Neurexins: synaptic cell surface proteins related to the alpha-latrotoxin receptor and laminin.
A family of highly polymorphic neuronal cell surface proteins, the neurexins, has been identified. At least two genes for neurexins exist. Each gene uses alternative promoters and multiple variably spliced exons to potentially generate more than a 100 different neurexin transcripts. The neurexins were discovered by the identification of one member of the family as the receptor for alpha-latrotoxin. This toxin is a component of the venom from black widow spiders; it binds to presynaptic nerve terminals and triggers massive neurotransmitter release. Neurexins contain single transmembrane regions and extracellular domains with repeated sequences similar to sequences in laminin A, slit, and agrin, proteins that have been implicated in axon guidance and synaptogenesis. An antibody to neurexin I showed highly concentrated immunoreactivity at the synapse. The polymorphic structure of the neurexins, their neural localization, and their sequence similarity to proteins associated with neurogenesis suggest a function as cell recognition molecules in the nerve terminal.
Ushkaryov
Y A
YA
Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas 75235.
Petrenko
A G
AG
Geppert
M
M
Südhof
T C
TC
D000591:Amino Acid Isomerases / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002352:Carrier Proteins / Q000235:genetics; D003001:Cloning, Molecular; D003524:Cyclosporins / Q000378:metabolism; D004247:DNA / Q000235:genetics; D005091:Exons; D007797:Laminin / Q000235:genetics*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D009928:Organ Specificity; D016716:PC12 Cells; D019696:Peptidylprolyl Isomerase; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011950:Receptors, Cholinergic / Q000235:genetics*; D018000:Receptors, Peptide; D012689:Sequence Homology, Nucleic Acid; D013111:Spider Venoms / Q000378:metabolism; D013569:Synapses / Q000502:physiology*
D000906:Antibodies; D002352:Carrier Proteins; D003524:Cyclosporins; D007797:Laminin; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011950:Receptors, Cholinergic; D018000:Receptors, Peptide; D013111:Spider Venoms; C034800:alpha-latrotoxin receptor; D004247:DNA; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase