title: Isoforms of agrin are widely expressed in the developing rat and may function as protease inhibitors.
abstract: The agrin family of extracellular matrix proteins may be important in the formation of the neuromuscular junction. Using in situ hybridization with a probe recognizing all agrin isoforms, we demonstrate that it is widely expressed during mammalian embryogenesis. In the developing rat, particularly high levels of expression are found in the dorsal root and cranial ganglia, gut, whisker rudiments, penis, snout, teeth, retina, hippocampus, cerebral cortex and the lining of brain ventricles. Functional analysis of the recombinant rat protein shows that it is a potent inhibitor of the proteases trypsin, chymotrypsin and plasmin but not thrombin or the plasminogen activators. We conclude that agrin and its isoforms may play multiple roles in mammalian development including the regulation of proteolysis in the extracellular matrix.
authors.affiliation: Department of Medicine, University of California at San Francisco 94143-0724.
authors.forename: S L
authors.initials: SL
authors.lastname: Biroc
authors.forename: D G
authors.initials: DG
authors.lastname: Payan
authors.forename: J M
authors.initials: JM
authors.lastname: Fisher
mesh_terms: D018171:Agrin / Q000096:biosynthesis* / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism; D005314:Embryonic and Fetal Development; D005260:Female; D015870:Gene Expression; D005865:Gestational Age; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology* / Q000378:metabolism*; D015345:Oligonucleotide Probes; D016376:Oligonucleotides, Antisense; D011247:Pregnancy; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D018171:Agrin; D015345:Oligonucleotide Probes; D016376:Oligonucleotides, Antisense; D011480:Protease Inhibitors; D011994:Recombinant Proteins