargo sorting is essential for plant survival and therefore necessitates complex molecular machinery. Adaptor proteins (APs) play key roles in this process by recruiting coat proteins and selecting cargos for different vesicle carriers. The µ1 subunit of AP-1 in Arabidopsis (Arabidopsis thaliana) was recently identified at the TGN/EE and shown to be essential for cytokinesis. However, little was known about other cellular activities affected by mutations in AP-1 or the developmental consequences of such mutations. We report here that HAPLESS13 (HAP13), the Arabidopsis µ1 adaptin, is essential for protein sorting at the TGN/EE. Functional loss of HAP13 displayed pleiotropic developmental defects, some of which were suggestive of disrupted auxin signaling. Consistent with this, the asymmetric localization of PIN-FORMED2 (PIN2), an auxin transporter, was compromised in the mutant. In addition, cell morphogenesis was disrupted. We further demonstrate that HAP13 is critical for brefeldin A-sensitive but wortmannin-insensitive post-Golgi trafficking. Our results show that HAP13 is a key link in the sophisticated trafficking network in plant cells.
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84
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Di Rubbo S, Irani NG, Kim SY, Xu ZY, Gadeyne A, Dejonghe W, Vanhoutte I, Persiau G, Eeckhout D, Simon S, Song K, Kleine-Vehn J, Friml J, De Jaeger G, Van Damme D, Hwang I, Russinova E. The clathrin adaptor complex AP-2 mediates endocytosis of brassinosteroid insensitive1 in Arabidopsis. THE PLANT CELL 2013; 25:2986-97. [PMID: 23975899 PMCID: PMC3784593 DOI: 10.1105/tpc.113.114058] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/22/2013] [Accepted: 08/06/2013] [Indexed: 05/18/2023]
Abstract
Clathrin-mediated endocytosis (CME) regulates many aspects of plant development, including hormone signaling and responses to environmental stresses. Despite the importance of this process, the machinery that regulates CME in plants is largely unknown. In mammals, the heterotetrameric adaptor protein complex-2 (AP-2) is required for the formation of clathrin-coated vesicles at the plasma membrane (PM). Although the existence of AP-2 has been predicted in Arabidopsis thaliana, the biochemistry and functionality of the complex is still uncharacterized. Here, we identified all the subunits of the Arabidopsis AP-2 by tandem affinity purification and found that one of the large AP-2 subunits, AP2A1, localized at the PM and interacted with clathrin. Furthermore, endocytosis of the leucine-rich repeat receptor kinase, brassinosteroid insensitive1 (BRI1), was shown to depend on AP-2. Knockdown of the two Arabidopsis AP2A genes or overexpression of a dominant-negative version of the medium AP-2 subunit, AP2M, impaired BRI1 endocytosis and enhanced the brassinosteroid signaling. Our data reveal that the CME machinery in Arabidopsis is evolutionarily conserved and that AP-2 functions in receptor-mediated endocytosis.
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Affiliation(s)
- Simone Di Rubbo
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Niloufer G. Irani
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Soo Youn Kim
- Division of Molecules and Life Sciences and Center for Plant Intracellular Trafficking, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Zheng-Yi Xu
- Division of Molecules and Life Sciences and Center for Plant Intracellular Trafficking, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Astrid Gadeyne
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Wim Dejonghe
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Isabelle Vanhoutte
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Geert Persiau
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Dominique Eeckhout
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Sibu Simon
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Kyungyoung Song
- Division of Molecules and Life Sciences and Center for Plant Intracellular Trafficking, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Jürgen Kleine-Vehn
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Jiří Friml
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Geert De Jaeger
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Daniël Van Damme
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
| | - Inhwan Hwang
- Division of Molecules and Life Sciences and Center for Plant Intracellular Trafficking, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Eugenia Russinova
- Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Address correspondence to
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85
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Kim SY, Xu ZY, Song K, Kim DH, Kang H, Reichardt I, Sohn EJ, Friml J, Juergens G, Hwang I. Adaptor protein complex 2-mediated endocytosis is crucial for male reproductive organ development in Arabidopsis. THE PLANT CELL 2013; 25:2970-85. [PMID: 23975898 PMCID: PMC3784592 DOI: 10.1105/tpc.113.114264] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/15/2013] [Accepted: 08/06/2013] [Indexed: 05/18/2023]
Abstract
Fertilization in flowering plants requires the temporal and spatial coordination of many developmental processes, including pollen production, anther dehiscence, ovule production, and pollen tube elongation. However, it remains elusive as to how this coordination occurs during reproduction. Here, we present evidence that endocytosis, involving heterotetrameric adaptor protein complex 2 (AP-2), plays a crucial role in fertilization. An Arabidopsis thaliana mutant ap2m displays multiple defects in pollen production and viability, as well as elongation of staminal filaments and pollen tubes, all of which are pivotal processes needed for fertilization. Of these abnormalities, the defects in elongation of staminal filaments and pollen tubes were partially rescued by exogenous auxin. Moreover, DR5rev:GFP (for green fluorescent protein) expression was greatly reduced in filaments and anthers in ap2m mutant plants. At the cellular level, ap2m mutants displayed defects in both endocytosis of N-(3-triethylammonium-propyl)-4-(4-diethylaminophenylhexatrienyl) pyridinium dibromide, a lypophilic dye used as an endocytosis marker, and polar localization of auxin-efflux carrier PIN FORMED2 (PIN2) in the stamen filaments. Moreover, these defects were phenocopied by treatment with Tyrphostin A23, an inhibitor of endocytosis. Based on these results, we propose that AP-2-dependent endocytosis plays a crucial role in coordinating the multiple developmental aspects of male reproductive organs by modulating cellular auxin level through the regulation of the amount and polarity of PINs.
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Affiliation(s)
- Soo Youn Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Zheng-Yi Xu
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Kyungyoung Song
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Dae Heon Kim
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Hyangju Kang
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Ilka Reichardt
- Developmental Genetics, Center for Plant Molecular Biology (Zentrum fur Molekularbiologie der Pflanzen), University of Tuebingen, 72076 Tuebingen, Germany
| | - Eun Ju Sohn
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Jiří Friml
- Department of Plant Systems Biology, Flamders Institute for Biotechnology (VIB), and Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium
- Institute of Science and Technology, A-3400 Klosterneuburg, Austria
| | - Gerd Juergens
- Developmental Genetics, Center for Plant Molecular Biology (Zentrum fur Molekularbiologie der Pflanzen), University of Tuebingen, 72076 Tuebingen, Germany
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
- Address correspondence to
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86
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Yamaoka S, Shimono Y, Shirakawa M, Fukao Y, Kawase T, Hatsugai N, Tamura K, Shimada T, Hara-Nishimura I. Identification and dynamics of Arabidopsis adaptor protein-2 complex and its involvement in floral organ development. THE PLANT CELL 2013; 25:2958-69. [PMID: 23975897 PMCID: PMC3784591 DOI: 10.1105/tpc.113.114082] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 07/16/2013] [Accepted: 08/06/2013] [Indexed: 05/18/2023]
Abstract
The adaptor protein-2 (AP-2) complex is a heterotetramer involved in clathrin-mediated endocytosis of cargo proteins from the plasma membrane in animal cells. The homologous genes of AP-2 subunits are present in the genomes of plants; however, their identities and roles in endocytic pathways are not clearly defined in plants. Here, we reveal the molecular composition of the AP-2 complex of Arabidopsis thaliana and its dynamics on the plasma membrane. We identified all of the α-, β-, σ-, and μ-subunits of the AP-2 complex and detected a weak interaction of the AP-2 complex with clathrin heavy chain. The μ-subunit protein fused to green fluorescent protein (AP2M-GFP) was localized to the plasma membrane and to the cytoplasm. Live-cell imaging using a variable-angle epifluorescence microscope revealed that AP2M-GFP transiently forms punctate structures on the plasma membrane. Homozygous ap2m mutant plants exhibited abnormal floral structures, including reduced stamen elongation and delayed anther dehiscence, which led to a failure of pollination and a subsequent reduction of fertility. Our study provides a molecular basis for understanding AP-2-dependent endocytic pathways in plants and their roles in floral organ development and plant reproduction.
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Affiliation(s)
- Shohei Yamaoka
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yuki Shimono
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Makoto Shirakawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yoichiro Fukao
- Plant Global Educational Project, Nara Institute of Science and Technology, Ikoma 630-0192, Japan
| | - Takashi Kawase
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Noriyuki Hatsugai
- Research Center for Cooperative Projects, Hokkaido University, Sapporo 060-8638, Japan
| | - Kentaro Tamura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Tomoo Shimada
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ikuko Hara-Nishimura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Address correspondence to
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87
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Xiang L, Van den Ende W. Trafficking of plant vacuolar invertases: from a membrane-anchored to a soluble status. Understanding sorting information in their complex N-terminal motifs. PLANT & CELL PHYSIOLOGY 2013; 54:1263-1277. [PMID: 23737500 DOI: 10.1093/pcp/pct075] [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: 06/02/2023]
Abstract
Vacuolar invertases (VIs) are highly expressed in young tissues and organs. They may have a substantial regulatory influence on whole-plant metabolism as well as on photosynthetic efficiency. Therefore, they are emerging as potentially interesting biotechnological targets to increase plant biomass production, especially under stress. On the one hand, VIs are well known as soluble and extractable proteins. On the other hand, they contain complex N-terminal propeptide (NTPP) regions with a basic region (BR) and a transmembrane domain (TMD). Here we analyzed in depth the Arabidopsis thaliana VI2 (AtVI2) NTPP by mutagenesis. It was found that correct sorting to the lytic vacuole (LV) depends on the presence of intact dileucine (SSDALLPIS), BR (RRRR) and TMD motifs. AtVI2 remains inserted into membranes on its way to the LV, and the classical sorting pathway (endoplasmic reticulum→Golgi→LV) is followed. However, our data suggest that VIs might follow an alternative, adaptor protein 3 (AP3)-dependent route as well. Membrane-anchored transport and a direct recognition of the dileucine motif in the NTPP of VIs might have evolved as a simple and more efficient sorting mechanism as compared with the vacuolar sorting receptor 1/binding protein of 80 kDa (VSR1/BP80)-dependent sorting mechanism followed by those proteins that travel to the vacuole as soluble proteins.
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Affiliation(s)
- Li Xiang
- Biology Department, Laboratory for Molecular Plant Biology, KU Leuven, Kasteelpark Arenberg 31, Box 2434, B-3001 Heverlee, Belgium
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88
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Arabidopsis μ-adaptin subunit AP1M of adaptor protein complex 1 mediates late secretory and vacuolar traffic and is required for growth. Proc Natl Acad Sci U S A 2013; 110:10318-23. [PMID: 23733933 DOI: 10.1073/pnas.1300460110] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Adaptor protein (AP) complexes are the predominant coat proteins of membrane vesicles in post-Golgi trafficking of mammalian cells. Each AP complex contains a specific medium subunit, μ-adaptin, that selects cargo proteins bearing sequence-specific sorting motifs. Much less is known about the AP complexes and their μ subunits in plants. Because of uncertain homology, the μ-adaptins of Arabidopsis have been designated muA through muD [Happel et al. (2004) Plant J 37(5):678-693]. Furthermore, only muD has been assigned to a specific AP complex, AP-3, involved in Golgi-vacuolar trafficking [Niihama et al. (2009) Plant Cell Physiol 50(12):2057-2068, Zwiewka et al. (2011) Cell Res 21(12):1711-1722, and Wolfenstetter et al. (2012) Plant Cell 24(1):215-232]. In contrast, the μ subunit of neither the post-Golgi trafficking AP-1 complex nor the endocytic AP-2 complex has been identified. Here, we report the functional analysis of redundant AP-1 μ-adaptins AP1M1 (also known as muB1) and AP1M2 (also known as muB2). Coimmunoprecipitation revealed that both AP1M2 and its less strongly expressed isoform AP1M1 are complexed with the large subunit γ-adaptin of AP-1. In addition, AP1M2 was localized at or near the trans-Golgi network. Knockout mutations of AP1M2 impaired pollen function and arrested plant growth whereas the ap1m1 ap1m2 double mutant was nearly pollen-lethal. At the cellular level, the absence of AP1M2 entailed inhibition of multiple trafficking pathways from the trans-Golgi network to the vacuole and to the plasma membrane in interphase and to the plane of cell division in cytokinesis. Thus, AP-1 is crucial in post-Golgi trafficking in plant cells and required for cell division and plant growth.
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89
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Pedrazzini E, Komarova NY, Rentsch D, Vitale A. Traffic Routes and Signals for the Tonoplast. Traffic 2013; 14:622-8. [DOI: 10.1111/tra.12051] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 01/23/2013] [Accepted: 01/28/2013] [Indexed: 01/17/2023]
Affiliation(s)
- Emanuela Pedrazzini
- Istituto di Biologia e Biotecnologia Agraria; Consiglio Nazionale delle Ricerche; Milano; Italy
| | | | - Doris Rentsch
- Institute of Plant Sciences; University of Bern; Bern; Switzerland
| | - Alessandro Vitale
- Istituto di Biologia e Biotecnologia Agraria; Consiglio Nazionale delle Ricerche; Milano; Italy
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90
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De Rybel B, Möller B, Yoshida S, Grabowicz I, Barbier de Reuille P, Boeren S, Smith R, Borst J, Weijers D. A bHLH Complex Controls Embryonic Vascular Tissue Establishment and Indeterminate Growth in Arabidopsis. Dev Cell 2013; 24:426-37. [DOI: 10.1016/j.devcel.2012.12.013] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/19/2012] [Accepted: 12/20/2012] [Indexed: 01/21/2023]
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91
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Xiang L, Etxeberria E, den Ende W. Vacuolar protein sorting mechanisms in plants. FEBS J 2013; 280:979-93. [DOI: 10.1111/febs.12092] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 11/08/2012] [Accepted: 12/11/2012] [Indexed: 01/12/2023]
Affiliation(s)
- Li Xiang
- Laboratory of Molecular Plant Biology KU Leuven Belgium
| | - Ed Etxeberria
- Horticulture Department Citrus Research and Education Center University of Florida Lake Alfred FL USA
| | - Wim den Ende
- Laboratory of Molecular Plant Biology KU Leuven Belgium
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92
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Feraru E, Feraru MI, Asaoka R, Paciorek T, De Rycke R, Tanaka H, Nakano A, Friml J. BEX5/RabA1b regulates trans-Golgi network-to-plasma membrane protein trafficking in Arabidopsis. THE PLANT CELL 2012; 24:3074-86. [PMID: 22773752 PMCID: PMC3426133 DOI: 10.1105/tpc.112.098152] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/14/2012] [Accepted: 06/23/2012] [Indexed: 05/18/2023]
Abstract
Constitutive endocytic recycling is a crucial mechanism allowing regulation of the activity of proteins at the plasma membrane and for rapid changes in their localization, as demonstrated in plants for PIN-FORMED (PIN) proteins, the auxin transporters. To identify novel molecular components of endocytic recycling, mainly exocytosis, we designed a PIN1-green fluorescent protein fluorescence imaging-based forward genetic screen for Arabidopsis thaliana mutants that showed increased intracellular accumulation of cargos in response to the trafficking inhibitor brefeldin A (BFA). We identified bex5 (for BFA-visualized exocytic trafficking defective), a novel dominant mutant carrying a missense mutation that disrupts a conserved sequence motif of the small GTPase, RAS GENES FROM RAT BRAINA1b. bex5 displays defects such as enhanced protein accumulation in abnormal BFA compartments, aberrant endosomes, and defective exocytosis and transcytosis. BEX5/RabA1b localizes to trans-Golgi network/early endosomes (TGN/EE) and acts on distinct trafficking processes like those regulated by GTP exchange factors on ADP-ribosylation factors GNOM-LIKE1 and HOPM INTERACTOR7/BFA-VISUALIZED ENDOCYTIC TRAFFICKING DEFECTIVE1, which regulate trafficking at the Golgi apparatus and TGN/EE, respectively. All together, this study identifies Arabidopsis BEX5/RabA1b as a novel regulator of protein trafficking from a TGN/EE compartment to the plasma membrane.
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Affiliation(s)
- Elena Feraru
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
| | - Mugurel I. Feraru
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
| | - Rin Asaoka
- Department of Biological Sciences, Graduate School of Science, Tokyo University, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomasz Paciorek
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
| | - Riet De Rycke
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
| | - Hirokazu Tanaka
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
| | - Akihiko Nakano
- Department of Biological Sciences, Graduate School of Science, Tokyo University, Bunkyo-ku, Tokyo 113-0033, Japan
- Molecular Membrane Biology Laboratory, RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan
| | - Jiří Friml
- Department of Plant Systems Biology, VIB, and Department of Plant Biotechnology and Genetics, Ghent University, 9052 Ghent, Belgium
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93
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Zwiewka M, Friml J. Fluorescence imaging-based forward genetic screens to identify trafficking regulators in plants. FRONTIERS IN PLANT SCIENCE 2012; 3:97. [PMID: 22654887 PMCID: PMC3359526 DOI: 10.3389/fpls.2012.00097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/25/2012] [Indexed: 05/25/2023]
Abstract
Coordinated, subcellular trafficking of proteins is one of the fundamental properties of the multicellular eukaryotic organisms. Trafficking involves a large diversity of compartments, pathways, cargo molecules, and vesicle-sorting events. It is also crucial in regulating the localization and, thus, the activity of various proteins, but the process is still poorly genetically defined in plants. In the past, forward genetics screens had been used to determine the function of genes by searching for a specific morphological phenotype in the organism population in which mutations had been induced chemically or by irradiation. Unfortunately, these straightforward genetic screens turned out to be limited in identifying new regulators of intracellular protein transport, because mutations affecting essential trafficking pathways often lead to lethality. In addition, the use of these approaches has been restricted by functional redundancy among trafficking regulators. Screens for mutants that rely on the observation of changes in the cellular localization or dynamics of fluorescent subcellular markers enable, at least partially, to circumvent these issues. Hence, such image-based screens provide the possibility to identify either alleles with weak effects or components of the subcellular trafficking machinery that have no strong impact on the plant growth.
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Affiliation(s)
- Marta Zwiewka
- Department of Plant Systems Biology, VIB Life Sciences Research InstituteGent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent UniversityGent, Belgium
| | - Jiří Friml
- Department of Plant Systems Biology, VIB Life Sciences Research InstituteGent, Belgium
- Department of Plant Biotechnology and Genetics, Ghent UniversityGent, Belgium
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94
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Larisch N, Schulze C, Galione A, Dietrich P. An N-Terminal Dileucine Motif Directs Two-Pore Channels to the Tonoplast of Plant Cells. Traffic 2012; 13:1012-22. [DOI: 10.1111/j.1600-0854.2012.01366.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 04/06/2012] [Accepted: 04/10/2012] [Indexed: 12/23/2022]
Affiliation(s)
- Nina Larisch
- Department Biology; Friedrich-Alexander-Universität Erlangen-Nürnberg, Molecular Plant Physiology and Erlangen Center of Plant Science; Staudtstrasse 5; 91058; Erlangen; Germany
| | - Christina Schulze
- Department Biology; Friedrich-Alexander-Universität Erlangen-Nürnberg, Molecular Plant Physiology and Erlangen Center of Plant Science; Staudtstrasse 5; 91058; Erlangen; Germany
| | - Antony Galione
- Department of Pharmacology; Oxford University; Oxford; OX1 3QT; UK
| | - Petra Dietrich
- Department Biology; Friedrich-Alexander-Universität Erlangen-Nürnberg, Molecular Plant Physiology and Erlangen Center of Plant Science; Staudtstrasse 5; 91058; Erlangen; Germany
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95
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Saiga S, Möller B, Watanabe-Taneda A, Abe M, Weijers D, Komeda Y. Control of embryonic meristem initiation in Arabidopsis by PHD-finger protein complexes. Development 2012; 139:1391-8. [DOI: 10.1242/dev.074492] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Plant growth is directed by the activity of stem cells within meristems. The first meristems are established during early embryogenesis, and this process involves the specification of both stem cells and their organizer cells. One of the earliest events in root meristem initiation is marked by re-specification of the uppermost suspensor cell as hypophysis, the precursor of the organizer. The transcription factor MONOPTEROS (MP) is a key regulator of hypophysis specification, and does so in part by promoting the transport of the plant hormone auxin and by activating the expression of TARGET OF MP (TMO) transcription factors, both of which are required for hypophysis specification. The mechanisms leading to the activation of these genes by MP in a chromatin context are not understood. Here, we show that the PHD-finger proteins OBERON (OBE) and TITANIA (TTA) are essential for MP-dependent embryonic root meristem initiation. TTA1 and TTA2 are functionally redundant and function in the same pathway as OBE1 and OBE2. These PHD-finger proteins interact with each other, and genetic analysis shows that OBE-TTA heterotypic protein complexes promote embryonic root meristem initiation. Furthermore, while MP expression is unaffected by mutations in OBE/TTA genes, expression of MP targets TMO5 and TMO7 is locally lost in obe1 obe2 embryos. PHD-finger proteins have been shown to act in initiation of transcription by interacting with nucleosomes. Indeed, we found that OBE1 binds to chromatin at the TMO7 locus, suggesting a role in its MP-dependent activation. Our data indicate that PHD-finger protein complexes are crucial for the activation of MP-dependent gene expression during embryonic root meristem initiation, and provide a starting point for studying the mechanisms of developmental gene activation within a chromatin context in plants.
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Affiliation(s)
- Shunsuke Saiga
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Barbara Möller
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Ayako Watanabe-Taneda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mitsutomo Abe
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Yoshibumi Komeda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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96
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Sparkes I, Brandizzi F. Fluorescent protein-based technologies: shedding new light on the plant endomembrane system. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2012; 70:96-107. [PMID: 22449045 DOI: 10.1111/j.1365-313x.2011.04884.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Without doubt, GFP and spectral derivatives have revolutionized the way biologists approach their journey toward the discovery of how plant cells function. It is fascinating that in its early days GFP was used merely for localization studies, but as time progressed researchers successfully explored new avenues to push the power of GFP technology to reach new and exciting research frontiers. This has had a profound impact on the way we can now study complex and dynamic systems such as plant endomembranes. Here we briefly describe some of the approaches where GFP has revolutionized in vivo studies of protein distribution and dynamics and focus on two emerging approaches for the application of GFP technology in plant endomembranes, namely optical tweezers and forward genetics approaches, which are based either on the light or on genetic manipulation of secretory organelles to gain insights on the factors that control their activities and integrity.
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Affiliation(s)
- Imogen Sparkes
- Biosciences,College of Life and Environmental Sciences, Geoffrey Pope, University of Exeter, Stocker Road, Exeter, UK
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97
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Wolfenstetter S, Wirsching P, Dotzauer D, Schneider S, Sauer N. Routes to the tonoplast: the sorting of tonoplast transporters in Arabidopsis mesophyll protoplasts. THE PLANT CELL 2012; 24:215-32. [PMID: 22253225 PMCID: PMC3289566 DOI: 10.1105/tpc.111.090415] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 12/22/2011] [Accepted: 12/28/2011] [Indexed: 05/05/2023]
Abstract
Vacuoles perform a multitude of functions in plant cells, including the storage of amino acids and sugars. Tonoplast-localized transporters catalyze the import and release of these molecules. The mechanisms determining the targeting of these transporters to the tonoplast are largely unknown. Using the paralogous Arabidopsis thaliana inositol transporters INT1 (tonoplast) and INT4 (plasma membrane), we performed domain swapping and mutational analyses and identified a C-terminal di-leucine motif responsible for the sorting of higher plant INT1-type transporters to the tonoplast in Arabidopsis mesophyll protoplasts. We demonstrate that this motif can reroute other proteins, such as INT4, SUCROSE TRANSPORTER2 (SUC2), or SWEET1, to the tonoplast and that the position of the motif relative to the transmembrane helix is critical. Rerouted INT4 is functionally active in the tonoplast and complements the growth phenotype of an int1 mutant. In Arabidopsis plants defective in the β-subunit of the AP-3 adaptor complex, INT1 is correctly localized to the tonoplast, while sorting of the vacuolar sucrose transporter SUC4 is blocked in cis-Golgi stacks. Moreover, we demonstrate that both INT1 and SUC4 trafficking to the tonoplast is sensitive to brefeldin A. Our data show that plants possess at least two different Golgi-dependent targeting mechanisms for newly synthesized transporters to the tonoplast.
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Affiliation(s)
| | | | | | | | - Norbert Sauer
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Molecular Plant Physiology and ECROPS (Erlangen Center of Plant Science), D-91058 Erlangen, Germany
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98
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Reinders A, Sivitz AB, Ward JM. Evolution of plant sucrose uptake transporters. FRONTIERS IN PLANT SCIENCE 2012; 3:22. [PMID: 22639641 PMCID: PMC3355574 DOI: 10.3389/fpls.2012.00022] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 01/20/2012] [Indexed: 05/18/2023]
Abstract
In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were not found in the chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean algae Chlorokybus atmosphyticus contains a SUT homolog (CaSUT1) and phylogenetic analysis indicated that it is basal to all other streptophyte SUTs analyzed. SUTs are present in both red algae and S. pombe but they are less related to plant SUTs than CaSUT1. Both Selaginella and Physcomitrella encode type II and III SUTs suggesting that both plasma membrane and vacuolar sucrose transporter activities were present in early land plants. It is likely that SUT transporters are important for scavenging sucrose from the environment and intracellular compartments in charophyte and non-vascular plants. Type I SUTs were only found in eudicots and we conclude that they evolved from type III SUTs, possibly through loss of a vacuolar targeting sequence. Eudicots utilize type I SUTs for phloem (vascular tissue) loading while monocots use type II SUTs for phloem loading. We show that HvSUT1 from barley, a type II SUT, reverted the growth defect of the Arabidopsis atsuc2 (type I) mutant. This indicates that type I and II SUTs evolved similar (and interchangeable) phloem loading transporter capabilities independently.
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Affiliation(s)
- Anke Reinders
- Department of Plant Biology, University of MinnesotaSt. Paul, MN, USA
| | - Alicia B. Sivitz
- Department of Biological Sciences, Dartmouth CollegeHanover, NH, USA
| | - John M. Ward
- Department of Plant Biology, University of MinnesotaSt. Paul, MN, USA
- *Correspondence: John M. Ward, Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Avenue, St. Paul, MN 55108, USA. e-mail:
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99
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Park M, Jürgens G. Membrane traffic and fusion at post-Golgi compartments. FRONTIERS IN PLANT SCIENCE 2011; 2:111. [PMID: 22645561 PMCID: PMC3355779 DOI: 10.3389/fpls.2011.00111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/19/2011] [Indexed: 05/18/2023]
Abstract
Complete sequencing of the Arabidopsis genome a decade ago has facilitated the functional analysis of various biological processes including membrane traffic by which many proteins are delivered to their sites of action and turnover. In particular, membrane traffic between post-Golgi compartments plays an important role in cell signaling, taking care of receptor-ligand interaction and inactivation, which requires secretion, endocytosis, and recycling or targeting to the vacuole for degradation. Here, we discuss recent studies that address the identity of post-Golgi compartments, the machinery involved in traffic and fusion or functionally characterized cargo proteins that are delivered to or pass through post-Golgi compartments. We also provide an outlook on future challenges in this area of research.
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Affiliation(s)
- Misoon Park
- Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of TübingenTübingen, Germany
| | - Gerd Jürgens
- Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of TübingenTübingen, Germany
- *Correspondence: Gerd Jürgens, Entwicklungsgenetik, Zentrum für Molekularbiologie der Pflanzen, University of Tübingen, Auf der Morgenstelle 3, 72076 Tübingen, Germany. e-mail:
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