Tyrosine phosphorylation of the N-methyl-D-aspartate receptor by exogenous and postsynaptic density-associated Src-family kinases
Tyrosine phosphorylation of the N-methyl-D-aspartate receptor by exogenous and postsynaptic density-associated Src-family kinases
复制标题
DOI：
10.1046/j.1471-4159.2001.00433.x
复制
发表时间：
2001-08-01
影响因子：
4.7
通讯作者：
Gurd, JW
中科院分区：
文献类型：
--
作者：
Cheung, HH;Gurd, JW
Src家族酪氨酸激酶对NMDA受体的磷酸化与受体功能的调节有关。我们研究了外源性Src和Fyn对NMDA受体亚基NR 2A和NR 2B的酪氨酸磷酸化，并将其与突触后密度（PSD）相关的酪氨酸激酶磷酸化进行了比较。外源性Src和Fyn对受体的磷酸化依赖于激酶通过其SH 2结构域与PSD的初始结合。Src和Fyn磷酸化NR 2A和NR 2B中的相似位点，胰蛋白酶肽图谱分别鉴定了来自NR 2A和NR 2B的七种和五种主要酪氨酸磷酸化肽。NR 2B上的所有五个酪氨酸磷酸化位点均定位于C-末端的胞质结构域。内源性PSD酪氨酸激酶对NR 2B的磷酸化只产生了三个酪氨酸磷酸化的胰蛋白酶肽，其中两个对应于Src磷酸化位点，其中一个是新的。磷酸化位点特异性抗体将NR 2B Tyr 1472鉴定为内源性PSD酪氨酸激酶的磷酸化位点。该位点的磷酸化被Src家族特异性抑制剂PP 2抑制。结果确定了几个潜在的磷酸化位点的Src在NMDA受体，并表明，并不是所有这些网站都可用于磷酸化的激酶位于结构框架内的PSD。
Phosphorylation of the NMDA receptor by Src-family tyrosine kinases has been implicated in the regulation of receptor function. We have investigated the tyrosine phosphorylation of NMDA receptor subunits NR2A and NR2B by exogenous Src and Fyn and compared this to phosphorylation by tyrosine kinases associated with the postsynaptic density (PSD). Phosphorylation of the receptor by exogenous Src and Fyn was dependent upon initial binding of the kinases to PSDs via their SH2-domains. Src and Fyn phosphorylated similar sites in NR2A and NR2B, tryptic peptide mapping identifying seven and five major tyrosine-phosphorylated peptides derived from NR2A and NR2B, respectively. All five tyrosine phosphorylation sites on NR2B were localized to the C-terminal, cytoplasmic domain. Phosphorylation of NR2B by endogenous PSD tyrosine kinases yielded only three tyrosine-phosphorylated tryptic peptides, two of which corresponded to Src phosphorylation sites, and one of which was novel. Phosphorylation-site specific antibodies identified NR2B Tyr1472 as a phosphorylation site for intrinsic PSD tyrosine kinases. Phosphorylation of this site was inhibited by the Src-family-specific inhibitor PP2. The results identify several potential phosphorylation sites for Src in the NMDA receptor, and indicate that not all of these sites are available for phosphorylation by kinases located within the structural framework of the PSD.