Astrotactin-1 and 2 (ASTN1/2) are integral membrane perforin-like, vertebrate-specific proteins that play critical roles in neurodevelopment [, ]. They consist of an N-terminal cytosolic domain suspended between two transmembrane α-helices with a large C-terminal domain, extracellular for ASTN1 and endosome luminal for ASTN2. ASTN1 acts as a neuronal receptor for granule neuron migration along astroglial fibres []. ASTN2 forms a complex with ASTN1, which regulates the surface expression of ASTN1. It mediates ASTN1 recycling by promoting its internalisation and transport during endocytosis []. ASTN2 is also involved in the planar cell polarity pathway in hair cells [].
This entry represents the N-terminal domain of ASTN1/2. This domain includes the transmembrane and cytosolic regions [].Astrotactin-1 and 2 (ASTN1/2) are integral membrane perforin-like, vertebrate-specific proteins that play critical roles in neurodevelopment [, ]. They consist of an N-terminal cytosolic domain suspended between two transmembrane α-helices with a large C-terminal domain, extracellular for ASTN1 and endosome luminal for ASTN2. ASTN1 acts as a neuronal receptor for granule neuron migration along astroglial fibres []. ASTN2 forms a complex with ASTN1, which regulates the surface expression of ASTN1. It mediates ASTN1 recycling by promoting its internalisation and transport during endocytosis []. ASTN2 is also involved in the planar cell polarity pathway in hair cells [].
This domain localises to the middle of the C-terminal region of ASTN1 and 2, which comprises a EGF- like domain (EGF4) and a fibronectin type III (Fn(III)) domain []. These subdomains are located between the MACPF and annexin-like domains. The structure of Fn(III) from ASTN2 revealed an unexpected feature which has two additional beta strands folded across the core. The junction between EGF-4 and Fn(III) domains in ASTN2 (but not in ASTN1) is thought to be an inositol triphosphate binding site [].Astrotactin-1 and 2 (ASTN1/2) are integral membrane perforin-like, vertebrate-specific proteins that play critical roles in neurodevelopment [, ]. They consist of an N-terminal cytosolic domain suspended between two transmembrane α-helices with a large C-terminal domain, extracellular for ASTN1 and endosome luminal for ASTN2. ASTN1 acts as a neuronal receptor for granule neuron migration along astroglial fibres []. ASTN2 forms a complex with ASTN1, which regulates the surface expression of ASTN1. It mediates ASTN1 recycling by promoting its internalisation and transport during endocytosis []. ASTN2 is also involved in the planar cell polarity pathway in hair cells [].
