2010 Fiscal Year Final Research Report

Regulation of synaptic plasticity by receptor-like protein tyrosine phosphatase

Research Project

Project/Area Number	21700416
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Neurochemistry/Neuropharmacology
Research Institution	National Institute for Basic Biology
Principal Investigator	FUJIKAWA Akihiro National Institute for Basic Biology, 統合神経生物学研究部門, 特別協力研究員 (50414016)
Project Period (FY)	2009 – 2010
Keywords	神経科学 / 生体分子 / 蛋白質 / 脳・神経
Research Abstract	The extracellular region of Ptprz is shedded by MMP-9 or plasmin, producing its membrane-tethered fragment. Both proteases are reportedly activated when synaptic remodeling is occurring. We revealed that Ptprz fragments are accumulated in the post synaptic density PSD fraction, indicating that this receptor is actually cleaved at central synapses. We identified the dephosphorylation sites in Git1 and Magi1. Alignment of the primary sequences surrounding the target phospho-tyrosine residue in these substrate proteins showed a considerable similarity, suggesting a consensus motif for substrate recognition by Ptprz. We found that the substrate motif thus deduced is present in some proteins, including at Tyr118 of paxillin. Finally, we verified that Ptprz efficiently dephosphorylates paxillin at this site in cultured cells.