Neurexins (NRXN) are a family of presynaptic cell adhesion proteins that have roles in connecting neurons at the synapse.[1] They are located mostly on the presynaptic membrane and contain a single transmembrane domain. The extracellular domain interacts with proteins in the synaptic cleft, most notably neuroligin, while the intracellular cytoplasmic portion interacts with proteins associated with exocytosis.[2] Neurexin and neuroligin "shake hands," resulting in the connection between the two neurons and the production of a synapse.[3] Neurexins mediate signaling across the synapse, and influence the properties of neural networks by synapse specificity.[4] Neurexins were discovered as receptors for α-latrotoxin, a vertebrate-specific toxin in black widow spider venom that binds to presynaptic receptors and induces massive neurotransmitter release.[5] In humans, alterations in genes encoding neurexins are implicated in autism and other cognitive diseases, such as Tourette syndrome and schizophrenia.[5]
