Neurexophilin Family

Neurexophilins (NXPH) are a family of neuropeptide-like secreted glycoproteins expressed in specific regions of the brain. NXPH1 is expressed mainly by cells that resemble inhibitory interneurons, while NXPH3 is found selectively in subplate-derived neurons in cortical layer 6b, granule cells in the vestibulocerebellum and Cajal-Retzius cells during development. NXPH1, 2 and 3 are tightly bound extracellular ligands of alpha-neurexins, synaptic transmembrane molecules that are essential for calcium-triggered neurotransmitter release. NXPH2 is not expressed in rodents, and NXPH4 does not bind alpha-neurexins.