Treatment of human erythrocyte membranes with dilute alkali (pH 11.5) generates sealed, protein-depleted vesicles that can be isolated by density gradient centrifugation. The vesicles are 0.5 to 2.0 micrometers in diameter, and their membranes are predominantly oriented inside-out. The vesicles lack protein bands 1, 2, 5, and 6 (nomenclature of Steck, T.L. (1974) J. Cell Biol. 62, 1-19) of the ...

Actively growing tumor cells shed membrane vesicles into the extracellular milieu both in vivo and in vitro. Extracellular membrane vesicles from tumor cells contain most surface antigens and proteases present on these cells. They facilitate the escape of tumors from immune surveillance and promote tumor cell invasion. Here, we demonstrate that tumor membrane vesicles stimulate an additional im...

We used fluorescence recovery after photobleaching (FRAP) to measure the mobility of synaptic vesicles in frog motor nerve terminals. Vesicles belonging to the recycling pool or to the reserve pool were selectively labeled with FM1-43. In resting terminals, vesicles in the reserve pool were immobile, while vesicles in the recycling pool were mobile. Nerve stimulation increased the mobility of r...

All living cells release extracellular vesicles having pleiotropic functions in intercellular communication. Mammalian extracellular vesicles, also known as exosomes and microvesicles, are spherical bilayered proteolipids composed of various bioactive molecules, including RNAs, DNAs, proteins, and lipids. Extracellular vesicles directly and indirectly control a diverse range of biological proce...

Monoaminergic innervation of the intermediolateral nucleus of the cat spinal cord was investigated by fluorescence histochemistry and electron microscopy. Large numbers of monoaminergic terminals were labeled by prior administration of the false neurotransmitter 5-hydroxydopamine (5-OHDA). Ultrastructurally, 5-OHDA-labeled terminals fell into three types. Type I, which made up 55% of the labele...

The topology of signal transduction is particularly important for neurons. Neurotrophic factors such as nerve growth factor (NGF) interact with receptors at distal axons and a signal is transduced by retrograde transport to the cell body to ensure survival of the neuron. We have discovered an organelle that may account for the retrograde transport of the neurotrophin signal. This organelle is d...

Giant Unilamellar Vesicles (GUVs) consisting in self-closed lipid bilayers of 0.5-100 μm diameter are considered as oversimplified models of cells because of their biological membrane and micrometric size while Large Unilamellar Vesicles (LUVs) of 100-500 nm diameter have applications in drug delivery. To improve structural and mechanical properties of these vesicles, we have developed two cate...

In the preceding paper the preparation and characterization of antiserum to purified D-lactate are described. In this paper the effects of the antibody on D-lactate dehydrogenase activity and D-lactate-dependent active transport in native Escherichia coli ML 308-225 membrane vesicles and ML 308-225dld-3 vesicles reconstituted with D-lactate dehydrogenase are described. The results demonstrate t...

pH changes of the reaction medium (pH 6.35) following addition of MgATP were determined at 4 degrees C with sarcoplasmic reticulum vesicles in the presence of 0.1 mM CaCl2 and 5 mM MgCl2. With intact vesicles, a pronounced acidification following a slight alkalinization was induced by MgATP, indicating H+ ejection from vesicles. This agrees with previous observations by several investigators th...