This entry represents the N-terminal domain of Astrotactin (ASTN) proteins 1 and 2, which includes the transmembrane and cytosolic regions. These are vertebrate-specific proteins involved in neuronal migration during neurodevelopment. ASTN1 is a neuronal receptor required for neuroblasts migration along glial fibers, especially in the cerebellum. ASTN2 is an endosome membrane protein that binds ASTN1 and mediates its recycling by promoting ASTN1 internalisation and transport during its endocytosis.