How do vesicular coats form on the donor membrane? Sebastian Springer,* Anne Spang,* and Randy Schekman*†‡ Do cargo proteins influence this process? Recent work *Department of Molecular and Cell Biology and on the exchange of proteins between the endoplasmic †Howard Hughes Medical Institute reticulum (ER) and the Golgi apparatus in SaccharoUniversity of California myces cerevisiae and higher eu...

Exposure of human erythrocytes to elevated intracellular calcium causes fragments of the cell membrane to be shed as microvesicles. This study tested the hypothesis that microvesicle release depends on microscopic membrane physical properties such as lipid order, fluidity, and composition. Membrane properties were manipulated by varying the experimental temperature, membrane cholesterol content...

Vesicle transport in eukaryotic cells is regulated by SNARE proteins, which play an intimate role in regulating the specificity of vesicle fusion between discrete intracellular organelles. In the present study we investigated the function and plasticity of v-SNAREs in insulin-regulated GLUT4 trafficking in adipocytes. Using a combination of knockout mice, v-SNARE cleavage by clostridial toxins ...

At presynaptic nerve terminals, neurotransmitter is stored in small membranebound organelles, termed ‘‘synaptic vesicles.’’ In order to release their contents into the synaptic cleft via membrane fusion, synaptic vesicles must first associate, or ‘‘dock,’’ with the plasma membrane. Recent data suggest that the cytoplasmic protein UNC-18 (a.k.a. nSec1/Munc18-1/rbsec-1 or Rop) promotes synaptic v...

In this paper, we study the effects of the spontaneous curvature on the static deformation of a vesicle membrane under the elastic bending energy, with prescribed bulk volume and surface area. Generalizing the phase field models developed in our previous works, we deduce a new energy formula involving the spontaneous curvature effects. Several axis-symmetric configurations are obtained through ...

Bilayer vesicles form readily from mixtures of charged and neutral surfactants. When such a mixed vesicle binds an oppositely charged object, its membrane partially demixes: the adhesion zone recruits more charged surfactants from the rest of the membrane. Given an unlimited supply of adhering objects one might expect the vesicle to remain attractive until it was completely covered. Contrary to...

While Munc18-1 interacts with Syntaxin1 and controls the formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) complex to regulate presynaptic vesicle fusion in developed neurons, this molecule is likely to be involved in brain development since its gene abnormalities cause early infantile epileptic encephalopathy with suppression-burst (Ohtahara syndrome),...

The dynamics of a spheroidal vesicle, bounded by an inextensible membrane, is analyzed in function of the enclosed fluid viscosity, and of the membrane mechanical properties. The two situations in which a bending rigidity and a shear elasticity are the potential energy source in the membrane have been compared, and the stability properties of quasi-spherical vesicle shapes discussed. The transi...

Giardia is an intestinal parasite that undergoes adaptation for survival outside the host. It secretes an extracellular cyst wall using a poorly understood process. An encystation-specific secretory vesicle (ESV) was previously described containing cyst wall proteins. The process of release of these vesicles has been suggested to occur after fragmentation of large ESV in small secretory vesicle...