Glycosylation and axon guidance
The secreted protein Slit is a repulsive axon guidance cue that binds to the receptor Roundabout (Robo). Manavalan et al. report that Mummy (Mmy), an enzyme of the glycosylation pathway, regulated the Slit-Robo signaling pathway in the developing nervous system of Drosophila melanogaster. In mmy mutants, Slit was not secreted from the midline cells of the ventral nerve cord, resulting in axon guidance defects. In addition, Mmy was also required for maintaining Robo abundance and distribution in axons. Thus, glycosylation affects axon tract establishment and maintenance through mechanisms that affect both the ligand and the receptor.
