Localization of caveolin-1 in photoreceptor synaptic ribbons.
OBJECTIVE
The purpose of this study is to determine whether caveolin-1 is a constituent of photoreceptor synaptic ribbons.


METHODS
Immunoblot assay and electron microscopic immunocytochemistry were used to localize caveolin-1 in synaptic ribbons.


RESULTS
Synaptic ribbons were localized close to the active site of presynaptic membranes and surrounded by a halo of synaptic vesicles. Immunosignals of caveolin-1 were clearly detected on the synaptic ribbons in rod and cone photoreceptors. However, the signal was seen neither on synaptic vesicles nor on presynaptic plasma membranes.


CONCLUSIONS
Caveolin-1 is a component protein of synaptic ribbons and may be involved in the regulation of transmitter release.
Department of Ophthalmology, Nagoya University, School of Medicine, 65 Tsurumai, Nagoya 466-8550, Japan.
S
S
Kachi
A
A
Yamazaki
J
J
Usukura
D000818:Animals; D002417:Cattle; D051242:Caveolin 1; D022461:Caveolins / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D016253:Microscopy, Immunoelectron; D020419:Photoreceptor Cells, Vertebrate / Q000737:chemistry*; D017729:Presynaptic Terminals / Q000737:chemistry*
C495541:Cav1 protein, mouse; D051242:Caveolin 1; D022461:Caveolins; D005136:Eye Proteins