Suzuki T, Okumura-Noji K
Department of Biochemistry, Nagoya City University Medical School, Japan.
Biochem Biophys Res Commun. 1995 Nov 13;216(2):582-8. doi: 10.1006/bbrc.1995.2662.
Fyn, protein tyrosine kinase, and its substrates were highly concentrated in the postsynaptic density (PSD) fraction prepared from the rat forebrain. There were a number of Fyn substrates unique to the PSD fraction. One of the major substrates in the PSD fraction was found to be a concanavalin A-binding glycoprotein, PSD-gp180, which is the N-methyl-D-aspartate (NMDA) receptor subunit epsilon 2 (NR2B). Western blotting and immunoprecipitation supported the phosphorylation of epsilon 2 by Fyn. NMDA receptor subunit epsilon 1 (NR2A) was also a substrate for Fyn. These results suggest that Fyn is involved in the modulation of synaptic efficacy through the phosphorylation of synapse-specific substrates such as the NMDA receptor/channel.
蛋白酪氨酸激酶Fyn及其底物高度集中于从大鼠前脑制备的突触后致密部（PSD）组分中。PSD组分中有许多独特的Fyn底物。PSD组分中的主要底物之一被发现是一种伴刀豆球蛋白A结合糖蛋白，即PSD-gp180，它是N-甲基-D-天冬氨酸（NMDA）受体亚基ε2（NR2B）。蛋白质印迹法和免疫沉淀法证实了Fyn对ε2的磷酸化作用。NMDA受体亚基ε1（NR2A）也是Fyn的底物。这些结果表明，Fyn通过对突触特异性底物（如NMDA受体/通道）的磷酸化作用参与突触效能的调节。
