Disease relevance of Syb

• Correspondingly, only synaptobrevin (n-syb), but not the ubiquitously expressed syb protein, is cleaved by tetanus toxin in vitro [1].

High impact information on Syb

• The structure of synaptobrevin, an intrinsic membrane protein of small synaptic vesicles from mammalian brain, was studied by purification and molecular cloning [2].
• Therefore, we find that Syb, which usually is not involved in synaptic function, can mediate Ca(2+)-triggered synaptic activity and that no particular specialization of the v-SNARE is required to differentiate synaptic exocytosis from other forms [3].
• Expression of syb can restore synaptic transmission to n-syb mutants as assayed both by electroretinogram and recordings of excitatory junctional currents at the neuromuscular junction [3].
• Synaptobrevins or VAMPs are vesicle-associated membrane proteins, often called v-SNARES, that are important for vesicle transport and fusion at the plasma membrane [3].
• The neuron-specific proteins SNAP-25 (synaptosome-associated protein 25 kDa), synaptobrevin and syntaxin, are localized to presynaptic terminals in mammals and have been found to associate with proteins involved in vesicle docking and membrane fusion [4].

Biological context of Syb

• Mutant phenotypes and gene-expression patterns indicate that n-Syb is exclusively neuronal and required only for synaptic vesicle secretion, whereas Syb is ubiquitous and, as shown here, essential for cell viability [3].
• A neuronal Drosophila vamp (n-syb) is described here and is localized to chromosome band 62A [5].
• This resulted in a notched-wing phenotype, the severity of which was enhanced when combined with mutants of VAMP/Synaptobrevin or Syntaxin, indicating that it results from impaired membrane trafficking [6].
• The Drosophila melanogaster VAMP-encoding gene (syb) comprises five exons [7].

Anatomical context of Syb

• The greatest concentration of syb transcripts was found in cells of the gut and malpighian tubules [7].

Associations of Syb with chemical compounds

• The Drosophila and Torpedo proteins show 61 and 81% amino acid identity to mouse SNAP-25, a degree of conservation similar to that previously reported for synaptobrevin [4].

References