Recent evidence suggests that endocytosis in neuroendocrine cells and neurons can be tightly coupled to exocytosis, allowing rapid retrieval from the plasma membrane of fused vesicles for future use. This can be a much faster mechanism for membrane recycling than classical clathrin-mediated endocytosis. During a fast exo-endocytotic cycle, the vesicle membrane does not fully collapse into the p...

Neurons in the central nervous system communicate by transmitting electrical signals at special sites of contact called synapses. Synapses contain neurotransmitter-filled synaptic vesicles, which fuse with the presynaptic plasma membrane. The neurotransmitter diffuses to the neighboring neuron and triggers a new electrical signal. In order to maintain synaptic transmission, the synaptic vesicle...

conclusions the results showed that the extracted omvs were conformationally stable, and there were no pyrogenic determinants in omv. also the results showed that the omv elicited high level of specific antibodies against n. meningitidis serogroup a. these results indicate that the omv obtained here, can be used as a meningococcal vaccine after further investigation. materials and methods omvs ...

M any types of cells maintain specialized plasma membrane domains to which different subsets of secretory vesicles are targeted, enabling the cells’ performance of specific functions. The budding yeast Saccharomyces cerevisiae spatially and temporally regulates exocytosis, directing surface growth and secretion to different plasma membrane sites at different cell cycle stages (21). In very smal...

Transmitter exocytosis from the neuronal soma is evoked by brief trains of high frequency electrical activity and continues for several minutes. Here we studied how active vesicle transport towards the plasma membrane contributes to this slow phenomenon in serotonergic leech Retzius neurons, by combining electron microscopy, the kinetics of exocytosis obtained from FM1-43 dye fluorescence as ve...

Synaptotagmin 1 (Syt1) is a synaptic vesicle integral membrane protein that regulates neurotransmitter release by activating fast synchronous fusion and suppressing slower asynchronous release. The cytoplasmic C2 domains of Syt1 interact with SNAREs and plasma membrane phospholipids in a Ca(2+)-dependent manner and can substitute for full-length Syt1 in in vitro membrane fusion assays. To deter...

Synaptic vesicles recycle repeatedly in order to maintain synaptic transmission. We have previously proposed that upon exocytosis the vesicle components persist as clusters, which would be endocytosed as whole units. It has also been proposed that the vesicle components diffuse into the plasma membrane and are then randomly gathered into new vesicles. We found here that while strong stimulation...

Synaptic vesicles dock at active zones on the presynaptic plasma membrane of a neuron's axon terminals as a precondition for fusing with the membrane and releasing their neurotransmitter to mediate synaptic impulse transmission. Typically, docked vesicles are next to aggregates of plasma membrane-bound macromolecules called active zone material (AZM). Electron tomography on tissue sections from...

We have developed procedures for detecting synaptic vesicle-binding proteins by using glutaraldehyde-fixed or native vesicle fractions as absorbent matrices. Both adsorbents identify a prominent synaptic vesicle-binding protein of 36 kD in rat brain synaptosomes and mouse brain primary cultures. The binding of this protein to synaptic vesicles is competed by synaptophysin, a major integral memb...

Exocytotic release of neuropeptides and hormones is generally believed to involve the complete merger of the secretory vesicle with the plasma membrane. However, recent data have suggested that ‘kissand-run’ mechanisms may also play a role. To analyse secretory events in neuroendocrine β-cells, we imaged chimaeric reporters targeted to either the vesicle membrane [chimaeras of synaptobrevin-2 a...