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| Van Dijk, Juliette; Bompard, Guillaume; Cau, Julien; Kunishima, Shinji; Rabeharivelo, Gabriel; Mateos-langerak, Julio; Cazevieille, Chantal; Cavelier, Patricia; Boizet-bonhoure, Brigitte; Delsert, Claude; Morin, Nathalie. |
| Background Upon maturation in the bone marrow, polyploid megakaryocytes elongate very long and thin cytoplasmic branches called proplatelets. Proplatelets enter the sinusoids blood vessels in which platelets are ultimately released. Microtubule dynamics, bundling, sliding, and coiling, drive these dramatic morphological changes whose regulation remains poorly understood. Microtubule properties are defined by tubulin isotype composition and post-translational modification patterns. It remains unknown whether microtubule post-translational modifications occur in proplatelets and if so, whether they contribute to platelet formation. Results Here, we show that in proplatelets from mouse megakaryocytes, microtubules are both acetylated and polyglutamylated. To... |
| Tipo: Text |
Palavras-chave: Microtubules; Acetylation; Polyglutamylation; Tubulin isotype; Platelets; Megakaryocytes; IIb3 integrin; CHO cells. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57463/59577.pdf |
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| Tozin,Luiz Ricardo dos Santos; Rodrigues,Tatiane Maria. |
| ABSTRACT Lamiaceae contains many species known for their aromatic properties that are produced by the production of essential oils in glandular trichomes. Hyptis is one of the most common genera of Lamiaceae in the Brazilian flora, and includes several species with medicinal value. However, studies on the morphology and functioning of their glandular trichomes are lacking. We analyzed the morphology, histochemistry and ultrastructure of the glandular trichomes in leaves of H. villosa, emphasizing the differential distribution of actin filaments and microtubules in cells secreting hydrophilic and lipophilic compounds. Four morphotypes of glandular trichomes were identified. Total lipid, terpenes, alkaloids, phenolic compounds, proteins and polysaccharides... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Actin microfilaments; Cytoskeleton; Glandular hairs; Microtubules; Ultrastructure. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000300330 |
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| Van Dijk, Juliette; Bompard, Guillaume; Rabeharivelo, Gabriel; Cau, Julien; Delsert, Claude; Morin, Nathalie. |
| Mature megakaryocytes extend long processes called proplatelets from which platelets are released in the blood stream. The Rho GTPases Cdc42 and Rac as well as their downstream target, p21-activated kinase 2 (PAK2), have been demonstrated to be important for platelet formation. Here we address the role, during platelet formation, of PAK1, another target of the Rho GTPases. PAK1 decorates the bundled microtubules (MTs) of megakaryocyte proplatelets. Using a validated cell model which recapitulates proplatelet formation, elongation and platelet release, we show that lack of PAK1 activity increases the number of proplatelets but restrains their elongation. Moreover, in the absence of PAK1 activity, cells have hyperacetylated MTs and lose their MT network... |
| Tipo: Text |
Palavras-chave: Microtubules; Acetylation; Megakaryocytes; Proplatelet; P21-activated kinase 1 PAK1; Acetyltransferase MEC-17. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00654/76594/77743.pdf |
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| Louveaux, Marion; Rochette, Sebastien; Beauzamy, Lena; Boudaoud, Arezki; Hamant, Olivier. |
| Exogenous mechanical perturbations on living tissues are commonly used to investigate whether cell effectors can respond to mechanical cues. However, in most of these experiments, the applied mechanical stress and/or the biological response are described only qualitatively. We developed a quantitative pipeline based on microindentation and image analysis to investigate the impact of a controlled and prolonged compression on microtubule behaviour in the Arabidopsis shoot apical meristem, using microtubule fluorescent marker lines. We found that a compressive stress, in the order of magnitude of turgor pressure, induced apparent microtubule bundling. Importantly, that response could be reversed several hours after the release of compression. Next, we tested... |
| Tipo: Text |
Palavras-chave: Mechanical stress; Indenter; Microtubules; Compression; Bundling; Arabidopsis thaliana; Technical advance. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00347/45829/45479.tiff |
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