2r16
Crystal Structure of bovine neurexin 1 alpha LNS/LG domain 4 (with no splice insert)
Structural highlights
FunctionNRX1A_BOVIN Cell surface protein involved in cell-cell-interactions, exocytosis of secretory granules and regulation of signal transmission. Function is isoform-specific. Alpha-type isoforms have a long N-terminus with six laminin G-like domains and play an important role in synaptic signal transmission. Alpha-type isoforms play a role in the regulation of calcium channel activity and Ca(2+)-triggered neurotransmitter release at synapses and at neuromuscular junctions. They play an important role in Ca(2+)-triggered exocytosis of secretory granules in pituitary gland. They may effect their functions at synapses and in endocrine cells via their interactions with proteins from the exocytotic machinery. Likewise, alpha-type isoforms play a role in regulating the activity of postsynaptic NMDA receptors, a subtype of glutamate-gated ion channels (By similarity). Both alpha-type and beta-type isoforms may play a role in the formation or maintenance of synaptic junctions via their interactions (via the extracellular domains) with neuroligin family members, CBLN1 or CBLN2. In vitro, triggers the de novo formation of presynaptic structures. May be involved in specification of excitatory synapses. Alpha-type isoforms were first identified as receptors for alpha-latrotoxin from spider venom. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedNeurexins and neuroligins play an essential role in synapse function, and their alterations are linked to autistic spectrum disorder. Interactions between neurexins and neuroligins regulate inhibitory and excitatory synaptogenesis in vitro through a "splice-insert signaling code." In particular, neurexin 1beta carrying an alternative splice insert at site SS#4 interacts with neuroligin 2 (found predominantly at inhibitory synapses) but much less so with other neuroligins (those carrying an insert at site B and prevalent at excitatory synapses). The structure of neurexin 1beta+SS#4 reveals dramatic rearrangements to the "hypervariable surface," the binding site for neuroligins. The splice insert protrudes as a long helix into space, triggers conversion of loop beta10-beta11 into a helix rearranging the binding site for neuroligins, and rearranges the Ca(2+)-binding site required for ligand binding, increasing its affinity. Our structures reveal the mechanism by which neurexin 1beta isoforms acquire neuroligin splice isoform selectivity. Regulation of neurexin 1beta tertiary structure and ligand binding through alternative splicing.,Shen KC, Kuczynska DA, Wu IJ, Murray BH, Sheckler LR, Rudenko G Structure. 2008 Mar;16(3):422-31. PMID:18334217[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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