Ssociation of Connexin36 and Zonula Occludens-1 Ith Zonula Occludens-2 and the Transcription Factor Onula Occludens-1-associated Nucleic Acid-binding Rotein at Neuronal Gap Junctions in Rodent Retina

bstract—Most gap junctions between neurons in mammaian retina contain abundant connexin36, often in association ith the scaffolding protein zonula occludens-1. We now nvestigate co-association of connexin36, zonula occludens-1, onula occludens-2 and Y-box transcription factor 3 (zonula ccludens-1-associated nucleic acid-binding protein) in ouse and rat retina. By immunoblotting, zonula occludens-associated nucleic acid-binding protein and zonula occluens-2 were both detected in retina, and zonula occludens-2 n retina was found to co-immunoprecipitate with conexin36. By immunofluorescence, the four proteins appeared s puncta distributed in the plexiform layers. In the inner lexiform layer, most connexin36-puncta were co-localized ith zonula occludens-1, and many were co-localized with onula occludens-1-associated nucleic acid-binding protein. oreover, zonula occludens-1-associated nucleic acid-bindng protein was often co-localized with zonula occludens-1. early all zonula occludens-2-puncta were positive for conexin36, zonula occludens-1 and zonula occludens-1-associted nucleic acid-binding protein. In the outer plexiform layer, onnexin36 was also often co-localized with zonula occluens-1-associated nucleic acid-binding protein. In conexin36 knockout mice, labeling of zonula occludens-1 was lightly reduced in the inner plexiform layer, zonula occluens-1-associated nucleic acid-binding protein was dereased in the outer plexiform layer, and both zonula occluens-1-associated nucleic acid-binding protein and zonula ccludens-2 were markedly decreased in the inner sublamina f the inner plexiform layer, whereas zonula occludens-1,