Role of Ribeye PXDLS/T-binding cleft in normal synaptic ribbon function.

Hair cell synaptic ribbons are evolutionarily conserved structures that appear dense in electron micrographs, extend from the release site into the cytoplasm and tether synaptic vesicles for release. Here, we show that Ribeye, the major component of the synaptic ribbon electron density is directed to ribbons via its PXDLS/T-binding site and that mutant isoforms of Ribeye with point mutations disrupting these interactions fail to rescue normal function in mutant zebrafish lacking most Ribeye.