Identification of SNAP-47, a novel Qbc-SNARE with ubiquitous expression.
The SNARE proteins are essential components of the intracellular fusion machinery. It is thought that they form a tight four-helix complex between membranes, in effect initiating fusion. Most SNAREs contain a single coiled-coil region, referred to as the SNARE motif, directly adjacent to a single transmembrane domain. The neuronal SNARE SNAP-25 defines a subfamily of SNARE proteins with two SNARE helices connected by a longer linker, comprising also the proteins SNAP-23 and SNAP-29. We now report the initial characterization of a novel vertebrate homologue termed SNAP-47. Northern blot and immunoblot analysis revealed ubiquitous tissue distribution, with particularly high levels in nervous tissue. In neurons, SNAP-47 shows a widespread distribution on intracellular membranes and is also enriched in synaptic vesicle fractions. In vitro, SNAP-47 substituted for SNAP-25 in SNARE complex formation with the neuronal SNAREs syntaxin 1a and synaptobrevin 2, and it also substituted for SNAP-25 in proteoliposome fusion. However, neither complex assembly nor fusion was as efficient as with SNAP-25.
Holt
Matthew
M
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Varoqueaux
Frédérique
F
Department of Molecular Neurobiology, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany.
Wiederhold
Katrin
K
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Takamori
Shigeo
S
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Urlaub
Henning
H
Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Fasshauer
Dirk
D
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Jahn
Reinhard
R
Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany. Electronic address: rjahn@gwdg.de.
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D050766:Qb-SNARE Proteins / Q000096:biosynthesis* / Q000737:chemistry; D050767:Qc-SNARE Proteins / Q000096:biosynthesis* / Q000737:chemistry; D051381:Rats; D050600:SNARE Proteins / Q000096:biosynthesis / Q000502:physiology*; D050825:Synaptosomal-Associated Protein 25 / Q000096:biosynthesis; D014018:Tissue Distribution; D033921:Vesicular Transport Proteins / Q000096:biosynthesis
D050766:Qb-SNARE Proteins; D050767:Qc-SNARE Proteins; D050600:SNARE Proteins; C107017:Snap23 protein, mouse; C498858:Snap23 protein, rat; C486621:Snap29 protein, mouse; C117418:Snap29 protein, rat; C512318:Snap47 protein, mouse; C512319:Snap47 protein, rat; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins