Consulta: subjectFacets:"Microtubules"
Registros recuperados: 6
Data/hora: 10/06/2024 03:00:00

The impact of mechanical compression on cortical microtubules in Arabidopsis: a quantitative pipeline
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Microtubule polyglutamylation and acetylation drive microtubule dynamics critical for platelet formation
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

PAK1 Regulates MEC-17 Acetyltransferase Activity and Microtubule Acetylation during Proplatelet Extension
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: 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

Morphology and histochemistry of glandular trichomes in Hyptis villosa Pohl ex Benth. (Lamiaceae) and differential labeling of cytoskeletal elements
Provedor de dados: Acta Botanica Brasilica
Autores: 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

Divalent cation hinder the solubilization of a tubulin kinase activity from Trypanosoma cruzi epimastigotes
Provedor de dados: Biological Research
Autores: UZCANGA,GRACIELA; GALÁN-CARIDAD,JOSÉ MANUEL; SUAREZ,KAREM NORIS; BUBIS,JOSÉ.
Trypanosoma cruzi epimastigotes were extracted under various conditions in order to examine the role of divalent cations in the solubilization of microtubule proteins. When epimastigotes were homogenized in the presence of 5 mM Mg+2 and 5 mM Ca+2, a protein kinase responsible for phosphorylating tubulin, as well as the tubulin that became phosphorylated, remained tightly associated with the parasite particulate and detergent-resistant fractions. On the contrary, tubulin kinase and its substrate were predominantly released into the parasite cytosolic and detergent-soluble fractions, when epimastigotes were extracted in the presence of 5 mM EDTA and 5 mM EGTA. These evidences demonstrated a divalent cation-dependent solubilization of the enzyme responsible...
Tipo: Journal article
Palavras-chave: Microtubules; Post-translational modification of tubulin; Protein kinase CK2; Protein phosphorylation-dephosphorylation; Signal transduction; Trypanosoma cruzi; Tubulin.
Ano: 2003
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300008

Changes in cell shape, cytoskeletal proteins and adhesion sites of cultured cells after extracellular Ca2+ chelation
Provedor de dados: Brazilian Journal of Medical and Biological Research
Autores: Mermelstein,C.S.; Rebello,M.I.L.; Amaral,L.M.; Costa,M.L.
Although much is known about the molecules involved in extracellular Ca2+ regulation, the relationship of the ion with overall cell morphology is not understood. The objective of the present study was to determine the effect of the Ca2+ chelator EGTA on the major cytoskeleton components, at integrin-containing adhesion sites, and their consequences on cell shape. Control mouse cell line C2C12 has a well-spread morphology with long stress fibers running in many different directions, as detected by fluorescence microscopy using rhodamine-phalloidin. In contrast, cells treated with EGTA (1.75 mM in culture medium) for 24 h became bipolar and showed less stress fibers running in one major direction. The adhesion plaque protein alpha5-integrin was detected by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cytoskeleton; Extracellular Ca2+; Cell shape; Microfilaments; Microtubules; Integrin.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000800018