Schlesinger Friedrich, Tammena Derk, Krampfl Klaus, Bufler Johannes
Neurological Department of Medical School Hannover, 30623 Hannover, Germany.
Synapse. 2005 Mar 1;55(3):176-82. doi: 10.1002/syn.20110.
AMPA-type glutamate receptor (GluR) channels are the most abundant excitatory transmitter receptors of the central nervous system. Four subunits with different posttranscriptional modifications and flip/flop splice variants are known. In vivo they occur as tetrameric heteromeric receptors. In the present study we analyzed the time course of desensitization (tau(D)) and resensitization (tau(rec)) kinetics of different homomeric (coassembly of splice or editing variants of one subunit) and heteromeric (coassembly of different subunits) GluR channels. We found that tau(D) had intermediate values depending on the amount of cDNA of the respective subunit at all heteromeric and homomeric GluR channels tested. The same holds true for tau(rec) except GluR2 flip channels were coexpressed with GluR1 channels. In this case, tau(rec) had values close to that of fast resensitizing GluR2 flip channels, even in the case of an abundance of GluR1 cDNA.
α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）型谷氨酸受体（GluR）通道是中枢神经系统中最丰富的兴奋性递质受体。已知有四个具有不同转录后修饰和翻转/非翻转剪接变体的亚基。在体内，它们以四聚体异源受体的形式存在。在本研究中，我们分析了不同同聚体（一个亚基的剪接或编辑变体的共组装）和异聚体（不同亚基的共组装）GluR通道脱敏（τD）和再敏化（τrec）动力学的时间进程。我们发现，在所测试的所有异聚体和同聚体GluR通道中，τD的值处于中间水平，这取决于各个亚基的cDNA量。除了GluR2翻转通道与GluR1通道共表达的情况外，τrec也是如此。在这种情况下，即使GluR1 cDNA含量丰富，τrec的值也接近快速再敏化的GluR2翻转通道的值。
