Cartography of neurexins: more than 1000 isoforms generated by alternative splicing and expressed in distinct subsets of neurons.
Neurexins, a family of cell surface proteins specific to brain, are transcribed from two promoters in three genes, resulting in three alpha- and three beta-neurexins. In situ hybridization revealed differential but overlapping distributions of neurexin isoforms in different classes of neurons. PCRs demonstrated that alpha-neurexins are alternatively spliced at five canonical positions, and beta-neurexins at two. Characterization of many independent bovine neurexin I alpha cDNAs suggests that different splice sites are used independently. This creates the potential to express more than 1000 distinct neurexin proteins in brain. The splicing pattern is conserved in rat and cow. Thus, in addition to somatic gene rearrangement (immunoglobulins and T cell receptors) and large gene families (odorant receptors), alternative splicing potentially represents a third mechanism for creating a large number of cell surface receptors that are expressed by specific subsets of cells.
Ullrich
B
B
Department of Molecular Genetics, Howard Hughes Medical Institute, University of Texas Southwestern Medical School, Dallas 75235.
Ushkaryov
Y A
YA
Südhof
T C
TC
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002417:Cattle; D003001:Cloning, Molecular; D017124:Conserved Sequence; D015870:Gene Expression; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction / Q000379:methods; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid
D009419:Nerve Tissue Proteins; D015345:Oligonucleotide Probes; D011994:Recombinant Proteins