1
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Graf A, Bassukas AEL, Xiao Y, Barbosa ICR, Mergner J, Grill P, Michalke B, Kuster B, Schwechheimer C. D6PK plasma membrane polarity requires a repeated CXX(X)P motif and PDK1-dependent phosphorylation. Nat Plants 2024; 10:300-314. [PMID: 38278951 PMCID: PMC10881395 DOI: 10.1038/s41477-023-01615-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/15/2023] [Indexed: 01/28/2024]
Abstract
D6 PROTEIN KINASE (D6PK) is a polarly localized plasma-membrane-associated kinase from Arabidopsis thaliana that activates polarly distributed PIN-FORMED auxin transporters. D6PK moves rapidly to and from the plasma membrane, independent of its PIN-FORMED targets. The middle D6PK domain, an insertion between kinase subdomains VII and VIII, is required and sufficient for association and polarity of the D6PK plasma membrane. How D6PK polarity is established and maintained remains to be shown. Here we show that cysteines from repeated middle domain CXX(X)P motifs are S-acylated and required for D6PK membrane association. While D6PK S-acylation is not detectably regulated during intracellular transport, phosphorylation of adjacent serine residues, in part in dependence on the upstream 3-PHOSPHOINOSITIDE-DEPENDENT PROTEIN KINASE, promotes D6PK transport, controls D6PK residence time at the plasma membrane and prevents its lateral diffusion. We thus identify new mechanisms for the regulation of D6PK plasma membrane interaction and polarity.
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Affiliation(s)
- Alina Graf
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | | | - Yao Xiao
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
- Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Inês C R Barbosa
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Julia Mergner
- Proteomics and Bioanalytics, School of Life Sciences, Technical University of Munich, Freising, Germany
- Bavarian Center for Biomolecular Mass Spectrometry at Klinikum rechts der Isar, Center for Translational Cancer Research, Munich, Germany
| | - Peter Grill
- Helmholtz Zentrum München, German Research Center for Environmental Health, Analytical BioGeoChemistry, Neuherberg, Germany
| | - Bernhard Michalke
- Helmholtz Zentrum München, German Research Center for Environmental Health, Analytical BioGeoChemistry, Neuherberg, Germany
| | - Bernhard Kuster
- Proteomics and Bioanalytics, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany.
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2
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Robinson DG, Ammer C, Polle A, Bauhus J, Aloni R, Annighöfer P, Baskin TI, Blatt MR, Bolte A, Bugmann H, Cohen JD, Davies PJ, Draguhn A, Hartmann H, Hasenauer H, Hepler PK, Kohnle U, Lang F, Löf M, Messier C, Munné-Bosch S, Murphy A, Puettmann KJ, Marchant IQ, Raven PH, Robinson D, Sanders D, Seidel D, Schwechheimer C, Spathelf P, Steer M, Taiz L, Wagner S, Henriksson N, Näsholm T. Mother trees, altruistic fungi, and the perils of plant personification. Trends Plant Sci 2024; 29:20-31. [PMID: 37735061 DOI: 10.1016/j.tplants.2023.08.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 09/23/2023]
Abstract
There are growing doubts about the true role of the common mycorrhizal networks (CMN or wood wide web) connecting the roots of trees in forests. We question the claims of a substantial carbon transfer from 'mother trees' to their offspring and nearby seedlings through the CMN. Recent reviews show that evidence for the 'mother tree concept' is inconclusive or absent. The origin of this concept seems to stem from a desire to humanize plant life but can lead to misunderstandings and false interpretations and may eventually harm rather than help the commendable cause of preserving forests. Two recent books serve as examples: The Hidden Life of Trees and Finding the Mother Tree.
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Affiliation(s)
- David G Robinson
- Centre for Organismal Studies, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany.
| | - Christian Ammer
- Silvicuture and Forest Ecology of the Temperate Zones, University of Göttingen, Büsgenweg 1, 37077 Göttingen, Germany
| | - Andrea Polle
- Forest Botany and Tree Physiology, University of Göttingen, Büsgenweg 2, 37077 Göttingen, Germany
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Tennenbacherstr. 4, 79085 Freiburg im Breisgau, Germany
| | - Roni Aloni
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Peter Annighöfer
- Forest and Agroforest Systems, Technische Universität München, Hans-Carl-v.-Carlowitz-Platz 2, 85354, Freising, Germany
| | - Tobias I Baskin
- Department of Biology, University of Massachusetts, 611 N. Pleasant St, Amherst, MA 01003, USA
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andreas Bolte
- Thünen Institute of Forest Ecosystems, A.-Möller-Str. 1, Haus 41/42, D-16225 Eberswalde, Germany
| | - Harald Bugmann
- Forest Ecology, Department of Environmental Systems Science, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
| | - Jerry D Cohen
- Department of Horticultural Science and Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - Peter J Davies
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Andreas Draguhn
- Medical Faculty, Department of Neuro- and Senory Physiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120 Heidelberg, Germany
| | - Henrik Hartmann
- Julius Kühn Institute Federal Research Centre for Cultivated Plants, Institute for Forest Protection, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany
| | - Hubert Hasenauer
- Institute of Silviculture, Department of Forest- and Soil Sciences, BOKU - University of Natural Resources and Life Sciences, Vienna, Peter-Jordan-Straße 82/II 1190, Wien, Austria
| | - Peter K Hepler
- Department of Biology, University of Massachusetts, 611 N. Pleasant St, Amherst, MA 01003, USA
| | - Ulrich Kohnle
- Department of Forest Growth, Forstliche Versuchs- und Forschungsanstalt Baden-Württemberg, Wonnhaldestraße 4, 79100 Freiburg, Germany
| | - Friederike Lang
- Chair of Soil Ecology, University of Freiburg, Bertholdstr. 17, 79098 Freiburg im Breisgau, Germany
| | - Magnus Löf
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Sundsvägen 3, P.O. Box 190, SE-234 22 Lomma, Sweden
| | - Christian Messier
- University of Quebec in Montréal (UQAM) and in Outaouais (UQO), Quebec, Canada
| | | | - Angus Murphy
- Plant Science and Landscape Architecture, University of Maryland, 5140 Plant Sciences Building 4291 Fieldhouse Drive College Park, MD 20742, USA
| | - Klaus J Puettmann
- Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331, USA
| | - Iván Quiroz Marchant
- Instituto Forestal, Calle Nueva Uno 3570 LT 4 Michaihue, San Pedro de la Paz, Concepción Chile, Chile
| | - Peter H Raven
- President Emeritus, Missouri Botanical Garden, 1037 Cy Ann Drive, Town and Country, MO 63017-8402, USA
| | - David Robinson
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
| | - Dale Sanders
- Department of Biology, University of York, Heslington York, YO10 5DD, UK
| | - Dominik Seidel
- Department for Spatial Structures and Digitization of Forests, Georg-August-Universität Göttingen, Büsgenweg 1, 37077 Göttingen, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 8, 85354 Freising, Germany
| | - Peter Spathelf
- Applied Silviculture, Eberswalde University for Sustainable Development, Alfred-Möller-Strasse 1, 16225 Eberswalde, Germany
| | - Martin Steer
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lincoln Taiz
- Molecular, Cell and Developmental Biology, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Sven Wagner
- Chair of Silviculture, Technische Universität Dresden, Pienner Str. 8, 01737 Tharandt, Germany
| | - Nils Henriksson
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umea, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umea, Sweden
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Schröder P, Hsu BY, Gutsche N, Winkler JB, Hedtke B, Grimm B, Schwechheimer C. B-GATA factors are required to repress high-light stress responses in Marchantia polymorpha and Arabidopsis thaliana. Plant Cell Environ 2023. [PMID: 37254806 DOI: 10.1111/pce.14629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2023]
Abstract
GATAs are evolutionarily conserved zinc-finger transcription factors from eukaryotes. In plants, GATAs can be subdivided into four classes, A-D, based on their DNA-binding domain, and into further subclasses based on additional protein motifs. B-GATAs with a so-called leucine-leucine-methionine (LLM)-domain can already be found in algae. In angiosperms, the B-GATA family is expanded and can be subdivided in to LLM- or HAN-domain B-GATAs. Both, the LLM- and the HAN-domain are conserved domains of unknown biochemical function. Interestingly, the B-GATA family in the liverwort Marchantia polymorpha and the moss Physcomitrium patens is restricted to one and four family members, respectively. And, in contrast to vascular plants, the bryophyte B-GATAs contain a HAN- as well as an LLM-domain. Here, we characterise mutants of the single B-GATA from Marchantia polymorpha. We reveal that this mutant has defects in thallus growth and in gemma formation. Transcriptomic studies uncover that the B-GATA mutant displays a constitutive high-light (HL) stress response, a phenotype that we then also confirm in mutants of Arabidopsis thaliana LLM-domain B-GATAs, suggesting that the B-GATAs have a protective role towards HL stress.
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Affiliation(s)
- Peter Schröder
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Bang-Yu Hsu
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Nora Gutsche
- Department of Botany, Osnabrück University, Osnabrück, Germany
| | - Jana Barbro Winkler
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Boris Hedtke
- Department of Plant Physiology, Humboldt University Berlin, Berlin, Germany
| | - Bernhard Grimm
- Department of Plant Physiology, Humboldt University Berlin, Berlin, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Freising, Germany
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4
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Sala J, Mosesso N, Isono E, Schwechheimer C. Arabidopsis thaliana B-GATA factors repress starch synthesis and gravitropic growth responses. New Phytol 2023. [PMID: 37219878 DOI: 10.1111/nph.18992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/26/2023] [Indexed: 05/24/2023]
Abstract
Plants perceive the direction of gravity during skotomorphogenic growth, and of gravity and light during photomorphogenic growth. Gravity perception occurs through the sedimentation of starch granules in shoot endodermal and root columella cells. In this study, we demonstrate that the Arabidopsis thaliana GATA factors GNC (GATA, NITRATE-INDUCIBLE, CARBON METABOLISM-INVOLVED) and GNL/CGA1 (GNC-LIKE/CYTOKININ-RESPONSIVE GATA1) repress starch granule growth and amyloplast differentiation in endodermal cells. In our comprehensive study, we analysed gravitropic responses in the shoot, root and hypocotyl. We performed an RNA-seq analysis, used advanced microscopy techniques to examine starch granule size, number and morphology and quantified transitory starch degradation patterns. Using transmission electron microscopy, we examined amyloplast development. Our results indicate that the altered gravitropic responses in hypocotyls, shoots and roots of gnc gnl mutants and GNL overexpressors are due to the differential accumulation of starch granules observed in the GATA genotypes. At the whole-plant level, GNC and GNL play a more complex role in starch synthesis, degradation and starch granule initiation. Our findings suggest that the light-regulated GNC and GNL help balance phototropic and gravitropic growth responses after the transition from skotomorphogenesis to photomorphogenesis by repressing the growth of starch granules.
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Affiliation(s)
- Jan Sala
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, 85354, Freising, Germany
| | - Niccolò Mosesso
- Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, 78457, Constance, Germany
| | - Erika Isono
- Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, 78457, Constance, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, 85354, Freising, Germany
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5
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Brajkovic S, Rugen N, Agius C, Berner N, Eckert S, Sakhteman A, Schwechheimer C, Kuster B. Getting Ready for Large-Scale Proteomics in Crop Plants. Nutrients 2023; 15:nu15030783. [PMID: 36771489 PMCID: PMC9921824 DOI: 10.3390/nu15030783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Plants are an indispensable cornerstone of sustainable global food supply. While immense progress has been made in decoding the genomes of crops in recent decades, the composition of their proteomes, the entirety of all expressed proteins of a species, is virtually unknown. In contrast to the model plant Arabidopsis thaliana, proteomic analyses of crop plants have often been hindered by the presence of extreme concentrations of secondary metabolites such as pigments, phenolic compounds, lipids, carbohydrates or terpenes. As a consequence, crop proteomic experiments have, thus far, required individually optimized protein extraction protocols to obtain samples of acceptable quality for downstream analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS). In this article, we present a universal protein extraction protocol originally developed for gel-based experiments and combined it with an automated single-pot solid-phase-enhanced sample preparation (SP3) protocol on a liquid handling robot to prepare high-quality samples for proteomic analysis of crop plants. We also report an automated offline peptide separation protocol and optimized micro-LC-MS/MS conditions that enables the identification and quantification of ~10,000 proteins from plant tissue within 6 h of instrument time. We illustrate the utility of the workflow by analyzing the proteomes of mature tomato fruits to an unprecedented depth. The data demonstrate the robustness of the approach which we propose for use in upcoming large-scale projects that aim to map crop tissue proteomes.
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Affiliation(s)
- Sarah Brajkovic
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Nils Rugen
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
- Institute of Plant Genetics, Leibniz University Hannover, 30167 Hannover, Germany
| | - Carlos Agius
- Chair of Plant Systems Biology, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Nicola Berner
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Stephan Eckert
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Amirhossein Sakhteman
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Claus Schwechheimer
- Chair of Plant Systems Biology, Technical University of Munich (TUM), 85354 Freising, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich (TUM), 85354 Freising, Germany
- Correspondence:
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6
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Sprunck S, Schwechheimer C, Morita MT. Editorial overview: Cell biology and cell signalling. Curr Opin Plant Biol 2022; 70:102312. [PMID: 36400664 DOI: 10.1016/j.pbi.2022.102312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- Stefanie Sprunck
- Institute of Plant Science, Department of Cell Biology and Plant Biochemistry, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany.
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany
| | - Miyo T Morita
- Division of Plant Environmental Responses, National Institute for Basic Biology, National Institutes of Natural Sciences, Nishigonaka 38, Myodaiji-cho, Okazaki-shi, Aichi, 444-8585, Japan
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7
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Abstract
GATA factors are evolutionarily conserved transcription factors that are found in animals, fungi, and plants. Compared to that of animals, the size of the plant GATA family is increased. In angiosperms, four main GATA classes and seven structural subfamilies can be defined. In recent years, knowledge about the biological role and regulation of plant GATAs has substantially improved. Individual family members have been implicated in the regulation of photomorphogenic growth, chlorophyll biosynthesis, chloroplast development, photosynthesis, and stomata formation, as well as root, leaf, and flower development. In this review, we summarize the current knowledge of plant GATA factors. Using phylogenomic analysis, we trace the evolutionary origin of the GATA classes in the green lineage and examine their relationship to animal and fungal GATAs. Finally, we speculate about a possible conservation of GATA-regulated functions across the animal, fungal, and plant kingdoms.
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Affiliation(s)
- Claus Schwechheimer
- School of Life Sciences, Plant Systems Biology, Technical University of Munich, Freising, Germany;
| | - Peter Michael Schröder
- School of Life Sciences, Plant Systems Biology, Technical University of Munich, Freising, Germany;
| | - Crysten E Blaby-Haas
- Biology Department, Brookhaven National Laboratory, Upton, New York, USA;
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, USA
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8
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Lanassa Bassukas AE, Xiao Y, Schwechheimer C. Phosphorylation control of PIN auxin transporters. Curr Opin Plant Biol 2022; 65:102146. [PMID: 34974229 DOI: 10.1016/j.pbi.2021.102146] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 10/22/2021] [Accepted: 10/23/2021] [Indexed: 06/14/2023]
Abstract
The directional transport of the phytohormone auxin is required for proper plant development and tropic growth. Auxin cell-to-cell transport gains directionality through the polar distribution of 'canonical' long PIN-FORMED (PIN) auxin efflux carriers. In recent years, AGC kinases, MAP kinases, Ca2+/CALMODULIN-DEPENDENT PROTEIN KINASE-RELATED KINASEs and receptor kinases have been implicated in the control of PIN activity, polarity and trafficking. In this review, we summarize the current knowledge in understanding the posttranslational regulation of PINs by these different protein kinase families. The proposed regulation of PINs by AGC kinases after salt stress and by the stress-activated MAP kinases suggest that abiotic and biotic stress factors may modulate auxin transport and thereby plant growth.
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Affiliation(s)
- Alkistis E Lanassa Bassukas
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany
| | - Yao Xiao
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354, Freising, Germany.
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9
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Abstract
From embryogenesis to fruit formation, almost every aspect of plant development and differentiation is controlled by the cellular accumulation or depletion of auxin from cells and tissues. The respective auxin maxima and minima are generated by cell-to-cell auxin transport via transporter proteins. Differential auxin accumulation as a result of such transport processes dynamically regulates auxin distribution during differentiation. In this review, we introduce all auxin transporter (families) identified to date and discuss the knowledge on prominent family members, namely, the PIN-FORMED exporters, ATP-binding cassette B (ABCB)-type transporters, and AUX1/LAX importers. We then concentrate on the biochemical features of these transporters and their regulation by posttranslational modifications and interactors.
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Affiliation(s)
- Ulrich Z Hammes
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Angus S Murphy
- Department of Plant Science and Landscape Architecture
- Agriculture Biotechnology Center, University of Maryland, College Park, Maryland 20742, USA
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
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10
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Koh SWH, Marhava P, Rana S, Graf A, Moret B, Bassukas AEL, Zourelidou M, Kolb M, Hammes UZ, Schwechheimer C, Hardtke CS. Mapping and engineering of auxin-induced plasma membrane dissociation in BRX family proteins. Plant Cell 2021; 33:1945-1960. [PMID: 33751121 PMCID: PMC8290284 DOI: 10.1093/plcell/koab076] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/03/2021] [Indexed: 05/04/2023]
Abstract
Angiosperms have evolved the phloem for the long-distance transport of metabolites. The complex process of phloem development involves genes that only occur in vascular plant lineages. For example, in Arabidopsis thaliana, the BREVIS RADIX (BRX) gene is required for continuous root protophloem differentiation, together with PROTEIN KINASE ASSOCIATED WITH BRX (PAX). BRX and its BRX-LIKE (BRXL) homologs are composed of four highly conserved domains including the signature tandem BRX domains that are separated by variable spacers. Nevertheless, BRX family proteins have functionally diverged. For instance, BRXL2 can only partially replace BRX in the root protophloem. This divergence is reflected in physiologically relevant differences in protein behavior, such as auxin-induced plasma membrane dissociation of BRX, which is not observed for BRXL2. Here we dissected the differential functions of BRX family proteins using a set of amino acid substitutions and domain swaps. Our data suggest that the plasma membrane-associated tandem BRX domains are both necessary and sufficient to convey the biological outputs of BRX function and therefore constitute an important regulatory entity. Moreover, PAX target phosphosites in the linker between the two BRX domains mediate the auxin-induced plasma membrane dissociation. Engineering these sites into BRXL2 renders this modified protein auxin-responsive and thereby increases its biological activity in the root protophloem context.
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Affiliation(s)
- Samuel W H Koh
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | - Petra Marhava
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | - Surbhi Rana
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | - Alina Graf
- Plant Systems Biology, Technical University of Munich, Freising 85354, Germany
| | - Bernard Moret
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
| | | | - Melina Zourelidou
- Plant Systems Biology, Technical University of Munich, Freising 85354, Germany
| | - Martina Kolb
- Plant Systems Biology, Technical University of Munich, Freising 85354, Germany
| | - Ulrich Z Hammes
- Plant Systems Biology, Technical University of Munich, Freising 85354, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technical University of Munich, Freising 85354, Germany
| | - Christian S Hardtke
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, Lausanne 1015, Switzerland
- Author for correspondence:
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11
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Schwechheimer C, Yalovsky S, Žárský V. Auxin does not inhibit endocytosis of PIN1 and PIN2 auxin efflux carriers. Plant Physiol 2021; 186:kiab132. [PMID: 33742679 PMCID: PMC8195515 DOI: 10.1093/plphys/kiab132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/10/2021] [Indexed: 06/12/2023]
Affiliation(s)
- Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences, Technical University of Munich, Emil-Ramann-Strasse 8, 85354 Freising, Germany
| | - Shaul Yalovsky
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12800 Prague, Czech Republic
- Laboratory of Cell Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 16502 Prague, Czech Republic
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12
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Saccomanno A, Potocký M, Pejchar P, Hála M, Shikata H, Schwechheimer C, Žárský V. Regulation of Exocyst Function in Pollen Tube Growth by Phosphorylation of Exocyst Subunit EXO70C2. Front Plant Sci 2021; 11:609600. [PMID: 33519861 PMCID: PMC7840542 DOI: 10.3389/fpls.2020.609600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
Exocyst is a heterooctameric protein complex crucial for the tethering of secretory vesicles to the plasma membrane during exocytosis. Compared to other eukaryotes, exocyst subunit EXO70 is represented by many isoforms in land plants whose cell biological and biological roles, as well as modes of regulation remain largely unknown. Here, we present data on the phospho-regulation of exocyst isoform EXO70C2, which we previously identified as a putative negative regulator of exocyst function in pollen tube growth. A comprehensive phosphoproteomic analysis revealed phosphorylation of EXO70C2 at multiple sites. We have now performed localization and functional studies of phospho-dead and phospho-mimetic variants of Arabidopsis EXO70C2 in transiently transformed tobacco pollen tubes and stably transformed Arabidopsis wild type and exo70C2 mutant plants. Our data reveal a dose-dependent effect of AtEXO70C2 overexpression on pollen tube growth rate and cellular architecture. We show that changes of the AtEXO70C2 phosphorylation status lead to distinct outcomes in wild type and exo70c2 mutant cells, suggesting a complex regulatory pattern. On the other side, phosphorylation does not affect the cytoplasmic localization of AtEXO70C2 or its interaction with putative secretion inhibitor ROH1 in the yeast two-hybrid system.
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Affiliation(s)
- Antonietta Saccomanno
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Martin Potocký
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Přemysl Pejchar
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Michal Hála
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
| | - Hiromasa Shikata
- Plant Systems Biology, Technische Universität München, Freising, Germany
| | | | - Viktor Žárský
- Laboratory of Cell Biology, Institute of Experimental Botany, Czech Academy of Sciences, Prague, Czechia
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czechia
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13
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Abas L, Kolb M, Stadlmann J, Janacek DP, Lukic K, Schwechheimer C, Sazanov LA, Mach L, Friml J, Hammes UZ. Naphthylphthalamic acid associates with and inhibits PIN auxin transporters. Proc Natl Acad Sci U S A 2021; 118:e2020857118. [PMID: 33443187 PMCID: PMC7817115 DOI: 10.1073/pnas.2020857118] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/12/2020] [Indexed: 12/22/2022] Open
Abstract
N-1-naphthylphthalamic acid (NPA) is a key inhibitor of directional (polar) transport of the hormone auxin in plants. For decades, it has been a pivotal tool in elucidating the unique polar auxin transport-based processes underlying plant growth and development. Its exact mode of action has long been sought after and is still being debated, with prevailing mechanistic schemes describing only indirect connections between NPA and the main transporters responsible for directional transport, namely PIN auxin exporters. Here we present data supporting a model in which NPA associates with PINs in a more direct manner than hitherto postulated. We show that NPA inhibits PIN activity in a heterologous oocyte system and that expression of NPA-sensitive PINs in plant, yeast, and oocyte membranes leads to specific saturable NPA binding. We thus propose that PINs are a bona fide NPA target. This offers a straightforward molecular basis for NPA inhibition of PIN-dependent auxin transport and a logical parsimonious explanation for the known physiological effects of NPA on plant growth, as well as an alternative hypothesis to interpret past and future results. We also introduce PIN dimerization and describe an effect of NPA on this, suggesting that NPA binding could be exploited to gain insights into structural aspects of PINs related to their transport mechanism.
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Affiliation(s)
- Lindy Abas
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria;
| | - Martina Kolb
- Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Johannes Stadlmann
- Department of Chemistry, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Dorina P Janacek
- Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Kristina Lukic
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Claus Schwechheimer
- Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Lukas Mach
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria
| | - Jiří Friml
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Ulrich Z Hammes
- Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany;
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14
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Lantzouni O, Alkofer A, Falter-Braun P, Schwechheimer C. GROWTH-REGULATING FACTORS Interact with DELLAs and Regulate Growth in Cold Stress. Plant Cell 2020; 32:1018-1034. [PMID: 32060178 PMCID: PMC7145461 DOI: 10.1105/tpc.19.00784] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/02/2020] [Accepted: 02/12/2020] [Indexed: 05/18/2023]
Abstract
DELLA proteins are repressors of the gibberellin (GA) hormone signaling pathway that act mainly by regulating transcription factor activities in plants. GAs induce DELLA repressor protein degradation and thereby control a number of critical developmental processes as well as responses to stresses such as cold. The strong effect of cold temperatures on many physiological processes has rendered it difficult to assess, based on phenotypic criteria, the role of GA and DELLAs in plant growth during cold stress. Here, we uncover substantial differences in the GA transcriptomes between plants grown at ambient temperature (21°C) and plants exposed to cold stress (4°C) in Arabidopsis (Arabidopsis thaliana). We further identify over 250, to the largest extent previously unknown, DELLA-transcription factor interactions using the yeast two-hybrid system. By integrating both data sets, we reveal that most members of the nine-member GRF (GROWTH REGULATORY FACTOR) transcription factor family are DELLA interactors and, at the same time, that several GRF genes are targets of DELLA-modulated transcription after exposure to cold stress. We find that plants with altered GRF dosage are differentially sensitive to the manipulation of GA and hence DELLA levels, also after cold stress, and identify a subset of cold stress-responsive genes that qualify as targets of this DELLA-GRF regulatory module.
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Affiliation(s)
- Ourania Lantzouni
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Angela Alkofer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Pascal Falter-Braun
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
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15
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Schwechheimer C. NEDD8-its role in the regulation of Cullin-RING ligases. Curr Opin Plant Biol 2018; 45:112-119. [PMID: 29909289 DOI: 10.1016/j.pbi.2018.05.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 05/26/2018] [Accepted: 05/31/2018] [Indexed: 05/10/2023]
Abstract
The ubiquitin-related protein NEDD8 is conjugated and deconjugated to and from proteins in processes related to ubiquitin conjugation and deconjugation. Neddylation is a well-studied posttranslational modification of Cullin-RING E3 ligases (CRLs). Biochemical and structural studies aiming at understanding the role of NEDD8 in CRL function have now resulted in a convincing model of how neddylation and deneddylation antagonistically regulate CRL stability, conformation, activity as well as degradation substrate receptor exchange. Studies of the Arabidopsis thaliana deneddylation-deficient den1 mutant led to the identification of many low abundant, non-Cullin NEDD8 conjugates. Examination of neddylated AUXIN RESISTANT1 (AXR1), a prominent neddylated protein in den1, suggests, however, that AXR1 neddylation may be an auto-catalytic side-reaction of Cullin-targeted neddylation and that DEN1 may serve to antagonize non-productive, auto-neddylation from substrates to provide free NEDD8 for CRL regulation.
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Affiliation(s)
- Claus Schwechheimer
- Plant Systems Biology, Emil-Ramann-Strasse 8, Technical University of Munich, 85354 Freising, Germany.
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16
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Lee BH, Weber ZT, Zourelidou M, Hofmeister BT, Schmitz RJ, Schwechheimer C, Dobritsa AA. Arabidopsis Protein Kinase D6PKL3 Is Involved in the Formation of Distinct Plasma Membrane Aperture Domains on the Pollen Surface. Plant Cell 2018; 30:2038-2056. [PMID: 30150313 PMCID: PMC6181024 DOI: 10.1105/tpc.18.00442] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/09/2018] [Accepted: 08/23/2018] [Indexed: 05/22/2023]
Abstract
Certain regions on the surfaces of developing pollen grains exhibit very limited deposition of pollen wall exine. These regions give rise to pollen apertures, which are highly diverse in their patterns and specific for individual species. Arabidopsis thaliana pollen develops three equidistant longitudinal apertures. The precision of aperture formation suggests that, to create them, pollen employs robust mechanisms that generate distinct cellular domains. To identify players involved in this mechanism, we screened natural Arabidopsis accessions and discovered one accession, Martuba, whose apertures form abnormally due to the disruption of the protein kinase D6PKL3. During pollen development, D6PKL3 accumulates at the three plasma membrane domains underlying future aperture sites. Both D6PKL3 localization and aperture formation require kinase activity. Proper D6PKL3 localization is also dependent on a polybasic motif for phosphoinositide interactions, and we identified two phosphoinositides that are specifically enriched at the future aperture sites. The other known aperture factor, INAPERTURATE POLLEN1, fails to aggregate at the aperture sites in d6pkl3 mutants, changes its localization when D6PKL3 is mislocalized, and, in turn, affects D6PKL3 localization. The discovery of aperture factors provides important insights into the mechanisms cells utilize to generate distinct membrane domains, develop cell polarity, and pattern their surfaces.
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Affiliation(s)
- Byung Ha Lee
- Department of Molecular Genetics and Center for Applied Plant Science, Ohio State University, Columbus, Ohio 43210
| | - Zachary T Weber
- Department of Molecular Genetics and Center for Applied Plant Science, Ohio State University, Columbus, Ohio 43210
| | - Melina Zourelidou
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | | | - Robert J Schmitz
- Department of Genetics, University of Georgia, Athens, Georgia 30602
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Anna A Dobritsa
- Department of Molecular Genetics and Center for Applied Plant Science, Ohio State University, Columbus, Ohio 43210
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17
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Marhava P, Bassukas AEL, Zourelidou M, Kolb M, Moret B, Fastner A, Schulze WX, Cattaneo P, Hammes UZ, Schwechheimer C, Hardtke CS. A molecular rheostat adjusts auxin flux to promote root protophloem differentiation. Nature 2018; 558:297-300. [DOI: 10.1038/s41586-018-0186-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 04/24/2018] [Indexed: 01/30/2023]
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18
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Barbosa ICR, Hammes UZ, Schwechheimer C. Activation and Polarity Control of PIN-FORMED Auxin Transporters by Phosphorylation. Trends Plant Sci 2018; 23:523-538. [PMID: 29678589 DOI: 10.1016/j.tplants.2018.03.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 03/11/2018] [Accepted: 03/14/2018] [Indexed: 05/09/2023]
Abstract
Auxin controls almost every aspect of plant development. Auxin is distributed within the plant by passive diffusion and active cell-to-cell transport. PIN-FORMED (PIN) auxin efflux transporters are polarly distributed in the plasma membranes of many cells, and knowledge about their distribution can predict auxin transport and explain auxin distribution patterns, even in complex tissues. Recent studies have revealed that phosphorylation is essential for PIN activation, suggesting that PIN phosphorylation needs to be taken into account in understanding auxin transport. These findings also ask for a re-examination of previously proposed mechanisms for phosphorylation-dependent PIN polarity control. We provide a comprehensive summary of the current knowledge on PIN regulation by phosphorylation, and discuss possible mechanisms of PIN polarity control in the context of recent findings.
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Affiliation(s)
- Inês C R Barbosa
- Department of Plant Molecular Biology, Biophore Building, Unil-Sorge, Université de Lausanne, 1015 Lausanne, Switzerland; These authors contributed equally to this review article and are listed in alphabetical order
| | - Ulrich Z Hammes
- Plant Systems Biology, Technical University Munich, Emil-Ramann-Strasse 8, 85354 Freising, Germany; These authors contributed equally to this review article and are listed in alphabetical order
| | - Claus Schwechheimer
- Plant Systems Biology, Technical University Munich, Emil-Ramann-Strasse 8, 85354 Freising, Germany; These authors contributed equally to this review article and are listed in alphabetical order.
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19
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Schwechheimer C. Claus Schwechheimer. Curr Biol 2018; 28:R684-R686. [DOI: 10.1016/j.cub.2018.04.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Haga K, Frank L, Kimura T, Schwechheimer C, Sakai T. Roles of AGCVIII Kinases in the Hypocotyl Phototropism of Arabidopsis Seedlings. Plant Cell Physiol 2018; 59:1060-1071. [PMID: 29490064 DOI: 10.1093/pcp/pcy048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/22/2018] [Indexed: 06/08/2023]
Abstract
Regulation of protein function by phosphorylation and dephosphorylation is an important mechanism in many cellular events. The phototropin blue-light photoreceptors, plant-specific AGCVIII kinases, are essential for phototropic responses. Members of the D6 PROTEIN KINASE (D6PK) family, representing a subfamily of the AGCVIII kinases, also contribute to phototropic responses, suggesting that possibly further AGCVIII kinases may potentially control phototropism. The present study investigates the functional roles of Arabidopsis (Arabidopsis thaliana) AGCVIII kinases in hypocotyl phototropism. We demonstrate that D6PK family kinases are not only required for the second but also for the first positive phototropism. In addition, we find that a previously uncharacterized AGCVIII protein, AGC1-12, is involved in the first positive phototropism and gravitropism. AGC1-12 phosphorylates serine residues in the cytoplasmic loop of PIN-FORMED 1 (PIN1) and shares phosphosite preferences with D6PK. Our work strongly suggests that the D6PK family and AGC1-12 are critical components for both hypocotyl phototropism and gravitropism, and that these kinases control tropic responses mainly through regulation of PIN-mediated auxin transport by protein phosphorylation.
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Affiliation(s)
- Ken Haga
- Department of Human Science and Common Education, Nippon Institute of Technology, 4-1 Gakuendai, Miyashiro-cho, Minamisaitama-gun, Saitama, 345-8501 Japan
| | - Lena Frank
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, D-85354 Freising-Weihenstephan, Germany
| | - Taro Kimura
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
- Research Fellow of the Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083 Japan
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, D-85354 Freising-Weihenstephan, Germany
| | - Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata, 950-2181 Japan
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21
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Robinson DG, Hawes C, Hillmer S, Jürgens G, Schwechheimer C, Stierhof YD, Viotti C. Auxin and Vesicle Traffic. Plant Physiol 2018; 176:1884-1888. [PMID: 29630496 PMCID: PMC5841702 DOI: 10.1104/pp.17.01510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Affiliation(s)
- David G Robinson
- Centre for Organismal Studies, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Chris Hawes
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Stefan Hillmer
- Electron Microscopy Core Facility, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Gerd Jürgens
- Center for Plant Molecular Biology, University of Tuebingen, D-72076 Tuebingen, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technical University of Munich, D-85354 Freising, Germany
| | - York-Dieter Stierhof
- Center for Plant Molecular Biology, University of Tuebingen, D-72076 Tuebingen, Germany
| | - Corrado Viotti
- Institut de Biologie Moléculaire des Plantes, CNRS, 67084 Strasbourg, France
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22
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Bastakis E, Hedtke B, Klermund C, Grimm B, Schwechheimer C. LLM-Domain B-GATA Transcription Factors Play Multifaceted Roles in Controlling Greening in Arabidopsis. Plant Cell 2018; 30:582-599. [PMID: 29453227 PMCID: PMC5894840 DOI: 10.1105/tpc.17.00947] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/02/2018] [Accepted: 02/14/2018] [Indexed: 05/20/2023]
Abstract
Chlorophyll accumulation and chloroplast development are regulated at multiple levels during plant development. The paralogous LLM-domain B-GATA transcription factors GNC and GNL contribute to chlorophyll biosynthesis and chloroplast formation in light-grown Arabidopsis thaliana seedlings. Whereas there is already ample knowledge about the transcriptional regulation of GNC and GNL, the identity of their downstream targets is largely unclear. Here, we identified genes controlling greening directly downstream of the GATAs by integrating data from RNA-sequencing and microarray data sets. We found that genes encoding subunits of the Mg-chelatase complex and 3,8-divinyl protochlorophyllide a 8-vinyl reductase (DVR) likely function directly downstream of the GATAs and that DVR expression is limiting in the pale-green gnc gnl mutants. The GATAs also regulate the nucleus-encoded SIGMA (SIG) factor genes, which control transcription in the chloroplast and suppress the greening defects of sig mutants. Furthermore, GNC and GNL act, at the gene expression level, in an additive manner with the GOLDEN2-LIKE1 (GLK1) and GLK2 transcription factor genes, which are also important for proper chlorophyll accumulation. We thus reveal that chlorophyll biosynthesis genes are directly controlled by LLM-domain B-GATAs and demonstrate that these transcription factors play an indirect role in the control of greening through regulating SIGMA factor genes.
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Affiliation(s)
- Emmanouil Bastakis
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Boris Hedtke
- Plant Physiology, Humboldt University Berlin, 10115 Berlin, Germany
| | - Carina Klermund
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Bernhard Grimm
- Plant Physiology, Humboldt University Berlin, 10115 Berlin, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
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23
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Bagchi R, Melnyk CW, Christ G, Winkler M, Kirchsteiner K, Salehin M, Mergner J, Niemeyer M, Schwechheimer C, Calderón Villalobos LIA, Estelle M. The Arabidopsis ALF4 protein is a regulator of SCF E3 ligases. EMBO J 2017; 37:255-268. [PMID: 29233834 DOI: 10.15252/embj.201797159] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 11/10/2017] [Accepted: 11/16/2017] [Indexed: 12/21/2022] Open
Abstract
The cullin-RING E3 ligases (CRLs) regulate diverse cellular processes in all eukaryotes. CRL activity is controlled by several proteins or protein complexes, including NEDD8, CAND1, and the CSN Recently, a mammalian protein called Glomulin (GLMN) was shown to inhibit CRLs by binding to the RING BOX (RBX1) subunit and preventing binding to the ubiquitin-conjugating enzyme. Here, we show that Arabidopsis ABERRANT LATERAL ROOT FORMATION4 (ALF4) is an ortholog of GLMN The alf4 mutant exhibits a phenotype that suggests defects in plant hormone response. We show that ALF4 binds to RBX1 and inhibits the activity of SCFTIR1, an E3 ligase responsible for degradation of the Aux/IAA transcriptional repressors. In vivo, the alf4 mutation destabilizes the CUL1 subunit of the SCF Reduced CUL1 levels are associated with increased levels of the Aux/IAA proteins as well as the DELLA repressors, substrate of SCFSLY1 We propose that the alf4 phenotype is partly due to increased levels of the Aux/IAA and DELLA proteins.
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Affiliation(s)
- Rammyani Bagchi
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA, USA
| | | | - Gideon Christ
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Halle, Germany
| | - Martin Winkler
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Halle, Germany.,Institute of Biology, Structural Biology/Biochemistry, Humboldt-University Berlin, Berlin, Germany
| | - Kerstin Kirchsteiner
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA, USA
| | - Mohammad Salehin
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA, USA
| | - Julia Mergner
- Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Michael Niemeyer
- Department of Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Halle, Germany
| | | | | | - Mark Estelle
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, CA, USA
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24
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Lantzouni O, Klermund C, Schwechheimer C. Largely additive effects of gibberellin and strigolactone on gene expression in Arabidopsis thaliana seedlings. Plant J 2017; 92:924-938. [PMID: 28977719 DOI: 10.1111/tpj.13729] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/01/2017] [Accepted: 09/27/2017] [Indexed: 05/22/2023]
Abstract
The phytohormones gibberellin (GA) and strigolactone (SL) are involved in essential processes in plant development. Both GA and SL signal transduction mechanisms employ α/β-hydrolase-derived receptors that confer E3 ubiquitin ligase-mediated protein degradation processes. This suggests a common evolutionary origin of these pathways and possibly a molecular interaction between them. One such indication stems from rice, where the DELLA protein of the GA pathway was reported to interact with the SL receptor. Here, we examine the physiological interaction between both pathways through the analysis of GA (ga1) and SL biosynthesis (max1 and max3) mutants. In ga1 max double mutants, we find indications only for additive interactions when examining several phenotypic readouts. We further identify short-term transcriptional responses to GA and the synthetic SL rac-GR24 through next-generation sequencing of poly-adenylated RNAs (RNA-seq) in ga1 max1. Remarkably, both hormones lead to predominantly additive transcriptional changes of a largely overlapping set of genes. The expression of only a few genes was altered in a synergistic manner but, interestingly, these include the genes encoding the GA catabolic enzyme GA2 OXIDASE2 (GA2ox2) as well as the SL pathway regulators BRANCHED1 (BRC1) and SUPPRESSOR OF max2 1-LIKE8 (SMXL8). We conclude that GA and rac-GR24 signaling in Arabidopsis seedlings converge at the level of transcription of a common gene-set.
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Affiliation(s)
- Ourania Lantzouni
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 8, 85354, Freising, Germany
| | - Carina Klermund
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 8, 85354, Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 8, 85354, Freising, Germany
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25
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Lutz U, Nussbaumer T, Spannagl M, Diener J, Mayer KF, Schwechheimer C. Natural haplotypes of FLM non-coding sequences fine-tune flowering time in ambient spring temperatures in Arabidopsis. eLife 2017; 6. [PMID: 28294941 PMCID: PMC5388537 DOI: 10.7554/elife.22114] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 03/09/2017] [Indexed: 11/18/2022] Open
Abstract
Cool ambient temperatures are major cues determining flowering time in spring. The mechanisms promoting or delaying flowering in response to ambient temperature changes are only beginning to be understood. In Arabidopsis thaliana, FLOWERING LOCUS M (FLM) regulates flowering in the ambient temperature range and FLM is transcribed and alternatively spliced in a temperature-dependent manner. We identify polymorphic promoter and intronic sequences required for FLM expression and splicing. In transgenic experiments covering 69% of the available sequence variation in two distinct sites, we show that variation in the abundance of the FLM-ß splice form strictly correlate (R2 = 0.94) with flowering time over an extended vegetative period. The FLM polymorphisms lead to changes in FLM expression (PRO2+) but may also affect FLM intron 1 splicing (INT6+). This information could serve to buffer the anticipated negative effects on agricultural systems and flowering that may occur during climate change. DOI:http://dx.doi.org/10.7554/eLife.22114.001
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Affiliation(s)
- Ulrich Lutz
- Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Thomas Nussbaumer
- Plant Genome and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Manuel Spannagl
- Plant Genome and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Julia Diener
- Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Klaus Fx Mayer
- Plant Genome and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
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26
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Mergner J, Kuster B, Schwechheimer C. DENEDDYLASE1 Protein Counters Automodification of Neddylating Enzymes to Maintain NEDD8 Protein Homeostasis in Arabidopsis. J Biol Chem 2017; 292:3854-3865. [PMID: 28096463 DOI: 10.1074/jbc.m116.767103] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/10/2017] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, the conjugation of the ubiquitin-like protein NEDD8 onto protein targets is an important post-translational modification. The best understood neddylation targets are the cullins, scaffold subunits of E3 ubiquitin ligases, where neddylation as well as deneddylation, facilitated by the protease activity of the CSN (COP9 signalosome), are required to control ubiquitin ligase assembly, function, and ultimately substrate degradation. Little is known about the role of other deneddylating enzymes besides CSN and the role of neddylation and deneddylation of their substrates. We previously characterized Arabidopsis thaliana mutants with defects in the conserved NEDD8-specific protease DEN1 (DENEDDYLASE1). These mutants display only subtle growth phenotypes despite the strong accumulation of a broad range of neddylated proteins. Specifically, we identified AXR1 (AUXIN-RESISTANT1), a subunit of the heterodimeric NAE (E1 NEDD8-ACTIVATING ENZYME), as highly neddylated in den1 mutants. Here, we examined the mechanism and consequences of AXR1 neddylation in more detail. We find that AXR1 as well as other neddylation enzymes are autoneddylated at multiple lysines. NAE autoneddylation can be linked to reduced NCE (E2 NEDD8-CONJUGATING ENZYME) NEDD8 thioester levels, either by critically reducing the pool of free NEDD8 or by reducing NAE activity. In planta, increasing NEDD8 gene dosage is sufficient to suppress den1 mutant phenotypes. We therefore suggest that DEN1 serves to recover diverted NEDD8 moieties from autoneddylated NAE subunits, and possibly also other neddylated proteins, to maintain NEDD8 pathway activity toward other NEDD8-dependent processes such as cullin E3 ligase regulation.
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Affiliation(s)
- Julia Mergner
- From the Chair of Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8 and.,the Chair of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Bernhard Kuster
- the Chair of Proteomics and Bioanalytics, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Claus Schwechheimer
- From the Chair of Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8 and
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Ge Y, Yan F, Zourelidou M, Wang M, Ljung K, Fastner A, Hammes UZ, Di Donato M, Geisler M, Schwechheimer C, Tao Y. SHADE AVOIDANCE 4 Is Required for Proper Auxin Distribution in the Hypocotyl. Plant Physiol 2017; 173:788-800. [PMID: 27872246 PMCID: PMC5210748 DOI: 10.1104/pp.16.01491] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/17/2016] [Indexed: 05/25/2023]
Abstract
The phytohormone auxin is involved in virtually every aspect of plant growth and development. Through polar auxin transport, auxin gradients can be established, which then direct plant differentiation and growth. Shade avoidance responses are well-known processes that require polar auxin transport. In this study, we have identified a mutant, shade avoidance 4 (sav4), defective in shade-induced hypocotyl elongation and basipetal auxin transport. SAV4 encodes an unknown protein with armadillo repeat- and tetratricopeptide repeat-like domains known to provide protein-protein interaction surfaces. C terminally yellow fluorescent protein-tagged SAV4 localizes to both the plasma membrane and the nucleus. Membrane-localized SAV4 displays a polar association with the shootward plasma membrane domain in hypocotyl and root cells, which appears to be necessary for its function in hypocotyl elongation. Cotransfection of SAV4 and ATP-binding cassette B1 (ABCB1) auxin transporter in tobacco (Nicotiana benthamiana) revealed that SAV4 blocks ABCB1-mediated auxin efflux. We thus propose that polarly localized SAV4 acts to inhibit ABCB-mediated auxin efflux toward shoots and facilitates the establishment of proper auxin gradients.
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Affiliation(s)
- Yanhua Ge
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Fenglian Yan
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Melina Zourelidou
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Meiling Wang
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Karin Ljung
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Astrid Fastner
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Ulrich Z Hammes
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Martin Di Donato
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Markus Geisler
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Claus Schwechheimer
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.)
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.)
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
| | - Yi Tao
- School of Life Sciences, Xiamen Plant Genetics Key Laboratory (Y.G., F.Y., M.W., Y.T.), and State Key Laboratory of Cellular Stress Biology (Y.G., Y.T.), Xiamen University, Xiamen 361102, China;
- Department of Plant Systems Biology, Technische Universität München, Freising 85354, Germany (M.Z., C.S.);
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden (K.L.);
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg 93047, Germany (A.F., U.Z.H.); and
- Department of Biology-Plant Biology, University of Fribourg, CH-1700 Fribourg, Switzerland (M.D.D., M.G.)
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Barbosa ICR, Shikata H, Zourelidou M, Heilmann M, Heilmann I, Schwechheimer C. Phospholipid composition and a polybasic motif determine D6 PROTEIN KINASE polar association with the plasma membrane and tropic responses. Development 2016; 143:4687-4700. [PMID: 27836964 DOI: 10.1242/dev.137117] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 10/27/2016] [Indexed: 01/16/2023]
Abstract
Polar transport of the phytohormone auxin through PIN-FORMED (PIN) auxin efflux carriers is essential for the spatiotemporal control of plant development. The Arabidopsis thaliana serine/threonine kinase D6 PROTEIN KINASE (D6PK) is polarly localized at the plasma membrane of many cells where it colocalizes with PINs and activates PIN-mediated auxin efflux. Here, we show that the association of D6PK with the basal plasma membrane and PINs is dependent on the phospholipid composition of the plasma membrane as well as on the phosphatidylinositol phosphate 5-kinases PIP5K1 and PIP5K2 in epidermis cells of the primary root. We further show that D6PK directly binds polyacidic phospholipids through a polybasic lysine-rich motif in the middle domain of the kinase. The lysine-rich motif is required for proper PIN3 phosphorylation and for auxin transport-dependent tropic growth. Polybasic motifs are also present at a conserved position in other D6PK-related kinases and required for membrane and phospholipid binding. Thus, phospholipid-dependent recruitment to membranes through polybasic motifs might not only be required for D6PK-mediated auxin transport but also other processes regulated by these, as yet, functionally uncharacterized kinases.
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Affiliation(s)
- Inês C R Barbosa
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany
| | - Hiromasa Shikata
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany
| | - Melina Zourelidou
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany
| | - Mareike Heilmann
- Institute for Biochemistry and Biotechnology, Cellular Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, Halle 06120, Germany
| | - Ingo Heilmann
- Institute for Biochemistry and Biotechnology, Cellular Biochemistry, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Strasse 3, Halle 06120, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 8, Freising 85354, Germany
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29
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Ranftl QL, Bastakis E, Klermund C, Schwechheimer C. LLM-Domain Containing B-GATA Factors Control Different Aspects of Cytokinin-Regulated Development in Arabidopsis thaliana. Plant Physiol 2016; 170:2295-311. [PMID: 26829982 PMCID: PMC4825128 DOI: 10.1104/pp.15.01556] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/29/2016] [Indexed: 05/17/2023]
Abstract
Leu-Leu-Met (LLM)-domain B-GATAs are a subfamily of the 30-membered GATA transcription factor family from Arabidopsis. Only two of the six Arabidopsis LLM-domain B-GATAs, i.e. GATA, NITRATE-INDUCIBLE, CARBON METABOLISM-INVOLVED (GNC) and its paralog GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR1 (GNL), have already been analyzed with regard to their biological function. Together, GNC and GNL control germination, greening, flowering time, and senescence downstream from auxin, cytokinin (CK), gibberellin (GA), and light signaling. Whereas overexpression and complementation analyses suggest a redundant biochemical function between GNC and GNL, nothing is known about the biological role of the four other LLM-domain B-GATAs, GATA15, GATA16, GATA17, and GATA17L (GATA17-LIKE), based on loss-of-function mutant phenotypes. Here, we examine insertion mutants of the six Arabidopsis B-GATA genes and reveal the role of these genes in the control of greening, hypocotyl elongation, phyllotaxy, floral organ initiation, accessory meristem formation, flowering time, and senescence. Several of these phenotypes had previously not been described for the gnc and gnl mutants or were enhanced in the more complex mutants when compared to gnc gnl mutants. Some of the respective responses may be mediated by CK signaling, which activates the expression of all six GATA genes. CK-induced gene expression is partially compromised in LLM-domain B-GATA mutants, suggesting that B-GATA genes play a role in CK responses. We furthermore provide evidence for a transcriptional cross regulation between these GATAs that may, in at least some cases, be at the basis of their apparent functional redundancy.
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Affiliation(s)
- Quirin L Ranftl
- Plant Systems Biology, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Strasse 8, 85354 Freising, Germany (Q.L.R., E.B., C.K., C.S.)
| | - Emmanouil Bastakis
- Plant Systems Biology, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Strasse 8, 85354 Freising, Germany (Q.L.R., E.B., C.K., C.S.)
| | - Carina Klermund
- Plant Systems Biology, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Strasse 8, 85354 Freising, Germany (Q.L.R., E.B., C.K., C.S.)
| | - Claus Schwechheimer
- Plant Systems Biology, Wissenschaftszentrum Weihenstephan, Technische Universität München, Emil-Ramann-Strasse 8, 85354 Freising, Germany (Q.L.R., E.B., C.K., C.S.)
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30
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Klermund C, Ranftl QL, Diener J, Bastakis E, Richter R, Schwechheimer C. LLM-Domain B-GATA Transcription Factors Promote Stomatal Development Downstream of Light Signaling Pathways in Arabidopsis thaliana Hypocotyls. Plant Cell 2016; 28:646-60. [PMID: 26917680 PMCID: PMC4826009 DOI: 10.1105/tpc.15.00783] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/05/2016] [Accepted: 02/22/2016] [Indexed: 05/18/2023]
Abstract
Stomata are pores that regulate the gas and water exchange between the environment and aboveground plant tissues, including hypocotyls, leaves, and stems. Here, we show that mutants of Arabidopsis thaliana LLM-domain B-GATA genes are defective in stomata formation in hypocotyls. Conversely, stomata formation is strongly promoted by overexpression of various LLM-domain B-class GATA genes, most strikingly in hypocotyls but also in cotyledons. Genetic analyses indicate that these B-GATAs act upstream of the stomata formation regulators SPEECHLESS(SPCH), MUTE, and SCREAM/SCREAM2 and downstream or independent of the patterning regulators TOO MANY MOUTHS and STOMATAL DENSITY AND DISTRIBUTION1 The effects of the GATAs on stomata formation are light dependent but can be induced in dark-grown seedlings by red, far-red, or blue light treatments. PHYTOCHROME INTERACTING FACTOR(PIF) mutants form stomata in the dark, and in this genetic background, GATA expression is sufficient to induce stomata formation in the dark. Since the expression of the LLM-domain B-GATAs GNC(GATA, NITRATE-INDUCIBLE, CARBON METABOLISM-INVOLVED) and GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR1 as well as that of SPCH is red light induced but the induction of SPCH is compromised in a GATA gene mutant background, we hypothesize that PIF- and light-regulated stomata formation in hypocotyls is critically dependent on LLM-domain B-GATA genes.
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Affiliation(s)
- Carina Klermund
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Quirin L Ranftl
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Julia Diener
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Emmanouil Bastakis
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - René Richter
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
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31
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Stanislas T, Hüser A, Barbosa ICR, Kiefer CS, Brackmann K, Pietra S, Gustavsson A, Zourelidou M, Schwechheimer C, Grebe M. Arabidopsis D6PK is a lipid domain-dependent mediator of root epidermal planar polarity. Nat Plants 2015; 1:15162. [PMID: 27251533 DOI: 10.1038/nplants.2015.162] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
Development of diverse multicellular organisms relies on coordination of single-cell polarities within the plane of the tissue layer (planar polarity). Cell polarity often involves plasma membrane heterogeneity generated by accumulation of specific lipids and proteins into membrane subdomains. Coordinated hair positioning along Arabidopsis root epidermal cells provides a planar polarity model in plants, but knowledge about the functions of proteo-lipid domains in planar polarity signalling remains limited. Here we show that Rho-of-plant (ROP) 2 and 6, phosphatidylinositol-4-phosphate 5-kinase 3 (PIP5K3), DYNAMIN-RELATED PROTEIN (DRP) 1A and DRP2B accumulate in a sterol-enriched, polar membrane domain during root hair initiation. DRP1A, DRP2B, PIP5K3 and sterols are required for planar polarity and the AGCVIII kinase D6 PROTEIN KINASE (D6PK) is a modulator of this process. D6PK undergoes phosphatidylinositol-4,5-bisphosphate- and sterol-dependent basal-to-planar polarity switching into the polar, lipid-enriched domain just before hair formation, unravelling lipid-dependent D6PK localization during late planar polarity signalling.
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Affiliation(s)
- Thomas Stanislas
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, DE-14476 Potsdam-Golm, Germany
| | - Anke Hüser
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
| | - Inês C R Barbosa
- Technische Universität München, Plant Systems Biology, Emil-Ramann-Str. 4,DE-85354 Freising, Germany
| | - Christian S Kiefer
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
| | - Klaus Brackmann
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
| | - Stefano Pietra
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
| | - Anna Gustavsson
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
| | - Melina Zourelidou
- Technische Universität München, Plant Systems Biology, Emil-Ramann-Str. 4,DE-85354 Freising, Germany
| | - Claus Schwechheimer
- Technische Universität München, Plant Systems Biology, Emil-Ramann-Str. 4,DE-85354 Freising, Germany
| | - Markus Grebe
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-90 187 Umeå, Sweden
- Institute of Biochemistry and Biology, Plant Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, Building 20, DE-14476 Potsdam-Golm, Germany
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Mergner J, Heinzlmeir S, Kuster B, Schwechheimer C. DENEDDYLASE1 deconjugates NEDD8 from non-cullin protein substrates in Arabidopsis thaliana. Plant Cell 2015; 27:741-53. [PMID: 25783028 PMCID: PMC4558671 DOI: 10.1105/tpc.114.135996] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/05/2015] [Accepted: 02/26/2015] [Indexed: 05/25/2023]
Abstract
The evolutionarily conserved 8-kD protein NEDD8 (NEURAL PRECURSOR CELL EXPRESSED, DEVELOPMENTALLY DOWN-REGULATED8) belongs to the family of ubiquitin-like modifiers. Like ubiquitin, NEDD8 is conjugated to and deconjugated from target proteins. Many targets and functions of ubiquitylation have been described; by contrast, few targets of NEDD8 have been identified. In plants as well as in non-plant organisms, the cullin subunits of cullin-RING E3 ligases are NEDD8 conjugates with a demonstrated functional role for the NEDD8 modification. The existence of other non-cullin NEDD8 targets has generally been questioned. NEDD8 is translated as a precursor protein and proteolytic processing exposes a C-terminal glycine required for NEDD8 conjugation. In animals and yeast, DENEDDYLASE1 (DEN1) processes NEDD8. Here, we show that mutants of a DEN1 homolog from Arabidopsis thaliana have no detectable defects in NEDD8 processing but do accumulate a broad range of NEDD8 conjugates; this provides direct evidence for the existence of non-cullin NEDD8 conjugates. We further identify AUXIN RESISTANT1 (AXR1), a subunit of the heterodimeric NEDD8 E1 activating enzyme, as a NEDD8-modified protein in den1 mutants and wild type and provide evidence that AXR1 function may be compromised in the absence of DEN1 activity. Thus, in plants, neddylation may serve as a regulatory mechanism for cullin and non-cullin proteins.
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Affiliation(s)
- Julia Mergner
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany Proteomics and Bioanalytics, Technische Universität München, 85354 Freising, Germany
| | - Stephanie Heinzlmeir
- Proteomics and Bioanalytics, Technische Universität München, 85354 Freising, Germany
| | - Bernhard Kuster
- Proteomics and Bioanalytics, Technische Universität München, 85354 Freising, Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
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Behringer C, Schwechheimer C. B-GATA transcription factors - insights into their structure, regulation, and role in plant development. Front Plant Sci 2015; 6:90. [PMID: 25755661 PMCID: PMC4337238 DOI: 10.3389/fpls.2015.00090] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/03/2015] [Indexed: 05/17/2023]
Abstract
GATA transcription factors are evolutionarily conserved transcriptional regulators that recognize promoter elements with a G-A-T-A core sequence. In comparison to animal genomes, the GATA transcription factor family in plants is comparatively large with approximately 30 members. Here, we review the current knowledge on B-GATAs, one of four GATA factor subfamilies from Arabidopsis thaliana. We show that B-GATAs can be subdivided based on structural features and their biological function into family members with a C-terminal LLM- (leucine-leucine-methionine) domain or an N-terminal HAN- (HANABA TARANU) domain. The paralogous GNC (GATA, NITRATE-INDUCIBLE, CARBON-METABOLISM INVOLVED) and CGA1/GNL (CYTOKININ-INDUCED GATA1/GNC-LIKE) are introduced as LLM-domain containing B-GATAs from Arabidopsis that control germination, greening, senescence, and flowering time downstream from several growth regulatory signals. Arabidopsis HAN and its monocot-specific paralogs from rice (NECK LEAF1), maize (TASSEL SHEATH1), and barley (THIRD OUTER GLUME) are HAN-domain-containing B-GATAs with a predominant role in embryo development and floral development. We also review GATA23, a regulator of lateral root initiation from Arabidopsis that is closely related to GNC and GNL but has a degenerate LLM-domain that is seemingly specific for the Brassicaceae family. The Brassicaceae-specific GATA23 and the monocot-specific HAN-domain GATAs provide evidence that neofunctionalization of B-GATAs was used during plant evolution to expand the functional repertoire of these transcription factors.
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Affiliation(s)
| | - Claus Schwechheimer
- *Correspondence: Claus Schwechheimer, Department of Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 4, 85354 Freising, Germany e-mail:
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Barbosa IC, Schwechheimer C. Dynamic control of auxin transport-dependent growth by AGCVIII protein kinases. Curr Opin Plant Biol 2014; 22:108-115. [PMID: 25305415 DOI: 10.1016/j.pbi.2014.09.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/19/2014] [Accepted: 09/22/2014] [Indexed: 05/10/2023]
Abstract
Recent years have seen important advances in understanding the Arabidopsis thaliana AGCVIII protein kinases D6 PROTEIN KINASE, PINOID/WAGs, and the phototropins. It has become apparent that these kinases control the distribution of the phytohormone auxin within the plant through phosphorylation of PIN-FORMED efflux carriers or of ABC transporters. Strikingly, D6PK and PID share the same phosphosites in PIN-FORMED proteins but have differential phosphosite preferences, which appear to control the activity and polar distribution of PIN-FORMED transporters. All three AGCVIII kinases are membrane-associated proteins that are dynamically transported to and from the plasma membrane. The implications of this dynamic transport for the activity and cell biological behavior of their phosphorylation substrates are just now starting to be understood.
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Affiliation(s)
- Inês Cr Barbosa
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 4, 85354 Freising Germany
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, Emil-Ramann-Strasse 4, 85354 Freising Germany.
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Behringer C, Bastakis E, Ranftl QL, Mayer KFX, Schwechheimer C. Functional diversification within the family of B-GATA transcription factors through the leucine-leucine-methionine domain. Plant Physiol 2014; 166:293-305. [PMID: 25077795 PMCID: PMC4149714 DOI: 10.1104/pp.114.246660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The transcription of the Arabidopsis (Arabidopsis thaliana) GATA transcription factors GATA, NITRATE-INDUCIBLE, CARBON METABOLISM-INVOLVED (GNC) and GNC-LIKE (GNL)/CYTOKININ-RESPONSIVE GATA FACTOR1 is controlled by several growth regulatory signals including light and the phytohormones auxin, cytokinin, and gibberellin. To date, GNC and GNL have been attributed functions in the control of germination, greening, flowering time, floral development, senescence, and floral organ abscission. GNC and GNL belong to the 11-member family of B-class GATA transcription factors that are characterized to date solely by their high sequence conservation within the GATA DNA-binding domain. The degree of functional conservation among the various B-class GATA family members is not understood. Here, we identify and examine B-class GATAs from Arabidopsis, tomato (Solanum lycopersicon), Brachypodium (Brachypodium distachyon), and barley (Hordeum vulgare). We find that B-class GATAs from these four species can be subdivided based on their short or long N termini and the presence of the 13-amino acid C-terminal leucine-leucine-methionine (LLM) domain with the conserved motif LLM. Through overexpression analyses and by complementation of a gnc gnl double mutant, we provide evidence that the length of the N terminus may not allow distinguishing between the different B-class GATAs at the functional level. In turn, we find that the presence and absence of the LLM domain in the overexpressors has differential effects on hypocotyl elongation, leaf shape, and petiole length, as well as on gene expression. Thus, our analyses identify the LLM domain as an evolutionarily conserved domain that determines B-class GATA factor identity and provides a further subclassification criterion for this transcription factor family.
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Affiliation(s)
- Carina Behringer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany (C.B., E.B., Q.L.R., C.S.); andMunich Information Centre for Protein Sequences, Institute for Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany (K.F.X.M.)
| | - Emmanouil Bastakis
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany (C.B., E.B., Q.L.R., C.S.); andMunich Information Centre for Protein Sequences, Institute for Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany (K.F.X.M.)
| | - Quirin L Ranftl
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany (C.B., E.B., Q.L.R., C.S.); andMunich Information Centre for Protein Sequences, Institute for Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany (K.F.X.M.)
| | - Klaus F X Mayer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany (C.B., E.B., Q.L.R., C.S.); andMunich Information Centre for Protein Sequences, Institute for Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany (K.F.X.M.)
| | - Claus Schwechheimer
- Plant Systems Biology, Technische Universität München, 85354 Freising, Germany (C.B., E.B., Q.L.R., C.S.); andMunich Information Centre for Protein Sequences, Institute for Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany (K.F.X.M.)
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Zourelidou M, Absmanner B, Weller B, Barbosa ICR, Willige BC, Fastner A, Streit V, Port SA, Colcombet J, de la Fuente van Bentem S, Hirt H, Kuster B, Schulze WX, Hammes UZ, Schwechheimer C. Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID. eLife 2014; 3. [PMID: 24948515 DOI: 10.7554/elife.02860.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/17/2014] [Indexed: 05/27/2023] Open
Abstract
The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the--in many cells--asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.
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Affiliation(s)
- Melina Zourelidou
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Birgit Absmanner
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Benjamin Weller
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Inês C R Barbosa
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Björn C Willige
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Astrid Fastner
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Verena Streit
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Sarah A Port
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Jean Colcombet
- Unité de Recherche en Génomique Végétale, Université Evry, Evry, France
| | | | - Heribert Hirt
- Unité de Recherche en Génomique Végétale, Université Evry, Evry, France
| | - Bernhard Kuster
- Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | | | - Ulrich Z Hammes
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
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Zourelidou M, Absmanner B, Weller B, Barbosa ICR, Willige BC, Fastner A, Streit V, Port SA, Colcombet J, de la Fuente van Bentem S, Hirt H, Kuster B, Schulze WX, Hammes UZ, Schwechheimer C. Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID. eLife 2014; 3. [PMID: 24948515 PMCID: PMC4091124 DOI: 10.7554/elife.02860] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/17/2014] [Indexed: 12/20/2022] Open
Abstract
The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the—in many cells—asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant. DOI:http://dx.doi.org/10.7554/eLife.02860.001 In plants, a hormone called auxin controls the growth of the stems and roots. This chemical is transported from cell to cell, and its flow though the plant is redirected continuously as the plant is developing. Auxin is pumped out of cells by proteins in the cell membrane called ‘auxin efflux carriers’. These proteins are usually found on one side of each cell and this is what gives the direction to auxin transport. Zourelidou, Absmanner et al. now report that being positioned on the correct side of a plant cell is not enough to enable an efflux carrier to do its job—it must also be turned on by kinases before it can pump auxin out of cells. Kinases are enzymes that add phosphate groups to specific sites on other proteins, and plants without certain kinases are unable to transport auxin. When Zourelidou, Absmanner et al. produced the efflux carrier and a plant kinase—which turns the efflux carrier on—in immature egg cells from frogs, auxin was rapidly pumped out of the cells. However, cells that contained the efflux carrier but not the kinase could not transport the hormone. Importantly egg cells from frogs do not normally transport auxin, but these cells are commonly used in experiments because they are large, which makes them easier to work with in the lab. One of at least two kinases must tag a number of sites on the efflux carrier to ensure that it is switched on. It was already known that some of these sites are involved in making sure that the efflux carrier is located on the correct side of the cell. Zourelidou, Absmanner et al. also found that auxin itself encourages the addition of phosphate groups onto the efflux carrier. Though it was thought that knowing where the auxin transporters are was enough to explain the direction of auxin transport in plants, it is now clear that activation by the kinases needs to be taken into account too. And since these kinases may activate the transporters to different extents, identifying how these proteins are controlled, for example by auxin itself, will be the next challenge in the field. DOI:http://dx.doi.org/10.7554/eLife.02860.002
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Affiliation(s)
- Melina Zourelidou
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Birgit Absmanner
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Benjamin Weller
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Inês C R Barbosa
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Björn C Willige
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Astrid Fastner
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Verena Streit
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Sarah A Port
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
| | - Jean Colcombet
- Unité de Recherche en Génomique Végétale, Université Evry, Evry, France
| | | | - Heribert Hirt
- Unité de Recherche en Génomique Végétale, Université Evry, Evry, France
| | - Bernhard Kuster
- Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | | | - Ulrich Z Hammes
- Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Technische Universität München, Freising, Germany
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Barbosa ICR, Zourelidou M, Willige BC, Weller B, Schwechheimer C. D6 PROTEIN KINASE activates auxin transport-dependent growth and PIN-FORMED phosphorylation at the plasma membrane. Dev Cell 2014; 29:674-85. [PMID: 24930721 DOI: 10.1016/j.devcel.2014.05.006] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 03/20/2014] [Accepted: 05/09/2014] [Indexed: 12/19/2022]
Abstract
The directed cell-to-cell transport of the phytohormone auxin by efflux and influx transporters is essential for proper plant growth and development. Like auxin efflux facilitators of the PIN-FORMED (PIN) family, D6 PROTEIN KINASE (D6PK) from Arabidopsis thaliana localizes to the basal plasma membrane of many cells, and evidence exists that D6PK may directly phosphorylate PINs. We find that D6PK is a membrane-bound protein that is associated with either the basal domain of the plasma membrane or endomembranes. Inhibition of the trafficking regulator GNOM leads to a rapid internalization of D6PK to endomembranes. Interestingly, the dissociation of D6PK from the plasma membrane is also promoted by auxin. Surprisingly, we find that auxin transport-dependent tropic responses are critically and reversibly controlled by D6PK and D6PK-dependent PIN phosphorylation at the plasma membrane. We conclude that D6PK abundance at the plasma membrane and likely D6PK-dependent PIN phosphorylation are prerequisites for PIN-mediated auxin transport.
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Affiliation(s)
- Inês C R Barbosa
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Melina Zourelidou
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Björn C Willige
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Benjamin Weller
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany.
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Kami C, Allenbach L, Zourelidou M, Ljung K, Schütz F, Isono E, Watahiki MK, Yamamoto KT, Schwechheimer C, Fankhauser C. Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport. Plant J 2014; 77:393-403. [PMID: 24286493 DOI: 10.1111/tpj.12395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/24/2013] [Accepted: 11/20/2013] [Indexed: 05/05/2023]
Abstract
Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution.
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Affiliation(s)
- Chitose Kami
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Genopode Building, 1015, Lausanne, Switzerland
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Abstract
NEDD8, in plants and yeasts also known as RELATED TO UBIQUITIN (RUB), is an evolutionarily conserved 76 amino acid protein highly related to ubiquitin. Like ubiquitin, NEDD8 can be conjugated to and deconjugated from target proteins, but unlike ubiquitin, NEDD8 has not been reported to form chains similar to the different polymeric ubiquitin chains that have a role in a diverse set of cellular processes. NEDD8-modification is best known as a post-translational modification of the cullin subunits of cullin-RING E3 ubiquitin ligases. In this context, structural analyses have revealed that neddylation induces a conformation change of the cullin that brings the ubiquitylation substrates into proximity of the interacting E2 conjugating enzyme. In turn, NEDD8 deconjugation destabilizes the cullin RING ligase complex allowing for the exchange of substrate recognition subunits via the exchange factor CAND1. In plants, components of the neddylation and deneddylation pathway were identified based on mutants with defects in auxin and light responses and the characterization of these mutants has been instrumental for the elucidation of the neddylation pathway. More recently, there has been evidence from animal and plant systems that NEDD8 conjugation may also regulate the behavior or fate of non-cullin substrates in a number of ways. Here, the current knowledge on NEDD8 processing, conjugation and deconjugation is presented, where applicable, in the context of specific signaling pathways from plants.
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Affiliation(s)
| | - Claus Schwechheimer
- *Correspondence: Claus Schwechheimer, Plant Systems Biology, Technische Universität München, Emil-Ramann-Straße 4, 85354 Freising, Germany e-mail:
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Hakenjos JP, Bejai S, Ranftl Q, Behringer C, Vlot AC, Absmanner B, Hammes U, Heinzlmeir S, Kuster B, Schwechheimer C. ML3 is a NEDD8- and ubiquitin-modified protein. Plant Physiol 2013; 163:135-49. [PMID: 23903439 PMCID: PMC3762636 DOI: 10.1104/pp.113.221341] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 07/30/2013] [Indexed: 05/23/2023]
Abstract
NEDD8 (NEURAL PRECURSOR CELL-EXPRESSED, DEVELOPMENTALLY DOWN-REGULATED PROTEIN8) is an evolutionarily conserved 8-kD protein that is closely related to ubiquitin and that can be conjugated like ubiquitin to specific lysine residues of target proteins in eukaryotes. In contrast to ubiquitin, for which a broad range of substrate proteins are known, only a very limited number of NEDD8 target proteins have been identified to date. Best understood, and also evolutionarily conserved, is the NEDD8 modification (neddylation) of cullins, core subunits of the cullin-RING-type E3 ubiquitin ligases that promote the polyubiquitylation of degradation targets in eukaryotes. Here, we show that Myeloid differentiation factor-2-related lipid-recognition domain protein ML3 is an NEDD8- as well as ubiquitin-modified protein in Arabidopsis (Arabidopsis thaliana) and examine the functional role of ML3 in the plant cell. Our analysis indicates that ML3 resides in the vacuole as well as in endoplasmic reticulum (ER) bodies. ER bodies are Brassicales-specific ER-derived organelles and, similar to other ER body proteins, ML3 orthologs can only be identified in this order of flowering plants. ML3 gene expression is promoted by wounding as well as by the phytohormone jasmonic acid and repressed by ethylene, signals that are known to induce and repress ER body formation, respectively. Furthermore, ML3 protein abundance is dependent on NAI1, a master regulator of ER body formation in Arabidopsis. The regulation of ML3 expression and the localization of ML3 in ER bodies and the vacuole is in agreement with a demonstrated importance of ML3 in the defense to herbivore attack. Here, we extend the spectrum of ML3 biological functions by demonstrating a role in the response to microbial pathogens.
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Richter R, Bastakis E, Schwechheimer C. Cross-repressive interactions between SOC1 and the GATAs GNC and GNL/CGA1 in the control of greening, cold tolerance, and flowering time in Arabidopsis. Plant Physiol 2013; 162:1992-2004. [PMID: 23739688 PMCID: PMC3729777 DOI: 10.1104/pp.113.219238] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/03/2013] [Indexed: 05/20/2023]
Abstract
The paralogous and functionally redundant GATA transcription factors GNC (for GATA, NITRATE-INDUCIBLE, CARBON-METABOLISM INVOLVED) and GNL/CGA1 (for GNC-LIKE/CYTOKININ-RESPONSIVE GATA FACTOR1) from Arabidopsis (Arabidopsis thaliana) promote greening and repress flowering downstream from the phytohormone gibberellin. The target genes of GNC and GNL with regard to flowering time control have not been identified as yet. Here, we show by genetic and molecular analysis that the two GATA factors act upstream from the flowering time regulator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) to directly repress SOC1 expression and thereby repress flowering. Interestingly, this analysis inversely also reveals that the MADS box transcription factor SOC1 directly represses GNC and GNL expression to control cold tolerance and greening, two further physiological processes that are under the control of SOC1. In summary, these findings support the case of a cross-repressive interaction between the GATA factors GNC and GNL and the MADS box transcription factor SOC1 in flowering time control on the one side and greening and cold tolerance on the other that may be governed by the various signaling inputs that are integrated at the level of SOC1 expression.
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Katsiarimpa A, Kalinowska K, Anzenberger F, Weis C, Ostertag M, Tsutsumi C, Schwechheimer C, Brunner F, Hückelhoven R, Isono E. The deubiquitinating enzyme AMSH1 and the ESCRT-III subunit VPS2.1 are required for autophagic degradation in Arabidopsis. Plant Cell 2013; 25:2236-52. [PMID: 23800962 PMCID: PMC3723623 DOI: 10.1105/tpc.113.113399] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In eukaryotes, posttranslational modification by ubiquitin regulates the activity and stability of many proteins and thus influences a variety of developmental processes as well as environmental responses. Ubiquitination also plays a critical role in intracellular trafficking by serving as a signal for endocytosis. We have previously shown that the Arabidopsis thaliana associated molecule with the SH3 domain of STAM3 (AMSH3) is a deubiquitinating enzyme (DUB) that interacts with endosomal complex required for transport-III (ESCRT-III) and is essential for intracellular transport and vacuole biogenesis. However, physiological functions of AMSH3 in the context of its ESCRT-III interaction are not well understood due to the severe seedling lethal phenotype of its null mutant. In this article, we show that Arabidopsis AMSH1, an AMSH3-related DUB, interacts with the ESCRT-III subunit vacuolar protein sorting2.1 (VPS2.1) and that impairment of both AMSH1 and VPS2.1 causes early senescence and hypersensitivity to artificial carbon starvation in the dark similar to previously reported autophagy mutants. Consistent with this, both mutants accumulate autophagosome markers and accumulate less autophagic bodies in the vacuole. Taken together, our results demonstrate that AMSH1 and the ESCRT-III-subunit VPS2.1 are important for autophagic degradation and autophagy-mediated physiological processes.
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Affiliation(s)
- Anthi Katsiarimpa
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Kamila Kalinowska
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Franziska Anzenberger
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Corina Weis
- Department of Phytopathology, Technische Universität München, 85354 Freising, Germany
| | - Maya Ostertag
- Department of Phytopathology, Technische Universität München, 85354 Freising, Germany
| | - Chie Tsutsumi
- Department of Botany, National Museum of Nature and Science, Tsukuba 305-0005, Japan
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Frédéric Brunner
- Department of Plant Biochemistry, Center for Plant Molecular Biology, Tübingen University, 72076 Tuebingen, Germany
| | - Ralph Hückelhoven
- Department of Phytopathology, Technische Universität München, 85354 Freising, Germany
| | - Erika Isono
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
- Address correspondence to
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Willige BC, Ahlers S, Zourelidou M, Barbosa IC, Demarsy E, Trevisan M, Davis PA, Roelfsema MRG, Hangarter R, Fankhauser C, Schwechheimer C. D6PK AGCVIII kinases are required for auxin transport and phototropic hypocotyl bending in Arabidopsis. Plant Cell 2013; 25:1674-88. [PMID: 23709629 PMCID: PMC3694699 DOI: 10.1105/tpc.113.111484] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/21/2013] [Accepted: 05/07/2013] [Indexed: 05/20/2023]
Abstract
Phototropic hypocotyl bending in response to blue light excitation is an important adaptive process that helps plants to optimize their exposure to light. In Arabidopsis thaliana, phototropic hypocotyl bending is initiated by the blue light receptors and protein kinases phototropin1 (phot1) and phot2. Phototropic responses also require auxin transport and were shown to be partially compromised in mutants of the PIN-FORMED (PIN) auxin efflux facilitators. We previously described the D6 PROTEIN KINASE (D6PK) subfamily of AGCVIII kinases, which we proposed to directly regulate PIN-mediated auxin transport. Here, we show that phototropic hypocotyl bending is strongly dependent on the activity of D6PKs and the PIN proteins PIN3, PIN4, and PIN7. While early blue light and phot-dependent signaling events are not affected by the loss of D6PKs, we detect a gradual loss of PIN3 phosphorylation in d6pk mutants of increasing complexity that is most severe in the d6pk d6pkl1 d6pkl2 d6pkl3 quadruple mutant. This is accompanied by a reduction of basipetal auxin transport in the hypocotyls of d6pk as well as in pin mutants. Based on our data, we propose that D6PK-dependent PIN regulation promotes auxin transport and that auxin transport in the hypocotyl is a prerequisite for phot1-dependent hypocotyl bending.
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Affiliation(s)
- Björn C. Willige
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising-Weihenstephan, Germany
| | - Siv Ahlers
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising-Weihenstephan, Germany
| | - Melina Zourelidou
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising-Weihenstephan, Germany
| | - Inês C.R. Barbosa
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising-Weihenstephan, Germany
| | - Emilie Demarsy
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Martine Trevisan
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Philip A. Davis
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - M. Rob G. Roelfsema
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Würzburg University, 97082 Wuerzburg, Germany
| | - Roger Hangarter
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Christian Fankhauser
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising-Weihenstephan, Germany
- Address correspondence to
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Willige BC, Ogiso-Tanaka E, Zourelidou M, Schwechheimer C. WAG2 represses apical hook opening downstream from gibberellin and PHYTOCHROME INTERACTING FACTOR 5. Development 2012; 139:4020-8. [PMID: 22992959 DOI: 10.1242/dev.081240] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
When penetrating the soil during germination, dicotyledonous plants protect their shoot apical meristem through the formation of an apical hook. Apical hook formation is a dynamic process that can be subdivided into hook formation, maintenance and opening. It has previously been established that these processes require the transport and signaling of the phytohormone auxin, as well as the biosynthesis and signaling of the phytohormones ethylene and gibberellin (GA). Here, we identify a molecular mechanism for an auxin-GA crosstalk by demonstrating that the auxin transport-regulatory protein kinase WAG2 is a crucial transcription target during apical hook opening downstream from GA signaling. We further show that WAG2 is directly activated by PHYTOCHROME INTERACTING FACTOR 5 (PIF5), a light-labile interactor of the DELLA repressors of the GA pathway. We find that wag2 mutants are impaired in the repression of apical hook opening in dark-grown seedlings and that this phenotype correlates with GA-regulated WAG2 expression in the concave (inner) side of the apical hook. Furthermore, wag2 mutants are also impaired in the maintenance or formation of a local auxin maximum at the site of WAG2 expression in the hook. WAG2 is a regulator of PIN auxin efflux facilitators and, in line with previous data, we show that this kinase can phosphorylate the central intracellular loop of all PIN-FORMED (PIN) proteins regulating apical hook opening. We therefore propose that apical hook opening is controlled by the differential GA-regulated accumulation of WAG2 and subsequent local changes in PIN-mediated auxin transport.
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Affiliation(s)
- Björn C Willige
- Department of Plant Systems Biology, Center for Life and Food Sciences, Technische Universtität München, Emil-Ramann-Strasse 4, 85354 Freising, Germany
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Abstract
The plant hormone gibberellin (GA) controls major aspects of plant growth such as germination, elongation growth, flower development, and flowering time. In recent years, a number of studies have revealed less apparent roles for GA in a surprisingly broad set of developmental as well as cell biological processes. The identification of GA receptor proteins on the one end of the signaling cascade, DELLA proteins as central repressors of the pathway and transcription regulators such as the phytochrome interacting factors and the GATA-type transcription factors GNC and CGA1/GNL on the current other end of the signaling cascade have extended our knowledge about how GA and DELLAs regulate a diverse set of plant responses.
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Affiliation(s)
- Claus Schwechheimer
- Plant Systems Biology, Center for Life and Food Sciences Weihenstephan, Technische Universität MünchenFreising, Germany
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Katsiarimpa A, Anzenberger F, Schlager N, Neubert S, Hauser MT, Schwechheimer C, Isono E. The Arabidopsis deubiquitinating enzyme AMSH3 interacts with ESCRT-III subunits and regulates their localization. Plant Cell 2011; 23:3026-40. [PMID: 21810997 PMCID: PMC3180808 DOI: 10.1105/tpc.111.087254] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 07/12/2011] [Accepted: 07/20/2011] [Indexed: 05/18/2023]
Abstract
Ubiquitination and deubiquitination regulate various cellular processes. We have recently shown that the deubiquitinating enzyme Associated Molecule with the SH3 domain of STAM3 (AMSH3) is involved in vacuole biogenesis and intracellular trafficking in Arabidopsis thaliana. However, little is known about the identity of its interaction partners and deubiquitination substrates. Here, we provide evidence that AMSH3 interacts with ESCRT-III subunits VPS2.1 and VPS24.1. The interaction of ESCRT-III subunits with AMSH3 is mediated by the MIM1 domain and depends on the MIT domain of AMSH3. We further show that AMSH3, VPS2.1, and VPS24.1 localize to class E compartments when ESCRT-III disassembly is inhibited by coexpression of inactive Suppressor of K+ transport Defect 1 (SKD1), an AAA-ATPase involved in the disassembly of ESCRT-III. We also provide evidence that AMSH3 and SKD1 compete for binding to VPS2.1. Furthermore, we show that the loss of AMSH3 enzymatic activity leads to the formation of cellular compartments that contain AMSH3, VPS2.1, and VPS24.1. Taken together, our study presents evidence that AMSH3 interacts with classical core ESCRT-III components and thereby provides a molecular framework for the function of AMSH3 in plants.
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Affiliation(s)
- Anthi Katsiarimpa
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Franziska Anzenberger
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
| | - Nicole Schlager
- Department of Applied Genetics and Cell Biology, BOKU, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Susanne Neubert
- Department of Applied Genetics and Cell Biology, BOKU, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Marie-Theres Hauser
- Department of Applied Genetics and Cell Biology, BOKU, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Claus Schwechheimer
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
- Department of Developmental Genetics, Center for Plant Molecular Biology, Tübingen University, 72076 Tuebingen, Germany
| | - Erika Isono
- Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany
- Department of Developmental Genetics, Center for Plant Molecular Biology, Tübingen University, 72076 Tuebingen, Germany
- Address correspondence to
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Willige BC, Isono E, Richter R, Zourelidou M, Schwechheimer C. Gibberellin regulates PIN-FORMED abundance and is required for auxin transport-dependent growth and development in Arabidopsis thaliana. Plant Cell 2011; 23:2184-95. [PMID: 21642547 PMCID: PMC3160035 DOI: 10.1105/tpc.111.086355] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/13/2011] [Accepted: 05/18/2011] [Indexed: 05/18/2023]
Abstract
Plants integrate different regulatory signals to control their growth and development. Although a number of physiological observations suggest that there is crosstalk between the phytohormone gibberellin (GA) and auxin, as well as with auxin transport, the molecular basis for this hormonal crosstalk remains largely unexplained. Here, we show that auxin transport is reduced in the inflorescences of Arabidopsis thaliana mutants deficient in GA biosynthesis and signaling. We further show that this reduced auxin transport correlates with a reduction in the abundance of PIN-FORMED (PIN) auxin efflux facilitators in GA-deficient plants and that PIN protein levels recover to wild-type levels following GA treatment. We also demonstrate that the regulation of PIN protein levels cannot be explained by a transcriptional regulation of the PIN genes but that GA deficiency promotes, at least in the case of PIN2, the targeting of PIN proteins for vacuolar degradation. In genetic studies, we reveal that the reduced auxin transport of GA mutants correlates with an impairment in two PIN-dependent growth processes, namely, cotyledon differentiation and root gravitropic responses. Our study thus presents evidence for a role of GA in these growth responses and for a GA-dependent modulation of PIN turnover that may be causative for these differential growth responses.
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Hakenjos JP, Richter R, Dohmann EMN, Katsiarimpa A, Isono E, Schwechheimer C. MLN4924 is an efficient inhibitor of NEDD8 conjugation in plants. Plant Physiol 2011; 156:527-36. [PMID: 21527421 PMCID: PMC3177256 DOI: 10.1104/pp.111.176677] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The conjugation of the ubiquitin-like modifier NEURAL PRECURSOR CELL-EXPRESSED DEVELOPMENTALLY DOWN-REGULATED PROTEIN8/RELATED TO UBIQUITIN1 (NEDD8/RUB1; neddylation) is best known as an important posttranslational modification of the cullin subunits of cullin-RING-type E3 ubiquitin ligases (CRLs). MLN4924 has recently been described as an inhibitor of NEDD8-ACTIVATING ENZYME1 (NAE1) in human. Here, we show that MLN4924 is also an effective and specific inhibitor of NAE1 enzymes from Arabidopsis (Arabidopsis thaliana) and other plant species. We found that MLN4924-treated wild-type seedlings have phenotypes that are highly similar to phenotypes of mutants with a partial defect in neddylation and that such neddylation-defective mutants are hypersensitive to MLN4924 treatment. We further found that MLN4924 efficiently blocks the neddylation of cullins in Arabidopsis and that MLN4924 thereby interferes with the degradation of CRL substrates and their downstream responses. MLN4924 treatments also induce characteristic phenotypes in tomato (Solanum lycopersicum), Cardamine hirsuta, and Brachypodium distachyon. Interestingly, MLN4924 also blocks the neddylation of a number of other NEDD8-modified proteins. In summary, we show that MLN4924 is a versatile and specific neddylation inhibitor that will be a useful tool to examine the role of NEDD8- and CRL-dependent processes in a wide range of plant species.
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Ragni L, Nieminen K, Pacheco-Villalobos D, Sibout R, Schwechheimer C, Hardtke CS. Mobile gibberellin directly stimulates Arabidopsis hypocotyl xylem expansion. Plant Cell 2011; 23:1322-36. [PMID: 21498678 PMCID: PMC3101547 DOI: 10.1105/tpc.111.084020] [Citation(s) in RCA: 149] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/23/2011] [Accepted: 04/04/2011] [Indexed: 05/18/2023]
Abstract
Secondary growth of the vasculature results in the thickening of plant structures and continuously produces xylem tissue, the major biological carbon sink. Little is known about the developmental control of this quantitative trait, which displays two distinct phases in Arabidopsis thaliana hypocotyls. The later phase of accelerated xylem expansion resembles the secondary growth of trees and is triggered upon flowering by an unknown, shoot-derived signal. We found that flowering-dependent hypocotyl xylem expansion is a general feature of herbaceous plants with a rosette growth habit. Flowering induction is sufficient to trigger xylem expansion in Arabidopsis. By contrast, neither flower formation nor elongation of the main inflorescence is required. Xylem expansion also does not depend on any particular flowering time pathway or absolute age. Through analyses of natural genetic variation, we found that ERECTA acts locally to restrict xylem expansion downstream of the gibberellin (GA) pathway. Investigations of mutant and transgenic plants indicate that GA and its signaling pathway are both necessary and sufficient to directly trigger enhanced xylogenesis. Impaired GA signaling did not affect xylem expansion systemically, suggesting that it acts downstream of the mobile cue. By contrast, the GA effect was graft transmissible, suggesting that GA itself is the mobile shoot-derived signal.
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Affiliation(s)
- Laura Ragni
- Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Kaisa Nieminen
- Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland
| | | | - Richard Sibout
- Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Claus Schwechheimer
- Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Christian S. Hardtke
- Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland
- Address correspondence to
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