Neurexin

<p>June 11, 2019, 1:58 PM</p>

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<p><strong>Neurexin</strong>&nbsp;(<strong>NRXN</strong>) is a <strong>presynaptic </strong>protein that helps to connect&nbsp;<a class="mw-redirect" title="Neurons" href="https://en.wikipedia.org/wiki/Neurons">neurons</a> at the&nbsp;<a title="Synapse" href="https://en.wikipedia.org/wiki/Synapse">synapse</a>.<sup id="cite_ref-pmid16882988_1-0" class="reference"><a href="https://en.wikipedia.org/wiki/Neurexin#cite_note-pmid16882988-1">[1]</a></sup> They are located mostly on the presynaptic membrane and contain a single&nbsp;<a title="Transmembrane protein" href="https://en.wikipedia.org/wiki/Transmembrane_protein">transmembrane</a> domain. The extracellular domain interacts with proteins in the synaptic cleft, most notably&nbsp;<a title="Neuroligin" href="https://en.wikipedia.org/wiki/Neuroligin">neuroligin</a>, while the intracellular cytoplasmic portion interacts with proteins associated with exocytosis.<sup id="cite_ref-pmid21620716_2-0" class="reference"><a href="https://en.wikipedia.org/wiki/Neurexin#cite_note-pmid21620716-2">[2]</a></sup><strong> Neurexin and neuroligin "shake hands," resulting in the connection between the two neurons and the production of a synapse</strong>.<sup id="cite_ref-pmid10892652_3-0" class="reference"><a href="https://en.wikipedia.org/wiki/Neurexin#cite_note-pmid10892652-3">[3]</a></sup> Neurexins mediate signaling across the synapse, and influence the properties of neural networks by synapse specificity. Neurexins were discovered as receptors for&nbsp;<a class="mw-redirect" title="&Alpha;-latrotoxin" href="https://en.wikipedia.org/wiki/%CE%91-latrotoxin">&alpha;-latrotoxin</a>, a vertebrate-specific toxin in&nbsp;<a title="Latrodectus" href="https://en.wikipedia.org/wiki/Latrodectus">black widow spider</a> venom that binds to presynaptic receptors and induces massive neurotransmitter release.<sup id="cite_ref-S&uuml;dhof_2008_4-0" class="reference"><a href="https://en.wikipedia.org/wiki/Neurexin#cite_note-S%C3%BCdhof_2008-4">[4]</a></sup> In humans, alterations in genes encoding neurexins are implicated in&nbsp;<a title="Autism" href="https://en.wikipedia.org/wiki/Autism">autism</a> and other cognitive diseases, such as&nbsp;<a title="Tourette syndrome" href="https://en.wikipedia.org/wiki/Tourette_syndrome">Tourette syndrome</a> and&nbsp;<a title="Schizophrenia" href="https://en.wikipedia.org/wiki/Schizophrenia">schizophrenia</a>.<sup id="cite_ref-S&uuml;dhof_2008_4-1" class="reference"><a href="https://en.wikipedia.org/wiki/Neurexin#cite_note-S%C3%BCdhof_2008-4">[4]</a></sup></p>