Membrane fusion in the secretory pathway is mediated by SNAREs (located on the vesicle membrane [v-SNARE] and the target membrane [t-SNARE]). In all cases examined, t-SNARE function is provided as a three-helix bundle complex containing three approximately 70-amino acid SNARE motifs. One SNARE motif is provided by a syntaxin family member (the t-SNARE heavy chain), and the other two helices are...

Whereas SNARE (soluble N -ethylmaleimide-sensitive factor attachment protein receptor) heptad-repeats are well studied, SNAREs also have upstream N-domains of indeterminate function. The assembly of yeast vacuolar SNAREs into complexes for fusion can be studied in chemically defined reactions. Complementary proteoliposomes bearing a Rab:GTP and either the vacuolar R-SNARE or one of the three in...

Upon Ca2+ influx synaptic vesicles fuse with the plasma membrane and release their neurotransmitter cargo into the synaptic cleft. Key players during this process are the Q-SNAREs syntaxin 1a and SNAP-25 and the R-SNARE synaptobrevin 2. It is thought that these membrane proteins gradually assemble into a tight trans-SNARE complex between vesicular and plasma membrane, ultimately leading to memb...

Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins are required for intracellular membrane fusion, and are differentially localized throughout the cell. SNAREs on vesicle and target membranes contain "SNARE motifs" which interact to form a four-helix bundle that contributes to the fusion of two membranes. SNARE motif sequences fall into four classes, homologo...

The docking and fusion of cargo-containing vesicles with target membranes of eukaryotic cells is mediated by the interaction of SNARE proteins present on both vesicle and target membranes. In many cases, the target membrane SNARE, or t-SNARE, exists as a complex of syntaxin with a member of the SNAP-25 family of palmitoylated proteins. We have identified a novel human kinase SNAK (SNARE kinase)...

Formation of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex provides mechanical thrust for membrane fusion, but its molecular mechanism is still unclear. Here using magnetic tweezers, we observe mechanical responses of a single neuronal SNARE complex under constant pulling force. Single SNARE complexes may be unzipped with 34 pN force. When rezipping i...

Intracellular membrane fusion mediates diverse processes including cell growth, division and communication. Fusion involves complex formation between SNARE proteins anchored to adjacent membranes. How and in what form interacting SNARE proteins reach their sites of action is virtually unknown. We have addressed this problem in the context of plant cell division in which a large number of TGN-de...

SNARE-dependent membrane fusion requires the disassembly of cis-SNARE complexes (formed by SNAREs anchored to one membrane) followed by the assembly of trans-SNARE complexes (SNAREs anchored to two apposed membranes). Although SNARE complex disassembly and assembly might be thought to be opposing reactions, the proteins promoting disassembly (Sec17p/Sec18p) and assembly (the HOPS complex) work ...