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Abstract
Abstract
Because of difficulties during the fixation in space and the often reported enhanced expression of stress-related genes in space experiments, we investigated the possible effect of fixation on gene expression. Comparing two fixatives (RNAlater® and 70% ethanol), two-day-old Brassica rapa seedlings were either fixed by gradual exposure or immediate and complete immersion in fixative for two days. Neither fixative yielded high amounts of rRNA; RNAlater® resulted in higher RNA yield in shoot tissue but qPCR data showed higher yield in ethanol-fixed material. qPCR analyses showed strongly enhanced transcripts of stress-related genes, especially in RNAlater®-fixed material. The data suggest that fixation artefacts may be partially responsible for effects commonly attributed to space syndromes.
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Chen T, Ji D, Tian S. Variable-angle epifluorescence microscopy characterizes protein dynamics in the vicinity of plasma membrane in plant cells. BMC PLANT BIOLOGY 2018. [PMID: 29540149 PMCID: PMC5853057 DOI: 10.1186/s12870-018-1246-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
BACKGROUND The assembly of protein complexes and compositional lipid patterning act together to endow cells with the plasticity required to maintain compositional heterogeneity with respect to individual proteins. Hence, the applications for imaging protein localization and dynamics require high accuracy, particularly at high spatio-temporal level. RESULTS We provided experimental data for the applications of Variable-Angle Epifluorescence Microscopy (VAEM) in dissecting protein dynamics in plant cells. The VAEM-based co-localization analysis took penetration depth and incident angle into consideration. Besides direct overlap of dual-color fluorescence signals, the co-localization analysis was carried out quantitatively in combination with the methodology for calculating puncta distance and protein proximity index. Besides, simultaneous VAEM tracking of cytoskeletal dynamics provided more insights into coordinated responses of actin filaments and microtubules. Moreover, lateral motility of membrane proteins was analyzed by calculating diffusion coefficients and kymograph analysis, which represented an alternative method for examining protein motility. CONCLUSION The present study presented experimental evidence on illustrating the use of VAEM in tracking and dissecting protein dynamics, dissecting endosomal dynamics, cell structure assembly along with membrane microdomain and protein motility in intact plant cells.
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Affiliation(s)
- Tong Chen
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Haidian District, Beijing, 100093 China
| | - Dongchao Ji
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Haidian District, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Shiping Tian
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Nanxincun 20, Xiangshan, Haidian District, Beijing, 100093 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
- Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture, Beijing, China
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3
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Abstract
Advances in microscopy techniques applied to living cells have dramatically transformed our view of the actin cytoskeleton as a framework for cellular processes. Conventional fluorescence imaging and static analyses are useful for quantifying cellular architecture and the network of filaments that support vesicle trafficking, organelle movement, and response to biotic stress. However, new imaging techniques have revealed remarkably dynamic features of individual actin filaments and the mechanisms that underpin their construction and turnover. In this review, we briefly summarize knowledge about actin and actin-binding proteins in plant systems. We focus on the quantitative properties of the turnover of individual actin filaments, highlight actin-binding proteins that participate in actin dynamics, and summarize the current genetic evidence that has been used to dissect specific aspects of the stochastic dynamics model. Finally, we describe some signaling pathways in which recent data implicate changes in actin filament dynamics and the associated cytoplasmic responses.
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Affiliation(s)
- Jiejie Li
- Department of Biological Sciences and
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4
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Henty-Ridilla JL, Shimono M, Li J, Chang JH, Day B, Staiger CJ. The plant actin cytoskeleton responds to signals from microbe-associated molecular patterns. PLoS Pathog 2013; 9:e1003290. [PMID: 23593000 PMCID: PMC3616984 DOI: 10.1371/journal.ppat.1003290] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 02/21/2013] [Indexed: 12/15/2022] Open
Abstract
Plants are constantly exposed to a large and diverse array of microbes; however, most plants are immune to the majority of potential invaders and susceptible to only a small subset of pathogens. The cytoskeleton comprises a dynamic intracellular framework that responds rapidly to biotic stresses and supports numerous fundamental cellular processes including vesicle trafficking, endocytosis and the spatial distribution of organelles and protein complexes. For years, the actin cytoskeleton has been assumed to play a role in plant innate immunity against fungi and oomycetes, based largely on static images and pharmacological studies. To date, however, there is little evidence that the host-cell actin cytoskeleton participates in responses to phytopathogenic bacteria. Here, we quantified the spatiotemporal changes in host-cell cytoskeletal architecture during the immune response to pathogenic and non-pathogenic strains of Pseudomonas syringae pv. tomato DC3000. Two distinct changes to host cytoskeletal arrays were observed that correspond to distinct phases of plant-bacterial interactions i.e. the perception of microbe-associated molecular patterns (MAMPs) during pattern-triggered immunity (PTI) and perturbations by effector proteins during effector-triggered susceptibility (ETS). We demonstrate that an immediate increase in actin filament abundance is a conserved and novel component of PTI. Notably, treatment of leaves with a MAMP peptide mimic was sufficient to elicit a rapid change in actin organization in epidermal cells, and this actin response required the host-cell MAMP receptor kinase complex, including FLS2, BAK1 and BIK1. Finally, we found that actin polymerization is necessary for the increase in actin filament density and that blocking this increase with the actin-disrupting drug latrunculin B leads to enhanced susceptibility of host plants to pathogenic and non-pathogenic bacteria.
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Affiliation(s)
- Jessica L. Henty-Ridilla
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Masaki Shimono
- Department of Plant Pathology, Michigan State University, East Lansing, Michigan, United States of America
| | - Jiejie Li
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Jeff H. Chang
- Department of Botany and Plant Pathology, and Molecular and Cellular Biology Program and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Brad Day
- Department of Plant Pathology, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail: (BD); (CJS)
| | - Christopher J. Staiger
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Bindley Bioscience Center, Discovery Park, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (BD); (CJS)
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5
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Abstract
Many of the best-studied actin regulatory proteins use non-covalent means to modulate the properties of actin. Yet, actin is also susceptible to covalent modifications of its amino acids. Recent work is increasingly revealing that actin processing and its covalent modifications regulate important cellular events. In addition, numerous pathogens express enzymes that specifically use actin as a substrate to regulate their hosts' cells. Actin post-translational alterations have been linked to different normal and disease processes and the effects associated with metabolic and environmental stressors. Herein, we highlight specific co-translational and post-translational modifications of actin and discuss the current understanding of the role that these modifications play in regulating actin.
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Affiliation(s)
- Jonathan R Terman
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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6
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Yemets AI, Krasylenko YA, Lytvyn DI, Sheremet YA, Blume YB. Nitric oxide signalling via cytoskeleton in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 181:545-54. [PMID: 21893251 DOI: 10.1016/j.plantsci.2011.04.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 04/25/2011] [Accepted: 04/27/2011] [Indexed: 05/19/2023]
Abstract
Nitric oxide (NO) in plant cell mediates processes of growth and development starting from seed germination to pollination, as well as biotic and abiotic stress tolerance. However, proper understanding of the molecular mechanisms of NO signalling in plants has just begun to emerge. Accumulated evidence suggests that in eukaryotic cells NO regulates functions of proteins by their post-translational modifications, namely tyrosine nitration and S-nitrosylation. Among the candidates for NO-downstream effectors are cytoskeletal proteins because of their involvement in many processes regulated by NO. This review discusses new insights in plant NO signalling focused mainly on the involvement of cytoskeleton components into NO-cascades. Herein, examples of NO-related post-translational modifications of cytoskeletal proteins, and also indirect NO impact, are discussed. Special attention is paid to plant α-tubulin tyrosine nitration as an emerging topic in plant NO research.
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Affiliation(s)
- Alla I Yemets
- Department of Genomics and Molecular Biotechnology, Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osipovskogo Str., 2a, Kyiv 04123, Ukraine.
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7
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Boutet I, Ripp R, Lecompte O, Dossat C, Corre E, Tanguy A, Lallier FH. Conjugating effects of symbionts and environmental factors on gene expression in deep-sea hydrothermal vent mussels. BMC Genomics 2011; 12:530. [PMID: 22034982 PMCID: PMC3218092 DOI: 10.1186/1471-2164-12-530] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/28/2011] [Indexed: 11/17/2022] Open
Abstract
Background The deep-sea hydrothermal vent mussel Bathymodiolus azoricus harbors thiotrophic and methanotrophic symbiotic bacteria in its gills. While the symbiotic relationship between this hydrothermal mussel and these chemoautotrophic bacteria has been described, the molecular processes involved in the cross-talking between symbionts and host, in the maintenance of the symbiois, in the influence of environmental parameters on gene expression, and in transcriptome variation across individuals remain poorly understood. In an attempt to understand how, and to what extent, this double symbiosis affects host gene expression, we used a transcriptomic approach to identify genes potentially regulated by symbiont characteristics, environmental conditions or both. This study was done on mussels from two contrasting populations. Results Subtractive libraries allowed the identification of about 1000 genes putatively regulated by symbiosis and/or environmental factors. Microarray analysis showed that 120 genes (3.5% of all genes) were differentially expressed between the Menez Gwen (MG) and Rainbow (Rb) vent fields. The total number of regulated genes in mussels harboring a high versus a low symbiont content did not differ significantly. With regard to the impact of symbiont content, only 1% of all genes were regulated by thiotrophic (SOX) and methanotrophic (MOX) bacteria content in MG mussels whereas 5.6% were regulated in mussels collected at Rb. MOX symbionts also impacted a higher proportion of genes than SOX in both vent fields. When host transcriptome expression was analyzed with respect to symbiont gene expression, it was related to symbiont quantity in each field. Conclusions Our study has produced a preliminary description of a transcriptomic response in a hydrothermal vent mussel host of both thiotrophic and methanotrophic symbiotic bacteria. This model can help to identify genes involved in the maintenance of symbiosis or regulated by environmental parameters. Our results provide evidence of symbiont effect on transcriptome regulation, with differences related to type of symbiont, even though the relative percentage of genes involved remains limited. Differences observed between the vent site indicate that environment strongly influences transcriptome regulation and impacts both activity and relative abundance of each symbiont. Among all these genes, those participating in recognition, the immune system, oxidative stress, and energy metabolism constitute new promising targets for extended studies on symbiosis and the effect of environmental parameters on the symbiotic relationships in B. azoricus.
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Affiliation(s)
- Isabelle Boutet
- CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29682 Roscoff, France.
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8
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Hofmann WA, Arduini A, Nicol SM, Camacho CJ, Lessard JL, Fuller-Pace FV, de Lanerolle P. SUMOylation of nuclear actin. ACTA ACUST UNITED AC 2009; 186:193-200. [PMID: 19635839 PMCID: PMC2717643 DOI: 10.1083/jcb.200905016] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Actin, a major component of the cytoplasm, is also abundant in the nucleus. Nuclear actin is involved in a variety of nuclear processes including transcription, chromatin remodeling, and intranuclear transport. Nevertheless, the regulation of nuclear actin by posttranslational modifications has not been investigated. We now show that nuclear actin is modified by SUMO2 and SUMO3 and that computational modeling and site-directed mutagenesis identified K68 and K284 as critical sites for SUMOylating actin. We also present a model for the actin–SUMO complex and show that SUMOylation is required for the nuclear localization of actin.
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Affiliation(s)
- Wilma A Hofmann
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA
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9
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Konopka-Postupolska D. Annexins: putative linkers in dynamic membrane-cytoskeleton interactions in plant cells. PROTOPLASMA 2007; 230:203-15. [PMID: 17458635 DOI: 10.1007/s00709-006-0234-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 03/14/2006] [Indexed: 05/08/2023]
Abstract
The plasma membrane, the most external cellular structure, is at the forefront between the plant cell and its environment. Hence, it is naturally adapted to function in detection of external signals, their transduction throughout the cell, and finally, in cell reactions. Membrane lipids and the cytoskeleton, once regarded as simple and static structures, have recently been recognized as significant players in signal transduction. Proteins involved in signal detection and transduction are organised in specific domains at the plasma membrane. Their aggregation allows to bring together and orient the downstream and upstream members of signalling pathways. The cortical cytoskeleton provides a structural framework for rapid signal transduction from the cell periphery into the nucleus. It leads to intracellular reorganisation and wide-scale modulation of cellular metabolism which results in accumulation of newly synthesised proteins and/or secondary metabolites which, in turn, have to be distributed to the appropriate cell compartments. And again, in plant cells, the secretory vesicles that govern polar cellular transport are delivered to their target membranes by interaction with actin microfilaments. In search for factors that could govern subsequent steps of the cell response delineated above we focused on an evolutionary conserved protein family, the annexins, that bind in a calcium-dependent manner to membrane phospholipids. Annexins were proposed to regulate dynamic changes in membrane architecture and to organise the interface between secretory vesicles and the membrane. Certain proteins from this family were also identified as actin binding, making them ideal mediators in cell membrane and cytoskeleton interactions.
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Affiliation(s)
- D Konopka-Postupolska
- Laboratory of Plant Pathogenesis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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10
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Aparicio-Fabre R, Guillén G, Estrada G, Olivares-Grajales J, Gurrola G, Sánchez F. Profilin tyrosine phosphorylation in poly-L-proline-binding regions inhibits binding to phosphoinositide 3-kinase in Phaseolus vulgaris. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 47:491-500. [PMID: 16827923 DOI: 10.1111/j.1365-313x.2006.02787.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The profilin family consists of a group of ubiquitous highly conserved 12-15 kDa eukaryotic proteins that bind actin, phosphoinositides, poly-l-proline (PLP) and proteins with proline-rich motifs. Some proteins with proline-rich motifs form complexes that have been implicated in the dynamics of the actin cytoskeleton and processes such as vesicular trafficking. A major unanswered question in the field is how profilin achieves the required specificity to bind such an array of proteins. It is now becoming clear that profilin isoforms are subject to differential regulation and that they may play distinct roles within the cell. Considerable evidence suggests that these isoforms have different functional roles in the sorting of diverse proteins with proline-rich motifs. All profilins contain highly conserved aromatic residues involved in PLP binding which are presumably implicated in the interaction with proline-rich motif proteins. We have previously shown that profilin is phosphorylated on tyrosine residues. Here, we show that profilin can bind directly to Phaseolus vulgaris phosphoinositide 3-kinase (PI3K) type III. We demonstrate that a new region around Y72 of profilin, as well as the N- and C-terminal PLP-binding domain, recognizes and binds PLP and PI3K. In vitro binding assays indicate that PI3K type III forms a complex with profilin in a manner that depends on the tyrosine phosphorylation status within the proline-rich-binding domain in profilin. Profilin-PI3K type III interaction suggests that profilin may be involved in membrane trafficking and in linking the endocytic pathway with actin reorganization dynamics.
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Affiliation(s)
- Rosaura Aparicio-Fabre
- Departmento de Biología Molecular de Plantas, Institute de Biotechnología, UNAM, México, Av. Universidad 2001, Chamilpa, Cuernavaca Mor 62210, Mexico
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11
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Blancaflor EB, Wang YS, Motes CM. Organization and function of the actin cytoskeleton in developing root cells. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 252:219-64. [PMID: 16984819 DOI: 10.1016/s0074-7696(06)52004-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The actin cytoskeleton is a highly dynamic structure, which mediates various cellular functions in large part through accessory proteins that tilt the balance between monomeric G-actin and filamentous actin (F-actin) or by facilitating interactions between actin and the plasma membrane, microtubules, and other organelles. Roots have become an attractive model to study actin in plant development because of their simple anatomy and accessibility of some root cell types such as root hairs for microscopic analyses. Roots also exhibit a remarkable developmental plasticity and possess a delicate sensory system that is easily manipulated, so that one can design experiments addressing a range of important biological questions. Many facets of root development can be regulated by the diverse actin network found in the various root developmental regions. Various molecules impinge on this actin scaffold to define how a particular root cell type grows or responds to a specific environmental signal. Although advances in genomics are leading the way toward elucidating actin function in roots, more significant strides will be realized when such tools are combined with improved methodologies for accurately depicting how actin is organized in plant cells.
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Affiliation(s)
- Elison B Blancaflor
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401, USA
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12
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Kudryashova E, Kudryashov D, Kramerova I, Spencer MJ. Trim32 is a Ubiquitin Ligase Mutated in Limb Girdle Muscular Dystrophy Type 2H that Binds to Skeletal Muscle Myosin and Ubiquitinates Actin. J Mol Biol 2005; 354:413-24. [PMID: 16243356 DOI: 10.1016/j.jmb.2005.09.068] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 09/19/2005] [Accepted: 09/21/2005] [Indexed: 11/15/2022]
Abstract
Trim32 belongs to the tripartite motif (TRIM) protein family, which is characterized by a common domain structure composed of a RING-finger, a B-box, and a coiled-coil motif. In addition to these motifs, Trim32 possesses six C-terminal NHL-domains. A point mutation in one NHL domain (D487N) has been linked to two forms of muscular dystrophy called limb girdle muscular dystrophy type 2H and sarcotubular myopathy. In the present study we demonstrate that Trim32 is an E3 ubiquitin ligase that acts in conjunction with ubiquitin-conjugating enzymes UbcH5a, UbcH5c, and UbcH6. Western blot analysis showed that Trim32 is expressed primarily in skeletal muscle, and revealed its differential expression from one muscle to another. The level of Trim32 expression was elevated significantly in muscle undergoing remodeling due to changes in weight bearing. Furthermore, expression of Trim32 was induced in myogenic differentiation. Thus, variability in Trim32 expression in different skeletal muscles could be due to induction of Trim32 expression upon changes in physiological conditions. We show that Trim32 associates with skeletal muscle thick filaments, interacting directly with the head and neck region of myosin. Our data indicate that myosin is not a substrate of Trim32; however, Trim32 was found to ubiquitinate actin in vitro and to cause a decrease in the level of endogenous actin when transfected into HEK293 cells. In conclusion, our results demonstrate that Trim32 is a ubiquitin ligase that is expressed in skeletal muscle, can be induced upon muscle unloading and reloading, associates with myofibrils and is able to ubiquitinate actin, suggesting its likely participation in myofibrillar protein turnover, especially during muscle adaptation.
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Affiliation(s)
- Elena Kudryashova
- Department of Neurology and Pediatrics, Duchenne Muscular Dystrophy Research Center, University of California at Los Angeles, CA 90095, USA
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13
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Tsurushima T, Don LD, Kawashima K, Murakami J, Nakayashiki H, Tosa Y, Mayama S. Pyrichalasin H production and pathogenicity of Digitaria-specific isolates of Pyricularia grisea. MOLECULAR PLANT PATHOLOGY 2005; 6:605-613. [PMID: 20565683 DOI: 10.1111/j.1364-3703.2005.00309.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Culture filtrates from 72 isolates of Pyricularia, grouped into 13 rDNA types, were analysed via HPLC. Of these isolates, 31 (r9 DNA type) from crabgrass (Digitaria sanguinalis), one (r9 DNA type) from pangolagrass (Digitaria smutsii) and six (r8 DNA type) from Digitaria horizontalis produced 20-280 microg pyrichalasin H per millilitre of culture. These same isolates were pathogenic on five Digitaria species. Interestingly, two isolates, KM-1 and Br 29, which were originally isolated from Digitaria plants, did not produce pyrichalasin H, nor caused blast lesion on Digitaria plants. Because these two isolates were identified as Digitaria pathogens by PCR analysis using Digitaria-specific primers, they are likely to be mutants lacking pyrichalasin H production. Isolates that belonged to the remaining 11 rDNA types did not produce pyrichalasin H and were avirulent to Digitaria plants. Therefore, the virulence of Pyricularia on Digitaria plants correlates with pyrichalasin H production. Pyrichalasin H was also present in spore germination fluid of a crabgrass isolate (IBDS 5-1-1), but not in that of isolates from rice, foxtail millet, finger millet, common millet and wheat. In addition, pyrichalasin H was detected in host leaves infected with IBDS 5-1-1, but not in leaves from other plants infected with compatible Pyricularia isolates. Pretreatment of leaf sheaths of crabgrass with 3 microg/mL pyrichalasin H led to the penetration and colonization by non-host isolates. Overall, these results indicate that production of pyrichalasin H is responsible for the genus-specific pathogenicity of Digitaria isolates.
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Affiliation(s)
- Tetsu Tsurushima
- Faculty of Business, Hannan University, Matsubara 580-8502, Japan
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Wan J, Torres M, Ganapathy A, Thelen J, DaGue BB, Mooney B, Xu D, Stacey G. Proteomic analysis of soybean root hairs after infection by Bradyrhizobium japonicum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:458-67. [PMID: 15915644 DOI: 10.1094/mpmi-18-0458] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Infection of soybean root hairs by Bradyrhizobium japonicum is the first of several complex events leading to nodulation. In the current proteomic study, soybean root hairs after inoculation with B. japonicum were separated from roots. Total proteins were analyzed by two-dimensional (2-D) polyacrylamide gel electrophoresis. In one experiment, 96 protein spots were analyzed by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) to compare protein profiles between uninoculated roots and root hairs. Another 37 spots, derived from inoculated root hairs over different timepoints, were also analyzed by tandem MS (MS/MS). As expected, some proteins were differentially expressed in root hairs compared with roots (e.g., a chitinase and phosphoenolpyruvate carboxylase). Out of 37 spots analyzed by MS/MS, 27 candidate proteins were identified by database comparisons. These included several proteins known to respond to rhizobial inoculation (e.g., peroxidase and phenylalanine-ammonia lyase). However, novel proteins were also identified (e.g., phospholipase D and phosphoglucomutase). This research establishes an excellent system for the study of root-hair infection by rhizobia and, in a more general sense, the functional genomics of a single, plant cell type. The results obtained also indicate that proteomic studies with soybean, lacking a complete genome sequence, are practical.
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Affiliation(s)
- Jinrong Wan
- National Center for Soybean Biotechnology, Department of Plant Microbiology and Pathology, University of Missouri, Columbia, MO 65211, USA
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15
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Takemoto D, Hardham AR. The cytoskeleton as a regulator and target of biotic interactions in plants. PLANT PHYSIOLOGY 2004; 136:3864-76. [PMID: 15591444 PMCID: PMC535820 DOI: 10.1104/pp.104.052159] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2004] [Revised: 10/15/2004] [Accepted: 10/18/2004] [Indexed: 05/18/2023]
Affiliation(s)
- Daigo Takemoto
- Plant Cell Biology Group, Research School of Biological Sciences, The Australian National University, Canberra, ACT 2601, Australia
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16
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Mohammad A, Miranda-Ríos J, Navarrete GE, Quinto C, Olivares JE, García-Ponce B, Sánchez F. Nodulin 22 from Phaseolus vulgaris protects Escherichia coli cells from oxidative stress. PLANTA 2004; 219:993-1002. [PMID: 15605176 DOI: 10.1007/s00425-004-1303-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2003] [Accepted: 05/03/2004] [Indexed: 05/03/2023]
Abstract
Plant genes that are induced during the formation and function of a root nodule are called nodulin genes. Cloning and functional analysis of nodule-specific gene products are of valuable help in establishing the role and requirements of the host plant for the specificity and effectiveness of the symbiosis. A cDNA clone (nod22) was isolated from Phaseolus vulgaris L. (common bean) cDNA library derived from Rhizobium-infected roots. Nodulin 22 (Nod22) transcripts are accumulated from early to late stages in root nodule development. RT-PCR in situ studies indicated that Nod22 transcripts are highly accumulated in cortical, vascular bundle and infected cells. The deduced Nod22 protein contains a highly hydrophobic N-terminus, with signal peptide characteristics, and a C-terminal extension with high identity to the alpha-crystallin domains found in alpha-crystallin lens chaperone, and other small heat-shock proteins. These domains have not been previously described in other known nodulins, but have been observed in small heat-shock proteins found in plant tissues exposed to elevated temperature and oxidative stress. Nod22, when it is over-expressed in Escherichia coli, cells confers protection against oxidative stress suggesting its possible role in plant host protection from oxidative toxicity during the Rhizobium-legume symbiosis.
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Affiliation(s)
- Asif Mohammad
- Departamento de Biología Molecular de Plantas, Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62271 Cuernavaca, Morelos, México
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17
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Kimbell JR, McFall-Ngai MJ. Symbiont-induced changes in host actin during the onset of a beneficial animal-bacterial association. Appl Environ Microbiol 2004; 70:1434-41. [PMID: 15006763 PMCID: PMC368416 DOI: 10.1128/aem.70.3.1434-1441.2004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2003] [Accepted: 12/01/2003] [Indexed: 01/01/2023] Open
Abstract
The influence of bacteria on the cytoskeleton of animal cells has been studied extensively only in pathogenic associations. We characterized changes in host cytoskeletal actin induced by the bacterial partner during the onset of a cooperative animal-bacteria association using the squid-vibrio model. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis revealed that Vibrio fischeri induced a dramatic increase in actin protein abundance in the bacteria-associated host tissues during the onset of the symbiosis. Immunocytochemistry revealed that this change in actin abundance correlated with a two- to threefold increase in actin in the apical cell surface of the epithelium-lined ducts, the route of entry of symbionts into host tissues. Real-time reverse transcriptase PCR and in situ hybridization did not detect corresponding changes in actin mRNA. Temporally correlated with the bacteria-induced changes in actin levels was a two- to threefold decrease in duct circumference, a 20% loss in the average number of cells interfacing with the duct lumina, and dramatic changes in duct cell shape. When considered with previous studies of the biomechanical and biochemical characteristics of the duct, these findings suggest that the bacterial symbionts, upon colonizing the host organ, induce modifications that physically and chemically limit the opportunity for subsequent colonizers to pass through the ducts. Continued study of the squid-vibrio system will allow further comparisons of the mechanisms by which pathogenic and cooperative bacteria influence cytoskeleton dynamics in host cells.
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Affiliation(s)
- Jennifer R Kimbell
- Pacific Biomedical Research Center, Kewalo Marine Laboratory, University of Hawaii, Honolulu, Hawaii 96813, USA
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Abstract
Exogenously and endogenously originated signals are propagated within the cell by functional and physical networks of proteins, leading to numerous biological outcomes. Many protein-protein interactions take place between binding domains and short peptide motifs. Frequently, these interactions are inducible by upstream signaling events, in which case one of the two binding surfaces may be created by a posttranslational modification. Here, we discuss two protein networks. One, the EH-network, is based on the Eps15 homology (EH) domain, which binds to peptides containing the sequence Asp-Pro-Phe (NPF). The other, which we define as the monoubiquitin (mUb) network, relies on monoubiquitination, which is emerging as an important posttranslational modification that regulates protein function. Both networks were initially implicated in the control of plasma membrane receptor endocytosis and in the regulation of intracellular trafficking routes. The ramifications of these two networks, however, appear to extend into many other aspects of cell physiology as well, such as transcriptional regulation, actin cytoskeleton remodeling, and DNA repair. The focus of this review is to integrate available knowledge of the EH- and mUb networks with predictions of genetic and physical interactions stemming from functional genomics approaches.
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Affiliation(s)
- Simona Polo
- Istituto FIRC di Oncologia Molecolare, Via Adamello 16, 20139 Milan, Italy
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Maule A, Leh V, Lederer C. The dialogue between viruses and hosts in compatible interactions. CURRENT OPINION IN PLANT BIOLOGY 2002; 5:279-284. [PMID: 12179959 DOI: 10.1016/s1369-5266(02)00272-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Understanding the biological principles behind virus-induced symptom expression in plants remains a longstanding challenge. By dissecting the compatible host-virus relationship temporally and genetically, we have begun to map out the relationships of its component parts. The picture that emerges is one in which host gene expression and physiology are under tight temporal control during infection.
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Affiliation(s)
- Andrew Maule
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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