Examining the function of Piccolino at the photoreceptor ribbon synapse
Final Report Abstract
In our study, we set out to examine the contribution of Piccolino to the structural maturation and maintenance of photoreceptor SRs and its putative role as a tether for synaptic vesicles. Since we were not permitted to breed the experimental animals in Erlangen due to their health status, we had to limit our analyses to adult animals. The key findings of our study were: Piccolino is most likely not playing a major role in the developmental organization of AZs at retinal ribbon synapses, but it is an important stabilizer of SR structure in the adult retina. - Piccolino and RIBEYE interact via multiple PxDLS-like motifs at the C-terminus of Piccolino. - The C-terminus of Piccolino interacts with RIBEYE, while the N-terminus possibly interacts with SVs in the cytosol. - In the rod photoreceptors of the Pclogt/gt rat, the number of SVs within 40nm of the SR was significantly reduced compared to wildtype controls. - Rab3A binds neither directly nor indirectly to Piccolino. - The SV-binding mechanism for Piccolino seems independent of a protein-protein interaction and may involve protein-lipid binding.
Publications
- (2019) A multiple Piccolino- RIBEYE interaction supports plate-shaped synaptic ribbons in retinal neurons. J Neurosci 39:2606-19
Müller TM, Gierke K, Joachimsthaler A, Sticht H, Izsvák Z, Hamra FK, Fejtová A, Ackermann F, Garner CC, Kremers J, Brandstätter JH, Regus-Leidig H
(See online at https://doi.org/10.1523/JNEUROSCI.2038-18.2019)
