Learn More
Using filipin as a probe for the presence of membrane cholesterol, the evolution of cholesterol distribution in the apical plasma membrane was studied during estrogen-induced ciliogenesis in quail oviduct and compared with the distribution of intramembrane particles (IMPs). Ciliary growth is preceded by the first step of microvillus differentiation.(More)
Ciliated cells are characterized by a highly organized cytoskeleton which is connected with the ciliary apparatus. The organization of microtubules, microfilaments, and cytokeratin filaments is described and the relationships of each network with the ciliary apparatus are emphasized. Possible functions of such a complex cytoskeleton are discussed.
The different steps of ciliogenesis occurring in quail oviduct were compared to the ciliogenesis pattern described in other metazoan species. Centrioles are generated according to pathways that are found within the same cell: the centriolar and the acentriolar pathways. In the acentriolar pathway, centrioles are generated in the Golgi area, without contact(More)
cholesterol depletion alters the apparent affinity of the internal cationic sites and the maximal translocation rate but not the affinity of the external cationic sites of the Na+-K+ pump in human erythrocytes. To test whether these effects were mediated by a direct cholesterol-internal site interaction or by a change in membrane lipid order, the effects of(More)
Actin microfilaments were localized in quail oviduct ciliated cells using decoration with myosin subfragment S1 and immunogold labeling. These polarized epithelial cells show a well developed cytoskeleton due to the presence of numerous cilia and microvilli at their apical pole. Most S1-decorated microfilaments extend from the microvilli downward towards(More)
Cilia from quail oviduct were isolated with their membrane. The ultrastructural study revealed a good preservation of cilia in the purified fraction. Electrophoresis on SDS-PAGE showed a reproducible pattern of ciliary proteins, the major bands being those of tubulins 57 kDa and dyneins above 250 kDa. Among the minor bands, an immunological study was(More)
A protein that was immunologically related to the erythrocyte and brain alpha-240-subunit and to the brain beta-235-subunit of spectrin was characterized by immunoblotting and was detected by immunofluorescence in the apical part of ciliated cells from quail oviduct. After immunogold-labeling electron immunocytochemistry, spectrin was detected mainly in a(More)
Filipin, a polyene antibiotic, was used to detect cholesterol in thyroid membranes in vivo and in culture during TSH stimulation. We found that apical and basolateral plasma membranes were heterogeneously modified by filipin which induced abundant lesions in apical membranes, whereas Golgi apparatus, endoplasmic reticulum, nuclear membranes were unmodified.(More)
Cholesterol depletion of erythrocytes, obtained after incubation with phosphatidylcholine vesicles, induces in most of the experiments: (1) a discocytestomatocyte transformation as observed by scanning electron microscopy; (2) a specific decrease in spectrin phosphorylation of intact erythrocytes; (3) an increase in lipid phosphorylation. It is concluded(More)