Functional analysis of LunaparkA in hindbrain development of zebrafish

• Antragsteller: Professor Dr. Reinhard W. Köster
• Fachliche Zuordnung: Entwicklungsneurobiologie
• Förderung: Förderung von 2012 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 206676348

Lunapark (Lnp) is a transmembrane protein of unknown function, which is highly conserved among plants, fungi and animals. We showed that the homolog zebrafish LnpA localizes to membranes of endosomes and lysosomes and interacts with factors for membrane traffic, including Syntaxin-7, a SNARE-protein required for endosome/lysosome fusion and Notch receptor removal and degradation by the endocytic pathway. Strikingly, the development of zebrafish hindbrain commissural interneurons (HCIs) expressing lnpA is impaired in migration and differentiation by experimental inhibition or overactivation of the Notch signaling pathway. We thus propose that LnpA is a novel factor for regulating Notch signaling by the endocytic pathway and therefore hindbrain development. We aim to test this hypothesis by determining the domains and localization of LnpA and Syntaxin-7 interaction in vitro and in vivo. We pursue to establish lnpA loss of function approaches either by targeted genome editing with engineered restriction enzymes, by targeted modulation of gene transcription or alternatively by dominant-negative LnpA variants. The transparency of zebrafish embryos will allow us to analyze putative differentiation and migration defects of LnpA-deficient HCIs by in vivo time lapse microscopy. Using the same approach, we will analyze the impact of LnpA on the endocytic pathway and Notch attenuation. These experiments will assign both a novel function to LnpA and a new mode of Notch regulation in hindbrain development.

• DFG-Verfahren: Sachbeihilfen