Chen C, Leonard J P
Department of Biological Sciences, Laboratory for Molecular Biology, University of Illinois at Chicago, 60607-7060, USA.
J Neurochem. 1996 Jul;67(1):194-200. doi: 10.1046/j.1471-4159.1996.67010194.x.
Although serine/threonine phosphorylation has been more commonly recognized as a mechanism to modulate the function of ion channels and receptors, tyrosine phosphorylation is under increasing scrutiny. An important subtype of glutamate receptor, the NMDA receptor, is shown to be regulated by insulin via protein tyrosine kinase (PTK). NMDA currents through cloned receptors are potentiated by insulin in a subunit-specific manner. The insulin-mediated potentiation of NMDA current is diminished by inhibitors of PTKs. At least one exogenous cytosolic PTK, pp60c-src, is also able to potentiate NMDA current. Because later application of PTK inhibitors can reverse the seemingly stable insulin-mediated potentiation of NMDA current, it appears that tyrosine residues responsible for potentiation are continually rephosphorylated by some long-term PTK activity that was induced via insulin treatment.
虽然丝氨酸/苏氨酸磷酸化作为调节离子通道和受体功能的一种机制已被更广泛地认识，但酪氨酸磷酸化正受到越来越多的关注。谷氨酸受体的一个重要亚型，即NMDA受体，已被证明可通过蛋白酪氨酸激酶（PTK）受胰岛素调节。通过克隆受体的NMDA电流以亚基特异性方式被胰岛素增强。PTK抑制剂可减弱胰岛素介导的NMDA电流增强作用。至少一种外源性胞质PTK，即pp60c-src，也能够增强NMDA电流。由于随后应用PTK抑制剂可逆转看似稳定的胰岛素介导的NMDA电流增强作用，似乎负责增强作用的酪氨酸残基会被胰岛素处理诱导的某种长期PTK活性持续重新磷酸化。
