SNARE-dependent membrane fusion in eukaryotic cells requires that the heptad-repeat SNARE domains from R- and Q-SNAREs, anchored to apposed membranes, assemble into four-helix coiled-coil bundles. In addition to their SNARE and transmembrane domains, most SNAREs have N-terminal domains (N-domains), although their functions are unclear. The N-domain of the yeast vacuolar Qc-SNARE Vam7p is a bind...

Munc18a is an SM protein required for SNARE-mediated fusion. The molecular details of how Munc18a acts to enhance neurosecretion have remained elusive. Here, we use in vitro fusion assays to characterize how specific interactions between Munc18a and the neuronal SNAREs enhance the rate and extent of fusion. We show that Munc18a interacts directly and functionally with the preassembled t-SNARE c...

Background and study aims  The evidence for efficacy and safety of cold snare polypectomy is limited. The aim of this study was to assess the completeness of resection and safety of cold snare polypectomy, using either traditional or dedicated cold snares. Patients and methods  This was a prospective, non-randomized study performed at a single tertiary hospital. Adult patients with at least o...

N-ethylmaleimide-sensitive factor (NSF) is a member of the type II AAA+ (ATPase associated with various cellular activities) family. It plays a critical role in intracellular membrane trafficking by disassembling soluble NSF attachment protein receptor (SNARE) complexes. Each NSF protomer consists of an N-terminal domain (N domain) followed by two AAA ATPase domains (D1 and D2) in tandem. The N...

Intracellular membrane trafficking pathways must be tightly regulated to ensure proper functioning of all eukaryotic cells. Central to membrane trafficking is the formation of specific SNARE (soluble N-ethylmeleimide-sensitive factor attachment protein receptor) complexes between proteins on opposing lipid bilayers. The Sec1/Munc18 (SM) family of proteins play an essential role in SNARE-mediate...

SNARE (SNAP [soluble NSF (N-ethylmaleimide-sensitive fusion protein) attachment protein] receptor) proteins are required for many fusion processes, and recent studies of isolated SNARE proteins reveal that they are inherently capable of fusing lipid bilayers. Cis-SNARE complexes (formed when vesicle SNAREs [v-SNAREs] and target membrane SNAREs [t-SNAREs] combine in the same membrane) are disrup...

Ca(2+) binding to synaptotagmin 1 triggers fast exocytosis of synaptic vesicles that have been primed for release by SNARE-complex assembly. Besides synaptotagmin 1, fast Ca(2+)-triggered exocytosis requires complexins. Synaptotagmin 1 and complexins both bind to assembled SNARE complexes, but it is unclear how their functions are coupled. Here we propose that complexin binding activates SNARE ...

Tethering factors mediate initial interaction of transport vesicles with target membranes. Soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNAREs) enable consequent docking and membrane fusion. We demonstrate that the vesicle tether conserved oligomeric Golgi (COG) complex colocalizes and coimmunoprecipitates with intra-Golgi SNARE molecules. In yeast cells, the ...

The fundamental processes of membrane fission and fusion determine size and copy numbers of intracellular organelles. Although SNARE proteins and tethering complexes mediate intracellular membrane fusion, fission requires the presence of dynamin or dynamin-related proteins. Here we study these reactions in native yeast vacuoles and find that the yeast dynamin homologue Vps1 is not only an essen...

to large flasks. A large inoculum is important for the success of such transfers. The standard procedures for doing this, i.e., several loopfuls or pipetting, are not always the most desirable procedures. The former increases the possibility of contamination of both air and culture, and the latter requires additional time for washing and sterilization. We have, therefore, developed a multiple l...