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Anistoroaei R, Markakis MN, Vissenberg K, Christensen K. Exclusion of candidate genes for coat colour phenotypes of the American mink (Neovison vison). Anim Genet 2012; 43:813-6. [PMID: 22497269 DOI: 10.1111/j.1365-2052.2012.02339.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2011] [Indexed: 11/29/2022]
Abstract
In a previous project, we screened the American mink Bacterial Artificial Chromosome library, CHORI-231, for genes potentially involved in various coat colour phenotypes in the American mink. Subsequently, we 454 sequenced the inserts containing these genes and developed microsatellite markers for each of these genes. Here, we describe a lack of association between three different 'roan-type' phenotypes represented by Cross, Stardust and Cinnamon in American mink and six different genes that we considered to be potentially linked to these phenotypes. Thus, c-KIT (HUGO-approved symbol KIT), ATOH-1 (HUGO-approved symbol ATOH1) and POMC were excluded as potential candidates for these three phenotypes. In addition, MITF and SLC24A5 were excluded for Cross and Cinnamon, and KITL (HUGO-approved symbol KITLG) for Cross and Stardust. Although most of these genes have been implicated as the cause of similar phenotypes in other mammals, including horses, pigs, cows, dogs, cats, mice and humans, they do not appear to be responsible for comparable phenotypes found in American mink.
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Affiliation(s)
- R Anistoroaei
- Division of Animal Genetics and Bioinformatics, Department of Basic Animal and Veterinary Sciences, The Faculty of Life Sciences, University of Copenhagen, Groennegaardsvej 3, Frederiksberg C, Denmark.
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52
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Sheremet IA, Emets AI, Azmi A, Vissenberg K, Verbelen JP, Blium IB. [Effect of inhibitors serine/threonine protein kinases and protein phosphatases on mitosis progression of synchronized tobacco by-2 cells]. Tsitol Genet 2012; 46:3-11. [PMID: 22679818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In order to investigate the role of various serine/ threonine protein kinases and protein phosphatases in the regulation of mitosis progression in plant cells the influence of cyclin-dependent (olomoucine) and Ca2+ -calmodulin-dependent (W7) protein kinases inhibitors, as well as protein kinase C inhibitors (H7 and staurosporine) and protein phosphatases inhibitor (okadaic acid) on mitosis progression in synchronized tobacco BY-2 cells has been studied. It was found that BY-2 culture treatment with inhibitors of cyclin dependent protein kinases and protein kinase C causes prophase delay, reduces the mitotic index and displaces of mitotic peak as compare with control cells. Inhibition of Ca2+ -calmodulin dependent protein kinases enhances the cell entry into prophase and delays their exit from mitosis. Meanwhile inhibition of serine/threonine protein phosphatases insignificantly enhances of synchronized BY-2 cells entering into all phases of mitosis.
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53
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Vandenbussche F, Suslov D, De Grauwe L, Leroux O, Vissenberg K, Van Der Straeten D. The role of brassinosteroids in shoot gravitropism. Plant Physiol 2011; 156:1331-6. [PMID: 21571670 PMCID: PMC3135960 DOI: 10.1104/pp.111.177873] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 05/11/2011] [Indexed: 05/18/2023]
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54
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Staal M, De Cnodder T, Simon D, Vandenbussche F, Van der Straeten D, Verbelen JP, Elzenga T, Vissenberg K. Apoplastic alkalinization is instrumental for the inhibition of cell elongation in the Arabidopsis root by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Plant Physiol 2011. [PMID: 21282405 DOI: 10.1104/pp110.168476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana; Columbia-0) roots, the so-called zone of cell elongation comprises two clearly different domains: the transition zone, a postmeristematic region (approximately 200-450 μm proximal of the root tip) with a low rate of elongation, and a fast elongation zone, the adjacent proximal region (450 μm away from the root tip up to the first root hair) with a high rate of elongation. In this study, the surface pH was measured in both zones using the microelectrode ion flux estimation technique. The surface pH is highest in the apical part of the transition zone and is lowest at the basal part of the fast elongation zone. Fast cell elongation is inhibited within minutes by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid; concomitantly, apoplastic alkalinization occurs in the affected root zone. Fusicoccin, an activator of the plasma membrane H(+)-ATPase, can partially rescue this inhibition of cell elongation, whereas the inhibitor N,N'-dicyclohexylcarbodiimide does not further reduce the maximal cell length. Microelectrode ion flux estimation experiments with auxin mutants lead to the final conclusion that control of the activity state of plasma membrane H(+)-ATPases is one of the mechanisms by which ethylene, via auxin, affects the final cell length in the root.
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Affiliation(s)
- Marten Staal
- Center for Ecological and Evolutionary Studies, Laboratory of Plant Physiology, University of Groningen, 9750 AA Haren, The Netherlands
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55
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Staal M, De Cnodder T, Simon D, Vandenbussche F, Van Der Straeten D, Verbelen JP, Elzenga T, Vissenberg K. Apoplastic alkalinization is instrumental for the inhibition of cell elongation in the Arabidopsis root by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Plant Physiol 2011; 155:2049-55. [PMID: 21282405 PMCID: PMC3091085 DOI: 10.1104/pp.110.168476] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 01/25/2011] [Indexed: 05/18/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana; Columbia-0) roots, the so-called zone of cell elongation comprises two clearly different domains: the transition zone, a postmeristematic region (approximately 200-450 μm proximal of the root tip) with a low rate of elongation, and a fast elongation zone, the adjacent proximal region (450 μm away from the root tip up to the first root hair) with a high rate of elongation. In this study, the surface pH was measured in both zones using the microelectrode ion flux estimation technique. The surface pH is highest in the apical part of the transition zone and is lowest at the basal part of the fast elongation zone. Fast cell elongation is inhibited within minutes by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid; concomitantly, apoplastic alkalinization occurs in the affected root zone. Fusicoccin, an activator of the plasma membrane H(+)-ATPase, can partially rescue this inhibition of cell elongation, whereas the inhibitor N,N'-dicyclohexylcarbodiimide does not further reduce the maximal cell length. Microelectrode ion flux estimation experiments with auxin mutants lead to the final conclusion that control of the activity state of plasma membrane H(+)-ATPases is one of the mechanisms by which ethylene, via auxin, affects the final cell length in the root.
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Affiliation(s)
| | | | | | | | | | | | | | - Kris Vissenberg
- Center for Ecological and Evolutionary Studies, Laboratory of Plant Physiology, University of Groningen, 9750 AA Haren, The Netherlands (M.S., T.E.); Department of Biology, Laboratory of Plant Growth and Development, University of Antwerp, B–2020 Antwerpen, Belgium (T.D.C., D.S., J.-P.V., K.V.); Department of Physiology, Laboratory of Functional Plant Biology, Ghent University, B–9000 Ghent, Belgium (F.V., D.V.D.S.)
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56
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Jacques E, Hectors K, Guisez Y, Prinsen E, Jansen MAK, Verbelen JP, Vissenberg K. UV radiation reduces epidermal cell expansion in Arabidopsis thaliana leaves without altering cellular microtubule organization. Plant Signal Behav 2011; 6:83-5. [PMID: 21301216 PMCID: PMC3122012 DOI: 10.4161/psb.6.1.14127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 05/04/2023]
Abstract
Upon chronic UV treatment pavement cell expansion in Arabidopsis leaves is reduced, implying alterations in symplastic and apoplastic properties of the epidermal cells. In this study, the effect of UV radiation on microtubule patterning is analysed, as microtubules are thought to serve as guiding rails for the cellulose synthase complexes depositing cellulose microfibrils. Together with hemicelluloses, these microfibrils are regarded as the load-bearing components of the cell wall. Leaves of transgenic plants with fluorescently tagged microtubules (GFP-TUA6) were as responsive to UV as wild type plants. Despite the UV-induced reduction in cell elongation, confocal microscopy revealed that cellular microtubule arrangements were seemingly not affected by the UV treatments. This indicates an unaltered deposition of cellulose microfibrils in the presence of UV radiation. Therefore, we surmise that the reduction in cell expansion in UV-treated leaves is most probably due to changes in cell wall loosening and/or turgor pressure.
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Affiliation(s)
- Eveline Jacques
- Department of Biology, Plant Growth and Development; University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
| | - Kathleen Hectors
- Department of Biology, Plant Growth and Development; University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
- Department of Biology, Molecular Plant Physiology and Biotechnology, University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
| | - Yves Guisez
- Department of Biology, Molecular Plant Physiology and Biotechnology, University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
| | - Els Prinsen
- Department of Biology, Plant Growth and Development; University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
| | - Marcel AK Jansen
- Department of Zoology, Ecology and Plant Science, University College Cork, Distillery Field; Cork, Ireland
| | - Jean-Pierre Verbelen
- Department of Biology, Plant Growth and Development; University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
| | - Kris Vissenberg
- Department of Biology, Plant Growth and Development; University of Antwerp, Groenenborgerlaan; Antwerpen, Belgium
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Maris A, Kaewthai N, Eklöf JM, Miller JG, Brumer H, Fry SC, Verbelen JP, Vissenberg K. Differences in enzymic properties of five recombinant xyloglucan endotransglucosylase/hydrolase (XTH) proteins of Arabidopsis thaliana. J Exp Bot 2011; 62:261-71. [PMID: 20732879 DOI: 10.1093/jxb/erq263] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Xyloglucan endotransglucosylase/hydrolases (XTHs) are cell wall enzymes that are able to graft xyloglucan chains to oligosaccharides or to other available xyloglucan chains and/or to hydrolyse xyloglucan chains. As they are involved in the modification of the load-bearing cell-wall components, they are believed to be very important in the regulation of growth and development. Given the large number (33) of XTH genes in Arabidopsis and the overlapping expression patterns, specific enzymic properties may be expected. Five predominantly root-expressed Arabidopsis thaliana XTHs belonging to subgroup I/II were analysed here. These represent two sets of closely related genes: AtXTH12 and 13 on the one hand (trichoblast-enriched) and AtXTH17, 18, and 19 on the other (expressed in nearly all cell types in the root). They were all recombinantly produced in the yeast Pichia pastoris and partially purified by ammonium sulphate precipitation before they were subsequently all subjected to a series of identical in vitro tests. The kinetic properties of purified AtXTH13 were investigated in greater detail to rule out interference with the assays by contaminating yeast proteins. All five proteins were found to exhibit only the endotransglucosylase (XET; EC 2.4.1.207) activity towards xyloglucan and non-detectable endohydrolytic (XEH; EC 3.2.1.151) activity. Their endotransglucosylase activity was preferentially directed towards xyloglucan and, in some cases, water-soluble cellulose acetate, rather than to mixed-linkage β-glucan. Isoforms differed in optimum pH (5.0-7.5), in temperature dependence and in acceptor substrate preferences.
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Affiliation(s)
- An Maris
- Department of Biology, Laboratory of Plant Growth and Development, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
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58
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Pelletier S, Van Orden J, Wolf S, Vissenberg K, Delacourt J, Ndong YA, Pelloux J, Bischoff V, Urbain A, Mouille G, Lemonnier G, Renou JP, Höfte H. A role for pectin de-methylesterification in a developmentally regulated growth acceleration in dark-grown Arabidopsis hypocotyls. New Phytol 2010; 188:726-39. [PMID: 20819179 DOI: 10.1111/j.1469-8137.2010.03409.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
• We focused on a developmentally regulated growth acceleration in the dark-grown Arabidopsis hypocotyl to study the role of changes in cell wall metabolism in the control of cell elongation. • To this end, precise transcriptome analysis on dissected dark-grown hypocotyls, Fourier transform infrared (FT-IR) microspectroscopy and kinematic analysis were used. • Using a cellulose synthesis inhibitor, we showed that the growth acceleration marks a developmental transition during which growth becomes uncoupled from cellulose synthesis. We next investigated the cellular changes that take place during this transition. FT-IR microspectroscopy revealed significant changes in cell wall composition during, but not after, the growth acceleration. Transcriptome analysis suggested a role for cell wall remodeling, in particular pectin modification, in this growth acceleration. This was confirmed by the overexpression of a pectin methylesterase inhibitor, which caused a delay in the growth acceleration. • This study shows that the acceleration of cell elongation marks a developmental transition in dark-grown hypocotyl cells and supports a role for pectin de-methylesterification in the timing of this event.
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Affiliation(s)
- Sandra Pelletier
- Institut Jean-Pierre Bourgin, UMR1318 INRA-AgroParisTech, INRA Centre de Versailles-Grignon, Versailles, France
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59
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Hectors K, Jacques E, Prinsen E, Guisez Y, Verbelen JP, Jansen MAK, Vissenberg K. UV radiation reduces epidermal cell expansion in leaves of Arabidopsis thaliana. J Exp Bot 2010; 61:4339-49. [PMID: 20702567 DOI: 10.1093/jxb/erq235] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plants have evolved a broad spectrum of mechanisms to ensure survival under changing and suboptimal environmental conditions. Alterations of plant architecture are commonly observed following exposure to abiotic stressors. The mechanisms behind these environmentally controlled morphogenic traits are, however, poorly understood. In this report, the effects of a low dose of chronic ultraviolet (UV) radiation on leaf development are detailed. Arabidopsis rosette leaves exposed for 7, 12, or 19 d to supplemental UV radiation expanded less compared with non-UV controls. The UV-mediated decrease in leaf expansion is associated with a decrease in adaxial pavement cell expansion. Elevated UV does not affect the number and shape of adaxial pavement cells, nor the stomatal index. Cell expansion in young Arabidopsis leaves is asynchronous along a top-to-base gradient whereas, later in development, cells localized at both the proximal and distal half expand synchronously. The prominent, UV-mediated inhibition of cell expansion in young leaves comprises effects on the early asynchronous growing stage. Subsequent cell expansion during the synchronous phase cannot nullify the UV impact established during the asynchronous phase. The developmental stage of the leaf at the onset of UV treatment determines whether UV alters cell expansion during the synchronous and/or asynchronous stage. The effect of UV radiation on adaxial epidermal cell size appears permanent, whereas leaf shape is transiently altered with a reduced length/width ratio in young leaves. The data show that UV-altered morphogenesis is a temporal- and spatial-dependent process, implying that common single time point or single leaf zone analyses are inadequate.
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Affiliation(s)
- Kathleen Hectors
- Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
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60
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Sheremet YA, Yemets AI, Vissenberg K, Verbelen JP, Blume YB. Effects of inhibitors of serine/threonine protein kinases on Arabidopsis thaliana root morphology and microtubule organization in its cells. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s1990519x10040139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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61
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Suslov D, Verbelen JP, Vissenberg K. Is acid-induced extension in seed plants only protein-mediated? Plant Signal Behav 2010; 5:757-759. [PMID: 20421739 PMCID: PMC3001582 DOI: 10.4161/psb.5.6.11771] [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] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 03/09/2010] [Indexed: 05/29/2023]
Abstract
Cell wall extensibility controls the rate of plant cell growth. It is determined by intrinsic mechanical properties of wall polymers and by wall proteins modifying these polymers and their interactions. Heat-inactivation of endogenous cell wall proteins inhibited acid-induced extension of onion epidermis peels transverse to the net cellulose alignment in the cell wall but not parallel to it. In the former case the acid-induced extension could be controlled by expansins and in the latter case by pectins restricting shear between microfibrils. Heat-inactivated cell walls stretched transversely to the net cellulose orientation extended faster at pH 5.7 and slower at pH 4.5 compared to native walls. Expansins seem to be inactive at pH 5.7, so that faster extension may result from heat-induced viscous flow of pectins and conformational changes in the cuticle of the epidermis. This stimulation of wall extension is not seen at pH 4.5 as it is outweighed by the inhibitory effect of expansin heat-inactivation. Thus, cell wall extension in higher plants might be controlled by a complex interplay between protein-dependent and protein-independent mechanisms, the result of which depends on pH and preferential orientation of main wall polymers.
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Affiliation(s)
- Dmitry Suslov
- Biology Dept, Plant Growth and Development, University of Antwerp, Antwerpen, Belgium
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62
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Van Loock B, Markakis MN, Verbelen JP, Vissenberg K. High-throughput transient transformation of Arabidopsis roots enables systematic colocalization analysis of GFP-tagged proteins. Plant Signal Behav 2010; 5:261-3. [PMID: 20023426 PMCID: PMC2881272 DOI: 10.4161/psb.5.3.10575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Determination of the subcellular localization of an unknown protein is a major step towards the elucidation of its function. Lately, the expression of proteins fused to fluorescent markers has been very popular and many approaches have been proposed to express these proteins. Stable transformation using Agrobacterium tumefaciens generates stable lines for downstream experiments, but is time-consuming. If only colocalization is required, transient techniques save time and effort. Several methods for transient assays have been described including protoplast transfection, biolistic bombardment, Agrobacterium tumefaciens cocultivation and infiltration. In general colocalizations are preferentially performed in intact tissues of the same species, resembling the native situation. High transformation rates were described for cotyledons of Arabidopsis, but never for roots. Here we report that it is possible to transform Arabidopsis root epidermal cells with an efficiency that is sufficient for colocalization purposes.
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Affiliation(s)
- Bram Van Loock
- Biology Department, University of Antwerp, Antwerpen, Belgium
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63
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Sheremet IA, Emets AI, Vissenberg K, Verbelen JP, Blium IB. [The effect of inhibitors of serinethreonine protein kinases on Arabidopsis thaliana root morphology and microtubules organization in its cells]. Tsitologiia 2010; 52:389-398. [PMID: 20586274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The effect of different types of serine/thereonine protein kinases inhibitors (cyclin-dependent, Ca2+-calmodulin-dependent and protein kinase C) on microtubules organization in cells of Arabidopsis thaliana main primary root zones were investigated in vivo. The microtubules in epidermal and cortex cells in the transition and elongation zones as well as microtubules in trichoblasts and atrichoblasts in the differentiation zone showed the greatest sensitivity to protein kinases inhibitors studied. It was established that microtubules in these cell types modified their initial transverse/oblique orientation to a chaotic or longitudinal relative to the major axis of primary root as a result of serinethereonine protein kinases inhibition. The microtubules in cells in root meristematic zone as well as in root hairs were less sensitive to influence of protein kinases inhibitors tested. Alterations of microtubules orientation in the cells in primary root zones under the influence of serinethereonine protein kinases inhibitors led to further disturbances in growth and differentiation processes. It was assumed that phosphorylation of microtubules proteins, especially tubulin, might be involved in the regulation of these processes.
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Jacques E, D'Haese D, Adriaensen D, Verbelen JP, Vissenberg K, Buytaert J. ‘Microfilament Analyzer’ as a tool to study the cytoskeletal (re)organisation during pavement cell development in the Arabidopsis thaliana leaf. Comp Biochem Physiol A Mol Integr Physiol 2009. [DOI: 10.1016/j.cbpa.2009.04.376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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65
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Jacques E, Hectors K, Guisez Y, Verbelen JP, Vissenberg K, Prinsen E, Jansen M. Leaf and cell development during UV-B acclimation in Arabidopsis thaliana. Comp Biochem Physiol A Mol Integr Physiol 2009. [DOI: 10.1016/j.cbpa.2009.04.639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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66
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Abstract
To elucidate the role of cellulose microfibrils in the control of growth anisotropy, a link between their net orientation, in vitro cell wall extensibility, and anisotropic cell expansion was studied during development of the adaxial epidermis of onion (Allium cepa) bulb scales using polarization confocal microscopy, creep tests, and light microscopy. During growth the net cellulose alignment across the whole thickness of the outer epidermal wall changed from transverse through random to longitudinal and back to transverse relative to the bulb axis. Cell wall extension in vitro was always higher transverse than parallel to the net cellulose alignment. The direction of growth anisotropy was perpendicular to the net microfibril orientation and changed during development from longitudinal to transverse to the bulb axis. The correlation between the degree of growth anisotropy and the net cellulose alignment was poor. Thus the net cellulose microfibril orientation across the whole thickness of the outer periclinal epidermis wall defines the direction but not the degree of growth anisotropy. Strips isolated from the epidermis in the directions perpendicular and transverse to a net cellulose orientation can be used as an extensiometric model to prove a protein involvement in the control of growth anisotropy.
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Affiliation(s)
- Dmitry Suslov
- Laboratory of Plant Growth and Development, Biology Department, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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67
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Maris A, Suslov D, Fry SC, Verbelen JP, Vissenberg K. Enzymic characterization of two recombinant xyloglucan endotransglucosylase/hydrolase (XTH) proteins of Arabidopsis and their effect on root growth and cell wall extension. J Exp Bot 2009; 60:3959-72. [PMID: 19635745 DOI: 10.1093/jxb/erp229] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Xyloglucan endotransglucosylase/hydrolases (XTHs) are enzymes involved in the modification of load-bearing cell wall components. They cleave xyloglucan chains and, often, re-form bonds to the non-reducing ends of available xyloglucan molecules in plant primary cell walls. The enzymic properties and effects on root growth of two Arabidopsis thaliana XTHs belonging to subgroup I/II, that are predominantly expressed in root hairs and in non-elongating zones of the root, were analysed here. AtXTH14 and AtXTH26 were recombinantly produced in Pichia and subsequently purified. Both proteins were found to exhibit xyloglucan endotransglucosylase (XET; EC 2.4.1.207) but not xyloglucan endohydrolase (XEH; EC 3.2.1.151) activity. Their endotransglucosylase activity was at least 70x greater on xyloglucan rather than on mixed-linkage beta-glucan. Differences were found in pH- and temperature-dependence as well as in acceptor-substrate preferences. Furthermore, the specific activity of XET was approximately equal for the two enzymes. Removal of N-linked sugar residues by Endo H treatment reduced XET activity to 60%. Constant-load extensiometry experiments revealed that the enzymes reduce the extension in a model system of heat-inactivated isolated cell walls. When given to growing roots, either of these XTH proteins reduced cell elongation in a concentration-dependent manner and caused abnormal root hair morphology. This is the first time that recombinant and purified XTHs added to growing roots have exhibited a clear effect on cell elongation. It is proposed that these specific XTH isoenzymes play a role in strengthening the side-walls of root-hairs and cell walls in the root differentiation zone after the completion of cell expansion.
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Affiliation(s)
- An Maris
- Department of Biology, University of Antwerp, Antwerpen, Belgium
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68
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Van Deun K, Pasmans F, Ducatelle R, Flahou B, Vissenberg K, Martel A, Van den Broeck W, Van Immerseel F, Haesebrouck F. Colonization strategy of Campylobacter jejuni results in persistent infection of the chicken gut. Vet Microbiol 2008; 130:285-97. [DOI: 10.1016/j.vetmic.2007.11.027] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 11/15/2007] [Accepted: 11/21/2007] [Indexed: 10/22/2022]
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69
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Jacques E, D'Haese D, Adriaensen D, Verbelen J, Vissenberg K. Microtubule and F-actin behaviour during Arabidopsis leaf development. Comp Biochem Physiol A Mol Integr Physiol 2008. [DOI: 10.1016/j.cbpa.2008.04.370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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70
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Vissenberg K. Arabidopsis root cell elongation and its control. Comp Biochem Physiol A Mol Integr Physiol 2008. [DOI: 10.1016/j.cbpa.2008.04.358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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71
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Van Loock B, Pilat Z, Verbelen J, Vissenberg K. Enhancer trap plants to study Arabidopsis root cell elongationand its control. Comp Biochem Physiol A Mol Integr Physiol 2008. [DOI: 10.1016/j.cbpa.2008.04.369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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72
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Van Sandt VST, Suslov D, Verbelen JP, Vissenberg K. Xyloglucan endotransglucosylase activity loosens a plant cell wall. Ann Bot 2007; 100:1467-73. [PMID: 17916584 PMCID: PMC2759230 DOI: 10.1093/aob/mcm248] [Citation(s) in RCA: 159] [Impact Index Per Article: 9.4] [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: 06/06/2007] [Accepted: 08/14/2007] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Plant cells undergo cell expansion when a temporary imbalance between the hydraulic pressure of the vacuole and the extensibility of the cell wall makes the cell volume increase dramatically. The primary cell walls of most seed plants consist of cellulose microfibrils tethered mainly by xyloglucans and embedded in a highly hydrated pectin matrix. During cell expansion the wall stress is decreased by the highly controlled rearrangement of the load-bearing tethers in the wall so that the microfibrils can move relative to each other. Here the effect was studied of a purified recombinant xyloglucan endotransglucosylase/hydrolase (XTH) on the extension of isolated cell walls. METHODS The epidermis of growing onion (Allium cepa) bulb scales is a one-cell-thick model tissue that is structurally and mechanically highly anisotropic. In constant load experiments, the effect of purified recombinant XTH proteins of Selaginella kraussiana on the extension of isolated onion epidermis was recorded. KEY RESULTS Fluorescent xyloglucan endotransglucosylase (XET) assays demonstrate that exogeneous XTH can act on isolated onion epidermis cell walls. Furthermore, cell wall extension was significantly increased upon addition of XTH to the isolated epidermis, but only transverse to the net orientation of cellulose microfibrils. CONCLUSIONS The results provide evidence that XTHs can act as cell wall-loosening enzymes.
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73
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Jia H, Liao M, Verbelen JP, Vissenberg K. Direct creation of marker-free tobacco plants from agroinfiltrated leaf discs. Plant Cell Rep 2007; 26:1961-5. [PMID: 17637995 DOI: 10.1007/s00299-007-0403-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 06/06/2007] [Accepted: 06/23/2007] [Indexed: 05/16/2023]
Abstract
Agroinfiltration is employed as a fast way to directly create marker-free transgenic tobacco plants. As an example for the efficiency of the method, Agrobacterium cells harboring a marker-free vector coding for beta-glucuronidase (GUS) were infiltrated into the leaf discs of Nicotiana tabacum, which were then used as explants for marker-free plant regeneration by tissue culture. Through GUS staining, a large number of small calli were shown to be stably transformed on the treated leaf discs at 17 days after agroinfiltration. Most importantly, after continuous culture of the leaf discs until shoot regeneration, about 15% of the regenerants were proven to be transformants by polymerase chain reaction (PCR) analysis.
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Affiliation(s)
- Hongge Jia
- Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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74
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Jia H, Van Loock B, Liao M, Verbelen JP, Vissenberg K. Combination of the ALCR/alcA ethanol switch and GAL4/VP16-UAS enhancer trap system enables spatial and temporal control of transgene expression in Arabidopsis. Plant Biotechnol J 2007; 5:477-82. [PMID: 17442066 DOI: 10.1111/j.1467-7652.2007.00255.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The experimental control of gene expression in specific tissues or cells at defined time points is a useful tool for the analysis of gene function. GAL4/VP16-UAS enhancer trap lines can be used to selectively express genes in specific tissues or cells, and an ethanol-inducible system can help to control the time of expression. In this study, the combination of the two methods allowed the successful regulation of gene expression in both time and space. For this purpose, a binary vector, 962-UAS::GUS, was constructed in which the ALCR activator and beta-glucuronidase (GUS) reporter gene were placed under the control of upstream activator sequence (UAS) elements and the alcA response element, respectively. Three different GAL4/VP16-UAS enhancer trap lines of Arabidopsis were transformed, resulting in transgenic plants in which GUS activity was detected only on ethanol induction and exclusively in the predicted tissues of the enhancer trap lines. As a library of different enhancer trap lines with distinct green fluorescent protein (GFP) patterns exist, transformation with a similar vector, in which GUS is replaced by another gene, would enable the control of the time and place of transgene expression. We have constructed two vectors for easy cloning of the gene of interest, one with a polylinker site and one that is compatible with the GATEWAY vector conversion system. The method can be extended to other species when enhancer trap lines become available.
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Affiliation(s)
- Hongge Jia
- University of Antwerp, Department of Biology, Plant Physiology and Morphology, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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75
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Vissenberg K, Maris A, Verbelen J. Production, purification and characterization of 10 Arabidopsis xyloglucan endotransglycosylases/hydrolases (XTHs). Comp Biochem Physiol A Mol Integr Physiol 2007. [DOI: 10.1016/j.cbpa.2007.01.627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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76
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Vissenberg K, Van Orden J, Pelletier S, Desprez T, Vernhettes S, Höfte H, Verbelen J. Cytoskeleton and cell wall changes during the biphasic growth of dark-grown Arabidopsis thaliana Col-0 hypocotyls. Comp Biochem Physiol A Mol Integr Physiol 2007. [DOI: 10.1016/j.cbpa.2007.01.628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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77
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Van Sandt VST, Guisez Y, Verbelen JP, Vissenberg K. Xyloglucan endotransglycosylase/hydrolase (XTH) is encoded by a multi-gene family in the primitive vascular land plant Selaginella kraussiana. Plant Biol (Stuttg) 2007; 9:142-6. [PMID: 17099842 DOI: 10.1055/s-2006-924661] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Xyloglucan endotransglycosylase/hydrolases (XTHs) are enzymes that cleave and rejoin xyloglucan chains. To trace the evolutionary origin of XTHs, we used Selaginella kraussiana, a representative of the most primitive land plants (Lycopodiophyta). A Southern blot with a digoxigenin-labeled probe, designed on the conserved catalytic site of XTHs, indicated nine genes. The presence of at least seven functional XTHs was detected by isoelectric focusing (IEF) followed by overlaying the gel with a XET-test paper. Together, these results indicate that XTHs are encoded by a multi-gene family that originated during or even before the colonization of land by plants.
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Affiliation(s)
- V S T Van Sandt
- Biology Department, Plant Physiology and Morphology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
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78
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Van Sandt VST, Stieperaere H, Guisez Y, Verbelen JP, Vissenberg K. XET activity is found near sites of growth and cell elongation in bryophytes and some green algae: new insights into the evolution of primary cell wall elongation. Ann Bot 2007; 99:39-51. [PMID: 17098750 PMCID: PMC2802975 DOI: 10.1093/aob/mcl232] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 08/24/2006] [Accepted: 09/11/2006] [Indexed: 05/12/2023]
Abstract
BACKGROUND AND AIMS In angiosperms xyloglucan endotransglucosylase (XET)/hydrolase (XTH) is involved in reorganization of the cell wall during growth and development. The location of oligo-xyloglucan transglucosylation activity and the presence of XTH expressed sequence tags (ESTs) in the earliest diverging extant plants, i.e. in bryophytes and algae, down to the Phaeophyta was examined. The results provide information on the presence of an XET growth mechanism in bryophytes and algae and contribute to the understanding of the evolution of cell wall elongation in general. METHODS Representatives of the different plant lineages were pressed onto an XET test paper and assayed. XET or XET-related activity was visualized as the incorporation of fluorescent signal. The Physcomitrella genome database was screened for the presence of XTHs. In addition, using the 3' RACE technique searches were made for the presence of possible XTH ESTs in the Charophyta. KEY RESULTS XET activity was found in the three major divisions of bryophytes at sites corresponding to growing regions. In the Physcomitrella genome two putative XTH-encoding cDNA sequences were identified that contain all domains crucial for XET activity. Furthermore, XET activity was located at the sites of growth in Chara (Charophyta) and Ulva (Chlorophyta) and a putative XTH ancestral enzyme in Chara was identified. No XET activity was identified in the Rhodophyta or Phaeophyta. CONCLUSIONS XET activity was shown to be present in all major groups of green plants. These data suggest that an XET-related growth mechanism originated before the evolutionary divergence of the Chlorobionta and open new insights in the evolution of the mechanisms of primary cell wall expansion.
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Affiliation(s)
| | - Herman Stieperaere
- National Botanic Garden of Belgium, Domein van Bouchout, B-1860 Meise, Belgium
| | - Yves Guisez
- Plant Physiology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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79
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Verbelen JP, De Cnodder T, Le J, Vissenberg K, Baluška F. The Root Apex of Arabidopsis thaliana Consists of Four Distinct Zones of Growth Activities: Meristematic Zone, Transition Zone, Fast Elongation Zone and Growth Terminating Zone. Plant Signal Behav 2006; 1:296-304. [PMID: 19517000 PMCID: PMC2634244 DOI: 10.4161/psb.1.6.3511] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Accepted: 10/06/2006] [Indexed: 05/17/2023]
Abstract
In the growing apex of Arabidopsis thaliana primary roots, cells proceed through four distinct phases of cellular activities. These zones and their boundaries can be well defined based on their characteristic cellular activities. The meristematic zone comprises, and is limited to, all cells that undergo mitotic divisions. Detailed in vivo analysis of transgenic lines reveals that, in the Columbia-0 ecotype, the meristem stretches up to 200 microm away from the junction between root and root cap (RCJ). In the transition zone, 200 to about 520 microm away from the RCJ, cells undergo physiological changes as they prepare for their fast elongation. Upon entering the transition zone, they progressively develop a central vacuole, polarize the cytoskeleton and remodel their cell walls. Cells grow slowly during this transition: it takes ten hours to triplicate cell length from 8.5 to about 35 microm in the trichoblast cell files. In the fast elongation zone, which covers the zone from 520 to about 850 microm from the RCJ, cell length quadruplicates to about 140 microm in only two hours. This is accompanied by drastic and specific cell wall alterations. Finally, root hairs fully develop in the growth terminating zone, where root cells undergo a minor elongation to reach their mature lengths.
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Affiliation(s)
| | - Tinne De Cnodder
- University of Antwerp; Biology Department; Groenenborgerlaan, Antwerp, Belgium
| | - Jie Le
- Purdue University; Agronomy Department; West-Lafayette, Indiana USA
| | - Kris Vissenberg
- University of Antwerp; Biology Department; Groenenborgerlaan, Antwerp, Belgium
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80
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De Cnodder T, Verbelen JP, Vissenberg K. The Control of Cell Size and Rate of Elongation in the Arabidopsis Root. The Expanding Cell 2006. [DOI: 10.1007/7089_2006_078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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81
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Van Sandt VST, Guisez Y, Verbelen JP, Vissenberg K. Analysis of a xyloglucan endotransglycosylase/hydrolase (XTH) from the lycopodiophyte Selaginella kraussiana suggests that XTH sequence characteristics and function are highly conserved during the evolution of vascular plants. J Exp Bot 2006; 57:2909-22. [PMID: 16873447 DOI: 10.1093/jxb/erl064] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A tissue print followed by a xyloglucan endotransglycosylase assay revealed that XET activity is present at sites of cell elongation in both roots and shoots of the lycopodiophyte Selaginella kraussiana. This paper provides the first report and analysis of a xyloglucan endotransglycosylase/hydrolase (XTH) cDNA sequence, isolated from a club moss. In silico analysis of the deduced amino acid sequence revealed a strong conservation of the XET-domain described in higher plants. The catalytic site (DEIDLEFLG) varies in only one amino acid compared with the consensus sequence and was shown to be functional after recombinant expression of Sk-XTH1 in Pichia pastoris. Sk-XTH1 displays xyloglucan endotransglycosylase activity over a broad pH (4.5-7.5) and temperature range (4-30 degrees C), but it shows no hydrolase activity. The catalytic site is followed by a consensus sequence for N-linked glycosylation. Four terminal cysteines were shown to stabilize a putative XET-C terminal extension region, which includes conserved amino acids, involved in the recognition and binding of the substrates. The N-linked sugar interactions as well as the disulphide bridges were shown to be necessary to perform XET activity. The presence of a highly conserved XTH sequence and function in a microphyllophyte suggests that XTHs were present before the divergence of lycopodiophytes and euphyllophytes. It also points to a possible key role for XTHs in the production of a cell wall that allowed the further evolution of land plants.
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Affiliation(s)
- Vicky S T Van Sandt
- University of Antwerpen, Biology Department, Plant Physiology and Morphology, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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82
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De Cnodder T, Vissenberg K, Van Der Straeten D, Verbelen JP. Regulation of cell length in the Arabidopsis thaliana root by the ethylene precursor 1-aminocyclopropane- 1-carboxylic acid: a matter of apoplastic reactions. New Phytol 2005; 168:541-50. [PMID: 16313637 DOI: 10.1111/j.1469-8137.2005.01540.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Treatment of the Arabidopsis thaliana root with the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) immediately imposes a reduced maximal cell length beyond which further elongation is blocked. Here, we investigated possible apoplastic reactions involved in the inhibition of cell elongation. Five-day-old Arabidopsis seedlings were transferred to a growth medium supplemented with ACC and the effect on root cell length was recorded after 3 h of treatment. Altered characteristics in the apoplast of the nonelongating cells in the ACC-treated root, such as 'reactive oxygen species' (ROS) production and callose deposition, were detected using specific fluorochromes. The presence of functional hydroxyproline-rich glycoproteins (HRGPs) and the crosslinking of these cell-wall proteins are essential in limiting cell elongation. The ROS that drive the oxidative crosslinking of HRGPs, accumulate in the apoplast of cells in the zone where cell elongation stops. In the same cells, callose is deposited in the cell wall. The final cell length in the Arabidopsis root treated for a short period with ACC is determined in the zone of fast elongation. Both HRGPs crosslinking by ROS and callose deposition in the cell wall of this zone are suggested as causes for the reduced cell elongation.
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Affiliation(s)
- T De Cnodder
- Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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83
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Devos S, Vissenberg K, Verbelen JP, Prinsen E. Infection of Chinese cabbage by Plasmodiophora brassicae leads to a stimulation of plant growth: impacts on cell wall metabolism and hormone balance. New Phytol 2005; 166:241-50. [PMID: 15760367 DOI: 10.1111/j.1469-8137.2004.01304.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The importance of plant hormones in clubroot infection has long been recognized. The morphological changes, such as cell division and cell elongation leading to gall formation are triggered in the early stages of infection. We analysed cell expansion by localizing Xyloglucan endoTransglucosylase/Hydrolase (XTH)-action and screened the endogenous concentrations of several classes of phytohormones by mass spectrometry in the early stages of Plasmodiophora brassicae infection in Chinese cabbage (Brassica rapa spp. pekinensis). Infected plants showed a general transient growth promotion early in infection. Furthermore a clear XTH action was visible in the epidermal layer of infected roots. Complex changes in the endogenous phytohormone profile were observed. Initially infection resulted in an increased total auxin pool. The auxin increase, together with an increased XTH action, results in wall loosening and consequently cell expansion. When the first secondary plasmodia are formed, thirteen days after infection (DAI), can be considered a switch point in phytohormone metabolism. Twenty-one DAI the plasmodia might act as a plant hormone sink resulting in a reduction in the active cytokinin pool and a lower indole-3-acetic acid content in the infected plants.
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Affiliation(s)
- Sylvie Devos
- Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium
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84
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Abstract
Sulphorhodamine-labelled oligosaccharides of xyloglucan are incorporated into the cell wall of Arabidopsis and tobacco roots, and of cultured Nicotiana tabacum cells by the transglucosylase (XET) action of XTHs. In the cell wall of diffusely growing cells, the subcellular pattern of XET action revealed a 'fibrillar' pattern, different from the xyloglucan localization. The fibrillar fluorescence pattern had no net orientation in spherical cultured cells. It changed to transverse to the long axis when the cells started to elongate, a feature mirroring the rearrangements of cortical microtubules and the accompanying cellulose deposition. Interference with the polymerization of microtubules and with cellulose deposition inhibited this strong and 'fibrillar'-organized XET-action, whereas interference with actin-polymerization only decreased the intensity of enzyme action. Epidermal cells of a mutant with reduced cellulose synthesis also had low XET action. Root hairs (tip-growing cells) exhibited high XET-action over all their length, but lacked the specific parallel pattern. In both diffuse- and tip-growing cell types extraction of the incorporated fluorescent xyloglucans by a xyloglucan-specific endoglucanase reduced the fluorescence, but the 'fibrillar' appearance in diffuse growing cells was not eliminated. These results show that XTHs act on the xyloglucans attached to cellulose microfibrils. After incorporation of the fluorescent oligosaccharides, the xyloglucans decorate the cellulose microfibrils and become inaccessible to hydrolytic enzymes.
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Affiliation(s)
- Kris Vissenberg
- University of Antwerp (Drie Eiken Campus), Department of Biology, Plant Physiology and Morphology, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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85
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Vissenberg K, Oyama M, Osato Y, Yokoyama R, Verbelen JP, Nishitani K. Differential Expression of AtXTH17, AtXTH18, AtXTH19 and AtXTH20 Genes in Arabidopsis Roots. Physiological Roles in Specification in Cell Wall Construction. ACTA ACUST UNITED AC 2005; 46:192-200. [PMID: 15659443 DOI: 10.1093/pcp/pci013] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of enzymes that are capable of splitting and reconnecting xyloglucan molecules, and are implicated in the construction and restructuring of the cellulose/xyloglucan framework. Thirty-three members of the XTH gene family are found in the genome of Arabidopsis thaliana, but their roles remain unclear. Here, we describe the tissue-specific and growth stage-dependent expression profiles of promoter::GUS fusion constructs for four Arabidopsis XTH genes, AtXTH17, AtXTH18, AtXTH19 and AtXTH20, which are phylogenetically closely related to one another. AtXTH17 and AtXTH18 were expressed in all cell types in the elongating and differentiating region of the root, while AtXTH19 was expressed in the apical dividing and elongating regions, as well as in the differentiation zone, and was up-regulated by auxin. In contrast, AtXTH20 was expressed specifically in vascular tissues in the basal mature region of the root. This expression analysis also disclosed cis-regulatory sequences that are conserved among the four genes, and are responsible for the root-specific expression profile. These results indicate that the four XTH genes, which were generated by gene duplication, have diversified their expression profile within the root in such a way as to take responsibility for particular physiological roles in the cell wall dynamics.
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Affiliation(s)
- Kris Vissenberg
- University of Antwerp, Department of Biology, Plant Physiology and Morphology, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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86
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Claes P, Van Kolen K, Roymans D, Blero D, Vissenberg K, Erneux C, Verbelen JP, Esmans EL, Slegers H. Reactive blue 2 inhibition of cyclic AMP-dependent differentiation of rat C6 glioma cells by purinergic receptor-independent inactivation of phosphatidylinositol 3-kinase. Biochem Pharmacol 2004; 67:1489-98. [PMID: 15041466 DOI: 10.1016/j.bcp.2003.12.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2003] [Accepted: 12/11/2003] [Indexed: 10/26/2022]
Abstract
Cyclic AMP-dependent differentiation of rat C6 glioma cells into an astrocyte type II is characterized by inhibition of cell growth and induction of glial fibrillary acidic protein (GFAP) synthesis. Activation of the P2Y(12) receptor with 2-methylthioadenosine-5'-diphosphate inhibited beta-adrenergic receptor-induced differentiation. The selective P2Y(12) receptor antagonist N(6)-(2-methylthioethyl)-2-(3,3,3-trifluoropropylthio)-beta,gamma-dichloromethylene ATP abolished the receptor-mediated effect on differentiation. In contrast non-selective antagonists of P2Y receptors did not revert the inhibiting effect of the P2Y(12) receptor on differentiation. Reactive blue 2 (RB2), a potent P2Y(12) receptor antagonist, completely inhibited the synthesis of GFAP, while the P2Y receptor antagonists suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid were less efficient. However, although P2Y receptor antagonists inhibited GFAP synthesis to a different extent they were unable to relieve the growth inhibition that accompanied induction of differentiation, whereas stimulation of the P2Y(12) receptor with 2-methylthioadenosine-5'-diphosphate inhibited GFAP expression and restored cell proliferation. Assay of the activity of phosphatidylinositol 3-kinase (PI 3-K), an enzyme required for GFAP expression [J. Neurochem. 76 (2001) 610], showed that RB2 inhibited this enzyme after cellular uptake, while suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid inhibited PI 3-K to a lesser extent. The intracellular concentration of RB2 increased in time and attained the ic(50) for PI 3-K inhibition (4microM) after 40-min incubation with 50microM RB2. In conclusion, cAMP-induced differentiation in C6 cells is inhibited by activation of the P2Y(12) receptor. In addition, synthesis of GFAP is also inhibited by cellular uptake of non-selective nucleotide receptor antagonists that inhibit PI 3-K, a kinase required for the cAMP-dependent induction of differentiation.
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Affiliation(s)
- Patrik Claes
- Laboratory of Cellular Biochemistry, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.
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87
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Affiliation(s)
- Jean-Pierre Verbelen
- Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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88
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Vissenberg K, Van Sandt V, Fry SC, Verbelen JP. Xyloglucan endotransglucosylase action is high in the root elongation zone and in the trichoblasts of all vascular plants from Selaginella to Zea mays. J Exp Bot 2003; 54:335-344. [PMID: 12493861 DOI: 10.1093/jxb/erg024] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The endotransglucosylase action of the enzyme xyloglucan endotransglucosylase/hydrolase (XTH) was localized in the roots of diverse vascular plants: club-mosses (lycopodiophytes), ferns, gymnosperms, monocots, and dicots. High action was always found in the epidermis cell wall of the elongation zone and in trichoblasts in the differentiation zone. Clearly XTH and its action in root development evolved before the evolutionary divergence of ferns and seed plants and also of the lycopodiophytes and euphyllophytes.
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Affiliation(s)
- K Vissenberg
- Laboratory of Plant Physiology and Morphology, Department of Biology, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Wilrijk, Belgium
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89
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Abstract
Immobilized cultured tobacco cells become polarized upon the addition of naphthalene-1-acetic acid and start to elongate from an initial spherical shape. The question as to how a diffuse-growing cell forms a polar axis is addressed here with approaches successfully applied to the study of tip growth. With two kinds of vibrating probes the electric current flow and proton fluxes were mapped around such elongating cells. No consistent polar pattern of ion fluxes, which is typical for actively tip-growing cells, was detected. Therefore, other signals must provide the positional information needed for polar axis formation. Furthermore, neither a specific pattern of intracellular Ca(2+) concentration nor a polar distribution of putative ion-channel antagonist-binding sites were found in elongating tobacco cells. Auxin flux, on the other hand, was found to be important as TIBA, an inhibitor of polar auxin transport, clearly inhibited elongation in a concentration-dependent way. Cross-linking of arabinogalactan-proteins with the beta-Yariv reagent also resulted in inhibition of elongation. A model is proposed for the induction of polar growth where localized auxin efflux starts a signal cascade that triggers molecules that reorient microtubules. These then guide cellulose deposition in the cell wall, which in turn alters cell wall mechanics and leads to elongation. In this scheme, arabinogalactan-proteins are not causal agents but are probably important regulators of growth and survival of the cell.
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Affiliation(s)
- K Vissenberg
- Department of Biology, Plant Physiology/Morphology, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Wilrijk, Belgium
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90
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Vissenberg K, Fry SC, Verbelen JP. Root hair initiation is coupled to a highly localized increase of xyloglucan endotransglycosylase action in Arabidopsis roots. Plant Physiol 2001; 127:1125-1135. [PMID: 11706192 DOI: 10.1104/pp.010295] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Root hairs are formed by two separate processes: initiation and subsequent tip growth. Root hair initiation is always accompanied by a highly localized increase in xyloglucan endotransglycosylase (XET) action at the site of future bulge formation, where the trichoblast locally loosens its cell wall. This suggests an important role of XET in the first stages of root hair initiation. The tip of growing root hairs is not marked by localized high XET action. Experiments in which root hair initiation was modulated and observations on root hair mutants support this view. The ethylene precursor 1-aminocyclopropane-1-carboxylic acid shifts both root hair initiation and the local increase in XET action toward the root tip. On the other hand, roots treated with the ethylene inhibitor aminoethoxyvinyl-glycine, as well as roots of mutants affected in root hair initiation (rhl1, rhd6-1, and axr2-1) revealed no localized increases of XET action at all and consequently did not initiate root hairs. Disruption of actin and microtubules did not prevent the localized increase in XET action. Also, the temporal and spatial pattern of action as the specific pH dependence suggest that different isoforms of XET act in different processes of root development.
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Affiliation(s)
- K Vissenberg
- University of Antwerp, Department of Biology, Universiteitsplein 1, B-2610 Wilrijk, Belgium
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Roymans D, Vissenberg K, De Jonghe C, Willems R, Engler G, Kimura N, Grobben B, Claes P, Verbelen JP, Van Broeckhoven C, Slegers H. Identification of the tumor metastasis suppressor Nm23-H1/Nm23-R1 as a constituent of the centrosome. Exp Cell Res 2001; 262:145-53. [PMID: 11139339 DOI: 10.1006/excr.2000.5087] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Processes like cell proliferation, differentiation, and tumor metastasis require a flexible adaptation of cell shape and cell plasticity. A regulator of cell structure and shape is the centrosome and its associated microtubules. Recently, oncogenes like p53, pRB, and the tumor suppressor BRCA1 have been characterized as members of the centrosome. In this communication, we identified rat Nm23-R1/NDPKbeta, a homologue of the human tumor metastasis suppressor Nm23-H1 and a regulator of cell proliferation and differentiation, as a component of the centrosomal complex. We used confocal laser scanning microscopy on different cell types and biochemical analysis of purified centrosomes to demonstrate that Nm23-R1 is located in the centrosome of dividing and nondividing cells. We also showed that the centrosomal enzyme is catalytically active and able to transfer the gamma-phosphate from a nucleoside triphosphate to a nucleoside diphosphate. In addition, Nm23-R1 coimmunoprecipitated with gamma-tubulin, a core centrosomal protein essential for microtubule nucleation. In addition, human Nm23-R1/-H1 was also shown to be present in the centrosome of different human and rat cell types, demonstrating that the presence of Nm23-H1 homologues in the latter organelle is a general event.
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Affiliation(s)
- D Roymans
- Cellular Biochemistry, University of Antwerp, Wilrijk-Antwerpen, B-2610, Belgium
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92
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Roymans D, Vissenberg K, De Jonghe C, Grobben B, Claes P, Verbelen JP, Van Broeckhoven C, Slegers H. Phosphatidylinositol 3-kinase activity is required for the expression of glial fibrillary acidic protein upon cAMP-dependent induction of differentiation in rat C6 glioma. J Neurochem 2001; 76:610-8. [PMID: 11208924 DOI: 10.1046/j.1471-4159.2001.00077.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glial fibrillary acidic protein (GFAP) is an intermediate filament (IF) protein expressed upon maturation of astrocytes and upregulated during reactive astrogliosis. Its expression is modulated by several growth factors and hormones. Although an upregulation of intracellular cAMP is required for the induction of GFAP expression in astrocytes, little information is available on other downstream factors of the signal transduction pathways involved in the regulation of its expression. In this communication, we identified phosphatidylinositol 3-kinase (PI 3-K) as a necessary enzyme for GFAP expression in rat C6 glioma cells. Use of the specific PI 3-K inhibitors wortmannin and LY294002 and transfection of C6 cells with a dominant negative PI 3-K construct, resulting in a decrease of the enzymatic activity of PI 3-K, inhibited the cAMP-dependent expression of GFAP. Furthermore, confocal laser scanning microscopy demonstrated that inhibition of the PI 3-K activity by LY294002 or wortmannin concomitant with induction of differentiation changes the cellular distribution leading to a pericentrosomal localization of GFAP and an altered cell shape lacking process formation. We conclude that the expression and cellular distribution of GFAP is mediated through a PI 3-K-dependent mechanism.
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Affiliation(s)
- D Roymans
- Department of Biochemistry, University of Antwerp, Wilrijk-Antwerpen, Belgium
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93
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Roymans D, Willems R, Vissenberg K, De Jonghe C, Grobben B, Claes P, Lascu I, Van Bockstaele D, Verbelen JP, Van Broeckhoven C, Slegers H. Nucleoside diphosphate kinase beta (Nm23-R1/NDPKbeta) is associated with intermediate filaments and becomes upregulated upon cAMP-induced differentiation of rat C6 glioma. Exp Cell Res 2000; 261:127-38. [PMID: 11082283 DOI: 10.1006/excr.2000.5037] [Citation(s) in RCA: 37] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nucleoside diphosphate kinases (Nm23/NDPK) are enzymes functional in cell proliferation, differentiation, development, tumor progression, and metastasis. Nevertheless, no consensus exists about the molecular mechanism by which Nm23/NDPK isoforms exert their role in these processes. We investigated the expression of the rat Nm23-R1/NDPKbeta and Nm23-R2/NDPKalpha isoforms, homologues of the human Nm23-H1/NDPK A and Nm23-H2/NDPK B proteins, respectively, upon cAMP-induced differentiation of rat C6 glioma cells and demonstrated a differential interaction with intermediate filaments. Semiquantitative RT-PCR, immunoblotting, and flow cytometry showed a constitutive expression of both Nm23 isoforms. After induction of differentiation in C6 cells with cAMP analogs or isoproterenol, a dose-dependent 2- and 2.5-fold upregulation of the Nm23-R1 mRNA and protein, respectively, was observed. In contrast, the expression of Nm23-R2 remained unchanged. Localization of both isoforms with confocal laser scanning microscopy demonstrated a punctate reticular staining pattern for both Nm23 isoforms in the cytosol and processes of the cells which was particularly intense in the perinuclear region. In addition, while Nm23-R2 was colocalized and coimmunoprecipitated with vimentin in nondifferentiated cells, both isoforms were associated with GFAP in differentiated cells. The significance of these findings in relation to a possible function of Nm23 isoforms in cell proliferation, differentiation, and tumor-associated mechanisms is discussed.
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Affiliation(s)
- D Roymans
- Laboratory of Cellular Biochemistry, University of Antwerp, Wilrijk-Antwerpen, B-2610, Belgium
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Vissenberg K, Martinez-Vilchez IM, Verbelen JP, Miller JG, Fry SC. In vivo colocalization of xyloglucan endotransglycosylase activity and its donor substrate in the elongation zone of Arabidopsis roots. Plant Cell 2000; 12:1229-37. [PMID: 10899986 PMCID: PMC149061 DOI: 10.1105/tpc.12.7.1229] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We have developed a method for the colocalization of xyloglucan endotransglycosylase (XET) activity and the donor substrates to which it has access in situ and in vivo. Sulforhodamine conjugates of xyloglucan oligosaccharides (XGO-SRs), infiltrated into the tissue, act as acceptor substrate for the enzyme; endogenous xyloglucan acts as donor substrate. Incorporation of the XGO-SRs into polymeric products in the cell wall yields an orange fluorescence indicative of the simultaneous colocalization, in the same compartment, of active XET and donor xyloglucan chains. The method is specific for XET, as shown by competition experiments with nonfluorescent acceptor oligosaccharides, by negligible reaction with cello-oligosaccharide-SR conjugates that are not XET acceptor substrates, by heat lability, and by pH optimum. Thin-layer chromatographic analysis of remaining unincorporated XGO-SRs showed that these substrates are not extensively hydrolyzed during the assays. A characteristic distribution pattern was found in Arabidopsis and tobacco roots: in both species, fluorescence was most prominent in the cell elongation zone of the root. Proposed roles of XET that include cell wall loosening and integration of newly synthesized xyloglucans could thus be supported.
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Affiliation(s)
- K Vissenberg
- University of Antwerp UIA, Department of Biology, Wilrijk, Belgium
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Vissenberg K, Quelo AH, Van Gestel K, Olyslaegers G, Verbelen JP. From hormone signal, via the cytoskeleton, to cell growth in single cells of tobacco. Cell Biol Int 2000; 24:343-9. [PMID: 10860569 DOI: 10.1006/cbir.1999.0516] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cultured mesophyll protoplasts of Nicotiana tabacum L. can be hormonally induced into different developmental pathways. In a medium containing auxins (NAA) and cytokinins (BAP) cells divide and eventually give rise to calli. When only auxins are present cells elongate and finally differentiate into very long tubular cells. We focused on the sequence of events leading to elongation. When cultured in a high (1 mg/l) auxin concentration elongating cells seem to pass a certain threshold and increase their nuclear DNA up to about 16C. Cells cultured in a low (0.065 mg/l) auxin concentration only have C-values up to 4C, are unable to pass this threshold and finally fail to elongate. Besides the concentration dependence of the auxin signal, the efflux of auxin seems to be necessary for elongation since addition of TIBA drastically reduces the amount of elongating cells. Concomitant with the changes in nuclear physiology, auxin-induced axiality is seen as sequential rearrangements of microtubules and actin-filaments and of cell wall cellulose microfibrils from 'randomly' arranged in spherical cells to an orientation perpendicular to the long axis of elongating cells.
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Affiliation(s)
- K Vissenberg
- Dept. Biology, University of Antwerp (UIA), Universiteitsplein 1, Wilrijk, B-2610, Belgium
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