The agrin gene codes for a family of basal lamina proteins that differ in function and distribution.
We isolated two cDNAs that encode isoforms of agrin, the basal lamina protein that mediates the motor neuron-induced aggregation of acetylcholine receptors on muscle fibers at the neuromuscular junction. Both proteins are the result of alternative splicing of the product of the agrin gene, but unlike agrin, they are inactive in standard acetylcholine receptor aggregation assays. They lack one (agrin-related protein 1) or two (agrin-related protein 2) regions in agrin that are required for its activity. Expression studies provide evidence that both proteins are present in the nervous system and muscle and that, in muscle, myofibers and Schwann cells synthesize the agrin-related proteins while the axon terminals of motor neurons are the sole source of agrin.
Ruegg
M A
MA
Department of Neurobiology, Stanford University School of Medicine, California 94305-5401.
Tsim
K W
KW
Horton
S E
SE
Kröger
S
S
Escher
G
G
Gensch
E M
EM
McMahan
U J
UJ
D018171:Agrin; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001485:Basement Membrane / Q000502:physiology; D002645:Chickens; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D015870:Gene Expression; D008969:Molecular Sequence Data; D005810:Multigene Family; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D015183:Restriction Mapping
D018171:Agrin; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004247:DNA