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Clayton EJ, Islam NS, Pannunzio K, Kuflu K, Sirjani R, Kohalmi SE, Dhaubhadel S. Soybean AROGENATE DEHYDRATASES (GmADTs): involvement in the cytosolic isoflavonoid metabolon or trans-organelle continuity? Front Plant Sci 2024; 15:1307489. [PMID: 38322824 PMCID: PMC10845154 DOI: 10.3389/fpls.2024.1307489] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/03/2024] [Indexed: 02/08/2024]
Abstract
Soybean (Glycine max) produces a class of phenylalanine (Phe) derived specialized metabolites, isoflavonoids. Isoflavonoids are unique to legumes and are involved in defense responses in planta, and they are also necessary for nodule formation with nitrogen-fixing bacteria. Since Phe is a precursor of isoflavonoids, it stands to reason that the synthesis of Phe is coordinated with isoflavonoid production. Two putative AROGENATE DEHYDRATASE (ADT) isoforms were previously co-purified with the soybean isoflavonoid metabolon anchor ISOFLAVONE SYNTHASE2 (GmIFS2), however the GmADT family had not been characterized. Here, we present the identification of the nine member GmADT family. We determined that the GmADTs share sequences required for enzymatic activity and allosteric regulation with other characterized plant ADTs. Furthermore, the GmADTs are differentially expressed, and multiple members have dual substrate specificity, also acting as PREPHENATE DEHYDRATASES. All GmADT isoforms were detected in the stromules of chloroplasts, and they all interact with GmIFS2 in the cytosol. In addition, GmADT12A interacts with multiple other isoflavonoid metabolon members. These data substantiate the involvement of GmADT isoforms in the isoflavonoid metabolon.
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Affiliation(s)
- Emily J. Clayton
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Nishat S. Islam
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
| | - Kelsey Pannunzio
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Kuflom Kuflu
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
| | - Ramtin Sirjani
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Susanne E. Kohalmi
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Sangeeta Dhaubhadel
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, ON, Canada
- Department of Biology, University of Western Ontario, London, ON, Canada
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2
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Sandor A, Samalova M, Brandizzi F, Kriechbaumer V, Moore I, Fricker MD, Sweetlove LJ. Characterization of intracellular membrane structures derived from a massive expansion of endoplasmic reticulum (ER) membrane due to synthetic ER-membrane-resident polyproteins. J Exp Bot 2024; 75:45-59. [PMID: 37715992 PMCID: PMC10735356 DOI: 10.1093/jxb/erad364] [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: 05/04/2023] [Accepted: 09/15/2023] [Indexed: 09/18/2023]
Abstract
The endoplasmic reticulum (ER) is a dynamic organelle that is amenable to major restructuring. Introduction of recombinant ER-membrane-resident proteins that form homo oligomers is a known method of inducing ER proliferation: interaction of the proteins with each other alters the local structure of the ER network, leading to the formation large aggregations of expanded ER, sometimes leading to the formation of organized smooth endoplasmic reticulum (OSER). However, these membrane structures formed by ER proliferation are poorly characterized and this hampers their potential development for plant synthetic biology. Here, we characterize a range of ER-derived membranous compartments in tobacco and show how the nature of the polyproteins introduced into the ER membrane affect the morphology of the final compartment. We show that a cytosol-facing oligomerization domain is an essential component for compartment formation. Using fluorescence recovery after photobleaching, we demonstrate that although the compartment retains a connection to the ER, a diffusional barrier exists to both the ER and the cytosol associated with the compartment. Using quantitative image analysis, we also show that the presence of the compartment does not disrupt the rest of the ER network. Moreover, we demonstrate that it is possible to recruit a heterologous, bacterial enzyme to the compartment, and for the enzyme to accumulate to high levels. Finally, transgenic Arabidopsis constitutively expressing the compartment-forming polyproteins grew and developed normally under standard conditions.
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Affiliation(s)
- Andras Sandor
- Department of Biology, University of Oxford, South Parks Road, Oxford, UK
| | - Marketa Samalova
- Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Federica Brandizzi
- MSU-DOE Plant Research Laboratory, Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - Verena Kriechbaumer
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Ian Moore
- Department of Biology, University of Oxford, South Parks Road, Oxford, UK
| | - Mark D Fricker
- Department of Biology, University of Oxford, South Parks Road, Oxford, UK
| | - Lee J Sweetlove
- Department of Biology, University of Oxford, South Parks Road, Oxford, UK
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3
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Kriechbaumer V, Botchway SW. Immunoprecipitation and FRET-FLIM to Determine Metabolons on the Plant ER. Methods Mol Biol 2024; 2772:169-177. [PMID: 38411813 DOI: 10.1007/978-1-0716-3710-4_12] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Metabolons are protein complexes that contain all the enzymes necessary for a metabolic pathway but also scaffolding proteins. Such a structure allows efficient channeling of intermediate metabolites form one active site to the next and is highly advantageous for labile or toxic intermediates. Here we describe two methods currently used to identify metabolons via protein-protein interaction methodology: immunoprecipitations using GFP-Trap®_A beads to find novel interaction partners and potential metabolon components and FRET-FLIM to test for and quantify protein-protein interactions in planta.
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Affiliation(s)
- Verena Kriechbaumer
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, UK
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4
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Hu L, Gao D, Lv H, Lian L, Wang M, Wang Y, Xie Y, Zhang J. Finding New Targets for the Treatment of Heart Failure: Endoplasmic Reticulum Stress and Autophagy. J Cardiovasc Transl Res 2023; 16:1349-1356. [PMID: 37432587 DOI: 10.1007/s12265-023-10410-9] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/28/2023] [Indexed: 07/12/2023]
Abstract
Heart failure is a progressive disease with an annual mortality rate of about 10% and is the end-stage stage of various heart diseases, which places a huge socioeconomic burden on the healthcare system. The development of heart failure has received increasing attention as a potential way to improve the treatment of this disease. Many studies have shown that endoplasmic reticulum stress and autophagy play an important role in the occurrence and development of heart failure. With the in-depth study of endoplasmic reticulum stress and autophagy, both are considered promising targets for pharmacological interventions to treat heart failure, but the mechanism of heart failure between the two is not clear. This review will highlight the effects of endoplasmic reticulum stress, autophagy, and their interactions in the development and development of heart failure, thereby helping to provide direction for the future development of targeted therapies for patients with heart failure. CLINICAL RELEVANCE: This study explored the new targets for the treatment of heart failure: endoplasmic reticulum stress and autophagy. Targeted drug therapy for endoplasmic reticulum stress and autophagy is expected to provide a new intervention target for the treatment of heart failure.
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Affiliation(s)
- Leilei Hu
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Dongjie Gao
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Hao Lv
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Lu Lian
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Mingyang Wang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Yunjiao Wang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China
- National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, 300193, China
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China
| | - Yingyu Xie
- Tianjin University of Traditional Chinese Medicine, Tianjin, 300193, China.
| | - Junping Zhang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, 300183, China.
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Breeze E, Vale V, McLellan H, Pecrix Y, Godiard L, Grant M, Frigerio L. A tell tail sign: a conserved C-terminal tail-anchor domain targets a subset of pathogen effectors to the plant endoplasmic reticulum. J Exp Bot 2023; 74:3188-3202. [PMID: 36860200 DOI: 10.1093/jxb/erad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 02/27/2023] [Indexed: 05/21/2023]
Abstract
The endoplasmic reticulum (ER) is the entry point to the secretory pathway and, as such, is critical for adaptive responses to biotic stress, when the demand for de novo synthesis of immunity-related proteins and signalling components increases significantly. Successful phytopathogens have evolved an arsenal of small effector proteins which collectively reconfigure multiple host components and signalling pathways to promote virulence; a small, but important, subset of which are targeted to the endomembrane system including the ER. We identified and validated a conserved C-terminal tail-anchor motif in a set of pathogen effectors known to localize to the ER from the oomycetes Hyaloperonospora arabidopsidis and Plasmopara halstedii (downy mildew of Arabidopsis and sunflower, respectively) and used this protein topology to develop a bioinformatic pipeline to identify putative ER-localized effectors within the effectorome of the related oomycete, Phytophthora infestans, the causal agent of potato late blight. Many of the identified P. infestans tail-anchor effectors converged on ER-localized NAC transcription factors, indicating that this family is a critical host target for multiple pathogens.
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Affiliation(s)
- Emily Breeze
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Victoria Vale
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Hazel McLellan
- Division of Plant Science, University of Dundee (at JHI), Invergowrie, Dundee DD2 5DA, UK
| | - Yann Pecrix
- CIRAD, UMR PVBMT, Peuplements Végétaux et Bioagresseurs en Milieu Tropical (UMR C53), Ligne Paradis, 97410 St Pierre, La Réunion, France
| | - Laurence Godiard
- Laboratoire des Interactions Plantes Microbes Environnement (LIPME), Institut National de Recherche pour l'Agriculture, l'Alimentation, et l'Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Université de Toulouse, Castanet-Tolosan, France
| | - Murray Grant
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Lorenzo Frigerio
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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6
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Wang X, Fan C, Liu Y, Zou Y. The interconnection of endoplasmic reticulum and microtubule and its implication in Hereditary Spastic Paraplegia. Comput Struct Biotechnol J 2023; 21:1670-7. [PMID: 36860342 DOI: 10.1016/j.csbj.2023.02.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
The endoplasmic reticulum (ER) and microtubule (MT) network form extensive contact with each other and their interconnection plays a pivotal role in ER maintenance and distribution as well as MT stability. The ER participates in a variety of biological processes including protein folding and processing, lipid biosynthesis, and Ca2+ storage. MTs specifically regulate cellular architecture, provide routes for transport of molecules or organelles, and mediate signaling events. The ER morphology and dynamics are regulated by a class of ER shaping proteins, which also provide the physical contact structure for linking of ER and MT. In addition to these ER-localized and MT-binding proteins, specific motor proteins and adaptor-linking proteins also mediate bidirectional communication between the two structures. In this review, we summarize the current understanding of the structure and function of ER-MT interconnection. We further highlight the morphologic factors which coordinate the ER-MT network and maintain the normal physiological function of neurons, with their defect causing neurodegenerative diseases such as Hereditary Spastic Paraplegia (HSP). These findings promote our understanding of the pathogenesis of HSP and provide important therapeutic targets for treatment of these diseases.
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Aboufares El Alaoui A, Buhl E, Galizia S, Hodge JJL, de Vivo L, Bellesi M. Increased interaction between endoplasmic reticulum and mitochondria following sleep deprivation. BMC Biol 2023; 21:1. [PMID: 36600217 PMCID: PMC9814192 DOI: 10.1186/s12915-022-01498-7] [Citation(s) in RCA: 1] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 12/07/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Prolonged cellular activity may overload cell function, leading to high rates of protein synthesis and accumulation of misfolded or unassembled proteins, which cause endoplasmic reticulum (ER) stress and activate the unfolded protein response (UPR) to re-establish normal protein homeostasis. Previous molecular work has demonstrated that sleep deprivation (SD) leads to ER stress in neurons, with a number of ER-specific proteins being upregulated to maintain optimal cellular proteostasis. It is still not clear which cellular processes activated by sleep deprivation lead to ER- stress, but increased cellular metabolism, higher request for protein synthesis, and over production of oxygen radicals have been proposed as potential contributing factors. Here, we investigate the transcriptional and ultrastructural ER and mitochondrial modifications induced by sleep loss. RESULTS We used gene expression analysis in mouse forebrains to show that SD was associated with significant transcriptional modifications of genes involved in ER stress but also in ER-mitochondria interaction, calcium homeostasis, and mitochondrial respiratory activity. Using electron microscopy, we also showed that SD was associated with a general increase in the density of ER cisternae in pyramidal neurons of the motor cortex. Moreover, ER cisternae established new contact sites with mitochondria, the so-called mitochondria associated membranes (MAMs), important hubs for molecule shuttling, such as calcium and lipids, and for the modulation of ATP production and redox state. Finally, we demonstrated that Drosophila male mutant flies (elav > linker), in which the number of MAMs had been genetically increased, showed a reduction in the amount and consolidation of sleep without alterations in the homeostatic sleep response to SD. CONCLUSIONS We provide evidence that sleep loss induces ER stress characterized by increased crosstalk between ER and mitochondria. MAMs formation associated with SD could represent a key phenomenon for the modulation of multiple cellular processes that ensure appropriate responses to increased cell metabolism. In addition, MAMs establishment may play a role in the regulation of sleep under baseline conditions.
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Affiliation(s)
- Amina Aboufares El Alaoui
- grid.7010.60000 0001 1017 3210Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy ,grid.5602.10000 0000 9745 6549School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Edgar Buhl
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Sabrina Galizia
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - James J. L. Hodge
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Luisa de Vivo
- grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK ,grid.5602.10000 0000 9745 6549School of Pharmacy, University of Camerino, Camerino, Italy
| | - Michele Bellesi
- grid.5602.10000 0000 9745 6549School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy ,grid.5337.20000 0004 1936 7603School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
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Tilsner J, Kriechbaumer V. Reticulons 3 and 6 interact with viral movement proteins. Mol Plant Pathol 2022; 23:1807-1814. [PMID: 35987858 PMCID: PMC9644274 DOI: 10.1111/mpp.13261] [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: 03/11/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 05/06/2023]
Abstract
Plant reticulon (RTN) proteins are capable of constricting membranes and are vital for creating and maintaining tubules in the endoplasmic reticulum (ER), making them prime candidates for the formation of the desmotubule in plasmodesmata (PD). RTN3 and RTN6 have previously been detected in an Arabidopsis PD proteome and have been shown to be present in primary PD at cytokinesis. It has been suggested that RTN proteins form protein complexes with proteins in the PD plasma membrane and desmotubule to stabilize the desmotubule constriction and regulate PD aperture. Viral movement proteins (vMPs) enable the transport of viruses through PD and can be ER-integral membrane proteins or interact with the ER. Some vMPs can themselves constrict ER membranes or localize to RTN-containing tubules; RTN proteins and vMPs could be functionally linked or potentially interact. Here we show that different vMPs are capable of interacting with RTN3 and RTN6 in a membrane yeast two-hybrid assay, coimmunoprecipitation, and Förster resonance energy transfer measured by donor excited-state fluorescence lifetime imaging microscopy. Furthermore, coexpression of the vMP CMV-3a and RTN3 results in either the vMP or the RTN changing subcellular localization and reduces the ability of CMV-3a to open PD, further indicating interactions between the two proteins.
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Affiliation(s)
- Jens Tilsner
- Biomedical Sciences Research ComplexSchool of Biology, Willie Russell LaboratoriesFifeUK
- Cell & Molecular SciencesThe James Hutton InstituteDundeeUK
| | - Verena Kriechbaumer
- Endomembrane Structure and Function Research Group, Department of Biological and Medical SciencesOxford Brookes UniversityOxfordUK
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9
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Li C, Duckney P, Zhang T, Fu Y, Li X, Kroon J, De Jaeger G, Cheng Y, Hussey PJ, Wang P. TraB family proteins are components of ER-mitochondrial contact sites and regulate ER-mitochondrial interactions and mitophagy. Nat Commun 2022; 13:5658. [PMID: 36163196 DOI: 10.1038/s41467-022-33402-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 09/16/2022] [Indexed: 01/18/2023] Open
Abstract
ER-mitochondrial contact sites (EMCSs) are important for mitochondrial function. Here, we have identified a EMCS complex, comprising a family of uncharacterised mitochondrial outer membrane proteins, TRB1, TRB2, and the ER protein, VAP27-1. In Arabidopsis, there are three TraB family isoforms and the trb1/trb2 double mutant exhibits abnormal mitochondrial morphology, strong starch accumulation, and impaired energy metabolism, indicating that these proteins are essential for normal mitochondrial function. Moreover, TRB1 and TRB2 proteins also interact with ATG8 in order to regulate mitochondrial degradation (mitophagy). The turnover of depolarised mitochondria is significantly reduced in both trb1/trb2 and VAP27 mutants (vap27-1,3,4,6) under mitochondrial stress conditions, with an increased population of dysfunctional mitochondria present in the cytoplasm. Consequently, plant recovery after stress is significantly perturbed, suggesting that TRB1-regulated mitophagy and ER-mitochondrial interaction are two closely related processes. Taken together, we ascribe a dual role to TraB family proteins which are component of the EMCS complex in eukaryotes, regulating both interaction of the mitochondria to the ER and mitophagy.
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Solovyev AG, Atabekova AK, Lezzhov AA, Solovieva AD, Chergintsev DA, Morozov SY. Distinct Mechanisms of Endomembrane Reorganization Determine Dissimilar Transport Pathways in Plant RNA Viruses. Plants 2022; 11:plants11182403. [PMID: 36145804 PMCID: PMC9504206 DOI: 10.3390/plants11182403] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/02/2022] [Accepted: 09/13/2022] [Indexed: 11/22/2022]
Abstract
Plant viruses exploit the endomembrane system of infected cells for their replication and cell-to-cell transport. The replication of viral RNA genomes occurs in the cytoplasm in association with reorganized endomembrane compartments induced by virus-encoded proteins and is coupled with the virus intercellular transport via plasmodesmata that connect neighboring cells in plant tissues. The transport of virus genomes to and through plasmodesmata requires virus-encoded movement proteins (MPs). Distantly related plant viruses encode different MP sets, or virus transport systems, which vary in the number of MPs and their properties, suggesting their functional differences. Here, we discuss two distinct virus transport pathways based on either the modification of the endoplasmic reticulum tubules or the formation of motile vesicles detached from the endoplasmic reticulum and targeted to endosomes. The viruses with the movement proteins encoded by the triple gene block exemplify the first, and the potyviral system is the example of the second type. These transport systems use unrelated mechanisms of endomembrane reorganization. We emphasize that the mode of virus interaction with cell endomembranes determines the mechanism of plant virus cell-to-cell transport.
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Affiliation(s)
- Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
- All-Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Anastasia K. Atabekova
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Alexander A. Lezzhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
| | - Anna D. Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Denis A. Chergintsev
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
| | - Sergey Y. Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
- Correspondence: ; Tel.: +7-(495)-939-31-98
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11
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Pain C, Tolmie F, Wojcik S, Wang P, Kriechbaumer V. intER-ACTINg: the structure and dynamics of ER and actin are interlinked. J Microsc 2022. [PMID: 35985796 DOI: 10.1111/jmi.13139] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 06/14/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 11/30/2022]
Abstract
The actin cytoskeleton is the driver of gross ER remodelling and the movement and positioning of other membrane-bound organelles such as Golgi bodies. Rapid ER membrane remodelling is a feature of most plant cells and is important for normal cellular processes, including targeted secretion, immunity and signalling. Modifications to the actin cytoskeleton, through pharmacological agents such as Latrunculin B and phalloidin, or disruption of normal myosin function also affect ER structure and/or dynamics. Here, we investigate the impact of changes in the actin cytoskeleton on structure and dynamics on the ER as well as in return the impact of modified ER structure on the architecture of the actin cytoskeleton. By expressing actin markers that affect actin dynamics, or expressing of ER-shaping proteins that influence ER architecture, we found that the structure of ER-actin networks is closely inter-related; affecting one component is likely to have a direct effect on the other. Therefore, our results indicate that a complicated regulatory machinery and cross-talk between these two structures must exist in plants to co-ordinate the function of ER-actin network during multiple subcellular processes. In addition, when considering organelle structure and dynamics, the choice of actin marker is essential in preventing off-target organelle structure and dynamics modifications. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Charlotte Pain
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Frances Tolmie
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Stefan Wojcik
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Pengwei Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Verena Kriechbaumer
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
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12
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Hao G, Zhao X, Zhang M, Ying J, Yu F, Li S, Zhang Y. Vesicle trafficking in
Arabidopsis
pollen tubes. FEBS Lett 2022; 596:2231-2242. [DOI: 10.1002/1873-3468.14343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Guang‐Jiu Hao
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Xin‐Ying Zhao
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | | | - Jun Ying
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Fei Yu
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Sha Li
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
| | - Yan Zhang
- State Key Laboratory of Crop Biology College of Life Sciences Shandong Agricultural University Tai’an, Shandong China
- College of Life Sciences Nankai University China
- Frontiers Science Center for Cell Responses Nankai University China
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13
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Kriechbaumer V, Botchway SW. Methods for Detection of Protein Interactions with Plasmodesmata-Localized Reticulons. Methods Mol Biol 2022; 2457:209-218. [PMID: 35349142 DOI: 10.1007/978-1-0716-2132-5_13] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plant reticulon family proteins (RTN) tubulate the ER by dimerization and oligomerization, creating localized ER membrane tensions that result in membrane curvature. Two RTN ER-shaping proteins have been found in the plasmodesmata (PD) proteome which could potentially contribute to the formation of the desmotubule, an ER-derived structure that crosses primary PD and physically connects the ER of two cells. Here we describe two methods used to identify partners of two PD-resident reticulon proteins, RTN3 and RTN6 that are located in primary PD at cytokinesis in tobacco (Nicotiana tabacum): immunoprecipitations using GFP-Trap®_A beads to find novel interaction partners and FRET-FLIM to test for and quantify direct protein-protein interactions in planta.
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Affiliation(s)
- Verena Kriechbaumer
- Endomembrane Structure and Function Research Group, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, UK
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14
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Včelařová L, Skalický V, Chamrád I, Lenobel R, Kubeš MF, Pěnčík A, Novák O. Auxin Metabolome Profiling in the Arabidopsis Endoplasmic Reticulum Using an Optimised Organelle Isolation Protocol. Int J Mol Sci 2021; 22:9370. [PMID: 34502279 DOI: 10.3390/ijms22179370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 11/17/2022] Open
Abstract
The endoplasmic reticulum (ER) is an extensive network of intracellular membranes. Its major functions include proteosynthesis, protein folding, post-transcriptional modification and sorting of proteins within the cell, and lipid anabolism. Moreover, several studies have suggested that it may be involved in regulating intracellular auxin homeostasis in plants by modulating its metabolism. Therefore, to study auxin metabolome in the ER, it is necessary to obtain a highly enriched (ideally, pure) ER fraction. Isolation of the ER is challenging because its biochemical properties are very similar to those of other cellular endomembranes. Most published protocols for ER isolation use density gradient ultracentrifugation, despite its suboptimal resolving power. Here we present an optimised protocol for ER isolation from Arabidopsis thaliana seedlings for the subsequent mass spectrometric determination of ER-specific auxin metabolite profiles. Auxin metabolite analysis revealed highly elevated levels of active auxin form (IAA) within the ER compared to whole plants. Moreover, samples prepared using our optimised isolation ER protocol are amenable to analysis using various “omics” technologies including analyses of both macromolecular and low molecular weight compounds from the same sample.
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15
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Grados-Torrez RE, López-Iglesias C, Ferrer JC, Campos N. Loose Morphology and High Dynamism of OSER Structures Induced by the Membrane Domain of HMG-CoA Reductase. Int J Mol Sci 2021; 22:ijms22179132. [PMID: 34502042 PMCID: PMC8430881 DOI: 10.3390/ijms22179132] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 11/16/2022] Open
Abstract
The membrane domain of eukaryotic HMG-CoA reductase (HMGR) has the conserved capacity to induce endoplasmic reticulum (ER) proliferation and membrane association into Organized Smooth Endoplasmic Reticulum (OSER) structures. These formations develop in response to overexpression of particular proteins, but also occur naturally in cells of the three eukaryotic kingdoms. Here, we characterize OSER structures induced by the membrane domain of Arabidopsis HMGR (1S domain). Immunochemical confocal and electron microscopy studies demonstrate that the 1S:GFP chimera co-localizes with high levels of endogenous HMGR in several ER compartments, such as the ER network, the nuclear envelope, the outer and internal membranes of HMGR vesicles and the OSER structures, which we name ER-HMGR domains. After high-pressure freezing, ER-HMGR domains show typical crystalloid, whorled and lamellar ultrastructural patterns, but with wide heterogeneous luminal spaces, indicating that the native OSER is looser and more flexible than previously reported. The formation of ER-HMGR domains is reversible. OSER structures grow by incorporation of ER membranes on their periphery and progressive compaction to the inside. The ER-HMGR domains are highly dynamic in their formation versus their disassembly, their variable spherical-ovoid shape, their fluctuating borders and their rapid intracellular movement, indicating that they are not mere ER membrane aggregates, but active components of the eukaryotic cell.
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Affiliation(s)
- Ricardo Enrique Grados-Torrez
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Department of Molecular Genetics, Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain;
| | - Carmen López-Iglesias
- Scientific and Technological Centers, University of Barcelona, 08028 Barcelona, Spain;
- Microscopy CORE Lab, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Joan Carles Ferrer
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain;
| | - Narciso Campos
- Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Department of Molecular Genetics, Campus UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona, Spain;
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain;
- Correspondence:
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16
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Rose RJ. Contribution of Massive Mitochondrial Fusion and Subsequent Fission in the Plant Life Cycle to the Integrity of the Mitochondrion and Its Genome. Int J Mol Sci 2021; 22:5429. [PMID: 34063907 PMCID: PMC8196625 DOI: 10.3390/ijms22115429] [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] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/24/2022] Open
Abstract
Plant mitochondria have large genomes to house a small number of key genes. Most mitochondria do not contain a whole genome. Despite these latter characteristics, the mitochondrial genome is faithfully maternally inherited. To maintain the mitochondrial genes-so important for energy production-the fusion and fission of mitochondria are critical. Fission in plants is better understood than fusion, with the dynamin-related proteins (DRP 3A and 3B) driving the constriction of the mitochondrion. How the endoplasmic reticulum and the cytoskeleton are linked to the fission process is not yet fully understood. The fusion mechanism is less well understood, as obvious orthologues are not present. However, there is a recently described gene, MIRO2, that appears to have a significant role, as does the ER and cytoskeleton. Massive mitochondrial fusion (MMF or hyperfusion) plays a significant role in plants. MMF occurs at critical times of the life cycle, prior to flowering, in the enlarging zygote and at germination, mixing the cells' mitochondrial population-the so-called "discontinuous whole". MMF in particular aids genome repair, the conservation of critical genes and possibly gives an energy boost to important stages of the life cycle. MMF is also important in plant regeneration, an important component of plant biotechnology.
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Affiliation(s)
- Ray J Rose
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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17
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Sandor A, Fricker MD, Kriechbaumer V, Sweetlove LJ. IntEResting structures: formation and applications of organized smooth endoplasmic reticulum in plant cells. Plant Physiol 2021; 185:550-561. [PMID: 33822222 PMCID: PMC8892044 DOI: 10.1104/pp.20.00719] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 07/21/2020] [Indexed: 06/12/2023]
Abstract
The endoplasmic reticulum (ER) is an organelle with remarkable plasticity, capable of rapidly changing its structure to accommodate different functions based on intra- and extracellular cues. One of the ER structures observed in plants is known as "organized smooth endoplasmic reticulum" (OSER), consisting of symmetrically stacked ER membrane arrays. In plants, these structures were first described in certain specialized tissues, e.g. the sieve elements of the phloem, and more recently in transgenic plants overexpressing ER membrane resident proteins. To date, much of the investigation of OSER focused on yeast and animal cells but research into plant OSER has started to grow. In this update, we give a succinct overview of research into the OSER phenomenon in plant cells with case studies highlighting both native and synthetic occurrences of OSER. We also assess the primary driving forces that trigger the formation of OSER, collating evidence from the literature to compare two competing theories for the origin of OSER: that OSER formation is initiated by oligomerizing protein accumulation in the ER membrane or that OSER is the result of ER membrane proliferation. This has long been a source of controversy in the field and here we suggest a way to integrate arguments from both sides into a single unifying theory. Finally, we discuss the potential biotechnological uses of OSER as a tool for the nascent plant synthetic biology field with possible applications as a synthetic microdomain for metabolic engineering and as an extensive membrane surface for synthetic chemistry or protein accumulation.
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Affiliation(s)
- Andras Sandor
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
| | - Verena Kriechbaumer
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Lee J Sweetlove
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
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18
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Brooks RL, Mistry CS, Dixon AM. Curvature sensing amphipathic helix in the C-terminus of RTNLB13 is conserved in all endoplasmic reticulum shaping reticulons in Arabidopsis thaliana. Sci Rep 2021; 11:6326. [PMID: 33737685 PMCID: PMC7973432 DOI: 10.1038/s41598-021-85866-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/05/2021] [Indexed: 11/24/2022] Open
Abstract
The reticulon family of integral membrane proteins are conserved across all eukaryotes and typically localize to the endoplasmic reticulum (ER), where they are involved in generating highly-curved tubules. We recently demonstrated that Reticulon-like protein B13 (RTNLB13) from Arabidopsis thaliana contains a curvature-responsive amphipathic helix (APH) important for the proteins' ability to induce curvature in the ER membrane, but incapable of generating curvature by itself. We suggested it acts as a feedback element, only folding/binding once a sufficient degree of curvature has been achieved, and stabilizes curvature without disrupting the bilayer. However, it remains unclear whether this is unique to RTNLB13 or is conserved across all reticulons-to date, experimental evidence has only been reported for two reticulons. Here we used biophysical methods to characterize a minimal library of putative APH peptides from across the 21 A. thaliana isoforms. We found that reticulons with the closest evolutionary relationship to RTNLB13 contain curvature-sensing APHs in the same location with sequence conservation. Our data reveal that a more distantly-related branch of reticulons developed a ~ 20-residue linker between the transmembrane domain and APH. This may facilitate functional flexibility as previous studies have linked these isoforms not only to ER remodeling but other cellular activities.
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Affiliation(s)
- Rhiannon L Brooks
- MAS Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Chandni S Mistry
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
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19
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Lazareva EA, Lezzhov AA, Chergintsev DA, Golyshev SA, Dolja VV, Morozov SY, Heinlein M, Solovyev AG. Reticulon-like properties of a plant virus-encoded movement protein. New Phytol 2021; 229:1052-1066. [PMID: 32866987 DOI: 10.1111/nph.16905] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [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: 06/26/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Plant viruses encode movement proteins (MPs) that ensure the transport of viral genomes through plasmodesmata (PD) and use cell endomembranes, mostly the endoplasmic reticulum (ER), for delivery of viral genomes to PD and formation of PD-anchored virus replication compartments. Here, we demonstrate that the Hibiscus green spot virus BMB2 MP, an integral ER protein, induces constrictions of ER tubules, decreases the mobility of ER luminal content, and exhibits an affinity to highly curved membranes. These properties are similar to those described for reticulons, cellular proteins that induce membrane curvature to shape the ER tubules. Similar to reticulons, BMB2 adopts a W-like topology within the ER membrane. BMB2 targets PD and increases their size exclusion limit, and these BMB2 activities correlate with the ability to induce constrictions of ER tubules. We propose that the induction of ER constrictions contributes to the BMB2-dependent increase in PD permeability and formation of the PD-associated replication compartments, therefore facilitating the virus intercellular spread. Furthermore, we show that the ER tubule constrictions also occur in cells expressing TGB2, one of the three MPs of Potato virus X (PVX), and in PVX-infected cells, suggesting that reticulon-like MPs are employed by diverse RNA viruses.
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Affiliation(s)
- Ekaterina A Lazareva
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
| | - Alexander A Lezzhov
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, 119991, Russia
| | - Denis A Chergintsev
- Department of Plant Physiology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
| | - Sergei A Golyshev
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
| | - Valerian V Dolja
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
| | - Sergey Y Morozov
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
| | - Manfred Heinlein
- Institute for Plant Molecular Biology (IBMP-CNRS), University of Strasbourg, Strasbourg, 67000, France
| | - Andrey G Solovyev
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119234, Russia
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
- Institute of Agricultural Biotechnology, Russian Academy of Agricultural Sciences, Moscow, 127550, Russia
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20
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Harant D, Lang I. 3D Dissection of Structural Membrane-Wall Contacts in Filamentous Moss Protonemata. Int J Mol Sci 2020; 22:ijms22010158. [PMID: 33375227 PMCID: PMC7796084 DOI: 10.3390/ijms22010158] [Citation(s) in RCA: 1] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/19/2020] [Accepted: 12/22/2020] [Indexed: 12/04/2022] Open
Abstract
In conventional light microscopy, the adjacent cell walls of filamentous moss protonemata are seen from its narrow side thereby obscuring the major area of cell–cell connection. Optical sectioning, segmentation and 3D reconstructions allow the tilting and rotation of intracellular structures thereby greatly improving our understanding of interaction between organelles, membranes and the cell wall. Often, the findings also allow for conclusions on the respective functions. The moss Physcomitrium (Physcomitrella) patens is a model organism for growth, development and morphogenesis. Its filamentous protonemata are ideal objects for microscopy. Here, we investigated the cell wall between two neighboring cells and the connection of membranes towards this wall after plasmolysis in 0.8 M mannitol. An m-green fluorescent protein (GFP)-HDEL cell line was used to visualize the endoplasmatic reticulum (ER), the plasma membrane (PM) was stained with FM4-64. Our studies clearly show the importance of cell–cell contacts in P. patens protonemata. In 86% of the investigated cell pairs, at least one of the protoplasts remained fully attached to the adjacent cell wall. By tilting of z-stacks, volume renderings and 3D reconstructions, we visualized the amount of attached/detached PM and ER components after plasmolysis and membrane piercings through the wall of cell neighbors.
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21
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Sun J, Zhang M, Qi X, Doyle C, Zheng H. Armadillo-repeat kinesin1 interacts with Arabidopsis atlastin RHD3 to move ER with plus-end of microtubules. Nat Commun 2020; 11:5510. [PMID: 33139737 PMCID: PMC7606470 DOI: 10.1038/s41467-020-19343-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022] Open
Abstract
In living cells, dynamics of the endoplasmic reticulum (ER) are driven by the cytoskeleton motor machinery as well as the action of ER-shaping proteins such as atlastin GTPases including RHD3 in Arabidopsis. It is not known if the two systems interplay, and, if so, how they do. Here we report the identification of ARK1 (Armadillo-Repeat Kinesin1) via a genetic screen for enhancers of the rhd3 mutant phenotype. In addition to defects in microtubule dynamics, ER organization is also defective in mutants lacking a functional ARK1. In growing root hair cells, ARK1 comets predominantly localize on the growing-end of microtubules and partially overlap with RHD3 in the cortex of the subapical region. ARK1 co-moves with RHD3 during tip growth of root hair cells. We show that there is a functional interdependence between ARK1 and RHD3. ARK1 physically interacts with RHD3 via its armadillo domain (ARM). In leaf epidermal cells where a polygonal ER network can be resolved, ARK1, but not ARK1ΔARM, moves together with RHD3 to pull an ER tubule toward another and stays with the newly formed 3-way junction of the ER for a while. We conclude that ARK1 acts together with RHD3 to move the ER on microtubules to generate a fine ER network.
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Affiliation(s)
- Jiaqi Sun
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada
| | - Mi Zhang
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada
- Biotechnology Research Center, Southwest University, Chongqing, 400715, China
| | - Xingyun Qi
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada
- Department of Biology, Rutgers University, Camden, NJ, 08103, USA
| | - Caitlin Doyle
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada
| | - Huanquan Zheng
- Department of Biology, McGill University, Montreal, Quebec, H3A 1B1, Canada.
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22
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Kriechbaumer V, Brandizzi F. The plant endoplasmic reticulum: an organized chaos of tubules and sheets with multiple functions. J Microsc 2020; 280:122-133. [PMID: 32426862 PMCID: PMC10895883 DOI: 10.1111/jmi.12909] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/08/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022]
Abstract
The endoplasmic reticulum is a fascinating organelle at the core of the secretory pathway. It is responsible for the synthesis of one third of the cellular proteome and, in plant cells, it produces receptors and transporters of hormones as well as the proteins responsible for the biosynthesis of critical components of a cellulosic cell wall. The endoplasmic reticulum structure resembles a spider-web network of interconnected tubules and cisternae that pervades the cell. The study of the dynamics and interaction of this organelles with other cellular structures such as the plasma membrane, the Golgi apparatus and the cytoskeleton, have been permitted by the implementation of fluorescent protein and advanced confocal imaging. In this review, we report on the findings that contributed towards the understanding of the endoplasmic reticulum morphology and function with the aid of fluorescent proteins, focusing on the contributions provided by pioneering work from the lab of the late Professor Chris Hawes.
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Affiliation(s)
- V Kriechbaumer
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, U.K
| | - F Brandizzi
- MSU-DOE Plant Research Laboratory, Department of Plant Biology, Michigan State University, East Lansing, Michigan, U.S.A
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23
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Domozych DS, Sun L, Palacio-Lopez K, Reed R, Jeon S, Li M, Jiao C, Sørensen I, Fei Z, Rose JKC. Endomembrane architecture and dynamics during secretion of the extracellular matrix of the unicellular charophyte, Penium margaritaceum. J Exp Bot 2020; 71:3323-3339. [PMID: 31974570 PMCID: PMC7289721 DOI: 10.1093/jxb/eraa039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 10/25/2019] [Accepted: 01/21/2020] [Indexed: 05/02/2023]
Abstract
The extracellular matrix (ECM) of many charophytes, the assemblage of green algae that are the sister group to land plants, is complex, produced in large amounts, and has multiple essential functions. An extensive secretory apparatus and endomembrane system are presumably needed to synthesize and secrete the ECM, but structural details of such a system have not been fully characterized. Penium margaritaceum is a valuable unicellular model charophyte for studying secretion dynamics. We report that Penium has a highly organized endomembrane system, consisting of 150-200 non-mobile Golgi bodies that process and package ECM components into different sets of vesicles that traffic to the cortical cytoplasm, where they are transported around the cell by cytoplasmic streaming. At either fixed or transient areas, specific cytoplasmic vesicles fuse with the plasma membrane and secrete their constituents. Extracellular polysaccharide (EPS) production was observed to occur in one location of the Golgi body and sometimes in unique Golgi hybrids. Treatment of cells with brefeldin A caused disruption of the Golgi body, and inhibition of EPS secretion and cell wall expansion. The structure of the endomembrane system in Penium provides mechanistic insights into how extant charophytes generate large quantities of ECM, which in their ancestors facilitated the colonization of land.
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Affiliation(s)
- David S Domozych
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
- Correspondence:
| | - Li Sun
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | | | - Reagan Reed
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Susan Jeon
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Mingjia Li
- Department of Biology, Skidmore College, Saratoga Springs, NY, USA
| | - Chen Jiao
- Boyce Thompson Institute, Ithaca, NY, USA
| | - Iben Sørensen
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, NY, USA
- U.S. Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY, USA
| | - Jocelyn K C Rose
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
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24
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Zhou Y, Tong Z, Jiang S, Zheng W, Zhao J, Zhou X. The Roles of Endoplasmic Reticulum in NLRP3 Inflammasome Activation. Cells 2020; 9:cells9051219. [PMID: 32423023 PMCID: PMC7291288 DOI: 10.3390/cells9051219] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 12/26/2022] Open
Abstract
The NLRP3 (nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3) inflammasome senses pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), and activates caspase-1, which provokes release of proinflammatory cytokines such as interleukin-1β (IL-1β) and IL-18 as well as pyroptosis to engage in innate immune defense. The endoplasmic reticulum (ER) is a large and dynamic endomembrane compartment, critical to cellular function of organelle networks. Recent studies have unveiled the pivotal roles of the ER in NLRP3 inflammasome activation. ER–mitochondria contact sites provide a location for NLRP3 activation, its association with ligands released from or residing in mitochondria, and rapid Ca2+ mobilization from ER stores to mitochondria. ER-stress signaling plays a critical role in NLRP3 inflammasome activation. Lipid perturbation and cholesterol trafficking to the ER activate the NLRP3 inflammasome. These findings emphasize the importance of the ER in initiation and regulation of the NLRP3 inflammasome.
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Affiliation(s)
- Yang Zhou
- College of Animal Science, Southwest University, Chongqing 402460, China; (Z.T.); (S.J.); (W.Z.); (J.Z.)
- Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, China
- Correspondence:
| | - Zhizi Tong
- College of Animal Science, Southwest University, Chongqing 402460, China; (Z.T.); (S.J.); (W.Z.); (J.Z.)
| | - Songhong Jiang
- College of Animal Science, Southwest University, Chongqing 402460, China; (Z.T.); (S.J.); (W.Z.); (J.Z.)
| | - Wenyan Zheng
- College of Animal Science, Southwest University, Chongqing 402460, China; (Z.T.); (S.J.); (W.Z.); (J.Z.)
| | - Jianjun Zhao
- College of Animal Science, Southwest University, Chongqing 402460, China; (Z.T.); (S.J.); (W.Z.); (J.Z.)
- Immunology Research Center, Medical Research Institute, Southwest University, Chongqing 402460, China
| | - Xiangmei Zhou
- State Key Laboratories for Agrobiotechnology, Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
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25
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Harant D, Lang I. Stay in Touch-The Cortical ER of Moss Protonemata in Osmotic Stress Situations. Plants (Basel) 2020; 9:plants9040421. [PMID: 32235617 PMCID: PMC7238208 DOI: 10.3390/plants9040421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 11/16/2022]
Abstract
Plasmolysis is usually introduced to cell biology students as a tool to illustrate the plasma membrane: hypertonic solutions cause the living protoplast to shrink by osmotic water loss; hence, it detaches from the surrounding cell wall. What happens, however, with the subcellular structures in the cell cortex during this process of turgor loss? Here, we investigated the cortical endoplasmic reticulum (ER) in moss protonema cells of Physcomitrella patens in a cell line carrying a transgenic ER marker (GFP-HDEL). The plasma membrane was labelled simultaneously with the fluorescent dye FM4-64 to achieve structural separation. By placing the protonemata in a hypertonic mannitol solution (0.8 M), we were able to follow the behaviour of the cortical ER and the protoplast during plasmolysis by confocal laser scanning microscopy (CLSM). The protoplast shape and structural changes of the ER were further examined after depolymerisation of actin microfilaments with latrunculin B (1 µM). In its natural state, the cortical ER is a dynamic network of fine tubes and cisternae underneath the plasma membrane. Under acute and long-term plasmolysis (up to 45 min), changes in the protoplast form and the cortical ER, as well as the formation of Hechtian strands and Hechtian reticula, were observed. The processing of the high-resolution z-scans allowed the creation of 3D models and gave detailed insight into the ER of living protonema cells before, during and after plasmolysis.
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Affiliation(s)
- Dominik Harant
- Core Facility Cell Imaging & Ultrastructure Research, Faculty of Life Sciences, The University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria;
| | - Ingeborg Lang
- Department of Functional and Evolutionary Ecology, Faculty of Life Sciences, The University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
- Correspondence:
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Abstract
The availability of quantification methods for subcellular organelle dynamic analysis has increased rapidly over the last 20 years. The application of these techniques to contiguous subcellular structures that exhibit dynamic remodelling over a range of scales and orientations is challenging, as quantification of 'movement' rarely corresponds to traditional, qualitative classifications of types of organelle movement. The plant endoplasmic reticulum represents a particular challenge for dynamic quantification as it itself is an entirely contiguous organelle that is in a constant state of flux and gross remodelling, controlled by the actinomyosin cytoskeleton.
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Affiliation(s)
- Charlotte Pain
- Oxford Brookes University, Faculty of Health and Life Sciences, Gipsy Lane, Plant Cell Biology, Oxford, UK
| | - Verena Kriechbaumer
- Oxford Brookes University, Faculty of Health and Life Sciences, Gipsy Lane, Plant Cell Biology, Oxford, UK
- Correspondence:
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27
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Li T, Xiao Z, Li H, Liu C, Shen W, Gao C. A Combinatorial Reporter Set to Visualize the Membrane Contact Sites Between Endoplasmic Reticulum and Other Organelles in Plant Cell. Front Plant Sci 2020; 11:1280. [PMID: 32973839 PMCID: PMC7461843 DOI: 10.3389/fpls.2020.01280] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 08/06/2020] [Indexed: 05/19/2023]
Abstract
The membrane contact sites (MCSs) enable interorganelle communication by associating organelles at distances of tens of nanometers over extended membrane surfaces and serve to maintain cellular homeostasis through efficient exchange of metabolites, lipid, and calcium between organelles, organelle fission, and movement. Most MCSs and a growing number of tethering proteins especially those involved in mediating the junctions between endoplasmic reticulum (ER) and other organelles have been extensively characterized in mammal and yeast. However, the studies of plant MCSs are still at stages of infancy, at least one reason might be due to the lack of bona fide markers for visualizing these membrane junctions in plant cells. In this study, a series of genetically encoded reporters using split super-folder GFP protein were designed to detect the possible MCSs between ER and three other cellular compartments including chloroplast, mitochondria and plasma membrane (PM) in plant cell. By expressing these genetically encoded reporter in Arabidopsis protoplasts as well as Nicotiana benthamiana leaf, we could intuitively observe the punctate signal surrounding chloroplast upon expression of ER-chloroplast MCS reporter, punctate signal of ER-mitochondria MCS reporter and punctate signal close to the PM upon expression of ER-PM MCS reporter. We also showed that the ER-chloroplast MCSs were dynamic structures that undergo active remodeling with concomitant occurrence of chloroplast dysfunction inside plant cells. This study demonstrates that ER associates with various organelles in close proximity in plant cells and provides tools that might be applicable for visualizing MCSs in plants.
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Affiliation(s)
| | | | | | | | | | - Caiji Gao
- *Correspondence: Wenjin Shen, ; Caiji Gao,
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28
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Hu X, Xiang J, Xiao B, Huang Y, Xie J. Wogonoside promotes apoptosis in gastric cancer AGS and SGC-7901 cells through induction of mitochondrial dysfunction and endoplasmic reticulum stress. FEBS Open Bio 2019; 9:1469-1476. [PMID: 31250981 PMCID: PMC6668368 DOI: 10.1002/2211-5463.12693] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 02/20/2019] [Accepted: 06/26/2019] [Indexed: 12/16/2022] Open
Abstract
Wogonoside (Wg), a natural flavonoid, has anticancer effects against several human cancers. The purpose of the present study was to investigate the antitumor effects and underlying mechanisms of Wg on gastric cancer (GC) cell lines. We report that Wg treatment inhibited cell viability and induced apoptosis in human GC cell lines AGS and SGC-7901, and also retarded GC tumor growth in xenograft mice in vivo. We also found that the Wg exerted its antitumor effects against GC cells via induction of reaction oxygen species accumulation, mitochondrial dysfunction, and endoplasmic reticulum stress. Furthermore, C/EBP homologous protein knockdown inhibited apoptosis and increased the viability of Wg-treated GC cells. Our findings may facilitate the development of novel therapeutic agents for the treatment of GC.
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Affiliation(s)
- Xiao‐Miao Hu
- Department of Gastrointestinal SurgeryThe First Hospital affiliated to Yangtze UniversityJingzhouChina
| | - Jin‐Jian Xiang
- Department of Gastrointestinal SurgeryThe First Hospital affiliated to Yangtze UniversityJingzhouChina
| | - Bao‐Lai Xiao
- Department of Gastrointestinal SurgeryThe First Hospital affiliated to Yangtze UniversityJingzhouChina
| | | | - Jian‐Ping Xie
- Department of Gastrointestinal SurgeryThe First Hospital affiliated to Yangtze UniversityJingzhouChina
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29
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Blanco NE, Liebsch D, Guinea Díaz M, Strand Å, Whelan J. Dual and dynamic intracellular localization of Arabidopsis thaliana SnRK1.1. J Exp Bot 2019; 70:2325-2338. [PMID: 30753728 DOI: 10.1093/jxb/erz023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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: 10/01/2018] [Accepted: 02/01/2019] [Indexed: 06/09/2023]
Abstract
Sucrose non-fermenting 1 (SNF1)-related protein kinase 1.1 (SnRK1.1; also known as KIN10 or SnRK1α) has been identified as the catalytic subunit of the complex SnRK1, the Arabidopsis thaliana homologue of a central integrator of energy and stress signalling in eukaryotes dubbed AMPK/Snf1/SnRK1. A nuclear localization of SnRK1.1 has been previously described and is in line with its function as an integrator of energy and stress signals. Here, using two biological models (Nicotiana benthamiana and Arabidopsis thaliana), native regulatory sequences, different microscopy techniques, and manipulations of cellular energy status, it was found that SnRK1.1 is localized dynamically between the nucleus and endoplasmic reticulum (ER). This distribution was confirmed at a spatial and temporal level by co-localization studies with two different fluorescent ER markers, one of them being the SnRK1.1 phosphorylation target HMGR. The ER and nuclear localization displayed a dynamic behaviour in response to perturbations of the plastidic electron transport chain. These results suggest that an ER-associated SnRK1.1 fraction might be sensing the cellular energy status, being a point of crosstalk with other ER stress regulatory pathways.
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Affiliation(s)
- Nicolás E Blanco
- Centro de Estudios Fotosintéticos y Bioquímicos, Universidad Nacional de Rosario (CEFOBI-CONICET/UNR), Rosario, Argentina
- Umeå Plant Science Centre, Department of Plant Physiologyogy, Umeå University, Sweden
| | - Daniela Liebsch
- Umeå Plant Science Centre, Department of Plant Physiologyogy, Umeå University, Sweden
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Rosario, Argentina
| | - Manuel Guinea Díaz
- Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland
| | - Åsa Strand
- Umeå Plant Science Centre, Department of Plant Physiologyogy, Umeå University, Sweden
| | - James Whelan
- Department of Animal, Plant and Soil Science, School of Life Sciences, Australian Research Council Centre of Excellence in Plant Energy Biology, La Trobe University, Bundoora, Victoria, Australia
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Lee E, Vanneste S, Pérez-Sancho J, Benitez-Fuente F, Strelau M, Macho AP, Botella MA, Friml J, Rosado A. Ionic stress enhances ER-PM connectivity via phosphoinositide-associated SYT1 contact site expansion in Arabidopsis. Proc Natl Acad Sci U S A 2019; 116:1420-9. [PMID: 30610176 DOI: 10.1073/pnas.1818099116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The interorganelle communication mediated by membrane contact sites (MCSs) is an evolutionary hallmark of eukaryotic cells. MCS connections enable the nonvesicular exchange of information between organelles and allow them to coordinate responses to changing cellular environments. In plants, the importance of MCS components in the responses to environmental stress has been widely established, but the molecular mechanisms regulating interorganelle connectivity during stress still remain opaque. In this report, we use the model plant Arabidopsis thaliana to show that ionic stress increases endoplasmic reticulum (ER)-plasma membrane (PM) connectivity by promoting the cortical expansion of synaptotagmin 1 (SYT1)-enriched ER-PM contact sites (S-EPCSs). We define differential roles for the cortical cytoskeleton in the regulation of S-EPCS dynamics and ER-PM connectivity, and we identify the accumulation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] at the PM as a molecular signal associated with the ER-PM connectivity changes. Our study highlights the functional conservation of EPCS components and PM phosphoinositides as modulators of ER-PM connectivity in eukaryotes, and uncovers unique aspects of the spatiotemporal regulation of ER-PM connectivity in plants.
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Liu H, Lu Y, Wang J, Hu J, Wuyun T. Genome-wide screening of long non-coding RNAs involved in rubber biosynthesis in Eucommia ulmoides. J Integr Plant Biol 2018; 60:1070-1082. [PMID: 29944209 DOI: 10.1111/jipb.12693] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
Increasing evidence indicates that long non-coding RNAs (lncRNAs) play pivotal roles in regulatory networks controlling plant and animal gene expression. However, lncRNA roles in regulating rubber biosynthesis in Eucommia ulmoides, an emerging source of natural rubber (Eu-rubber), are currently unknown. Here, we report on RNA deep-sequencing of E. ulmoides fruits at two developmental stages. Based on application of a stringent pipeline, 29,103 lncRNAs and 9,048 transcripts of uncertain coding potential (TUCPs) were identified. Two differentially expressed (DE) TUCPs appear to simultaneously regulate 12 protein-coding genes involved in Eu-rubber biosynthesis (GIEBs), as well as 95 DE genes. Functional categorization of these 95 DE genes indicated their involvement in subcellular microstructures and cellular processes, such as cell wall, cell division, and growth. These DE genes may participate in the differentiation and development of laticifers, where Eu-rubber is synthesized. A model is proposed in which "commanders" (DE TUCPs) direct the "builders" (DE genes) to construct a "storehouse" of materials needed for Eu-rubber synthesis, and the "workers" (GIEBs) to synthesize Eu-rubber. These findings provide insights into both cis- and trans-polyisoprene biosynthesis in plants, laying the foundation for additional studies of this crucial process.
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Affiliation(s)
- Huimin Liu
- State Key Laboratory of Tree Genetics and Breeding, Non-timber Forest Research and Development Center, Chinese Academy of Forestry, Zhengzhou 450003, China
| | - Yan Lu
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Juan Wang
- Chemistry department, University of Missouri-Columbia, Columbia MO 65201, USA
| | - Jingjing Hu
- Inertia Shanghai Biotechnology Co., Ltd., Shanghai 200335, China
| | - Tana Wuyun
- State Key Laboratory of Tree Genetics and Breeding, Non-timber Forest Research and Development Center, Chinese Academy of Forestry, Zhengzhou 450003, China
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32
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Kriechbaumer V, Breeze E, Pain C, Tolmie F, Frigerio L, Hawes C. Arabidopsis Lunapark proteins are involved in ER cisternae formation. New Phytol 2018; 219:990-1004. [PMID: 29797722 PMCID: PMC6055799 DOI: 10.1111/nph.15228] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [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: 02/26/2018] [Accepted: 04/17/2018] [Indexed: 05/04/2023]
Abstract
The plant endoplasmic reticulum (ER) is crucial to the maintenance of cellular homeostasis. The ER consists of a dynamic and continuously remodelling network of tubules and cisternae. Several conserved membrane proteins have been implicated in formation and maintenance of the ER network in plants, such as RHD3 and the reticulon proteins. Despite the recent work in mammalian and yeast cells, the detailed molecular mechanisms of ER network organization in plants remain largely unknown. Recently, novel ER network-shaping proteins called Lunapark (LNP) have been identified in yeast and mammalian cells. Here we identify two Arabidopsis LNP homologues and investigate their subcellular localization via confocal microscopy and potential function in shaping the ER network using protein-protein interaction assays and mutant analysis. We show that AtLNP1 overexpression in tobacco leaf epidermal cells mainly labels cisternae in the ER network, whereas AtLNP2 labels the whole ER. Overexpression of LNP proteins results in an increased abundance of ER cisternae and lnp1 and lnp1lnp2 amiRNA lines display a reduction in cisternae and larger polygonal areas. Thus, we hypothesize that AtLNP1 and AtLNP2 are involved in determining the network morphology of the plant ER, possibly by regulating the formation of ER cisternae.
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Affiliation(s)
- Verena Kriechbaumer
- Plant Cell Biology, Biological and Medical SciencesOxford Brookes UniversityOxfordOX3 0BPUK
| | - Emily Breeze
- School of Life SciencesUniversity of WarwickGibbet HillCoventryCV4 7ALUK
| | - Charlotte Pain
- Plant Cell Biology, Biological and Medical SciencesOxford Brookes UniversityOxfordOX3 0BPUK
| | - Frances Tolmie
- Plant Cell Biology, Biological and Medical SciencesOxford Brookes UniversityOxfordOX3 0BPUK
| | - Lorenzo Frigerio
- School of Life SciencesUniversity of WarwickGibbet HillCoventryCV4 7ALUK
| | - Chris Hawes
- Plant Cell Biology, Biological and Medical SciencesOxford Brookes UniversityOxfordOX3 0BPUK
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Wang S, Xie K, Xu G, Zhou H, Guo Q, Wu J, Liao Z, Liu N, Wang Y, Liu Y. Plant G proteins interact with endoplasmic reticulum luminal protein receptors to regulate endoplasmic reticulum retrieval. J Integr Plant Biol 2018; 60:541-561. [PMID: 29573168 DOI: 10.1111/jipb.12648] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Maintaining endoplasmic reticulum (ER) homeostasis is essential for the production of biomolecules. ER retrieval, i.e., the retrograde transport of compounds from the Golgi to the ER, is one of the pathways that ensures ER homeostasis. However, the mechanisms underlying the regulation of ER retrieval in plants remain largely unknown. Plant ERD2-like proteins (ERD2s) were recently suggested to function as ER luminal protein receptors that mediate ER retrieval. Here, we demonstrate that heterotrimeric G protein signaling is involved in ERD2-mediated ER retrieval. We show that ERD2s interact with the heterotrimeric G protein Gα and Gγ subunits at the Golgi. Silencing of Gα, Gβ, or Gγ increased the retention of ER luminal proteins. Furthermore, overexpression of Gα, Gβ, or Gγ caused ER luminal proteins to escape from the ER, as did the co-silencing of ERD2a and ERD2b. These results suggest that G proteins interact with ER luminal protein receptors to regulate ER retrieval.
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Affiliation(s)
- Shanshan Wang
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ke Xie
- Advanced Biotechnology and Application Research Center, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Guoyong Xu
- The Institute for Advanced Studies (IAS), Wuhan University, Wuhan 430072, China
| | - Huarui Zhou
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiang Guo
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jingyi Wu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zengwei Liao
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Na Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yan Wang
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Xu QH, Song BJ, Liu D, Chen YH, Zhou Y, Liu WB, Li H, Long TL, Zhang R, Liu W. The MKK7 inhibitor peptide GADD45β-I attenuates ER stress-induced mitochondrial dysfunction in HT22 cells: Involvement of JNK-Wnt pathway. Brain Res 2018; 1691:1-8. [PMID: 29684334 DOI: 10.1016/j.brainres.2018.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 03/29/2018] [Accepted: 04/12/2018] [Indexed: 12/17/2022]
Abstract
JNK, a member of the mitogen activated protein kinases (MAPKs) superfamily, plays a key role in cell death in many neurological disorders, but systemic inhibition of JNK has detrimental side effects. JNK can be regulated by two direct upstream kinases: MAPK kinase 4 (MKK4) and MAPK kinase 7 (MKK7). Here, we investigated the effect of GADD45β-I, a recently designed cell-permeable inhibitor peptide for MKK7, on endoplasmic reticulum (ER) stress-induced cytotoxicity in neuronal HT22 cells. We found that treatment with the ER stress inducer tunicamycin (TM) increased the phosphorylation of JNK and MKK7 in HT22 cells, which was nullified by GADD45β-I. GADD45β-I significantly attenuated TM-induced toxicity via inhibiting apoptotic cell death, as evidenced by decreased number of TUNEL-positive cells and reduced caspase-3 activity. GADD45β-I treatment also decreased expression of ER stress associated pro-apoptotic proteins and prevented morphological changes of the ER after TM exposure. In addition, inhibition of mitochondrial oxidative stress and preservation of intracellular ATP levels were observed in GADD45β-I-treated cells. The experiments using siRNA transfection and Topflash reporter assay revealed a possible involvement of Wnt/β-catenin pathway in GADD45β-I-induced protection in HT22 cells. In summary, our results demonstrated that GADD45β-I exerted protective effects against TM-induced cytotoxicity via regulating JNK-Wnt pathway. Targeting MKK7 could represent a new therapeutic strategy for the treatment of neurological diseases where ER stress associated neuronal injury are involved.
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Affiliation(s)
- Quan-Hua Xu
- Department of Neurosurgery, Bijie First People's Hospital, Bijie, Guizhou 551700, China
| | - Bing-Jun Song
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China
| | - Dan Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Anesthesiology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Yu-Hua Chen
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China
| | - Yuan Zhou
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China
| | - Wen-Bo Liu
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China
| | - Hua Li
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China
| | - Tian-Lin Long
- Department of Neurosurgery, Bijie First People's Hospital, Bijie, Guizhou 551700, China
| | - Rui Zhang
- Department of Neurosurgery, Bijie First People's Hospital, Bijie, Guizhou 551700, China
| | - Wei Liu
- Basic Medical Sciences Research Center, Shaanxi Fourth People's Hospital, Xi'an, Shaanxi 710043, China.
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Liu D, Zhou Y, Peng Y, Su P, Li Z, Xu Q, Tu Y, Tian X, Yang H, Wu Z, Mei W, Gao F. Endoplasmic Reticulum Stress in Spinal Cord Contributes to the Development of Morphine Tolerance. Front Mol Neurosci 2018; 11:72. [PMID: 29559889 PMCID: PMC5845556 DOI: 10.3389/fnmol.2018.00072] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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: 11/05/2017] [Accepted: 02/20/2018] [Indexed: 12/12/2022] Open
Abstract
Morphine tolerance remains an intractable problem, which hinders its prolonged use in clinical practice. Endoplasmic reticulum (ER) stress has been proved to play a fundamental role in the pathogenesis of Alzheimer's disease, diabetes, atherosclerosis, cancer, etc. In this study, we provide the first direct evidence that ER stress may be a significant driver of morphine tolerance. Binding immunoglobulin protein (BiP), the ER stress marker, was significantly upregulated in neurons in spinal dorsal horn in rats being treated with morphine for 7 days. Additionally, chronic morphine treatment resulted in the activation of three arms of unfolded protein response (UPR): inositol-requiring enzyme 1/X-box binding protein 1 (IRE1/XBP1), protein kinase RNA-like ER kinase/eukaryotic initiation factor 2 subunit alpha (PERK/eIF2α), and activating transcription factor 6 (ATF6). More importantly, inhibiting either one of the three cascades could attenuate the development of morphine tolerance. Taken together, our results suggest that ER stress in spinal cord might contribute to the development of morphine tolerance. These findings implicate a potential clinical strategy for preventing morphine tolerance and may contribute to expanding the morphine usage in clinic.
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Affiliation(s)
- Daiqiang Liu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yaqun Zhou
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yawen Peng
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Hubei General Hospital, Wuhan, China
| | - Peng Su
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zheng Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiaoqiao Xu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ye Tu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xuebi Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Yang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhen Wu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Mei
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Gao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Yan WJ, Liu RB, Wang LK, Ma YB, Ding SL, Deng F, Hu ZY, Wang DB. Sirt3-Mediated Autophagy Contributes to Resveratrol-Induced Protection against ER Stress in HT22 Cells. Front Neurosci 2018. [PMID: 29535606 PMCID: PMC5835095 DOI: 10.3389/fnins.2018.00116] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [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] [Indexed: 01/02/2023] Open
Abstract
Endoplasmic reticulum (ER) stress occurring in stringent conditions is critically involved in neuronal survival and death. Resveratrol is a non-flavonoid polyphenol that has neuroprotective effects against many neurological disorders. Here, we investigated the potential protective effects of resveratrol in an in vitro ER stress model mimicked by tunicamycin (TM) treatment in neuronal HT22 cells. We found that TM dose-dependently decreased cell viability and increased apoptosis, which were both significantly attenuated by resveratrol treatment. Resveratrol markedly reduced the expression or activation of ER stress-associated factors, including GRP78, CHOP, and caspase-12. The results of immunocytochemistry and western blot showed that resveratrol promoted autophagy in TM-treated cells, as evidenced by increased LC3II puncta number, bcelin1 expression and LC3II/LC3I ratio. Pretreatment with the autophagy inhibitor chloroquine could reduce the protective effects of resveratrol. In addition, the expression of Sirt3 protein and its downstream enzyme activities were significantly increased in resveratrol-treated HT22 cells. To confirm the involvement of Sirt3-mediated mechanisms, siRNA transfection was used to knockdown Sirt3 expression in vitro. The results showed that downregulation of Sirt3 could partially prevented the autophagy and protection induced by resveratrol after TM treatment. Our study demonstrates a pivotal role of Sirt3-mediated autophagy in mediating resveratrol-induced protection against ER stress in vitro, and suggests the therapeutic values of resveratrol in ER stress-associated neuronal injury conditions.
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Affiliation(s)
- Wen-Jun Yan
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Ruo-Bin Liu
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Ling-Kai Wang
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Ya-Bing Ma
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Shao-Li Ding
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Fei Deng
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Zhong-Yuan Hu
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
| | - Da-Bin Wang
- Department of Anesthesiology, Gansu Provincial Hospital, Lanzhou, China
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Kriechbaumer V, Maneta-Peyret L, Fouillen L, Botchway SW, Upson J, Hughes L, Richardson J, Kittelmann M, Moreau P, Hawes C. The odd one out: Arabidopsis reticulon 20 does not bend ER membranes but has a role in lipid regulation. Sci Rep 2018; 8:2310. [PMID: 29396477 PMCID: PMC5797236 DOI: 10.1038/s41598-018-20840-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 01/22/2018] [Indexed: 12/19/2022] Open
Abstract
Reticulons are integral ER membrane proteins characterised by a reticulon homology domain comprising four transmembrane domains which results in the proteins sitting in the membrane in a W-topology. Here we report on a novel subgroup of reticulons with an extended N-terminal domain and in particular on arabidopsis reticulon 20. Using high resolution confocal microscopy we show that reticulon 20 is located in a unique punctate pattern on the ER membrane. Its closest homologue reticulon 19 labels the whole ER. Other than demonstrated for the other members of the reticulon protein family RTN20 and 19 do not display ER constriction phenotypes on over expression. We show that mutants in RTN20 or RTN19, respectively, display a significant change in sterol composition in roots indicating a role in lipid regulation. A third homologue in this family -3BETAHSD/D1- is unexpectedly localised to ER exit sites resulting in an intriguing location difference for the three proteins.
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Affiliation(s)
- Verena Kriechbaumer
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom.
| | - Lilly Maneta-Peyret
- Laboratoire Biogenèse Membranaire, UMR 5200 CNRS-Université de Bordeaux, Villenave d'Ornon, France
| | - Laetitia Fouillen
- Laboratoire Biogenèse Membranaire, UMR 5200 CNRS-Université de Bordeaux, Villenave d'Ornon, France.,MetaboHub-Metabolome Facility of Bordeaux, Functional Genomics Center, Bordeaux, France
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, OX11 0QX, United Kingdom
| | - Jessica Upson
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom.,J.U.: The Sainsbury Laboratory, Norwich, United Kingdom
| | - Louise Hughes
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom
| | - Jake Richardson
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom
| | - Maike Kittelmann
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom
| | - Patrick Moreau
- Laboratoire Biogenèse Membranaire, UMR 5200 CNRS-Université de Bordeaux, Villenave d'Ornon, France
| | - Chris Hawes
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, United Kingdom
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Gao YX, He WT, Pan LF, Feng H, Sun JL, Zhang B, Yu L, Li LJ. Downregulation of Akt2 attenuates ER stress-induced cytotoxicity through JNK-Wnt pathway in cardiomyocytes. Bioorg Med Chem Lett 2018; 28:394-399. [PMID: 29275936 DOI: 10.1016/j.bmcl.2017.12.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [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: 11/06/2017] [Revised: 12/10/2017] [Accepted: 12/13/2017] [Indexed: 02/05/2023]
Abstract
Akt, also known as protein kinase B (PKB), is a serine/threonine kinase that promotes survival and growth in response to extracellular signals. Akt1 has been demonstrated to play vital roles in cardiovascular diseases, but the role of Akt2 in cardiomyocytes is not fully understood. This study investigated the effect of Akt2 knockdown on tunicamycin (TM)-induced cytotoxicity in cardiomyocytes and the underlying mechanisms with a focus on the JNK-Wnt pathway. TM treatment significantly increased the expression of Akt2 at both mRNA and protein levels, which was shown to be mediated by the induction of reactive oxygen species (ROS). Knockdown of Akt2 expression via siRNA transfection markedly increased cell viability, decreased lactate dehydrogenase (LDH) release and reduced cell apoptosis after TM exposure. The results of western blot showed that downregulation of Akt2 also attenuated the TM-induced activation of the unfolded protein response (UPR) factors and ER stress associated pro-apoptotic proteins. In addition, Si-Akt2 transfection partially prevented the TM-induced decrease in nuclear localization of β-catenin. By using the selective inhibitor SP-600,125 to inhibit JNK phosphorylation, we found that knockdown of Akt2-induced protection and inhibition of ER stress was mediated by reversing TM-induced decrease of Wnt through the JNK pathway. In summary, these data suggested that Akt2 play a pivotal role in regulating cardiomyocyte survival during ER stress by modulating the JNK-Wnt pathway.
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Affiliation(s)
- Yan-Xia Gao
- Department of Emergency Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Wen-Ting He
- Department of Medicine, The Fourth Hospital of Xi'an, Xi'an, Shannxi 710004, China
| | - Long-Fei Pan
- Department of Emergency Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Hui Feng
- Department of Emergency Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Jiang-Li Sun
- Department of Emergency Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Bin Zhang
- Department of Neurology, The First Hospital of Yulin, Yulin, Shannxi 718000, China
| | - Lei Yu
- Department of Basic Medical Science, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Li-Jun Li
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, Shaanxi 710004, China.
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Abstract
Metabolons are protein complexes that contain all the enzymes necessary for a metabolic pathway but also scaffolding proteins. Such a structure allows efficient channeling of intermediate metabolites from one active site to the next and is highly advantageous for labile or toxic intermediates. Here we describe two methods currently used to identify metabolons via protein-protein interaction methodology: immunoprecipitations using GFP-Trap®_A beads to find novel interaction partners and potential metabolon components and FRET-FLIM to test for and quantify protein-protein interactions in planta.
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Bayer EM, Sparkes I, Vanneste S, Rosado A. From shaping organelles to signalling platforms: the emerging functions of plant ER-PM contact sites. Curr Opin Plant Biol 2017; 40:89-96. [PMID: 28865976 DOI: 10.1016/j.pbi.2017.08.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/24/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
The plant endoplasmic reticulum (ER) defines the biosynthetic site of lipids and proteins destined for secretion, but also contains important signal transduction and homeostasis components that regulate multiple hormonal and developmental responses. To achieve its various functions, the ER has a unique architecture, both reticulated and highly plastic, that facilitates the spatial-temporal segregation of biochemical reactions and the establishment of inter-organelle communication networks. At the cell cortex, the cortical ER (cER) anchors to and functionally couples with the PM through largely static structures known as ER-PM contact sites (EPCS). These spatially confined microdomains are emerging as critical regulators of the geometry of the cER network, and as highly specialized signalling hubs. In this review, we share recent insights into how EPCS regulate cER remodelling, and discuss the proposed roles for plant EPCS components in the integration of environmental and developmental signals at the cER-PM interface.
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Affiliation(s)
- Emmanuelle M Bayer
- Laboratory of Membrane Biogenesis, UMR 5200 CNRS, University of Bordeaux, 71 avenue Edouard Bourlaux, 33140 Villenave d'Ornon, France
| | - Imogen Sparkes
- Biosciences, CLES, Exeter University, Geoffrey Pope Building, Stocker Rd, Exeter EX4 4QD, UK; School of Biological Sciences, University of Bristol, Bristol Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Steffen Vanneste
- Ghent University, Department of Plant Biotechnology and Bioinformatics, 9052 Ghent, Belgium; VIB Center for Plant Systems Biology, 9052 Ghent, Belgium
| | - Abel Rosado
- Department of Botany, Faculty of Sciences, University of British Columbia, Vancouver V6T 1Z4, Canada.
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He YM, Zhang Q, Zheng M, Fan ZH, Li YH, Zhang D, Zhang Z, Yuan SS, Wang YY, Zhou P, Yang HJ. Protective effects of a G. lucidum proteoglycan on INS-1 cells against IAPP-induced apoptosis via attenuating endoplasmic reticulum stress and modulating CHOP/JNK pathways. Int J Biol Macromol 2018; 106:893-900. [PMID: 28893685 DOI: 10.1016/j.ijbiomac.2017.08.089] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 08/03/2017] [Accepted: 08/14/2017] [Indexed: 01/09/2023]
Abstract
Fudan-Yueyang-G. lucidum (FYGL) is a water-soluble macromolecular proteoglycan extracted from Ganoderma lucidum which has been used for health promotion for a long time in China. The aim of this study was to investigate the protective effects of FYGL on INS-1 rat insulinoma beta cells against IAPP-induced cell apoptosis, as well as the underlying mechanisms. The results showed that apoptotic cells were significantly increased when incubated with islet amyloid polypeptide (IAPP). However, cytotoxicity of IAPP was significantly attenuated by co-incubation of the cells with FYGL. The results of RT-PCR showed that mRNA expression of caspase-3, caspase-12 and C/EBP homologous protein (CHOP) in IAPP-treated cells were inhibited by FYGL. Moreover, FYGL significantly prevented the IAPP-induced abnormal expression of inositol-requiring protein-1α (IRE1α), protein kinase RNA (PKR)-like ER kinase (PERK), activating transcription factor 6 (ATF6), as well as suppressed the activation of CHOP and c-Jun N-terminal kinase (JNK). Taken together, our results suggest that FYGL protects INS-1 pancreatic beta cells against IAPP-induced apoptosis through attenuating endoplasmic reticulum stress (ERS) and modulating CHOP/JNK pathways.
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Wang P, Hawes C, Hussey PJ. Plant Endoplasmic Reticulum-Plasma Membrane Contact Sites. Trends Plant Sci 2017; 22:289-297. [PMID: 27955928 DOI: 10.1016/j.tplants.2016.11.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [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: 08/03/2016] [Revised: 11/05/2016] [Accepted: 11/10/2016] [Indexed: 05/08/2023]
Abstract
The endoplasmic reticulum (ER) acts as a superhighway with multiple sideroads that connects the different membrane compartments including the ER to the plasma membrane (PM). ER-PM contact sites (EPCSs) are a common feature in eukaryotic organisms, but have not been studied well in plants owing to the lack of molecular markers and to the difficulty in resolving the EPCS structure using conventional microscopy. Recently, however, plant protein complexes required for linking the ER and PM have been identified. This is a further step towards understanding the structure and function of plant EPCSs. We highlight some recent studies in this field and suggest several hypotheses that relate to the possible function of EPCSs in plants.
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Affiliation(s)
- Pengwei Wang
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Patrick J Hussey
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK.
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Abstract
Purpose of Review We provide an overview of the current knowledge on cytochrome P450-mediated metabolism organized as metabolons and factors that facilitate their stabilization. Essential parameters will be discussed including those that are commonly disregarded using the dhurrin metabolon from Sorghum bicolor as a case study. Recent Findings Sessile plants control their metabolism to prioritize their resources between growth and development, or defense. This requires fine-tuned complex dynamic regulation of the metabolic networks involved. Within the recent years, numerous studies point to the formation of dynamic metabolons playing a major role in controlling the metabolic fluxes within such networks. Summary We propose that P450s and their partners interact and associate dynamically with POR, which acts as a charging station possibly in concert with Cytb5. Solvent environment, lipid composition, and non-catalytic proteins guide metabolon formation and thereby activity, which have important implications for synthetic biology approaches aiming to produce high-value specialized metabolites in heterologous hosts.
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Affiliation(s)
- Jean-Etienne Bassard
- Plant Biochemistry Laboratory, Center for Synthetic Biology, VILLUM Research Center “Plant Plasticity,” Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen Denmark
| | - Birger Lindberg Møller
- Plant Biochemistry Laboratory, Center for Synthetic Biology, VILLUM Research Center “Plant Plasticity,” Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen Denmark
- Carlsberg Research Laboratory, Gamle Carlsberg Vej 10, DK-1799 Copenhagen V, Denmark
| | - Tomas Laursen
- Plant Biochemistry Laboratory, Center for Synthetic Biology, VILLUM Research Center “Plant Plasticity,” Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Copenhagen Denmark
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, CA 94608 USA
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van de Meene AML, Doblin MS, Bacic A. The plant secretory pathway seen through the lens of the cell wall. Protoplasma 2017; 254:75-94. [PMID: 26993347 DOI: 10.1007/s00709-016-0952-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [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: 12/23/2015] [Revised: 01/27/2016] [Accepted: 02/01/2016] [Indexed: 05/18/2023]
Abstract
Secretion in plant cells is often studied by looking at well-characterised, evolutionarily conserved membrane proteins associated with particular endomembrane compartments. Studies using live cell microscopy and fluorescent proteins have illuminated the highly dynamic nature of trafficking, and electron microscopy studies have resolved the ultrastructure of many compartments. Biochemical and molecular analyses have further informed about the function of particular proteins and endomembrane compartments. In plants, there are over 40 cell types, each with highly specialised functions, and hence potential variations in cell biological processes and cell wall structure. As the primary function of secretion in plant cells is for the biosynthesis of cell wall polysaccharides and apoplastic transport complexes, it follows that utilising our knowledge of cell wall glycosyltransferases (GTs) and their polysaccharide products will inform us about secretion. Indeed, this knowledge has led to novel insights into the secretory pathway, including previously unseen post-TGN secretory compartments. Conversely, our knowledge of trafficking routes of secretion will inform us about polarised and localised deposition of cell walls and their constituent polysaccharides/glycoproteins. In this review, we look at what is known about cell wall biosynthesis and the secretory pathway and how the different approaches can be used in a complementary manner to study secretion and provide novel insights into these processes.
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Affiliation(s)
- A M L van de Meene
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - M S Doblin
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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45
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Atabekova AK, Pankratenko AV, Makarova SS, Lazareva EA, Owens RA, Solovyev AG, Morozov SY. Phylogenetic and functional analyses of a plant protein related to human B-cell receptor-associated proteins. Biochimie 2017; 132:28-37. [PMID: 27770627 DOI: 10.1016/j.biochi.2016.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [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: 09/17/2016] [Accepted: 10/17/2016] [Indexed: 12/20/2022]
Abstract
Human B-cell receptor-associated protein BAP31 (HsBAP31) is the endoplasmic reticulum-resident protein involved in protein sorting and transport as well as pro-apoptotic signaling. Plant orthologs of HsBAP31 termed 'plant BAP-like proteins' (PBL proteins) have thus far remained unstudied. Recently, the PBL protein from Nicotiana tabacum (NtPBL) was identified as an interactor of Nt-4/1, a plant protein known to interact with plant virus movement proteins and affect the long-distance transport of potato spindle tuber viroid (PSTVd) via the phloem. Here, we have compared the sequences of PBL proteins and studied the biochemical properties of NtPBL. Analysis of a number of fully sequenced plant genomes revealed that PBL-encoding genes represent a small multigene family with up to six members per genome. Two conserved motifs were identified in the C-terminal region of PBL proteins. The NtPBL C-terminal hydrophilic region (NtPBL-C) was expressed in bacterial cells, purified, and used for analysis of its RNA binding properties in vitro. In gel shift experiments, NtPBL-C was found to bind several tested RNAs, showing the most efficient binding to microRNA precursors (pre-miRNA) and less efficient interaction with PSTVd. Mutational analysis suggested that NtPBL-C has a composite RNA-binding site, with two conserved lysine residues in the most C-terminal protein region being involved in binding of pre-miRNA but not PSTVd RNA. Virus-mediated transient expression of NtPBL-C in plants resulted in stunting and leaf malformation, developmental abnormalities similar to those described previously for blockage of miRNA biogenesis/function. We hypothesize that the NtPBL protein represents a previously undiscovered component of the miRNA pathway.
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Affiliation(s)
- Anastasia K Atabekova
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia
| | - Anna V Pankratenko
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia
| | - Svetlana S Makarova
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia
| | - Ekaterina A Lazareva
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia
| | - Robert A Owens
- Molecular Plant Pathology Laboratory, USDA-ARS, Beltsville, MD, 20705, USA
| | - Andrey G Solovyev
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia; Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Moscow, 119991, Russia
| | - Sergey Y Morozov
- Department of Virology, Biological Faculty, Moscow State University, Moscow, 119992, Russia; Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119992, Russia.
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46
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Zhang Y, Gao X, Chen S, Zhao M, Chen J, Liu R, Cheng S, Qi M, Wang S, Liu W. Cyclin-dependent kinase 5 contributes to endoplasmic reticulum stress induced podocyte apoptosis via promoting MEKK1 phosphorylation at Ser280 in diabetic nephropathy. Cell Signal 2016; 31:31-40. [PMID: 28024901 DOI: 10.1016/j.cellsig.2016.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 09/01/2016] [Revised: 12/01/2016] [Accepted: 12/23/2016] [Indexed: 11/28/2022]
Abstract
Endoplasmic reticulum (ER) stress has been reported to be associated with podocyte apoptosis in diabetic nephropathy, but the mechanism of ER signaling in podocyte apoptosis hasn't been fully understood. Our previous studies have demonstrated that Cyclin-dependent kinase 5 (Cdk5) was associated with podocyte apoptosis in diabetic nephropathy. The present study was designed to examine whether and how Cdk5 activity plays a role in ER stress induced podocyte apoptosis in diabetic nephropathy. The results showed that along with induction of Cdk5 and apoptosis, GRP78 and its two sensors as well as CHOP and cleaved caspase-12 were induced in high glucose treated podocytes. These responses were attenuated by treated salubrinal. The ER stress inducer, tunicamycin, also up-regulated the kinase activity and protein expression of Cdk5 in podocytes accompanied with the increasing of GRP78. On the other hand, Cdk5 phosphorylates MEKK1 at Ser280 in tunicamycin treated podocytes, and together, they increase the JNK phosphorylation. Moreover, disruption of this pathway can decrease the podocyte apoptosis induced by tunicamycin. Therefore, our study proved that Cdk5 may play an important role in ER stress induced podocyte apoptosis through MEKK1/JNK pathway in diabetic nephropathy.
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Affiliation(s)
- Yue Zhang
- Department of Diagnostics, Hebei Medical University, Shijiazhuang 050017, China
| | - Xiang Gao
- Department of Surgery, Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Shuanggang Chen
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Min Zhao
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Jing Chen
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Rui Liu
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Shengyang Cheng
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Mengyuan Qi
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Shuo Wang
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China
| | - Wei Liu
- Department of Pathology and Key Laboratory of Kidney Diseases of Hebei Province, Hebei Medical University, Shijiazhuang 050017, China.
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47
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Breeze E, Dzimitrowicz N, Kriechbaumer V, Brooks R, Botchway SW, Brady JP, Hawes C, Dixon AM, Schnell JR, Fricker MD, Frigerio L. A C-terminal amphipathic helix is necessary for the in vivo tubule-shaping function of a plant reticulon. Proc Natl Acad Sci U S A 2016; 113:10902-7. [PMID: 27621477 PMCID: PMC5047209 DOI: 10.1073/pnas.1605434113] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Reticulons (RTNs) are a class of endoplasmic reticulum (ER) membrane proteins that are capable of maintaining high membrane curvature, thus helping shape the ER membrane into tubules. The mechanism of action of RTNs is hypothesized to be a combination of wedging, resulting from the transmembrane topology of their conserved reticulon homology domain, and scaffolding, arising from the ability of RTNs to form low-mobility homo-oligomers within the membrane. We studied the plant RTN isoform RTN13, which has previously been shown to locate to ER tubules and the edges of ER cisternae and to induce constrictions in ER tubules when overexpressed, and identified a region in the C terminus containing a putative amphipathic helix (APH). Here we show that deletion of this region or disruption of the hydrophobic face of the predicted helix abolishes the ability of RTN13 to induce constrictions of ER tubules in vivo. These mutants, however, still retain their ability to interact and form low-mobility oligomers in the ER membrane. Hence, our evidence indicates that the conserved APH is a key structural feature for RTN13 function in vivo, and we propose that RTN, like other membrane morphogens, rely on APHs for their function.
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Affiliation(s)
- Emily Breeze
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Natasha Dzimitrowicz
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Verena Kriechbaumer
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Rhiannon Brooks
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0QX, United Kingdom
| | - Jacob P Brady
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Chris Hawes
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, United Kingdom
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Jason R Schnell
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Mark D Fricker
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom
| | - Lorenzo Frigerio
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom;
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48
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Kriechbaumer V, Botchway SW, Hawes C. Localization and interactions between Arabidopsis auxin biosynthetic enzymes in the TAA/YUC-dependent pathway. J Exp Bot 2016; 67:4195-207. [PMID: 27208541 DOI: 10.1093/jxb/erw195] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The growth regulator auxin is involved in all key developmental processes in plants. A complex network of a multiplicity of potential biosynthetic pathways as well as transport, signalling plus conjugation and deconjugation lead to a complex and multifaceted system system for auxin function. This raises the question how such a system can be effectively organized and controlled. Here we report that a subset of auxin biosynthetic enzymes in the TAA/YUC route of auxin biosynthesis is localized to the endoplasmic reticulum (ER). ER microsomal fractions also contain a significant percentage of auxin biosynthetic activity. This could point toward a model of auxin function using ER membrane location and subcellular compartmentation for supplementary layers of regulation. Additionally we show specific protein-protein interactions between some of the enzymes in the TAA/YUC route of auxin biosynthesis.
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Affiliation(s)
- Verena Kriechbaumer
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Stanley W Botchway
- Central Laser Facility, Science and Technology Facilities Council (STFC) Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0QX, UK
| | - Chris Hawes
- Plant Cell Biology, Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
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49
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Wang P, Richardson C, Hawkins TJ, Sparkes I, Hawes C, Hussey PJ. Plant VAP27 proteins: domain characterization, intracellular localization and role in plant development. New Phytol 2016; 210:1311-26. [PMID: 27159525 DOI: 10.1111/nph.13857] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [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: 08/24/2015] [Accepted: 12/14/2015] [Indexed: 05/24/2023]
Abstract
The endoplasmic reticulum (ER) is connected to the plasma membrane (PM) through the plant-specific NETWORKED protein, NET3C, and phylogenetically conserved vesicle-associated membrane protein-associated proteins (VAPs). Ten VAP homologues (VAP27-1 to 27-10) can be identified in the Arabidopsis genome and can be divided into three clades. Representative members from each clade were tagged with fluorescent protein and expressed in Nicotiana benthamiana. Proteins from clades I and III localized to the ER as well as to ER/PM contact sites (EPCSs), whereas proteins from clade II were found only at the PM. Some of the VAP27-labelled EPCSs localized to plasmodesmata, and we show that the mobility of VAP27 at EPCSs is influenced by the cell wall. EPCSs closely associate with the cytoskeleton, but their structure is unaffected when the cytoskeleton is removed. VAP27-labelled EPCSs are found in most cell types in Arabidopsis, with the exception of cells in early trichome development. Arabidopsis plants expressing VAP27-GFP fusions exhibit pleiotropic phenotypes, including defects in root hair morphogenesis. A similar effect is also observed in plants expressing VAP27 RNAi. Taken together, these data indicate that VAP27 proteins used at EPCSs are essential for normal ER-cytoskeleton interaction and for plant development.
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Affiliation(s)
- Pengwei Wang
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Christine Richardson
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Timothy J Hawkins
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Imogen Sparkes
- College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Chris Hawes
- Department of Biological and Biomedical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK
| | - Patrick J Hussey
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK
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Saberianfar R, Sattarzadeh A, Joensuu JJ, Kohalmi SE, Menassa R. Protein Bodies in Leaves Exchange Contents through the Endoplasmic Reticulum. Front Plant Sci 2016; 7:693. [PMID: 27242885 PMCID: PMC4876836 DOI: 10.3389/fpls.2016.00693] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/05/2016] [Indexed: 05/22/2023]
Abstract
Protein bodies (PBs) are organelles found in seeds whose main function is the storage of proteins that are used during germination for sustaining growth. PBs can also be induced to form in leaves when foreign proteins are produced at high levels in the endoplasmic reticulum (ER) and when fused to one of three tags: Zera®, elastin-like polypeptides (ELP), or hydrophobin-I (HFBI). In this study, we investigate the differences between ELP, HFBI and Zera PB formation, packing, and communication. Our results confirm the ER origin of all three fusion-tag-induced PBs. We show that secretory pathway proteins can be sequestered into all types of PBs but with different patterns, and that different fusion tags can target a specific protein to different PBs. Zera PBs are mobile and dependent on actomyosin motility similar to ELP and HFBI PBs. We show in vivo trafficking of proteins between PBs using GFP photoconversion. We also show that protein trafficking between ELP or HFBI PBs is faster and proteins travel further when compared to Zera PBs. Our results indicate that fusion-tag-induced PBs do not represent terminally stored cytosolic organelles, but that they form in, and remain part of the ER, and dynamically communicate with each other via the ER. We hypothesize that the previously documented PB mobility along the actin cytoskeleton is associated with ER movement rather than independent streaming of detached organelles.
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Affiliation(s)
- Reza Saberianfar
- Agriculture and Agri-Food CanadaLondon, ON, Canada
- Department of Biology, University of Western OntarioLondon, ON, Canada
| | - Amirali Sattarzadeh
- Department of Molecular Biology and Genetics, Cornell UniversityIthaca, NY, USA
| | | | | | - Rima Menassa
- Agriculture and Agri-Food CanadaLondon, ON, Canada
- Department of Biology, University of Western OntarioLondon, ON, Canada
- *Correspondence: Rima Menassa
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