Ca2+ signals:
Molecular Mechanisms and Integrative Functions Collaborative Research Center 894

Project A7 - Frank Schmitz

Ca2+-dependent vesicle trafficking in the photoreceptor synapse

We want to analyze the structural and functional organization of Ca2+-dependent processes in the photoreceptor synapse of the mammalian retina. Photoreceptor synapses are tonically active synapses with large active zones that contain synaptic ribbons. Ca2+-dependent exocytic and endocytic trafficking events are highly enriched around the synaptic ribbon. We propose that the synaptic ribbon organizes and controls these synaptic membrane trafficking events in the active zone and peri-active zone around the synaptic ribbon. The molecular organization of these Ca2+-dependent processes in the photoreceptor synapse and their functional importance will be addressed in the research proposal. The importance of different Ca2+-regulating systems in the presynaptic terminal will be analyzed with recombinant transgenic reporter mice as well as other techniques. Furthermore, we want to characterize the role of a novel component of the synaptic ribbon complex (ArfGAP3).