title: Plasmin-mediated processing of protein tyrosine phosphatase receptor type Z in the mouse brain.
abstract: Protein tyrosine phosphatase receptor type Z (Ptprz, also known as PTPzeta or RPTPbeta) is preferentially expressed in the CNS as a major chondroitin sulfate proteoglycan (CSPG). Ptprz interacts with the PSD95 family through its intracellular carboxyl-terminal PDZ-binding motif in the postsynaptic density. Ptprz-deficient adult mice display impairments in spatial and contextual learning. Here, we identified the proteolytic processing of Ptprz by plasmin in the mouse brain, which is markedly enhanced after kainic acid (KA)-induced seizures. We mapped plasmin cleavage sites in the extracellular region of Ptprz by cell-based assays and in vitro digestion experiments with recombinant proteins. These findings indicate that Ptprz is a physiological target for activity-dependent proteolytic processing by the tPA/plasmin system, and suggest that the proteolytic cleavage is involved in the functional processes of the synapses during learning and memory.
authors.affiliation: Division of Molecular Neurobiology, National Institute for Basic Biology, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan.
authors.forename: Jeremy Pak Hong
authors.initials: JP
authors.lastname: Chow
authors.forename: Akihiro
authors.initials: A
authors.lastname: Fujikawa
authors.forename: Hidetada
authors.initials: H
authors.lastname: Shimizu
authors.forename: Masaharu
authors.initials: M
authors.lastname: Noda
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D002460:Cell Line; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005341:Fibrinolysin / Q000378:metabolism*; D006801:Humans; D007608:Kainic Acid / Q000494:pharmacology; D007858:Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5 / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced
chemical_list: D018690:Excitatory Amino Acid Agonists; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D005341:Fibrinolysin; D007608:Kainic Acid