RT Journal Article
SR Electronic
T1 A SNARE Complex Containing Syntaxin 3 Is Present in Ribbon Synapses of the Retina
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6713
OP 6721
DO 10.1523/JNEUROSCI.16-21-06713.1996
VO 16
IS 21
A1 Morgans, Catherine W.
A1 Brandstätter, Johann H.
A1 Kellerman, Joseph
A1 Betz, Heinrich
A1 Wässle, Heinz
YR 1996
UL http://www.jneurosci.org/content/16/21/6713.abstract
AB In contrast to conventional synapses, which release neurotransmitter transiently, ribbon synapses formed by photoreceptors and bipolar cells of the retina release neurotransmitter continuously and modulate the rate in response to light. Both modes of release are mediated by synaptic vesicles but probably differ in the regulation of docking and fusion of synaptic vesicles with the plasma membrane. We have found that syntaxin 1, an essential component of the core fusion complex in conventional synapses, is absent from ribbon synapses of the retina, raising the possibility that these synapses contain a different type of syntaxin or syntaxin-like protein. By immunoprecipitating syntaxin 1-depleted retina and brain extracts with a SNAP-25 antibody and microsequencing the precipitated proteins, syntaxin 3 was detected in retina complexed with SNAP-25, synaptobrevin, and complexin. Using an anti-syntaxin 3 antiserum, syntaxin 3 was demonstrated to be present at high levels in retina compared to brain. Immunofluorescent staining of rat retina sections confirmed that syntaxin 3 is expressed by photoreceptor and bipolar cells in the retina. Thus, in the retina, expression of syntaxin 3 is correlated with ribbon synapses and may play a role in the tonic release of neurotransmitter.