3poy
Crystal Structure of the alpha-Neurexin-1 ectodomain, LNS 2-6
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. Publication Abstract from PubMedalpha- and beta-neurexins (NRXNs) are transmembrane cell adhesion proteins that localize to presynaptic membranes in neurons and interact with the postsynaptic neuroligins (NLGNs). Their gene mutations are associated with the autism spectrum disorders. The extracellular region of alpha-NRXNs, containing nine independently folded domains, has structural complexity and unique functional characteristics, distinguishing it from the smaller beta-NRXNs. We have solved the X-ray crystal structure of seven contiguous domains of the alpha-NRXN-1 extracellular region at 3.0 A resolution. The structure reveals an arrangement where the N-terminal five domains adopt a more rigid linear conformation and the two C-terminal domains form a separate arm connected by a flexible hinge. In an extended conformation the molecule is suitably configured to accommodate a bound NLGN molecule, as supported by structural comparison and surface plasmon resonance. These studies provide the structural basis for a multifunctional synaptic adhesion complex mediated by alpha-NRXN-1. The Crystal Structure of the alpha-Neurexin-1 Extracellular Region Reveals a Hinge Point for Mediating Synaptic Adhesion and Function.,Miller MT, Mileni M, Comoletti D, Stevens RC, Harel M, Taylor P Structure. 2011 Jun 8;19(6):767-78. Epub 2011 May 27. PMID:21620717[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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