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Yadav P, Khatri N, Gupta R, Mudgil Y. Proteomic profiling of Arabidopsis G-protein β subunit AGB1 mutant under salt stress. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:571-586. [PMID: 38737318 PMCID: PMC11087450 DOI: 10.1007/s12298-024-01448-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 03/26/2024] [Accepted: 04/06/2024] [Indexed: 05/14/2024]
Abstract
Salt stress is a limiting environmental factor that inhibits plant growth in most ecological environments. The functioning of G-proteins and activated downstream signaling during salt stress is well established and different G-protein subunits and a few downstream effectors have been identified. Arabidopsis G-protein β-subunit (AGB1) regulates the movement of Na+ from roots to shoots along with a significant role in controlling Na+ fluxes in roots, however, the molecular mechanism of AGB1 mediated salt stress regulation is not well understood. Here, we report the comparative proteome profiles of Arabidopsis AGB1 null mutant agb1-2 to investigate how the absence of AGB1 modulates the protein repertoire in response to salt stress. High-resolution two-dimensional gel electrophoresis (2-DE) showed 27 protein spots that were differentially modulated between the control and NaCl treated agb1-2 seedlings of which seven were identified by mass spectrometry. Functional annotation and interactome analysis indicated that the salt-responsive proteins were majorly associated with cellulose synthesis, structural maintenance of chromosomes, DNA replication/repair, organellar RNA editing and indole glucosinolate biosynthesis. Further exploration of the functioning of these proteins could serve as a potential stepping stone for dissection of molecular mechanism of AGB1 functions during salt stress and in long run could be extrapolated to crop plants for salinity stress management.
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Affiliation(s)
- Poonam Yadav
- Department of Botany, University of Delhi, New Delhi, 110007 India
| | - Nisha Khatri
- Department of Botany, University of Delhi, New Delhi, 110007 India
| | - Ravi Gupta
- College of General Education, Kookmin University, Seoul, 02707 South Korea
| | - Yashwanti Mudgil
- Department of Botany, University of Delhi, New Delhi, 110007 India
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Xu D, Tang W, Ma Y, Wang X, Yang Y, Wang X, Xie L, Huang S, Qin T, Tang W, Xu Z, Li L, Tang Y, Chen M, Ma Y. Arabidopsis G-protein β subunit AGB1 represses abscisic acid signaling via attenuation of the MPK3-VIP1 phosphorylation cascade. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1615-1632. [PMID: 37988280 DOI: 10.1093/jxb/erad464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 11/20/2023] [Indexed: 11/23/2023]
Abstract
Heterotrimeric G proteins play key roles in cellular processes. Although phenotypic analyses of Arabidopsis Gβ (AGB1) mutants have implicated G proteins in abscisic acid (ABA) signaling, the AGB1-mediated modules involved in ABA responses remain unclear. We found that a partial AGB1 protein was localized to the nucleus where it interacted with ABA-activated VirE2-interacting protein 1 (VIP1) and mitogen-activated protein kinase 3 (MPK3). AGB1 acts as an upstream negative regulator of VIP1 activity by initiating responses to ABA and drought stress, and VIP1 regulates the ABA signaling pathway in an MPK3-dependent manner in Arabidopsis. AGB1 outcompeted VIP1 for interaction with the C-terminus of MPK3, and prevented phosphorylation of VIP1 by MPK3. Importantly, ABA treatment reduced AGB1 expression in the wild type, but increased in vip1 and mpk3 mutants. VIP1 associates with ABA response elements present in the AGB1 promoter, forming a negative feedback regulatory loop. Thus, our study defines a new mechanism for fine-tuning ABA signaling through the interplay between AGB1 and MPK3-VIP1. Furthermore, it suggests a common G protein mechanism to receive and transduce signals from the external environment.
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Affiliation(s)
- Dongbei Xu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Wensi Tang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Yanan Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Xia Wang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Yanzhi Yang
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xiaoting Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Lina Xie
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Suo Huang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Tengfei Qin
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Weilin Tang
- College of Agronomy, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhaoshi Xu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Lei Li
- State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yimiao Tang
- Institute of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Ming Chen
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Youzhi Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
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Hu B, Yang N, Zhou Z, Shi X, Qin Y, Fang Y, Long X. Transcriptome analysis reveals the molecular mechanisms of rubber biosynthesis and laticifer differentiation during rubber seed germination. FRONTIERS IN PLANT SCIENCE 2024; 15:1337451. [PMID: 38328702 PMCID: PMC10847244 DOI: 10.3389/fpls.2024.1337451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/03/2024] [Indexed: 02/09/2024]
Abstract
The molecular mechanisms underlying the initiation of natural rubber synthesis and laticifer differentiation have not been fully elucidated. In this study, we conducted a time-series transcriptome analysis of five rubber tree tissues at four stages of seed germination. A total of 161,199 DEGs were identified between the two groups, including most 16,673 DEGs (A3 vs B3 and A3 vs C3) and lest 1,210 DEGs (C2 vs D2). We found that the maturation of the seed is accompanied by the formation of laticifer cells in cotyledon. Meanwhile, the analysis of hormones related genes expression may provide effective clues for us to promote the differentiation of laticifer cells in seeds by hormones in the future. In this study, hormone-related gene enrichment analyses revealed that IAA, GA, and CTK were activated in laticifer containing tissues. Similarly, GO and GEGG analysis showed that hormone pathways, especially the auxin pathway, are enriched. Gene expression clustering was analyzed using the short time-series expression miner (STEM), and the analysis revealed four distinct trends in the gene expression profiles. Moreover, we enriched transcription factor (TF) enrichment in cotyledon and embryonic axis tissues, and the MYB type exhibited the most significant difference. Furthermore, our findings revealed that genes related to rubber synthesis exhibited tissue-specific expression patterns during seed germination. Notably, key genes associated with rubber biosynthesis, specifically small rubber particle protein (SRPP) and cis-prenyltransferase (CPT), exhibited significant changes in expression in cotyledon and embryonic axis tissues, suggesting synchronous rubber synthesis with seed germination. Our staining results reveled that laticifer cells were exits in the cotyledon before seed imbibition stage. In conclusion, these results lay the foundation for exploring the molecular mechanisms underlying laticifer differentiation and rubber synthesis during seed germination, deepening our understanding of the initiation stages of rubber biosynthesis and laticifer differentiation.
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Affiliation(s)
- Bin Hu
- National Key Laboratory for Tropical Crop Breeding, Ministry of Agriculture Key Laboratory of Biology and Genetic Resources of Rubber Tree, State Key Laboratory Breeding Base of Cultivation and Physiology for Tropical Crops, Rubber Research Institute, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
| | - Na Yang
- National Key Laboratory for Tropical Crop Breeding, Ministry of Agriculture Key Laboratory of Biology and Genetic Resources of Rubber Tree, State Key Laboratory Breeding Base of Cultivation and Physiology for Tropical Crops, Rubber Research Institute, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Zaihui Zhou
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
| | - Xiangyu Shi
- Danxin College, Hainan University, Danzhou, China
| | - Yunxia Qin
- National Key Laboratory for Tropical Crop Breeding, Ministry of Agriculture Key Laboratory of Biology and Genetic Resources of Rubber Tree, State Key Laboratory Breeding Base of Cultivation and Physiology for Tropical Crops, Rubber Research Institute, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
| | - Yongjun Fang
- National Key Laboratory for Tropical Crop Breeding, Ministry of Agriculture Key Laboratory of Biology and Genetic Resources of Rubber Tree, State Key Laboratory Breeding Base of Cultivation and Physiology for Tropical Crops, Rubber Research Institute, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Xiangyu Long
- National Key Laboratory for Tropical Crop Breeding, Ministry of Agriculture Key Laboratory of Biology and Genetic Resources of Rubber Tree, State Key Laboratory Breeding Base of Cultivation and Physiology for Tropical Crops, Rubber Research Institute, Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Haikou, China
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China
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Law KC, Chung KK, Zhuang X. An Update on Coat Protein Complexes for Vesicle Formation in Plant Post-Golgi Trafficking. FRONTIERS IN PLANT SCIENCE 2022; 13:826007. [PMID: 35283904 PMCID: PMC8905187 DOI: 10.3389/fpls.2022.826007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/11/2022] [Indexed: 05/13/2023]
Abstract
Endomembrane trafficking is an evolutionarily conserved process for all eukaryotic organisms. It is a fundamental and essential process for the transportation of proteins, lipids, or cellular metabolites. The aforementioned cellular components are sorted across multiple membrane-bounded organelles. In plant cells, the endomembrane mainly consists of the nuclear envelope, endoplasmic reticulum (ER), Golgi apparatus, trans-Golgi network or early endosome (TGN/EE), prevacuolar compartments or multivesicular bodies (PVCs/MVBs), and vacuole. Among them, Golgi apparatus and TGN represent two central sorting intermediates for cargo secretion and recycling from other compartments by anterograde or retrograde trafficking. Several protein sorting machineries have been identified to function in these pathways for cargo recognition and vesicle assembly. Exciting progress has been made in recent years to provide novel insights into the sorting complexes and also the underlying sorting mechanisms in plants. Here, we will highlight the recent findings for the adaptor protein (AP) complexes, retromer, and retriever complexes, and also their functions in the related coated vesicle formation in post-Golgi trafficking.
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Arora D, Damme DV. Motif-based endomembrane trafficking. PLANT PHYSIOLOGY 2021; 186:221-238. [PMID: 33605419 PMCID: PMC8154067 DOI: 10.1093/plphys/kiab077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/17/2021] [Indexed: 05/08/2023]
Abstract
Endomembrane trafficking, which allows proteins and lipids to flow between the different endomembrane compartments, largely occurs by vesicle-mediated transport. Transmembrane proteins intended for transport are concentrated into a vesicle or carrier by undulation of a donor membrane. This is followed by vesicle scission, uncoating, and finally, fusion at the target membrane. Three major trafficking pathways operate inside eukaryotic cells: anterograde, retrograde, and endocytic. Each pathway involves a unique set of machinery and coat proteins that pack the transmembrane proteins, along with their associated lipids, into specific carriers. Adaptor and coatomer complexes are major facilitators that function in anterograde transport and in endocytosis. These complexes recognize the transmembrane cargoes destined for transport and recruit the coat proteins that help form the carriers. These complexes use either linear motifs or posttranslational modifications to recognize the cargoes, which are then packaged and delivered along the trafficking pathways. In this review, we focus on the different trafficking complexes that share a common evolutionary branch in Arabidopsis (Arabidopsis thaliana), and we discuss up-to-date knowledge about the cargo recognition motifs they use.
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Affiliation(s)
- Deepanksha Arora
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent 9052, Belgium
| | - Daniёl Van Damme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, Ghent 9052, Belgium
- VIB Center for Plant Systems Biology, Technologiepark 71, Ghent 9052, Belgium
- Author for communication:
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Liu C, Hu J, Fan W, Zhu P, Cao B, Zheng S, Xia Z, Zhu Y, Zhao A. Heterotrimeric G-protein γ subunits regulate ABA signaling in response to drought through interacting with PP2Cs and SnRK2s in mulberry (Morus alba L.). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 161:210-221. [PMID: 33639589 DOI: 10.1016/j.plaphy.2021.02.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
ABA signaling plays a central role in regulating plants respond to drought. Although much progress has been made in understanding the functions of ABA signaling in drought response, very little information is available regarding woody plants. In this study, the components of ABA signaling pathway were identified in mulberry which has excellent adaptation to drought, including three PYLs, two PP2Cs, two SnRK2s, four ABFs, and an ABA responsive gene MaRD29B. The gene expression of ABA signaling components exhibited significant response to ABA and drought, and their roles in drought response were revealed using a transient transformation system in mulberry seedlings. We discovered the ABA signaling components, MaABI1/2 and MaSnRK2.1/2.4, could directly interact with G-protein γ subunits, MaGγ1 and MaGγ2, which indicated that G-protein γ subunits may mediate the signal crosstalk between G-proteins and ABA signaling. Transient activation assay in tobacco and RNAi silencing assay in mulberry further demonstrated that MaGγ1 and MaGγ2 regulated drought response by enhancing ABA signaling. This study expands the repertoire of ABA signaling controlling drought responses in plants and provides the direct evidence about the crosstalk between ABA signaling and G-proteins for the first time.
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Affiliation(s)
- Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China; Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, PR China
| | - Jie Hu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Wei Fan
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Panpan Zhu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Sha Zheng
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Zhongqiang Xia
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Yingxue Zhu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Southwest University, Chongqing, 400716, PR China.
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7
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Jose J, Roy Choudhury S. Heterotrimeric G-proteins mediated hormonal responses in plants. Cell Signal 2020; 76:109799. [PMID: 33011291 DOI: 10.1016/j.cellsig.2020.109799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 01/27/2023]
Abstract
Phytohormones not only orchestrate intrinsic developmental programs from germination to senescence but also regulate environmental inputs through complex signalling pathways. Despite building an own signalling network, hormones mutually contribute several signalling systems, which are also essential for plant growth and development, defense, and responses to abiotic stresses. One of such important signalling cascades is G-proteins, which act as critical regulators of a wide range of fundamental cellular processes by transducing receptor signals to the intracellular environment. G proteins are composed of α, β, and γ subunits, and the molecular switching between active and inactive conformation of Gα controls the signalling cycle. The active GTP bound Gα and freed Gβγ have both independent and tightly coordinated roles in the regulation of effector molecules, thereby modulating multiple responses, including hormonal responses. Therefore, an interplay of hormones with G-proteins fine-tunes multiple biological processes of plants; however, their molecular mechanisms are largely unknown. Functional characterization of hormone biosynthesis, perception, and signalling components, as well as identification of few effector molecules of G-proteins and their interaction networks, reduces the complexity of the hormonal signalling networks related to G-proteins. In this review, we highlight a valuable insight into the mechanisms of how the G-protein signalling cascades connect with hormonal responses to regulate increased developmental flexibility as well as remarkable plasticity of plants.
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Affiliation(s)
- Jismon Jose
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India
| | - Swarup Roy Choudhury
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India.
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AP3M harbors actin filament binding activity that is crucial for vacuole morphology and stomatal closure in Arabidopsis. Proc Natl Acad Sci U S A 2019; 116:18132-18141. [PMID: 31431522 DOI: 10.1073/pnas.1901431116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Stomatal movement is essential for plant growth. This process is precisely regulated by various cellular activities in guard cells. F-actin dynamics and vacuole morphology are both involved in stomatal movement. The sorting of cargoes by clathrin adaptor protein (AP) complexes from the Golgi to the vacuole is critical for establishing a normal vacuole morphology. In this study, we demonstrate that the medium subunit of the AP3 complex (AP3M) binds to and severs actin filaments in vitro and that it participates in the sorting of cargoes (such as the sucrose exporter SUC4) to the tonoplast, and thereby regulates stomatal closure in Arabidopsis thaliana Defects in AP3 or SUC4 led to more rapid water loss and delayed stomatal closure, as well as hypersensitivity to drought stress. In ap3m mutants, the F-actin status was altered compared to the wild type, and the sorted cargoes failed to localize to the tonoplast. AP3M contains a previously unidentified F-actin binding domain that is conserved in AP3M homologs in both plants and animals. Mutations in the F-actin binding domain of AP3M abolished its F-actin binding activity in vitro, leading to an aberrant vacuole morphology and reduced levels of SUC4 on the tonoplast in guard cells. Our findings indicate that the F-actin binding activity of AP3M is required for the precise localization of AP3-dependent cargoes to the tonoplast and for the regulation of vacuole morphology in guard cells during stomatal closure.
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Pandey S. Heterotrimeric G-Protein Signaling in Plants: Conserved and Novel Mechanisms. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:213-238. [PMID: 31035831 DOI: 10.1146/annurev-arplant-050718-100231] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Heterotrimeric GTP-binding proteins are key regulators of a multitude of signaling pathways in all eukaryotes. Although the core G-protein components and their basic biochemistries are broadly conserved throughout evolution, the regulatory mechanisms of G proteins seem to have been rewired in plants to meet specific needs. These proteins are currently the focus of intense research in plants due to their involvement in many agronomically important traits, such as seed yield, organ size regulation, biotic and abiotic stress responses, symbiosis, and nitrogen use efficiency. The availability of massive sequence information from a variety of plant species, extensive biochemical data generated over decades, and impressive genetic resources for plant G proteins have made it possible to examine their role, unique properties, and novel regulation. This review focuses on some recent advances in our understanding of the mechanistic details of this critical signaling pathway to enable the precise manipulation and generation of plants to meet future needs.
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Affiliation(s)
- Sona Pandey
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA;
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10
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Yu Y, Chakravorty D, Assmann SM. The G Protein β-Subunit, AGB1, Interacts with FERONIA in RALF1-Regulated Stomatal Movement. PLANT PHYSIOLOGY 2018; 176:2426-2440. [PMID: 29301953 PMCID: PMC5841690 DOI: 10.1104/pp.17.01277] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 01/03/2018] [Indexed: 05/04/2023]
Abstract
Heterotrimeric guanine nucleotide-binding (G) proteins are composed of Gα, Gβ, and Gγ subunits and function as molecular switches in signal transduction. In Arabidopsis (Arabidopsis thaliana), there are one canonical Gα (GPA1), three extra-large Gα (XLG1, XLG2, and XLG3), one Gβ (AGB1), and three Gγ (AGG1, AGG2, and AGG3) subunits. To elucidate AGB1 molecular signaling, we performed immunoprecipitation using plasma membrane-enriched proteins followed by mass spectrometry to identify the protein interactors of AGB1. After eliminating proteins present in the control immunoprecipitation, commonly identified contaminants, and organellar proteins, a total of 103 candidate AGB1-associated proteins were confidently identified. We identified all of the G protein subunits except XLG1, receptor-like kinases, Ca2+ signaling-related proteins, and 14-3-3-like proteins, all of which may couple with or modulate G protein signaling. We confirmed physical interaction between AGB1 and the receptor-like kinase FERONIA (FER) using bimolecular fluorescence complementation. The Rapid Alkalinization Factor (RALF) family of polypeptides have been shown to be ligands of FER. In this study, we demonstrate that RALF1 regulates stomatal apertures and does so in a G protein-dependent manner, inhibiting stomatal opening and promoting stomatal closure in Columbia but not in agb1 mutants. We further show that AGGs and XLGs, but not GPA1, participate in RALF1-mediated stomatal signaling. Our results suggest that FER acts as a G protein-coupled receptor for plant heterotrimeric G proteins.
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Affiliation(s)
- Yunqing Yu
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - David Chakravorty
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Sarah M Assmann
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
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Identifying Novel Regulators of Vacuolar Trafficking by Combining Fluorescence Imaging-Based Forward Genetic Screening and In Vitro Pollen Germination. Methods Mol Biol 2017. [PMID: 28861829 DOI: 10.1007/978-1-4939-7262-3_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Subcellular targeting of vacuolar proteins depends on cellular machinery regulating vesicular trafficking. Plant-specific vacuolar trafficking routes have been reported. However, regulators mediating these processes are obscure. By combining a fluorescence imaging-based forward genetic approach and in vitro pollen germination system, we show an efficient protocol of identifying regulators of plant-specific vacuolar trafficking routes.
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12
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Feng QN, Li S, Zhang Y. Update on adaptor protein-3 in Arabidopsis. PLANT SIGNALING & BEHAVIOR 2017; 12:e1356969. [PMID: 28786748 PMCID: PMC5616146 DOI: 10.1080/15592324.2017.1356969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
Adaptor proteins (APs) mediate protein sorting within endomembrane compartments in eukaryotic cells. AP-3 is an ancient AP complex mediating vacuolar trafficking in different phyla. Only recently, a few tonoplast proteins have been identified as AP-3 cargos in Arabidopsis whereas the function of AP-3 was largely unexplored. Here, we summarize recent advances on AP-3 in Arabidopsis, pointing at the potential roles of AP-3 in plant development and cellular processes.
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Affiliation(s)
- Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China
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Liu C, Xu Y, Long D, Cao B, Hou J, Xiang Z, Zhao A. Plant G-protein β subunits positively regulate drought tolerance by elevating detoxification of ROS. Biochem Biophys Res Commun 2017; 491:897-902. [PMID: 28754592 DOI: 10.1016/j.bbrc.2017.07.133] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 11/16/2022]
Abstract
Heterotrimeric guanine-nucleotide-binding proteins (G-proteins) consist of α, β and γ subunits and play important roles in response and tolerance to abiotic stresses in plants, but the function of the heterotrimeric G-protein β subunit in response to drought remains unclear. In the present study, the AGB1 mutants (agb1-2-1 and agb1-3-2) were more sensitive to drought than the wild-type. The overexpression of mulberry (Morus alba L.) G-protein β subunit in transgenic tobacco (Nicotiana tabacum L.) significantly enhanced the plants' drought tolerance. The transgenic tobacco plants had higher proline contents and peroxidase activities, and lower malonaldehyde and hydrogen peroxide contents and superoxide free radical accumulations under drought conditions. Additionally, transcript levels of the tobacco antioxidative genes, NtSOD and NtCAT, increased in drought-stressed transgenic tobacco plants. Thus, the heterotrimeric G-protein β subunits positively regulate drought tolerance in plants.
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Affiliation(s)
- Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Yazhen Xu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Dingpei Long
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Jiamin Hou
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
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Feng QN, Song SJ, Yu SX, Wang JG, Li S, Zhang Y. Adaptor Protein-3-Dependent Vacuolar Trafficking Involves a Subpopulation of COPII and HOPS Tethering Proteins. PLANT PHYSIOLOGY 2017; 174:1609-1620. [PMID: 28559361 PMCID: PMC5490925 DOI: 10.1104/pp.17.00584] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/25/2017] [Indexed: 05/20/2023]
Abstract
Plant vacuoles are versatile organelles critical for plant growth and responses to environment. Vacuolar proteins are transported from the endoplasmic reticulum via multiple routes in plants. Two classic routes bear great similarity to other phyla with major regulators known, such as COPII and Rab5 GTPases. By contrast, vacuolar trafficking mediated by adaptor protein-3 (AP-3) or that independent of the Golgi has few recognized cargos and none of the regulators. In search of novel regulators for vacuolar trafficking routes and by using a fluorescence-based forward genetic screen, we demonstrated that the multispan transmembrane protein, Arabidopsis (Arabidopsis thaliana) PROTEIN S-ACYL TRANSFERASE10 (PAT10), is an AP-3-mediated vacuolar cargo. We show that the tonoplast targeting of PAT10 is mediated by the AP-3 complex but independent of the Rab5-mediated post-Golgi trafficking route. We also report that AP-3-mediated vacuolar trafficking involves a subpopulation of COPII and requires the vacuolar tethering complex HOPS. In addition, we have identified two novel mutant alleles of AP-3δ, whose point mutations interfered with the formation of the AP-3 complex as well as its membrane targeting. The results presented here shed new light on the vacuolar trafficking route mediated by AP-3 in plant cells.
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Affiliation(s)
- Qiang-Nan Feng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Shi-Jian Song
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Shi-Xia Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Jia-Gang Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Sha Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
| | - Yan Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
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15
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Park Y, Xu ZY, Kim SY, Lee J, Choi B, Lee J, Kim H, Sim HJ, Hwang I. Spatial Regulation of ABCG25, an ABA Exporter, Is an Important Component of the Mechanism Controlling Cellular ABA Levels. THE PLANT CELL 2016; 28:2528-2544. [PMID: 27697789 PMCID: PMC5134978 DOI: 10.1105/tpc.16.00359] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 09/13/2016] [Accepted: 09/29/2016] [Indexed: 05/22/2023]
Abstract
The phytohormone abscisic acid (ABA) plays crucial roles in various physiological processes, including responses to abiotic stresses, in plants. Recently, multiple ABA transporters were identified. The loss-of-function and gain-of-function mutants of these transporters show altered ABA sensitivity and stomata regulation, highlighting the importance of ABA transporters in ABA-mediated processes. However, how the activity of these transporters is regulated remains elusive. Here, we show that spatial regulation of ATP BINDING CASETTE G25 (ABCG25), an ABA exporter, is an important mechanism controlling its activity. ABCG25, as a soluble green fluorescent protein (sGFP) fusion, was subject to posttranslational regulation via clathrin-dependent and adaptor protein complex-2-dependent endocytosis followed by trafficking to the vacuole. The levels of sGFP:ABCG25 at the plasma membrane (PM) were regulated by abiotic stresses and exogenously applied ABA; PM-localized sGFP:ABCG25 decreased under abiotic stress conditions via activation of endocytosis in an ABA-independent manner, but increased upon application of exogenous ABA via activation of recycling from early endosomes in an ABA-dependent manner. Based on these findings, we propose that the spatial regulation of ABCG25 is an important component of the mechanism by which plants fine-tune cellular ABA levels according to cellular and environmental conditions.
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Affiliation(s)
- Youngmin Park
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Zheng-Yi Xu
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Soo Youn Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Jihyeong Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Bongsoo Choi
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Juhun Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Hyeran Kim
- Center for Genome Engineering Institute for Basic Science, Yuseong-gu 305-811, Daejeon, South Korea
| | - Hee-Jung Sim
- Center for Genome Engineering Institute for Basic Science, Yuseong-gu 305-811, Daejeon, South Korea
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea
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Xu DB, Chen M, Ma YN, Xu ZS, Li LC, Chen YF, Ma YZ. A G-protein β subunit, AGB1, negatively regulates the ABA response and drought tolerance by down-regulating AtMPK6-related pathway in Arabidopsis. PLoS One 2015; 10:e0116385. [PMID: 25635681 PMCID: PMC4312036 DOI: 10.1371/journal.pone.0116385] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 12/05/2014] [Indexed: 01/08/2023] Open
Abstract
Heterotrimeric G-proteins are versatile regulators involved in diverse cellular processes in eukaryotes. In plants, the function of G-proteins is primarily associated with ABA signaling. However, the downstream effectors and the molecular mechanisms in the ABA pathway remain largely unknown. In this study, an AGB1 mutant (agb1-2) was found to show enhanced drought tolerance, indicating that AGB1 might negatively regulate drought tolerance in Arabidopsis. Data showed that AGB1 interacted with protein kinase AtMPK6 that was previously shown to phosphorylate AtVIP1, a transcription factor responding to ABA signaling. Our study found that transcript levels of three ABA responsive genes, AtMPK6, AtVIP1 and AtMYB44 (downstream gene of AtVIP1), were significantly up-regulated in agb1-2 lines after ABA or drought treatments. Other ABA-responsive and drought-inducible genes, such as RD29A (downstream gene of AtMYB44), were also up-regulated in agb1-2 lines. Furthermore, overexpression of AtVIP1 resulted in hypersensitivity to ABA at seed germination and seedling stages, and significantly enhanced drought tolerance in transgenic plants. These results suggest that AGB1 was involved in the ABA signaling pathway and drought tolerance in Arabidopsis through down-regulating the AtMPK6, AtVIP1 and AtMYB44 cascade.
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Affiliation(s)
- Dong-bei Xu
- College of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
| | - Ming Chen
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
| | - Ya-nan Ma
- College of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
| | - Zhao-shi Xu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
| | - Lian-cheng Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
| | - Yao-feng Chen
- College of Agriculture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- * E-mail: (YC); (YZM)
| | - You-zhi Ma
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, 100081, China
- * E-mail: (YC); (YZM)
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Arabidopsis G-protein β subunit AGB1 interacts with NPH3 and is involved in phototropism. Biochem Biophys Res Commun 2014; 445:54-7. [DOI: 10.1016/j.bbrc.2014.01.106] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 01/22/2014] [Indexed: 01/12/2023]
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