The membrane fusion process is mediated by a conserved set of SNARE proteins: vesicular synaptobrevin and plasma membrane syntaxin and SNAP-25. Recent data suggest that the fusion process may be subject to regulation by local lipid metabolism. Here, we have performed a screen of lipid compounds to identify positive regulators of vesicular synaptobrevin. We show that sphingosine, a releasable backbone of sphingolipids, activates synaptobrevin in synaptic vesicles to form the SNARE complex implicated in membrane fusion.
COBISS.SI-ID: 25625305
We combined biochemical and electrophysiological analyses of mice selectively deficient in peripheral tryptophan hydroxylase (Tph1-/-) and 5-HT to show that intracellular 5-HT regulates insulin secretion by serotonylation of intracellular GTPases.
COBISS.SI-ID: 63941377
We labeled astrocytic vesicles by exposing the slices to antibodies recognizing th elumenal antigens and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. We report thatthe vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.
COBISS.SI-ID: 26269401
Here we investigated compound exocytotic events in lactotrophs by using optical and cell-attached patch-clamp capacitance measurements. Elementary compound exocytotic events were characterized by multiple-amplitude on-steps in synaptopHluorin fluorescence and in membrane capacitance signals. Out of many mechanisms, these interactions may enable the diffusion of fusion proteins from the plasma membrane to the membrane of the primary fused vesicles, consequently enabling vesicle-to-vesicle fusion. The incidence of compound exocytotic events increased by 33% after stimulation.
COBISS.SI-ID: 25314265
Plant cells exhibit a lively activity of exocytosis and endocytosis at the plasma membrane. Here we use real-time patch-clamp recording to monitor single-vesicle fusion and fission in order to resolve the kinetic properties of these elementary processes. The data show that single vesicles can, in a rhythmic fashion, make and break contact with the plasma membrane of plant protoplasts. The fact that similar rhythmic fusion/fission activity is also present in constitutive exocytosis in animal cells implies that the underlying mechanisms appear universal in eukaryotic cells.
COBISS.SI-ID: 25470937